Asian Journal of Chemistry

1259-1265

Authors: Pankaj Giri, Simran Kaur Zandu and Inderbir Singh*

Guar gum is a natural excipient extracted from the plant seed of Cyamopsis tetragonolobus, belonging to the Leguminosae family. In the pharmaceutical industries, it contributes an important role due to its non-toxicity, ease of availability, biodegradability and eco-friendly nature. The major constituents of guar gum is galactomannan which is composed of D-galactose anhydride and mannose anhydride. Hydroxyl groups present in galactomannan can be modified by carboxymethylation, grafting or cross-linking with other excipients for developing modified polymers having desirable properties. Guar gum is commonly used as a suspending, emulsifying, stabilizing, gelling and thickening agent in various dosage forms. The guar gum derivatives are also useful in controlling the drug release from the pharmaceutical dosage forms. In this review, different aspects of synthesis of guar gum derivatives and its applications in various drug delivery systems is described.

1273-1278

Authors: Malik A. Elsheikh*, Dafaalla M.H. Ali and Saad H. Alotaibi

In Turabah province of Saudi Arabia, infant formula and children′s food products were investigated to determine the concentrations of essential trace elements, namely Mn, Ni, V and Si, and toxic trace elements, namely Al, Ba, Pb, Cd, and As, present in them. Their daily intake amounts were calculated and compared with provisional tolerable daily intake (PTDI), which was calculated based on the provisional tolerable weekly intake (PTWI), which was recommended by joint FAO/WHO. The results obtained were found to be below the PTDI levels. Some samples exhibited a large amount of Al. The PTWI of Si and V is not established; however, their concentrations were compared with those reported in other studies. In some samples, a high concentration of Si was observed. The method employed for evaluation was based on the limit of quantification (LOQ), limit of detection (LOD), and recovery percent of 92.3–101.6%. Accuracy and precision were employed for evaluating the results.

1286-1290

Authors: Savita Belwal*, Sujana Kariveda and Saritha Ramagiri

Green chemistry was used to obtain nano-range sized titanium and zinc compounds from their macro-sizes by using an aqueous extract of horse gram (Macrotyloma uniflorum). Ultraviolet-visible (UV-vis) and Fourier-transform infrared (FTIR) spectrophotometers were employed for characterizing the nanoparticles of biosynthesized metal nanoparticles. Transmission electron microscopy (TEM) was used to analyse the reduced nanoparticles of Ti and Zn metals. Microdilution was employed to determine in vitro properties, such as effects of nanocomplex antimicrobials on Mycobacterium tuberculosis (MTB) H37RV strain. MTB strains isolated from patients with multidrug-resistant tuberculosis (MDR-TB) were resistant to first-line drugs. Novel synthesized nano-complexes exhibited potential antituberculosis activities. Titanium nanocomplexes exhibited the highest minimal inhibitory concentration (MIC) in comparison to zinc nanocomplex. In a cytotoxic study, an IC50 of 1000 μg/mL, for both Ti and Zn nanocomplexes, was reported, and thus, these complexes were non-toxic when compared to isoniazid.

1297-1302

Authors: Muktar Shaikh* and Jayshree K. Khedkar

Binding of N,N′-dimethyl-4,4′-bipyridinium (methyl viologen, MV2+) and its radical (MV+•) to novel p-sulfonatocalix[n]arene (CX[4]-S,) host has been investigated using the density functional theory (DFT). The hydrogen bonded interactions between α-, β- and -CH3 protons of methyl viologen with SO3 − groups of CX[4]-S render stability to their complexes. In the lowest energy structures, one of the methyl groups of MV2+ was partially penetrated within the cavity of CX[4]-S host owing to C-H···O interactions with upper rim of host while the remaining methyl group excluded from the cavity. The radical MV+• revealed qualitatively similar binding patterns to CX[4]-S host as that of MV2+. Moreover, interaction energy of methyl viologen dication was predicted to be larger than that of the corresponding radical cation.

