003149   BROLI N, VALLJA L, VASJARI M, SHEHU A, DUKA S (Chemistry Dep, Tirana Univ, Tirana, Albania, Email: nevilabroli@yahoo.com, nevila.broli@fshn.edu.al) : Electrochemical behaviour of gold thin film glassy carbon electrode for determination of Chromium(VI). Asian J Chem 2021, 33 (5), 1001 - 5.

A modified glassy carbon electrode (Au_film/GCE) using a gold film was constructed for determination of chromium(VI) in real water samples. A GCE was immersed in HAuCl₄ solution (10^-3 M) and the thin layer of gold was electrodeposited for 10 min at −0.4 V (vs. Ag/ AgCl). Compared with only GCE, a strong affinity between chromium and gold species was observed with an increase in Cr(VI) signal. The type of supporting electrolytes, electrodeposition time, scan rate, pH, modulation time and the modulation amplitude were optimized through differential pulse-anodic stripping voltammetry (DP-ASV). A calibration graph acquired using the accumulation time of 120 s with a sensitivity of 1.3 × 10^-2 µA/µgL^-1 was linear in the range of 10-120 µg L^-1. A low detection limit of 5.5 µg/L Cr(VI) and a strong correlation coefficient R² = 0.9971 were obtained under the optimal experimental conditions. Signals were reproducible and exhibited a relative standard deviation of ±4.5%. A modified sensor was employed to determine the Cr(VI) content in the sewage water samples.

4 illus, 3 tables, 17 ref

003148   PADMAPRIYA M, PARVATHI K, RAMESHKUMAR S (Chemistry Dep, Sri Vasavi Coll, Erode - 638 316, Email: srksvc2016@gmail.com) : Interaction of midazolam with glassy carbon supported lipid membrane in the presence and absence of marker ions. Asian J Chem 2021, 33 (5), 994 - 1000.

A biomimetic membrane was formed on the surface of electrochemically activated glassy carbon electrode in NaCl bath solutions. The variation of electrochemical properties of solid supported bilayer lipid membrane (s-BLM) with NaCl concentration in the bath solutions in the presence and absence of ferri/ferrocyanide marker ions was discussed using electrochemical impedance spectroscopy. The extent of pore formation on the s-BLM surface was discussed using bode phase diagram. The electrochemical impedance studies show that the partition of midazolam into the s-BLM strongly depends on Cl– ion concentration in the bath solutions. The variation of membrane capacitance with drug dose shows the ionized form of midazolam interaction with the surface of s-BLM while the neutral and ion pair forms get partitioned into the membrane. In the presence of marker ions, the membrane resistance increases with decrease in NaCl concentration in the bath solution. The cyclic voltammetric responses of marker ions for bare and drug doped s-BLMs in NaCl bath solutions were recorded and variation of redox peak currents with drug dose was discussed.

11 illus, 2 tables, 49 ref

003147   KANAGARAJ E, MAHALINGAM P, SIDDHARTHAN R, SATHISHKUMAR C (Chemistry Dep, Arignar Anna Government Arts Coll, Namakkal - 637 002, Email: ponmahanano@gmail.com) : Effect of temperature on gravity assisted synthesis of carbon nanotubes by spray pyrolysis. Asian J Chem 2021, 33 (5), 989 - 93.

Carbon nanotubes were prepared along the gravity direction in a spray pyrolysis setup over the silica supported Fe-Co-Ni catalyst. The silica supported Fe-Co-Ni catalyst coated by jet nebulized spray pyrolysis method over copper strip was inverted to face downward, so that carbon nanotubes can be prepared along the direction of gravity. From the point of view of green chemistry, instead of commonly used hydrocarbons, a plant based natural precursor, pine oil is used as carbon precursor for preparation of carbon nanotubes. The effect of temperature on yield and morphology of carbon nanotubes grown along gravity was studied. The yield of carbon nanotubes was calculated as mass percentage of catalyst and support. The carbon nanotubes were characterized using XRD, SEM, Raman and TGA techniques. The carbon deposit obtained at 650 ºC contains multi-walled carbon nanotubes in larger quantity with very less amorphous carbon. A narrow, lengthy and well graphitized multi-walled carbon nanotubes were formed when the carbon nanotubes grow along the gravity.

4 illus, 17 ref

003146   SINGH A K, SINGH S K, DHARIYAL K, KUMAR R, KUMAR A, SINGH S K (Chemistry Dep, Lucknow Univ, Lucknow - 226 007, Email: singhaks3@rediffmail.com) : Synthesis, characterization and antimycobacterial activity of phenanthrenequinone thiosemicarbazones and their ruthenium and zinc complexes. Asian J Chem 2021, 33 (5), 983 - 8.

The substituted phenanthrenequinone thiosemicarbazones (HL1, HL2 and HL3), and their metal complexes (M = Ru(II) or Zn(II); SM1, SM2, SM3 and SM4) were synthesized and characterized by FT-IR, ¹ H & ¹³C NMR and ESI-MS. The spectral data IR, ¹ H & ¹³C NMR and ESI-MS indicates two tridentate ligands coordinating in the form of an octahedral geometry. The gas phase geometry of all the zinc(II) and ruthenium(II) complexes was carried by using density functional theory (DFT). The antimycobacterial susceptibility testing at 100 µM of the complexes using resazurin microtiter plate assay resulted in growth inhibition. Complexes SM2, SM3 and SM4 showed good antimycobacterial activity at 100 µM concentration by using rifampicin as inhibition control.

5 illus, 1 table, 26 ref

003144   ADHIKARI H S, GARAI A, KHANAL C, ADHIKARI R, YADAV P N (Chemistry Dep, Tribhuvan Univ, Kathmandu, Nepal, Email: pnyadav219@gmail.com) : Imidazole-2-carboxaldehyde Chitosan Thiosemicarbazones and their Copper(II) Complexes: Synthesis, characterization and antitumorigenic activity against madin-darby canine kidney cell line. Asian J Chem 2021, 33 (5), 969 - 76.

Chitosan oligosaccharide and high molecular weight crab shell chitosan were functionalized as imidazole-2-carboxaldehyde chitosan thiosemicarbazones and their copper(II) complexes were synthesized. The synthesized compounds were characterized by FT-IR, ¹³C NMR, EPR spectroscopy, powder X-ray diffraction (PXRD) analysis, elemental analysis and magnetic susceptibility measurements. The low molecular weight chitosan thiosemicarbazones showed higher in vitro inhibitory activity as studied by MTT assay against the tumorigenic epithelial Madin-Darby Canine Kidney (MDCK) cell line than the corresponding high molecular weight chitosan derivative. The antitumorigenic enhancement upon the complex formation was revealed by the better inhibitory activity of copper(II) chitosan thiosemicarbazone chelates.

4 illus, 6 tables, 59 ref

003043   NURSYAMSIAH D, SOLIHUDIN, EDDY D A (Chemistry Dep, Univ Padjadjaran, Indonesia, Email: diana.rahmawati@unpad.ac.id) : Green synthesis of zero valent iron (ZVI) using tea leaves extract and its application as fenton like catalyst for textile dyes removal. Asian J Chem 2021, 33 (5), 963 - 8.

This study aims to develop an alternative method in the green synthesis of zero valent iron (ZVI) from tea leaves extract and its application as a Fenton catalyst for textile dyes removal. Tea leaves extract having high polyphenolic contents were used as reducing agents in this study and the ZVI obtained from them was characterized by UV-VIS, SEM-EDS, FTIR, PSA and XRD techniques. The synthesized zero valent iron (ZVI) was utilized as a Fenton like catalyst for textile dyes removal. The results showed that this system was highly efficient regarding the dyes removal of about 95.96 % using 80 mg/L ZVI. Moreover, using 100 mg/L ZVI, the COD number reduced to 94.68%.

11 illus, 2 tables, 42 ref

003142   CHANDERIYA A, NAIKOO G A, DAS R, HASSAN I U, KASHAW S K, PANDEY S (Chemistry Dep, Dr. Harisingh Gour Univ, Sagar - 470 003, Email: gahmed@du.edu.om, naikgowhar@gmail.com, ratneshdas1@gmail.com) : Recent advances in metal nanoparticles for the synthesis of N-Containing heterocyclic compounds. Asian J Chem 2021, 33 (5), 949 - 55.