1309-1313

Authors: Duggirala Parvatha Venkata Vardhani Devi*, Kapavarapu Maruthi Venkata Narayanarao, Pulipaka Shyamala, Rallabhandi Murali Krishna and Komali Siva Prasad

A new gradient elution mode HPLC method was developed and validated to detect and monitor the novel impurity namely methyl ezitimibe in ezetimibe drug substances. Chromatographic detection and analysis of methyl ezetimibe was performed on XBridge C18 column with mobile phase consisting of 0.02 M phosphate buffer (pH 5) and acetonitrile with 1 mL/min flow rate in gradient elution mode. Methyl ezetimibe was detected and monitored at 248 nm. The calibration curve was linear over range of 0.015 to 0.219% concentration. The limit of detection and quantification were computed as 0.005% (signal to noise ratio 3.60) and 0.015% (signal to noise ratio 15.96), respectively. The precision was 0.97% (%RSD) and accuracy was 93.2 to 98.2% (recovery). The developed method was proved suitable to detect and monitor methyl ezetimibe impurity in ezetimibe drug substances

1321-1328

Authors: Priyabrata Mohanty, Dibakar Behera*, Shiv kumari Panda, Tapan Kumar Bastia and Prasanta Rath

The development of an inter-cross-linked polymer network of thermoset-thermoset blends have been extensively studied due to their enhanced mechanical properties. Among various polymer blends, modifications of unsaturated polyester (UPE) resin with epoxidized soybean oil acrylate (ESOA) combinations are an attractive route to promote the performance of the thermoset matrix and to overcome the inferior properties of both the components. Biodegradable and effectively accessible chitosan biodegradable waste material can shape the new stage for cutting-edge innovation items. Blend of both recyclable fibrous reinforcement and eco-friendly filler with two miscible thermosetting polymers will provide enhanced properties. At this time, chitosan up to 15 wt% (based on matrix weight) was utilized as reinforcing filler. At last, an interesting result was built up by confirming that chitosan filled chemically tailored bamboo and UPE/ESOA (80:20) biocomposites offered enhanced properties by 10 wt% of filler concentration with the most enhancements in whole properties. They have extensive variety of applications in the sector of low cost housing, structural projects and structural laminates.

1335-1342

Authors: Kh. E. Yunusov*, , A.A. Sarymsakov, S.V. Mullajonova, F.M. Turakulov and S. Sh. Rashidova

Stable silver nanoparticles in solutions of sodium-carboxymethylcellulose (Na-CMC) were synthesized and their structure and physico-chemical properties were evaluated. The form and sizes of silver nanoparticles formed in solutions of CMC and cotton fabrics were studied using UV-VIS spectroscopy, atomic force microscopy and transmission electron microscopy methods. It was found that silver nitrate concentration increase in sodium carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. Investigations have also shown that spherical silver nanoparticles with sizes of 5-35 nm and content of 0.0086 mass% in cotton fabrics possess high bactericidal activity. Stabilization of silver nanoparticles has preserved bactericidal and bacteriostatic activities during the washing of cotton fabrics and textiles on their base.

1352-1360

Authors: J. Prakash*, S. Vedanayaki* and K. Karthick

The studies open up an innovative approach and investigate porous, efficient raw carbon from Zephyranthes citrina bulb, which was used as an adsorbent to remove organic dyes. The well-dried and finely powdered Zephyranthes citrina bulb was carbonized at 900 ºC. The carbonized crude Z. citrina sample was characterized by FT-IR, UV-visible, scanning electron microscopy (SEM), BET, X-ray diffraction (XRD) techniques and their adsorption potential to remove the basic methylene blue dye from an aqueous sample. Adsorption studies comprise both adsorption isotherm and kinetic methods. The processes were carried out with diverse adsorbate concentrations and adsorbent quantities at various time intervals in the batch process. Kinetic models of Lagergren first order, pseudo-second order and intra particle diffusion were used to assess the kinetics and adsorption mechanism. The results revealed that the adsorption process follows the first order kinetic model of Lagergren. The BET isotherm model confirmed that it has an excellent adsorption capacity in an adsorption process. Based on the results obtained, the maximum removal (81%) of dye was achieved in a solution containing 50 mg of 50 mL dye at 3 h for methylene blue. The results indicated that the bulb of Zephyranthes citrina carbon is a proficient adsorption material and is also used as a cost effective alternative that can adsorb dye from an aqueous solution without activation treatment.

1370-1378

Authors: S.R. Arunima

The present study beneficially explores nano TiO2 incorporated hot-dip zinc coatings for the enhanced corrosion protection of steel. Various electrochemical analyses such as open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies were adopted to evaluate the enhanced galvanic performance and the stability of nano TiO2 composite incorporated coatings. The low corrosion current density and high polarization resistance of tuned composition of TiO2 incorporated hot-dip zinc coatings confirm its enhanced galvanic and corrosion resistant properties. The enhanced performance of TiO2 incorporated zinc coating was attributed to the combined effect of barrier and sacrificial behaviours

1384-1392

Authors: N. M'hanni, M. Galai*, T. Anik, M. Ebn Touhami, E.H. Rifi and Z. Asfari

The autocatalytic nickel bath uses sodium hypophosphite as a reducing agent, sodium citrate as a complexing agent and sodium acetate as an accelerator. The effect of calix[4]arene molecule type H4L named (dicarboxylic acid p-tert-butylcalix[4]arene) was studied and used at various concentrations of 10-3 to 10-6 M to improve the microstructure, the microhadness and properties of nickel deposit obtained. The effect of varying the concentration of H4L, on the deposition rate, the composition, the microstructure and morphology of chemical deposition was studied. The results showed that depending on the concentration of calix[4]arene, the deposition rate decreases from 11, to 7.75 μm/h. The microstructure and microhardness improves significantly at a concentration of 10-6 M of additive. It was also shown that the coating obtained is adherent and compact and the chemical bath has become more stable in the presence of calix[4]arenic additives. Indeed, in both cases, the nickel content decreased with the addition of concentration. This decrease of nickel content might be related to the increase of deposition rate depending on the concentration. The X-ray diffraction analysis revealed peak intensification in the {111} orientation of plane in the presence of a concentration of 10-6 M; this may be in agreement with the results of metallographic study which showed that the coatings are adherent and have a good resistance. Hence, the Vickers microhardness of deposited coatings has a better value (376 HV) at the concentration 10-6 M. The corrosion resistance in 3% NaCl solution has been proven at the same concentration as found. Finally, the cyclic voltammetry and electrochemical impedance spectroscopic studies revealed that the additive strongly influences the cathodic process and affects slightly oxidation of hypophosphite.

1399-1403

Authors: Tan Phat Dao, Hoang Thang Do, Quang Khoi Le, Nguyen Van Gia Phap, Long Giang Bach, Nguyen Van Muoi and Mai Huyng Cang*

Study on kinetics and modeling of the essential oil steam distillation are required for the optimization of the energy requirement, parameters and the process scale-up. In this study, hydrodistillation for extraction of essential oils from lemongrass (Cymbopogon citratus) steam distillation was investigated. The recovery of essential oils was carried out on an industrial scale instrument and with with different material quantities. The experimental results are determined by the integral method of analysis. The kinetic parameters were evaluated from experimental data, which were generated at the different weights of the lemongrass. The extraction rate constant explaining the extraction efficiency achieved from this study is found to be k2 of 0.0661 min-1 in 710 kg using a second-order kinetic model. The GC/MS results revealed that 14 components were identified in Cymbopogon citratusoils. The oil is extremely rich in citral (69.775%), which obtained in 180 min.

1409-1412

Authors: K. Kavitha Priya*, V. Anuradha, G. Jayalakshmi and S. Ratna Kumari

A new steroidal triterpenoid was isolated from hexane washed ethanolic extract of flowers of Leucas cephalotes. Its structure was elucidated as (Z)-17-(4,4-dimethylhept-2en-2-yl)-8,10,14-trimethyl- 2,3,4,5,6,7,8,10,12,13,14,15,16,17-tetradecahydro-1H-cyclopent[a]phenanthren-3-ol (1). The structure of the new compound was determined by 1D and 2D NMR and MS and DEPT experiments as well as by comparison of their data with the reported values.

1421-1426

Authors: J. Dharani and S. Ravi*

Drug development involves assessment of absorption, distribution, metabolism, excretion and toxicity (ADMET) increasingly earlier in the discovery process. in silico ADMET studies are expected to reduce the risk of late-stage attrition of drug development and to optimize screening and testing by looking at only the promising compounds. To this end, several in silico approaches for predicting ADMET properties of compounds from their chemical structure have been developed, ranging from data-based approaches. In this study, ADMET prediction has been done for 20 compounds from the plant Cyanthillium cinereum extracts. Some of the compounds were predicted to be non-toxic.