Heterocyclic compounds are indispensable organic structures because of their promising potential applications in medicinal, pharmaceutical and other related fields of chemistry. Exploring these heterocyclic compounds by evaluating metal nanoparticles as efficient nanocatalysts have attracted the researchers over the past decades, due to their stability, recyclability, reusability rather than conventional catalysts. Most of the nano-catalyzed organic reactions are taking place in benign and under green conditions. In this mini-review, we have documented synthesis of some of the recent N-containing heterocyclic compounds by utilizing advanced nanoparticles as effective catalysts. It has been concluded that exercising these nanocatalysts for the synthesis of N-containing heterocyclic compounds not only enhanced the yield of the product but has extensively increased the selectivity of the desired products via greener approach.

90 ref

003141   SINGH A, DIXIT A K, FAROOQ S, MEHMOOD Z, CHHIMWAL S L (Chemistry Dep, Uttaranchal Univ, Dehradun - 248 007, Email: dixit.arunesh@gmail.com) : An Indian folkore phytomedicine perilla frutescens L.: free radical scavenging property along with metal detection by ICP-MS. Asian J Chem 2021, 33 (4), 945 - 8.

In present study, free radical scavenging activity of methanolic extract of all parts (leaves, seeds, root, stem and flower) of Perilla frutescens L. has been estimated. The promising results, among the five plant parts leaves, seeds, root, stem, flower and the standard tested for the in vitro antioxidant activity using the DPPH method, the crude methanolic extracts of all parts showed antioxidant activity, with IC₅₀ values of 5.95 ± 0.10, 8.28 ± 0.20, 66.27 ± 0.17, 80.03 ± 0.10 and 122.35 ± 0.17 µg/mL, respectively. The IC₅₀ value for ascorbic acid was 5.19 ± 0.26 µg/mL. While butylated hydroxyl toluene (BHT) a synthetic commercial antioxidant has comparatively high IC₅₀ value of 108.46 ± 0.57 µg/mL. Presence of zinc in all parts of plant in the range 17.20 ± 0.22 to 33.56 ± 0.32 ppm further supports the strong antioxidant activity of Perilla frutescens L. The phytochemical tests indicated that all parts of Perilla frutescens L. have considerable proportion of important phytochemicals and are in rich source of secondary metabolites like polyphenols, tannins, alkaloids and flavonoids. Several of such compounds are known to possess potent antioxidant activity.

5 tables, 26 ref

003140   SENTHILKUMAR K, MOHAMMED S S N, KALAISELVAN S (Chemistry Dep, M. Kumarasamy Coll of Engineering, Karur - 639 113, Email: kalaichem82@gmail.com) : Free radical scavenging activity of dihydrocaffeic acid: A quantum chemical approach. Asian J Chem 2021, 33 (4), 937 - 44.

Based on density functional theory (DFT), to investigate relationships between the antioxidant activity and structure of dihydrocaffeic acid, quantum chemical calculation is used. The optimized structures of the neutral, radical and ionic forms have been carried out by DFTB3LYP method with the 6-311G(d,p) basis set. Reaction enthalpies related with the hydrogen atom transfer (HAT), single electron transfer proton transfer (SET-PT) and sequential proton loss and electron transfer (SPLET) were calculated in gas and water phase. The HOMO-LUMO energy gap, electron affinity, electronegativity, ionization energy, hardness, chemical potential, global softness and global electrophilicity were calculated by using the same level of theory. Surfaces with a molecular electrostatic potential (MEP) were studied to determine the reactive sites of dihydrocaffeic acid. The difference in energy between the donor and acceptor as well as the stabilization energy was determined through the natural bond orbital (NBO) analysis. The Fukui index (FI) based on electron density was employed to predict reaction sites. Reaction enthalpies are compared with previously published data for phenol and 3,4-dihydroxycinnamic acid.

5 illus, 7 tables, 42 ref

003138   VALLJA L, BROLI N, SHEHU A, DUKA S, VASJARI M (Chemistry Dep, Univ of Tirana, Tirana, Albania, Email: loreta.vallja@fshn.edu.al) : Seasonal assessment of physico-chemical parameters and water quality evaluation of kune-vaini lagoon complex, Lezha, Albania. Asian J Chem 2021, 33 (4), 925 - 9.

The evaluation of the water quality of the Kune-Vain lagoon complex with regard to general physico-chemical and chemical parameters was the main focus of the present study. This evaluation was based on the requirement of Council Directive of 18 July 1978 on the “quality of fresh waters needing protection or improvement in order to support fish life”, [78/659/EEC] and the requirement of Council Directive of 3 November 1998 relating to the “quality of water intended for human consumption”, [98/83/EC]. Five sampling stations were selected to successfully perform the water monitoring on the Kune-Vaini lagoon complex with a frequency of every two months, from July, 2018- July, 2019. The parameters measured were temperature, pH, conductivity, salinity, DO, BOD, TDS, total hardness, Ca²⁺, Mg²⁺, Cl^– and some heavy metals. The monitored lagoons have shown notable differences based on physico-chemical parameters.

7 illus, 3 tables, 11 ref

003137   LAWRENCE A J, ABRAHAM A, ALI F, ARIF S, FATIMA S, FATIMA U, KHAN T (Chemistry Dep, Integral Univ, Lucknow - 226 026, Email: tahminakhan30@yahoo.com) : Air quality in six northern indian cities during diwali 2020: The real tragedy in disguise. Asian J Chem 2021, 33 (4), 909 - 18.

North Indian cities have been highly polluted, especially in winters, which coincide with the Diwali festival. This year, the government imposed ban on the burning of firecrackers. This study was undertaken from 4^th-21^st November, 2020 to monitor the air quality variation with respect to PM₁₀ and PM_2.5 for Delhi, Lucknow, Ghaziabad, Muzaffarnagar, Greater Noida and Bulandshahar cities during and post Diwali period, to know whether there was any impact of the warnings. The hourly variations in the AQI were very poor between 8:00 p.m.-10:00 p.m. on Diwali day. Significant short term variation in the AQI was observed during the night. A weak positive correlation was obtained between the temperature and AQI, whereas a negative relationship was established with humidity. As compared to last year’s AQI, higher values were obtained this year. The short-term variation in air quality may prove crucial in future in the wake of COVID-19 pandemic.

5 illus, 7 tables, 27 ref

003035   YAIPHABA N (Chemistry Dep, D.M. Coll of Science, Imphal - 795 001, Email: ningombam.y@gmail.com) : Effect of Ce³⁺ Co-doping on GdPO₄:Tb³⁺ Nanoparticles: Photoluminescence and energy transfer studies. Asian J Chem 2021, 33 (4), 903 - 8.

Low temperature synthesis of Tb³⁺-doped GdPO₄ nanoparticles sensitized with Ce³⁺ (Ce³⁺ = 0, 3, 5, 7 and 10 at.%) have been reported. Ethylene glycol was used as capping agent as well as reaction medium at 160 ºC. The as-prepared particles crystallized in a monoclinic structure with an average crystallite size of 25-46 nm. From the photoluminescence study, enhanced emission of Tb³⁺ with co-doping of Ce³⁺ was attributed to efficient energy transfer from the sensitizer to activator. The luminescence emission intensity increases upto 5 at.% of Ce³⁺ and then decreases. Less efficient energy transfer from sensitizer to the activator with increasing concentration of sensitizer may be attributed to critical concentration of Ce³⁺ with the host or dipole-quadrupole interaction amongst the Ce³⁺ ions. Moreover, presence of -OH group in the samples will make them a potential target for biological labeling and optical devices.

9 illus, 1 table, 33 ref

003133   SENG T H, SURATMAN S, ABAS M R, TAHIR N M (Univ Malaysia Terengganu, Malaysia, Email: miman@umt.edu.my) : Emission of polycyclic aromatic hydrocarbons in smoke particulates at three different combustion stages from burning of rhizophora apiculate, melaleuca leucadendron and hevea brasiliensis wood. Asian J Chem 2021, 33 (4), 892 - 6.

The purpose of this study was to characterize and determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) emitted in smoke particulates from burning of Rhizophora apiculata, Melaleuca leucadendron and Hevea Brasilensis at the smouldering, flaming and charring stages. Smoke particulates were sampled using a total suspended particulate Hi-volume sampler (HVS) at a rate of 1.13 m³ / min and PAHs were extracted with a mixture of dichloromethane-methanol (3:1 v/v) using ultrasonic agitation. Fractionation of PAHs was carried out on an alumina-silica column and analysis by gas chromatography-mass spectrometry (GC-MS). The results showed that most of the samples exhibited the highest total identified PAHs in the smouldering stage with formation of PAHs with three rings or more increasing from the smouldering to flaming stages and reducing as combustion entered the charring stage. Naphthalene, phenanthrene and pyrene were the dominant PAHs detected in the wood smoke particulates, depending on combustion stage. Overall the emission and formation of PAHs are strongly dependent on combustion stage as well as other factors such as wood morphology, species, moisture content and combustion temperature.

3 illus, 2 tables, 20 ref

003132   BORHADE S S, TRYAMBAKE P T (Chemistry Dep, D.J.M. Commerce and B.N.S. Science Coll, Sangamner - 422 605, Email: pravintryambake21@rediffmail.com) : Synthesis, characterization, antibacterial, antifungal and antimalarial study of mixed ligand metal complexes derived from azo quinoline with thiosemicarbazone. Asian J Chem 2021, 33 (4), 885 - 91.

Mixed ligand metal complexes of azo quinoline and thiosemicarbazone with Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) metal ions were synthesized. The structure and possible geometry of all the metal(II) complexes were analyzed and supported by IR, mass spectrum, elemental analysis, TG-DTA, electronic spectra (UV), magnetic susceptibility and molar conductance. The synthesized compounds were studied for their antibacterial, antifungal and antimalarial activities. The antimicrobial activity was carried out against bacteria (two Grampositive bacteria and two Gram-negative bacteria), three fungal strain and one malarial pathogen.

2 illus, 5 tables, 40 ref

003131   QABAHA K, HIJAWI T, MAHAMID A, MANSOUR H, NAEEM A, ABBADI J, AL-RIMAWI F (Chemistry Dep, Al-Quds Univ, East Jerusalem, Palestine, Email: falrimawi@staff.alquds.edu) : Anti-inflammatory and antioxidant activities of teucrium polium leaf extract and its phenolic and flavonoids content. Asian J Chem 2021, 33 (4), 881 - 4.

Teucrium polium leaf is one of the folkloric medicinal plants used traditionally to treat many diseases in the Palestinian community. It has antibacterial antioxidant and anti-inflammatory consequences. Present study aims the evaluating the in vitro inhibitory effect of Teucrium polium leaf extracts on tumor necrosis factor-α (TNF-α) using polymorphonuclear cells (PMNCs), in addition to determine its antioxidant and total phenolic and flavonoids contents. Polymorphonuclear cells were withdrawn from whole blood according to Histopaque (Ficol1077) method. Blood cells were cultured in an enriched Roswell Park Memorial Institute (RBMI) medium. The levels of tumor necrosis factor (TNF-α) were determined after 24 h using LPS stimulation. Total phenolic contents, flavonoids contents and antioxidant activity were measured using spectrophotometric method. The TNF-α concentrations were compared using paired-samples t test. The leaf extracts of Teucrium polium revealed significant reduction in terms of TNF-α levels. The extract contained high phenolic and flavonoids contents and its antioxidant activities were remarkable. The reduced values in the TNF-α levels as affected by Teucrium polium leaf extracts indicate its effect in anti-inflammation. The plant is rich with polyphenolic compounds and flavonoids and has strong antioxidant activity. The observed anti-inflammatory effect of the extracts under study may be discussed as the influence of the significant presence of the phenolic compounds and flavonoids.

3 tables, 25 ref

003130   ADHIKARI D, GHOSH T (Chemistry Dep, Durgapur Government Coll, Durgapur - 713 214, Email: tuhinghoshbuchem@gmail.com) : Structural Insight and in vitro free radical scavenging capacity of arabinogalactan polysaccharides from the peels of punica granatum. Asian J Chem 2021, 33 (4), 873 - 80.

The juice extracted from Punica granatum L. fruit has been used for ages as an important functional food that can endow with healthcare benefits besides fundamental nutritional food that we intake. Although demonstration of antioxidant activity has been shown here, the target molecule responsible for this phenomenon remains unidentified. In this present work, we report a structural insight and antioxidant activity of its polysaccharide (PF-1), purified from water extract (WE) by precipitation with ethanol, ethanol soluble fraction (PF-2) and acetone extracted fraction (PF-3). The purified polysaccharide (PF-1) contains mainly arabinose, galactose together with lesser amount of rhamnose and glucose residues, and the molecular mass was determined 180 kDa. This fraction consists of T-(1,5)- and (1,3,5)-linked Ara_f; T-(1,6)- and (1,3,6)-linked Gal_p alongside (1,2,4)-linked Rha_p residues. The glucan is found to be β-(1→3)-linked glucopyranosyl residues with a molecular mass of 9 kDa. The in vitro antioxidant activity of the active fractions was determined by using 1,1-diphenyl2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), hydroxyl radical scavenging and total antioxidant activity (TAA) assays. The arabinogalactan showed the highest potential among the polysaccharides. This work involves an economically viable simple extraction method and reports promising antioxidant capacity. The studies suggest that this polysaccharide from Punica granatum L. fruit could be a natural antioxidant.

5 illus, 2 tables, 30 ref

003129   MAMILLAPALLI S P, KOYYA S, SUBBAIAH B V, ANNAPURNA N (Dr Reddys Laboratories Ltd, Hyderabad - 502 325, Email: suryapm@drreddys.com, suryanfg@gmail.com) : A new validated stability indicating RP-HPLC method for simultaneous quantification of impurities of fluticasone propionate and salmeterol xenafoate in metered dose inhalation aerosol. Asian J Chem 2021, 33 (4), 867 - 72.

A simple, specific, precise, accurate and stability indicating reversed phase HPLC method for simultaneous quantification of total 12 impurities of fluticasone propionate and salmeterol xenafoate in metered dose inhalation aerosol has been developed in the present work. Chromatographic separation between impurities of both compounds were achieved on Altima C18 250 × 4.6 mm, 5 µ column using a stepgradient elution at a flow rate of 1.4 mL/min, 0.1% v/v orthophosphoric acid as buffer and acetonitrile as mobile phase constituents. Forced degradation studies for drug product were performed and revealed that Salmeterol is acid sensitive (about 21.3%), degrades to IMP-D and fluticasone is alkali sensitive (about 7.6%) and degrades to IMP-A. All degradant and process related impurities of both compounds were monitored at 214 nm and spectral purity along with % mass balance is assessed using PDA detector, which proved stability indicating capability of the method. The developed method is fully validated as per current ICH guidelines, where precision is achieved at % RSD of < 5, Correlation of < 0.999 for linearity, LOD-LOQ at < 0.02% and < 0.05%, along with satisfactory system suitability results under robustness conditions.

5 illus, 4 tables, 19 ref

003128   KALITA R M, BARUAH R S, MEDHI C (Chemistry Dep, Gauhati Univ, Guwahati - 781 014, Email: chitranimedhi@gmail.com) : Synthesis, crystal structure, spectroscopic and antimicrobial properties of ruthenium complexes of vinyl imidazole and 4-ethylaminomethyl pyridine ligands. Asian J Chem 2021, 33 (4), 859 - 66.

Ruthenium complexes of vinylimidazole (VIMD) and 4-ethylaminomethyl pyridine (EMP) ligands were synthesized and characterized by XRD and spectroscopic methods. The binding of these Ru(IIII) complexes with calf thymus-DNA has been studied by UV-visible spectroscopic and electrochemical studies. A prominent increase in the intensity of fluorescence spectra of these complexes with CT-DNA was observed and a distinct UV-visible spectral shift in presence of CT-DNA is probably due to an interaction of these complexes with CT-DNA. The evidence of DNA binding has been found from the change in the intensity of fluorescence and UV visible spectra. Also, the electron transfer ability of these complexes is very important in order to rationalize their activity towards the biological system therefore, we have studied the electrochemical studies of these complexes by using cyclic voltammetry. From this study, it is possible to draw some ideas on electrochemical potentials of the complexes relevant to biological reduction possibly Ru(III)/Ru(II). Both complexes were also tested for antimicrobial activity against bacterial strain and responses well as antimicrobial agent.

7 illus, 3 tables, 31 ref

003126   KRISHNA R, RAMAKRISHNA C, SAINI B, GOPI T, SWETHA G, SHEKAR S C, SRINIVAS A (Defense R&D Establishment, Gwalior - 474 002, Email: chem.krishna24@gmail.com, srinivasmessage@gmail.com) : Carbon molecular sieve supported Pd catalyzed hydrogenation of cinnamaldehyde in alkaline medium. Asian J Chem 2021, 33 (4), 846 - 52.