1433-1436

Authors: Tran Thi Kim Ngan, Nguyen Van Muoi, Pham Minh Quan and Mai Huynh Cang*

This study attempted the extraction of essential oils from the peels of pomelo (Citrus grandis L.) grown in Ben Tre province, Vietnam through hydrodistillation method. In addition, the chemical composition and physio-chemical properties of the essential oils were reported. The results showed that the extraction yield of the extraction process achieved about 1.67%. The physico-chemical index of essential oils is determined by specific gravity (0.8572 g/cm3), acid index (0.3556 mg KOH/g), ester index (2.4216 mg KOH/g), and refractive index (1.476). The GC-MS analyses of the oil indicated the component with highest content in the oil was α-limonene (96.491%), followed by α-pinene (0.686%), β-pinene (0.248%), β-myrcene (1.644%), α-phellandrene (0.793%) and β-cis-ocimene (0.138%). These results suggested that wastes from fruit peeling process can be converted into a new material source with great potential for industrial use.

1443-1450

Authors: H.C. Charan Kumar, R. Shilpa and Sannaiah Ananda*

Aluminium sulfide (Al2S3) nanoparticles were successfully synthesized by electrochemical method. Further, the synthesized nanoparticles were used as a photocatalyst for degradation of trichloroacetic acid, chloroacetic acid, acetic acid and degradation kinetics was studied by volumetric method using NaOH under various experimental conditions. The Al2S3 nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction and SEM-EDAX. The study of UV-visible spectroscopy indicates that Al2S3 nanoparticles shows maximum intensity peak at 222 nm in the UV region and there is no absorption peak in the visible region, therefore the synthesized nanoparticles is active under UV light and band gap energy was found to be 3.07 eV, which was calculated using Tauc plot. The structure of Al2S3 was found to be tetragonal structure and average crystal size was found to be 25.76 nm, which was calculated using Debye-Scherrer′s formula. The SEM results showed that Al2S3 appears as nanoflakes with agglomerated. The presence of aluminium and sulfur was confirmed using EDAX spectra. The photocatalytic activity of the synthesized Al2S3 nanoparticles was examined by taking three carboxylic acids by volumetric method. Taft LFER was tested, the isokinetic temperature β was calculated for oxidation of carboxylic acids. The antibacterial activity was investigated for synthesized nanoparticles by using Bacillus subtilis MTCC 2763 and Escherichia coli MTCC 40 of different bacteria.

1456-1462

Authors: V.L.N. Balaji Gupta Tiruveedhi*, Venkateswara Rao Battula and Kishore Babu Bonige

A novel liquid chromatographic method was established and validated for the quantification of tazarotene and halobetasol in the presence of degradation products obtained during stress conditions. The liquid chromatographic method was based on isocratic elution on Knauer Eurospher II C18 (5 μm particle size, 250 mm × 4.5 mm) column using a mobile phase consisting of methanol, acetonitrile and 0.5 mM perchloric acid (40:45:15 v/v/v) mixture at flow rate of 0.9 mL/min. Quantization of tazarotene and halobetasol was done with UV detection at 234 nm. The method validity was assessed in agreement with the recommendations of the International Conference on Harmonization. Linearity, accuracy and precision were satisfactory over the concentration ranges of 2.25-13.5 and 0.5-3.0 μg/mL for tazarotene and halobetasol, respectively. Detection limit values of 0.006 μg/mL and 0.01 μg/mL were found for halobetsol and tazarotene, respectively, while the quantization limit values of 0.02 μg/mL and 0.033 μg/mL were found for halobetsol and tazarotene, respectively. The developed method is appropriate for routine analysis and quality control of tazarotene and halobetasol combination in lotion dosage form.

1467-1472

Authors: N.M. Mkolo, O.O. Olaokun*, J.O. Olowoyo, J.N. Eloff, and V. Naidoo

Hypoxis hemerocallidea is wild harvested and widely used due inter alia to its strong antioxidant activity. Antioxidant activity is linked to plant stressors like soil heavy metals concentrations and pH. If high antioxidant activity is caused by heavy metals stressing the plant, the plant may not be completely safe. Soils and H. hemerocallidea corms were collected from five different geographical regions of South Africa. The highest corm and soil heavy metals concentration were Fe, Mn and Cr, with Fe having the highest, particularly for corms collected from Ga-rankuwa (83.7 ± 0.03 μg/g). The soil and corm samples from Ga-rankuwa with high levels of metals (Fe, Cr, Ni, Pb) had greater antioxidant activity (EC50 of 1.68 ± 0.49 μg/mL). Despite corms showing ability to bio-accumulate heavy metals, the antioxidant activity could not be linked to environmental conditions. The results highlight potential danger of using naturally harvested bulbs growing in unidentified soils.