Synthesis of various fine chemicals and pharmaceuticals are regulated through selective hydrogenation of α,β-unsaturated aldehydes. Hydrocinnamaldehyde is one of the important compounds in perfumery and flavouring industries. It is highly precarious and challenging to control the product selectivity as well as conversion in cinnamaldehyde hydrogenation. In this study, an effective hydrogenation of cinnamaldehyde was attained in presence of aqueous-protic organic medium by utilizing Pd/CMS and other additives of alkali such as K₂CO₃. The Pd/CMS catalyst along with alkali media catalyzed the hydrogenation of C=C selectively in cinnamaldehyde in order to form hydrocinnamaldehyde with 100% conversion rate. Additionally, the parallel hydrogenation of C=O and C=C bonds in cinnamaldehyde takes place in absence of media. The C=O bond reduction in cinnamaldehyde can be restricted through K₂CO₃ addition to aqueous-protic solution. The active sites of palladium were found to be uniform and analyzed using HRTEM data. Based on the mechanism involved in micropores of carbon molecular sieves, the key role of promoter is associated with hydrogenation of cinnamaldehyde. The catalytic criterion was appropriate with the acquired activity data.

9 illus, 2 tables, 28 ref

003125   SINGH K, SOHAL H S, SINGH B (Chemistry Dep, Punjabi Univ, Patiala -147 002, Email: baljit_chemz@yahoo.co.in) : Synthesis of α-hydroxycarboxylic acids from various aldehydes and ketones by direct electrocarboxylation: A facile, efficient and atom economy protocol. Asian J Chem 2021, 33 (4), 839 - 45.

In present work, the formation of α-hydroxycarboxylic acids have been described from various aromatic aldehydes and ketones via direct electrocarboxylation method with 80-92% of yield without any side product and can be purified by simple recrystallization using sacrificial Mg anode and Pt cathode in an undivided cell, CO2 at (1 atm) was continuously bubbled in the cell throughout the reaction using tetrapropylammonium chloride as a supporting electrolyte in acetonitrile. The synthesized compounds obtained in fair to excellent yield with a high level of purity. The characterization of electrocarboxylated compounds was done with spectroscopic techniques like IR, NMR (¹ H & ¹³C), mass and elemental analysis.

3 tables, 28 ref

003124   SAHU T K, KAR B, SAHOO N, BEHERA A, PATTNAIK G (Centurion Univ of Technology and Management, Bhubaneswar - 752 050, Email: tapangouri1981@gmail.com, biswa_kanth2005@yahoo.co.in) : An overview on ethnopharmacology, phytochemical and pharmacology of eleusine indica. Asian J Chem 2021, 33 (4), 833 - 8.

Many efforts have been made through publication of traditional studies on plants to increase the interest and improve on natural remedy since past few years. Eleusine indica is a diploid species of genus Eleusine belongs to family Poaceae. More than 20 diseases are traditionally treated by this plant around the different tropical and subtropical region of world. Phytochemically many inorganic and organic active constituents have been isolated from the plant. Many secondary metabolites has been isolated and identified such as vitexin, isovitexin, orientin, isoorientin, lutein, β-sitosterol, stigmasterol and derivatives of sterol glucosides belongs to categories of flavonoids, caretenoid and sterols. Plant possesses active constituents attributes several pharmacological actions like antimicrobial, antiinflammatory, diuretic, anticonvulsant, antiobesity, anticancer, antihypertensive, antioxidant, hepatoprotective, etc. Further investigations are essential to fulfil many research gaps which were identified and still many bioactive constituents have to be discover in respect to traditional and pharmacological use.

1 table, 89 ref

003123   KOTHA S S K C, DODDIPALLA R, GANDHAM H, RUMALLA C S, KALIYAPERUMAL M, MANCHINENI S (Engineering Chemistry Dep, Andhra Univ, Visakhapatnam - 530 003, Email: himabinduauce@gmail.com) : Degradation studies of tadalafil: Identification, isolation and structure characterization of stress degradation product using LC-MS, Mass Mediated Prep-HPLC, NMR, HRMS. Asian J Chem 2021, 33 (4), 827 - 32.

The degradation behaviour of tadalafil performed under different stress conditions according to International Conference on Harmonization guidelines (ICH) was studied. A novel degradation product (DP) of tadalafil was observed only in acidic condition. An isolated degradation product [(R)-3-((1H-indol-3-yl)methyl)-4-(benzo[d][1,3]dioxole-5-carbonyl)-1-methylpiperazine-2,5-dione)] was identified by UPLCMS technique and its structure was confirmed by high resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) studies. Acquity BEH C18 (50 mm × 2.1 mm, 1.7 µm) column was used in LC-MS, gradient run was performed with mobile phases 0.05% formic acid in acetonitrile and 0.05% formic acid in water, flow rate was 0.6 mL/min. The sample was diluted with acetonitrile and water.

5 illus, 3 tables, 14 ref

003122   ADEPPAGARI N C, OMKARAPPA N K, MALINGAPPA P (Chemistry Dep, Bangalore City Univ, Bengaluru - 560 001, Email: mprangachem@gmail.com) : Speciation study of nitrite/nitrate through diazo-coupling reaction using silica-perchloric acid as a novel catalyst at trace level: Application to environmental samples. Asian J Chem 2021, 33 (4), 819 - 26.

A simple, sensitive and rapid spectrophotometric method has been developed based on the diazo coupling reaction in the quantification of nitrite/nitrate at trace level using silica perchloric acid (SPCA) as an acid catalyst. 5-Amino-2-mercapto benzimidazole has been used as a novel amine and coupled with N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) to produce an intense coloured azo dye. The proposed method showed wide linearity in the concentration range 0.1-1000 ppm of nitrite. The molar absorptivity and Sandell′s sensitivity were found to be 1.6 × 10⁶ L mol^–1 cm^–1 and 0.0012 µg cm–2 respectively. Nitrate was measured after its reduction to nitrite using optimized copper-cadmium reductor column. The proposed method has been successfully applied to measure trace level nitrite/nitrate from a variety of sample matrices like water, soil, milk and radiator coolant.

5 illus, 6 tables, 35 ref

003120   MOON D, CHOI J H (Chemistry Dep, Andong National Univ, Republic of Korea, Email: jhchoi@anu.ac.kr) : Crystal structure and infrared spectroscopy of trans-[Cr(NCS)₂(Me₂tn)₂][Cr(NCS)₄(Me₂tn)] Moiety. Asian J Chem 2021, 33 (4), 807 - 13.

A novel double complex, trans-[Cr(NCS)₂(Me₂tn)₂][Cr(NCS)₄(Me₂tn)]·NaSCN·i-PrOH, (1) (Me₂tn = 2,2-dimethyl-1,3-propanediamine, C₅H₁₄N₂; i-PrOH = isopropyl alcohol), was prepared and its structure was determined by single-crystal X-ray diffraction at 95 K. The complex 1 crystallized in the space group P1 of the triclinic system with two nuclear formula units in a cell of dimensions a = 13.220(3), b = 13.699(3), c = 15.087(3) Å and α = 116.193(3), β = 102.73(3) and γ = 104.48(3)°. X-ray structural analysis revealed two crystallographically independent Cr(III) complex cations in the complex 1. The asymmetric unit contains two halves of trans-[Cr(NCS)₂(Me₂tn)₂] + cations (2 and 3), one cis-[Cr(NCS)₄(Me₂tn)]− anion (4), one NaSCN salt and one isopropyl alcohol molecule. In two independent complex cations, the chromium(III) ions are coordinated by four N atoms of two chelating Me₂tn and two NCS groups in a distorted octahedral geometry while the chromium(III) ion in cis-[Cr(NCS)₄(Me₂tn)]- has a distorted octahedral coordination with two N atoms of one Me₂tn and four NCS groups. The two six-membered rings in trans-[Cr(NCS)₂(Me₂tn)₂] + cations adopt both anti chair-chair conformations. The Cr–N(Me₂tn) bond lengths range from 2.0624(18) to 2.0877(16) Å, while the Cr–N(NCS) bond lengths range from 2.0718(16) to 2.0428 (16) Å. The crystal lattice is stabilized by hydrogen bonding interactions among the NH groups of the Me₂tn ligand, OH group of i-PrOH and the S atoms of the NCS groups. The infrared spectral properties are also described.

6 illus, 5 tables, 25 ref

003119   KONDOH E, EDEM K K, BODJONA M B, KILI K A, TCHANGBEDJI G (Lomé Univ, Lomé, Togo, Email: bodjonabenoit@yahoo.fr, bodjonabassai@gmail.com) : Survey and quantification of household waste in Tsévié City, Togo. Asian J Chem 2021, 33 (4), 802 - 6.

The management of solid household wastes in Tsévié is the environmental concerns that the municipality faces on a daily basis. The aim of this study is to assess the amount of waste produced daily per resident in Tsévié and then to determine the socio-economic dynamics involved in the production of waste. A quantification campaign coupled with the socio-economic assessment are carried out. The households selected are chosen at random from different parts of the city and their number is defined on the basis of the size of the population so as to cover at least one hundredth of this population. The results obtained indicate that the ratios vary by neighborhood and by the lifestyle of population. These ratios range from 0.476 kg/hab/d to 0.587 kg/hab/d with an average of 0.54 0.10 kg/hab/d. The production of household wastes in the city of Tsévié is estimated at 13440 tonnes per year. For the other sectors, especially the central market and commercial structures, production is estimated at 744 tonnes and 149 tonnes of waste respectively per year. With an estimated annual waste production in the city of Tsévié of approximately 14,333 tonnes, urgent steps must be taken toward the efficient management of this waste.

5 tables, 27 ref

003118   GUNASEKARAN S G, STEPHEN L D, ARIVALAGAN V, SOUNDARRAJAN M (Chemistry Dep, SRM Valliammai Engineering Coll, Kattankulathur - 603 203, Email: gunasekaransg.chemistry@valliammai.co.in) : Structurally designed imine skeletal pyrenyl pendant pyridine core polybenzoxazine nSiO₂/PBZ hybrid polymer nanocomposites. Asian J Chem 2021, 33 (4), 793 - 801.

Novel polybenzoxazine-silica (nSiO₂/PBZ) hybrid nanocomposites were designed and synthesized using carbazole terminal pyrenyl pyridine core imine skeletal benzoxazine monomer (PYCBZ) and nanosilica (nSiO₂) through in situ sol-gel method. The FT-IR and Raman spectral studies ascertained the formation of nanosilica reinforced polybenzoxazine hybrid nanocomposites. The nSiO₂/PBZ hybrid nanocomposites exhibited excellent thermal stability and higher char yield than that of neat PBZ. The elevation in glass transition temperature of the nanocomposites was evidenced by the limited motion of the polymeric network with the introduction of nanosilica particles in the PBZ matrices. The hydrophobic nature of a less polar nSiO₂ in the composites zipped the water uptake behaviour of (nSiO₂/PBZ) hybrid nanocomposites to low percentage. The shift in the absorption peak reveals that the nanosilica particles were successfully incorporated through thermal ring opening polymerization of benzoxazine. The homogeneous reinforcement of nSiO₂ particles retains the fluorescent properties of polybenzoxazine. The uniform molecular level dispersion of nano SiO₂ onto polybenzoxazine networks were confirmed from transmission electron microscope and scanning electron microscope images.

11 illus, 2 tables, 43 ref

003116   FAUZIAH S, SULLAHI F A, SOEKAMTO N H, TABA P, SAPAR A (Chemistry Dep, Hasanuddin Univ, Indonesia, Email: stfauziah@unhas.ac.id) : Synthesis of molecularly imprinted polymers using methacrylic acid and ethylene glycol dimethacrylate by precipitation polymerization method. Asian J Chem 2021, 33 (4), 785 - 8.

The synthesis of molecularly imprinted polymers (MIPs) was carried out by using methacrylic acid as a monomer, ethylene glycol dimethacrylate as a crosslink and dibutyl phthalate as a mold through the precipitation polymerization method. The MIP was characterized with FTIR, surface area analyzer, SEM-EDS and ultraviolet-visible spectrophotometer. The MIP adsorption ability test variables for dibutyl phthalate were time and concentration. The FTIR indicates that the functional groups –OH, –C=O and –C=C contribute to the formation of MIP and the SEM-EDS analysis showed that the prepared MIP resembles as beads. The MIP’s ability to adsorb dibutyl phthalate is better than NIP and the optimum time to adsorb dibutyl phthalate is 60 min.

5 illus, 4 tables, 13 ref

003115   ERDAG E (Pharmaceutical Chemistry Dep, Near East Univ, Turkish Republic of Northern Cyprus, Email: emine.erdag@neu.edu.tr) : Synthesis and characterization of 3-substituted indole derivatives as novel mannich bases. Asian J Chem 2021, 33 (4), 781 - 4.

In this study, ten 3-substituted indole derivatives at the 3^rd position of indole nucleus were synthesized via Mannich reaction with microwave assisted synthesis and the conventional reflux heating method. Microwave assisted synthesis is more preferrable than reflux method since the microwave irradiation lead to a higher product yields with better purity and improved energy efficiency with shortened reaction time. The structures of 3-substituted indole derivatives were characterized by FT-IR, elemental analysis, ¹ H NMR and ¹³C NMR spectroscopy.

1 table, 16 ref

003114   MANOHONG P, SORNKAEW N, MEEMON K, CHUMPHOOCHAI K, SOBHON P, TAMTIN M, SICHAEM J, MINGVANISH W, SRISUWANNAKET C, MINGVANISH W (Chemistry Dep, King Mongkut's Univ of Technology Thonburi, Bangkok 10140, Thailand, Email: nakorn.nia@kmutt.ac.th) : Isolation of 3-(Hydroxyacetyl)indole and Indole-3-carboxylic acid from Red Alga Halymenia durvillei: their anti-lung cancer cell and in vivo anti-aging activity. Asian J Chem 2021, 33 (4), 775 - 80.

This study aimed to evaluate the bioactivity and phytochemical investigation in red algae Halymenia durvillei. The polarity based solvent partition (hexane, ethyl acetate, butanol and water) of H. durvillei ethanolic crude were used for characterization. The present results of the ethyl acetate extract of red alga H. durvillei generated a 3-(hydroxyacetyl)indole (1), indole-3-carboxylic acid (2) as well as two fatty acids viz. palmitic acid (3) and α-linoleic acid (4). The viability against lung cancer cells of compounds 1 and 2 showed moderate activities against the A549 cell line with inhibition percentages of 12.97% and 25.81%, respectively. Analysis of the dose response of C. elegans anti-aging assay indicated that the survival rate of compound 1 was 12.62% while it was 11.04% for compound 2. Furthermore, H. durvillei isolation was used as an antioxidant, anti-cancer cell and anti-aging resource.

2 illus, 7 tables, 20 ref

003112   PANDA B S, AHEMAD M A (Integrated Coastal Zone Management Project, Bhubaneswar - 751 024, Email: bpanda607@gmail.com) : Synthesis of silver nanoparticles from mimusops elengi extract of raw fruits and characterization of PVA-silver polymer nanocomposite films. Asian J Chem 2021, 33 (4), 762 - 6.

The present work concerns on the synthesis of silver nanoparticles at 25 ºC using raw fruits extract of Bakul (Mimusops elengi) tree via chemical reduction route development of poly(vinyl alcohol) PVA-silver polymer nanocomposite films. The nanocomposite films were subjected to characterization by UV-visible, FTIR, X-ray diffraction, field emission scanning electron microscope (FESEM) and thermal studies. The UV-visible spectrum shows a characteristic broad absorption band observed near 465 nm suggesting presence of silver nanoparticles in polymer nanocomposites (PNCs) film. The vibrational band shift of –OH group of poly(vinyl alcohol) in the presence of nanoparticle designated the chemical interaction between –OH group of poly(vinyl alcohol) and silver nanoparticles. The FESEM study confirmed that PVA is not only acted as a capping agent, but also a cross-linking agent. X-ray diffraction study shows that the existence of AgNPs in the poly nanocomposite film and nanoaparticles are crystalline in nature. Thermal studies suggest that the enhanced thermal stability is because of the good packing of the polar crystallites in β-PVA composites as compared to the non-polar α-phase of neat poly(vinyl alcohol) (PVA).

5 illus, 37 ref

003111   SETIARSO P, SARI N P (Chemistry Dep, State Univ of Surabaya, Indonesia, Email: pirimsetiarso@unesa.ac.id) : Graphene oxide-paraffin-nanobentonite as working electrode for cyclic voltammetry analysis for nicotinic acid. Asian J Chem 2021, 33 (4), 757 - 61.

The composition of graphene oxide (GO):paraffin:nanobentonite electrode was optimized to acquire the optimal working electrode to analyze nicotinic acid under the optimum conditions through cyclic voltammetry. Graphene oxide was synthesized from graphite by employing the improved Hummer method. Bentonite was synthesized using the sonothermal method. The ratio of GO:paraffin:nanobentonite electrodes of 3:3:4 provided the optimal voltammogram. The results indicated that the composition of the comparative working electrodes of GO-modified nanobentonite was best 3:3:4 with a good peak recovery averaged value of 96.16%.