1482-1490

Authors: Manju Mathew, Raja Chinnamanayakar and Ezhilarasi Muthuvel Ramanathan*

A series of 1-(5-(5-(4-chlorophenyl)furan-2-yl)-4,5-dihyropyrazol-1-yl ethanone (5a-h) was synthesized through E-(3-(5-(4-chloro-phenyl)furan-2-yl)-1-phenylprop-2-en-1-one (3a-h) with hydrazine monohydrate and sodium acetate. Totally, eight compounds were synthesized and their structures were elucidated by infrared, 1H & 13C NMR, elemental analysis, antimicrobial studies, in silico molecular docking studies and also in silico ADME prediction. Antimicrobial studies of the synthesized compounds showed good to moderate activity against the all the stains compared with standard drugs. in silico Molecular docking study was carried out using bacterial protein and BC protein. Synthesized compounds (5a-h) showed good docking score compared with ciprofloxacin. Antimicrobial study was carried out for 4-chlorophenyl furfuran pyrazole derivatives (5a-h). The results of assessment of toxicities, drug likeness and drug score profiles of compounds (5a-j) are promising.

1497-1504

Authors: S. Fuloria, O.J. Hong, C.B. Kim, B.Y.S. Ting, S. Karupiah, N. Paliwal, U. Kumari, K. Sathasivam, S. Vetriselvan and N.K. Fuloria*

Present study was intended to synthesize silver nanoparticles (AgNPs) using corn silk aqueous extract (CSAE) and evaluate for antimicrobial and antiurolithiatic potential. The aqueous decoction of corn silk offered light yellow CSAE. Treatment of AgNO3 with CSAE offered AgNPs with absorbance 430 nm. Optimization study established 5 mM silver nitrate, 2.5:7.5 extract to AgNO3 ratio, pH 8, and 24 h time as parametric requirement for synthesis of AgNPs using CSAE. Stability study supported the AgNPs stability based on retention of SPR signal between 428 to 450 nm. The synthesis of AgNPs was confirmed on broad and shifted FTIR bands; XRD signals at 2θ values of 32.27º, 40.72º, 46.20º, 65.69º, 69.31º and 76.49º indexed to 111, 200, 220 and 311 planes, respectively; particle size range from 22.05-36.69 nm in FESEM; and elemental silver content of 62.17% as per EDX spectrum. The synthesized AgNPs exhibited high antibacterial and antiurolithiatic potential. Present study recommends that synthesis of AgNPs using CSAE is a facile and eco-friendly method.

1511-1514

Authors: Ilyas S. Nizamov*, Ramazan Z. Salikhov, Ilnar D. Nizamov, Yevgeniy N. Nikitin, Gulnur G. Sergeenko4, Rustam R. Davletshin1, Marina P. Shulaeva, Oscar K. Pozdeev, Elvira S. Batyeva and Rafael A. Cherkasov

Dithiophosphoric acids in the terms of (S)-(–)-menthol, (1S)-endo-(–)-borneol,(1R)-endo-(+)-fenchyl alcohol and (1S,2S,3S,5R)-(+)-isopinocampheol react with melatonin to form chiral N-acetyl 5-methoxytryptammonium dithiophosphates. The interations proceed via increase in the coordination of indole nitrogen of melatonin. The antibacterial and antifungal activity of N-acetyl 5-methoxytryptammonium dithiophosphate containing (+)-fenchyl substituent was established.

1520-1524

Authors: Anil H. Shinde and C.J. Patil*

Azo salicylaldehyde (I5) was synthesized by reaction of 5-bromo-salicylaldehyde with diazonium salt of 4-nitroaniline by diazotization method. Thus, synthesized azoaldehyde was treated with variable 2-aminobenzothiazoles (I6a-f) to synthesize the Schiff bases (I7a-f). The β-lactam derivatives (I8a-f) were also synthesized. All the newly synthesized compounds were characterized by TLC, UV-visible and FT-IR techniques.