7 illus, 6 tables, 14 ref

003110   ANUSUYA N, THISWARAN C P, MARY J V (Chemistry Dep, Periyar E.V.R. Coll, Thiruchirappalli - 620 023, Email: anu88.eversmile@gmail.com) : Catalytic reduction of 4-nitrophenol to 4-aminophenol using chitosan Ag-TiO₂ nanocomposite and its applications in the removal of malachite green by photodegradation technique. Asian J Chem 2021, 33 (4), 752 - 6.

A simple colloidal processing method was used to synthesize chitosan Ag-TiO₂ nanocomposite and its use aimed at the catalytic reduction of 4-nitrophenol to 4-aminophenol in the presence of NaBH₄ as reductant. The nanocomposite catalyst was characterized using different technquies and revealed its better catalytic ability than pure TiO₂. Since the nanocomposites are readily improved from the solution phase without centrifugation or filtration. The catalytic activity trials were examined by changing the catalyst dose, concentration of NaBH₄, amount of nitrobenzene and temperature. The reduction reactions were affected by the temperature of reaction medium and the concentration of NaBH₄. The photodegradation conditions were optimized by changing different parameters such as irradiation time, dosage, pH and initial dye concentration.

9 illus, 37 ref

003109   DESAI P S, PAREKH D V (Chemistry Dep, Arts, Science and Commerce Coll, Surat - 394 185, Email: psdesai69@gmail.com) : Synthesis, characterization and biological screening of novel metal(II) Complexes of 2-{[2-(5-Benzoyl-1H-benzotriazol-1-yl)-2-oxoethyl]amino}-5-bromobenzoic Acid. Asian J Chem 2021, 33 (4), 747 - 51.

In this work, 5-bromoanthranilic acid was condensed with 1-(5-benzoyl-1H-1,2,3-benzotriazole-1-yl)-2-chloro-ethanone to form 2-{[2- (5-benzoyl-1H-benzotriazol-1-yl)-2-oxoethyl]amino}-5-bromobenzoic acid. The newly synthesized ligand and its metal(II) complexes with first transition metal series (Cu(II), Ni(II), Co(II), Zn(II) and Mn(II)) have been synthesized and characterized by using elemental analysis, infrared and electronic spectra. The IR spectra, NMR spectra and atomic absorption analysis show that the benzotriazole ligand formed chelates with metal in a 2:1 (ligand:metal) stochiometry. All the metal(II) complexes were screened for their antibacterial activity against Gram-positive and Gram-negative bacteria. Among the synthesized metal(II) complexes, Cu(II) complex showed the highest antibacterial activity.

3 tables, 40 ref

003107   SHAFI S S, SUBASHINI P, GAJALAKSHMI S, KUMAR V V (Chemistry Dep, Thiruvalluvar Univ, Vellore - 632 115, Email: suban_shafi@yahoo.com) : An efficient suitable synthesis for pyrazole, pyrimidine derivatives and biological evaluation. Asian J Chem 2021, 33 (4), 734 - 40.

Novel quinazoline derivatives were synthesized by reacting isatoic anhydride and 4-amino acetanilide to synthesize N-(4-(2,4-dioxo-1,2- dihydroquinazolin-3(4H)-yl)phenyl)acetamide which in turn reacted with substituted aromatic aldehydes to synthesize novel chalcones. The chalcones were allowed to react with hydrazine hydrochloride and guanidine to form pyrazoline and pyrimidine derivatives, respectively. The newly synthesized compounds were characterized by IR, NMR (¹ H, ¹³C), mass and elemental analysis. All the newly synthesized derivatives were screened for in vitro antimicrobial and antioxidant activities to evaluate their biological potency.

2 tables, 21 ref

003106   GHOSH A, SAHA A, SARKER K, MISHRA S, SEN S (Coll of Pharmaceutical Sciences, Mohuda, Berhampur - 760 002, Email: prof.dr.subratasen@gmail.com) : Design, synthesis, molecular docking and in vitro evaluation of N-(4-Ethoxyphenylsulfonyl)pyrrolidine-2-carboxylic acid analogues as antiangiogenic and anticancer agents on multiple myeloma. Asian J Chem 2021, 33 (4), 727 - 33.

In present work, N-(4-ethoxyphenylsulfonyl)pyrrolidine-2-carboxylic acid analogs were designed, synthesized and biologically evaluated as an antiangiogenic and anticancer agent on multiple myeloma. Compounds 3i, 3k and 3m exhibited the cytotoxic action on human multiple myeloma cell line RPMI8226 with IC₅₀ (µM) value 3.72, 3.89 2.28, respectively. These compounds possessed the antiangiogenic property and are selectively cytotoxic to cancer cells, as observed from the in vitro study of human umbilical vein endothelial cell (HUVEC) and African green monkey epithelial cell (VERO), respectively. Antiproliferative assay of the compounds on HUVECs was carried out using the dye exclusion method with trypan blue. Molecular docking study of compound 3m with vascular endothelial growth factor receptor-2 (VEGFR-2) showed possible interaction with a binding energy -62.27 kcal/mol.

3 illus, 1 table, 25 ref

003105   NKUTHA C S, SHOOTO N D, NAIDOO E B (Chemistry Dep, Vaal Univ of Technology, South Africa, Email: cynthiankutha61@gmail.com) : Coral limestone modified by magnetite and maghemite nanocomposites for sequestration of lead(II) and Chromium(VI) ions from aqueous solution. Asian J Chem 2021, 33 (4), 712 - 26.

In present work, a one pot synthesis of magnetic nanocomposites was synthesized by using co-precipitation method in air atmosphere. The synthesis of magnetite and maghemite supported on biogenic coral limestone was done by varying the ratio of Fe(II)/Fe(III) in solution to obtain the two phases of iron oxide and capping with sucrose in air atmosphere. The nanocomposites were characterized by FTIR, where the results showed a distinct peak for Fe-O, while UV/vis showed an absorption in the visible region which is typical of iron oxide. Photoluminescence results showed that the nanocomposites were both red shifted for magnetite-PCLS (PCLS = pristine coral limestone) and magnetite-CCLS (CCLS = calcined coral limestone); while a blue shift and red shift was observed for the maghemitePCLS and maghemite-CCLS. From the SEM a deviation of sphericity of the nanocomposites, with maghemite having an uneven distribution was observed. Equilibrium was reached within 60 min, of which maghemite showed higher metal uptake. The kinetic data fit PSOM better as compared to PFOM, this means that adsorption was due to the charge density on the surface of the nanocomposites. The good fit for intraparticle diffusion (IPD) also suggested that adsorption was also observed due to mass transfer, it was observed that the rate limiting step was due to surface adsorption. This was in good correlation with the better fit of PSOM. The mechanism of adsorption was found to be better explained by physisorption and the surface was heterogeneous whereby multilayer adsorption was possible. The data was also subjected to Dubinin-Radushkevich isotherm, which suggests that the uptake of the pollutants was due to physisorption. The adsorption process was spontaneous and favourable which is supported by the negative values of Gibb’s free energy for the system.

12 illus, 5 tables, 87 ref

003102   KUMAR S G P, KOTTAM N, PREETHAM R, MONIKA D L (Chemistry Dep, M.S. Ramaiah Institute of Technology, Bangalore - 560 054, Email: nagaraju@msrit.edu) : Role of NH₄Cl as flux on photoluminescence properties of Ca_1-xZrO₃:Eu_x (x = 0.05) synthesized by solution combustion route. Asian J Chem 2021, 33 (3), 686 - 90.

CaZrO₃ ceramics exhibits high chemical, thermal and structural stability. However, its application as a host for various luminophores/ activators has not been clearly explored. In present study, CaZrO₃ doped with Eu³⁺, as a potential orange-red phosphor and the effect of NH₄Cl as flux during combustion synthesis is investigated. Ca_1-xZrO₃:Eu_x (x = 0.05) nanophosphor was prepared through a low temperature, one pot solution combustion synthesis approach using glycine as fuel. Various wt.% of NH4Cl (wt.% = 0, 1, 3, 5, 7) as flux added to the reaction mixture and combustion reaction was performed. X-ray diffraction results showed that the addition of flux has significant effect on the crystallite size and the crystallinity of Ca_1-xZrO₃:Eu_x (x = 0.05) phosphor. From SEM morphology, the particles were found to be significantly agglomerated. The extent of agglomeration varies with varying the wt.% of flux. The photoluminescence excitation and emission spectra were recorded under similar condition to evaluate the effect of flux on the optical properties. Interestingly, the amount of flux was found to have significant effect on the photoluminescence emission characteristics. The photoluminescence intensity was found to be the maximum when the flux used was 5 wt.% and further increase in flux amount the photoluminescence intensity decreases. The mechanistic aspects of effect of flux on the photoluminescence were also discussed.

4 illus, 1 table, 28 ref

003100   RATHORE B R S, CHAUHAN N P S , RAWAL M K , AMETA S C, AMETA R (Chemistry Dep, J.R.N. Rajasthan Vidyapeeth, Udaipur - 313 001, Email: rakshit_ameta@yahoo.in) : Synthesis and characterization of chitosan-polyaniline-manganese dioxide nanocomposite for removal of methyl orange dye. Asian J Chem 2021, 33 (3), 671 - 6.

An ecofriendly polymer composite based on chitosan, polyaniline and manganese dioxide has been prepared using batch adsorption method and analyzed by Fourier transform infrared (FTIR), UV-vis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). FTIR results suggested the presence of functional groups like hydroxyl and amino groups and also shown a significant shift in IR bands in CS-PANI-MnO₂ composite. The surface of composite was quite rough within the folds of pleated regions as observed from the SEM and TEM morphologies. The prepared composite was also utilized as an adsorbent for the treatment of methyl orange from the aqueous solution and achieved a reasonably good adsorption capacity of 96.2%. The biochemical oxygen demand (BOD) and chemical oxygen demand (COD) tests also suggested their suitability for the adsorption of methyl orange dye.

7 illus, 1 table, 31 ref

003097   PHUNGPIS B, HAHNVAJANAWONG V (Rajamangala Univ of Technology Isan Sakonnakhon Campus, Thailand, Email: barameephungpis@yahoo.com) : 1-Butyl-3-methylimidazol-2-ylidene as an efficient catalyst for cross-coupling between aromatic aldehydes and N-aroylbenzotriazoles. Asian J Chem 2021, 33 (3), 651 - 7.

Cross-coupling of aromatic aldehydes with N-aroylbenzotriazoles in [Bmim]Br in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) provided an efficient procedure for the synthesis of 1,2-diarylethane-1,2-diones.

2 tables, 28 ref

003096   BADAL M M R, ISLAM M T, PARVIN R, MOROL M A K, MANIRUZZAMAN M, YOUSUF M A, HALIM M E (Chemistry Dep, Khulna Univ of Engineering &Technology, Bangladesh, Email: mizan@chem.kuet.ac.bd) : Antimicrobial, structure-activity relationship and computational studies of some synthesized chalcone derivatives. Asian J Chem 2021, 33 (3), 644 - 50.

Several chalcones viz. 1,3-diaryl-2-propane-1-one (1a), 3-(4-hydroxy phenyl)-1-phenyl-2-propane-1-one (1b), 3-(4-amino-phenyl)-1-phenyl2-propane-1-one (1c) and their derivatives 2-ethoxy-4,6-diphenyl-4H-pyran-3-carboxylic acid ethyl ester (2a), 4-(4-hydroxy-phenyl)- 7,7-dimethyl-2-phenyl-4,6,7,8-tetrahydro-chromen-5-one (2b) and 7-(4-amino-phenyl)-5-phenyl-1,5-dihydropyrano[2,3-d]pyrimidine2,4-dione (2c ) have been synthesized following both conventional and microwave irradiation methods. The structures of the isolated compounds were elucidated on the basis of UV-visible, FTIR, 1 H NMR spectral data. The antimicrobial results showed some remarkable facts about the structure–activity relationship, which states that the electronic atmosphere around the chalcone derivative moieties and substituents considerably affect the antimicrobial potential of the synthesized compounds. Theoretical calculation as well as antimicrobial activity of the compounds were also studied.

3 illus, 3 tables, 30 ref

003095   BERKALOU K, NOUNAH A, CHAAIR H, KHAMAR M, BOUSSEN R, DRIOUICH A (Mohammed V Univ, Rabat, Morocco, Email: kaoutar.berkalou@gmail.com) : Modelling and optimizing the solvent extraction of cadmium from phosphoric acid using experimental design. Asian J Chem 2021, 33 (3), 637 - 43.

The removal of cadmium from phosphoric acid was carried out using the solvent extraction process, taking into account factors such as pH, concentration of the extracting agent [EA], organic phase/aqueous phase (O/A) ratio, stirring time and stirring rate. In order to study the effect of these involved factors and their interactions on the extraction percentage of cadmium, a composite central design (CCD) of 24 experiments was adopted. An empirical model was developed and validated by applying ANOVA analysis. The graphical representation of this model in the variable space allowed to determine the optimal conditions of these factors. The extraction of cadmium from phosphoric acid reached a percentage of the order of 98%, under the following conditions: pH = 3, [EA] = 10^-2 M, O/A = 1.1, stirring time 90 min, stirring rate 800 rpm.

4 illus, 6 tables, 17 ref

003094   SEPTIANI A, ANGGRAENI A, HARDIANTO A, EDDY D R, BAHTI H H (Chemistry Dep, Padjadjaran Univ, Indonesia, Email: diana.rahmawati@unpad.ac.id) : Microencapsulation of gadolinium citrate using silica for contrast agent development. Asian J Chem 2021, 33 (3), 632 - 6.

Gadolinium is a potential T₁ contrast agent because it provides a better image for magnetic resonance imaging (MRI). However, as toxic gadolinium ions can be released from the coordination compounds, it is often encapsulated using silica. Silica-encapsulated gadolinium citrate is a colloid, therefore, encapsulation efficiency should be determined by the standard addition method, not the external standard, to minimize errors in the matrix. Silica-encapsulated gadolinium citrate (Gd-C₆H₅O₇@SiO₂) was prepared via the Stöber sol-gel method by mixing gadolinium citrate, ethanol, aqua proinjection, tetraethylorthosilicate (TEOS) and ammonia, then the encapsulation efficiency was determined using the standard addition method. Particle size analysis revealed that the average size of Gd-C₆H₅O₇@SiO₂ particles was 1.53 µm having a encapsulation efficiency of 90.44%.

5 illus, 17 ref

003092   GOPAL S, CHINNASAMY U, ARUMUGAM R (Chemistry Dep, Government Arts Coll, Salem - 636 007, Email: 72000senthil@gmail.com) : Synthesis of novel corrosion inhibitor N-(1,3-Benzothiazol-2-yl)-4-aminobenzamide in 1 N hydrochloric acid medium. Asian J Chem 2021, 33 (3), 622 - 6.

A novel corrosion inhibitor i.e. N-(1,3-benzothiazol-2-yl)-4-aminobenzamide was synthesized and its corrosion inhibitor on controlling the rate of mild steel material in hydrochloric acid medium (1 N) at different temperatures was investigated. Rate of corrosion and inhibition efficiency were analyzed and calculated using mass loss method and electrochemical studies. As the concentration of the inhibitor increase the inhibitor efficiency also increases gradually with decrease in the rate of corrosion. Therefore from this study the efficiency of the inhibitor was good at different temperature in 1 N HCl. The relative corrosion inhibition efficiency of synthesized organic compound has been explained on the basis of its structure dependent-electron donating properties of the inhibitor. Further the structure and compound present in the synthesized organic inhibitor compound was confirmed by FTIR and NMR studies.

6 illus, 3 tables, 19 ref

003091   GOPAL M, SASI S (Chemistry Dep, Maharaja’s Coll, Ernakulam - 682 011, Email: sreeshasasi@gmail.com, sreeshasasi@maharajas.ac.in) : Synthesis and structural characterization of lanthanum(III) complexes of 4-nitrosoantipyrine. Asian J Chem 2021, 33 (3), 617 - 21.

A new series of La(III) complexes of the ligand with the general formula [La(L)₂(a)₃] and [La₂(L)₄(aa)₃], (a = nitrate (1), thiocyanate (2), acetate (3) and propionate (4) ions, aa = sulphate (5), thiosulphate (6), oxalate (7) and malonate (8) ions with the ligand 4-nitrosoantipyrine (L) were synthesized and characterized using various physico-chemical studies. The primary ligand L acts as a bidentate ligand utilizing the carbonyl group and the nitroso group for bonding. The nitrate, thiocyanate, acetate and propionate ions are monovalent unidentate ligands, whereas sulphate, thiosulphate, oxalate and malonate ions are divalent bidentate ligands in the complexes 1-8. Based on spectral data and magnetic susceptibility measurements, geometry of the lanthanum(III) complexes were also proposed.

2 illus, 3 tables, 43 ref

003090   PRABHAKARAN A, DOSS M A, DHINESHKUMAR E, RAJKUMAR R (Chemistry Dep, Thiruvalluvar Univ Coll of Arts and Science, Kallakurichi - 606 213, Email: rajkumarphd.r@gmail.com) : Synthesis, Crystal Structure and DFT Studies of 4-(2-(4,5-Dimethyl-2-(3,4,5-trimethoxyphenyl)-1H-imidazol-1-yl)ethyl)morpholine. Asian J Chem 2021, 33 (3), 611 - 6.

The title compound 4-(2-(4,5-dimethyl-2-(3,4,5-trimethoxyphenyl)-1H-imidazol-1-yl)morpholine (DMTPM) was synthesized using a one-pot multicomponent approach. The molecular structure of the compound was charcterized with ¹ H & ¹³C NMR, HR-MS and singlecrystal X-ray diffraction. In the ground-state, DMTPM molecular geometry was determined using the DFT based on B3LYP/6-31G(d,p) and compared to the experimental results. In addition, molecular electrostatic potential (MEP) map and molecular frontier orbitals (MFO) were performed and the results obtained were compatible with the electronic properties.

6 illus, 5 tables, 34 ref

003089   RAPETI D, NARAYANARAO K M V, SHYAMALA P, KRISHNA R M (GVK Biosciences Pvt. Ltd, Hyderabad - 500 076, Email: durgababu_chem416@yahoo.com) : Identification of the organic volatile impurities in ezitamibe using GC-HS Technique. Asian J Chem 2021, 33 (3), 605 - 10.

Ezetimibe prevents intestinal cholesterol synthesis, which in turn reduces the quantity of cholesterol and thereby helps to reduce heart problems and strokes. In the production of ezetimibe, several organic chemical solvents such as methanol, acetone, isopropyl alcohol, dichloromethane, n-hexane, ethyl acetate, tetrahydrofuran, toluene and dimethyl formamide were used. The measurement of residual solvents is necessary for release checks of all drug substances, based on sound manufacturing processes. The analysis of above mentioned nine solvents in ezetimibe drug was investigated using gas chromatographic method employing detection with flame ionization mode. All analyses were performed using ZB-624 column (30 m length × 0.53 mm identification, 3.0 µm thickness film). The column oven temperature flux was managed to maintain for 11 min at 40 ºC and then continued to upsurge to a temperature close of 240 ºC at a rate of 20 ºC/min and retained for 4 min. The flame ionization detector and injector port were managed at 260 and 200 ºC, respectively. Results after the validation of the gas chromatographic method showed the satisfactory linearity, sensitivity, robustness, accuracy, selectivity and precision for the tested organic solvents. This gas chromatographic approach can therefore be exploited in the assessment of studied nine residual chemical solvents for periodic analysis by gas chromatography for samples of ezetimibe drug.

2 illus, 8 tables, 15 ref

003088   MERRY T, MADDELA P (Chemistry Dep, Nagaland Univ, Lumami - 798 627, Email: prab.chem@gmail.com) : Efficient synthesis and characterization of anthracene based 1,3,5-trisubstituted pyrazoline derivatives. Asian J Chem 2021, 33 (3), 600 - 4.

A new series of anthracene scaffold containing 1,3,5-trisubstituted pyrazoline derivatives (3a-p) were synthesized and well characterized by ¹ H NMR, ¹³C NMR, FTIR, mass spectroscopic and elemental analysis methods. The reactions were carried out from anthracenyl pyrazolines (1a-p) and benzoyl chloride (2) in presence of anhydrous K₂CO₃ in acetone under reflux conditions for 2-7 h. The obtained yields were good to excellent (80-94 %).

1 table, 32 ref

003086   GEETHA V T, INDUJA S (Chemistry Dep, Sri Sairam Engineering Coll, Chennai - 600 044, Email: geethavt@yahoo.com) : Nd-Doped Fe₃O₄ nanoparticles: Microwave synthesis, catalytic properties in selective oxidation of styrene. Asian J Chem 2021, 33 (3), 583 - 90.

Nanocrystalline powder of neodymium substituted iron oxides samples were synthesized through the microwave approach. The synthesized pristine Fe3O4 and Nd-doped Fe3O4 structural properties were analyzed by the X-ray diffraction technique. The microstructural details, morphology and elemental composition were assessed by transmission and scanning electron microscopy attached with EDX. The Fe₃O₄ nanostructures possess spherical morphology as well as consistent particle size distribution, which is confirmed by HR-SEM. The formation of Fe₃O₄ with high purity was confirmed by EDX and XRD analysis. The particle size calculated by HR-TEM images and crystallite size through the XRD study showed that the value obtained by both the methods is nearly the same. The catalytic properties of Fe₃O₄ nanoparticles are examined in the selective oxidation of styrene.

7 illus, 2 tables, 31 ref

003085   REDDY B S, PRASAD K R S (Chemistry Dep, Koneru Lakshmaiah Education Foundation, Guntur - 522 502, Email: bassi.sivareddy@gmail.com) : Design, synthesis and antibacterial activity of N-(3-((4-(6-(2,2,2- Trifluoroethoxy)pyridin-3-yl)-1H-imidazol-2-yl)methyl)oxetan-3-yl)amide Derivatives. Asian J Chem 2021, 33 (3), 577 - 82.

A new series of N-(3-((4-(6-(2,2,2-trifluoroethoxy)pyridin-3-yl)-1H-imidazol-2-yl)methyl)oxetan-3-yl)amide derivatives (10a-h) were synthesized by the reaction of 3-((4-(6-(2,2,2-trifluoroethoxy)pyridin-3-yl)-1H-imidazol-2-yl)methyl)oxetan-3-amine (8) with various carboxylic acids in the presence of T3P catalyst. The reaction is usually furnished within 60 min with good isolated yields. Coupling of 6-(2,2,2-trifluoroethoxy) nicotinic acid (1) with Weinreb amine hydrochloride gave N-methoxy-N-methyl-6-(2,2,2-trifluoroethoxy) nicotinamide (2). Compound 3 was synthesized by the Grignard reaction of compound 2 with methylmagnesium bromide. Bromination of compound 3 with N-bromo succinamide to obtain 2-bromo-1-(6-(2,2,2-trifluoroethoxy)pyridin-3-yl)ethan-1-one (4), which was reacted with 2-(3-(((benzyloxy)carbonyl)amino)oxetan-3-yl)acetic acid (5) gave 2-oxo-2-(6-(2,2,2-trifluoroethoxy)pyridin-3-yl)ethyl 2-(3- (((benzyloxy)carbonyl)amino)oxetan-3-yl)acetate (6). Compound 7 was synthesized by the cyclization of compound 6 with ammonium acetate. Finally, debenzylation of compound 7 gave 3-((4-(6-(2,2,2-trifluoroethoxy)pyridin-3-yl)-1H-imidazol-2-yl)methyl)oxetan-3-amine (8). All the synthesized amide compounds were characterized by analytical spectral techniques, like 1 H & 13C NMR and LCMS and also evaluated their antibacterial activity.

2 tables, 17 ref

003084   SWETHARANYAM A, KUNJITHAM R (Chemistry Dep, Poompuhar (Autonomous) Coll, Melaiyur - 609 107, Email: kunjithamr@gmail.com) : Chemical and plant mediated synthesis of La₂O₃ nanoparticles and comparison of their structural, antibacterial, photocatalytic and optical properties. Asian J Chem 2021, 33 (3), 570 - 6.

The La₂O₃ nanoparticles have been synthesized successfully with a chemical and biosynthesized method. The optical bandgap energy and of chemically synthesized or biosynthesized (M. oppositifolia and T. portlacaustrum leaf extract) La₂O₃ nanoparticles was calculated from UV-visible absorption between 5.10, 4.26 and 4.46 eV. The good polycrystalline cubic nature of synthesized La₂O₃ nanoparticles was evident from the bright circular SAED pattern, consistent with the XRD outcome. It is clear that the non-polar extracts could function as stabilizers for La₂O₃ nanoparticles through attachment to the counterions. The La₂O₃ nanoparticles have been used as efficient photocatalyst to degrade acid black 1 dye under sunlight irradiation. Besides, this biocatalyst showed excellent ability to degrade biosynthesized La₂O₃ nanoparticles (T. portlacaustrum) under visible light irradiation 87%. Synthesis of La₂O₃ nanoparticles by green chemistry process presented good antibacterial activity against Gram-negative and Gram-positive bacteria.

9 illus, 4 tables, 36 ref