Asian Journal of Chemistry

477-487

Authors: G. Santosh

Tetrapyrrolic porphyrins are the molecules of choice for nature where light absorption and metal based chemistry plays an important role in biological systems. Constant efforts are directed at modifying the porphyrin skeletal structure to result in porphyrins with fine-tuned physical properties. This review focusses on the chemistry of porphyrins with five-membered aromatic rings such as furan, pyrrole and thiophene as substituents at the meso position of porphyrins. Substitution with these five-membered rings at the meso-position of porphyrins brings about significant modulation of HOMO-LUMO gap, which reflects in shifts in the absorption and fluorescence spectra and in their electrochemical properties compared to the conventional porphyrins with six-membered aryl substituents. The synthetic modification of these five-membered rings by introdcution of various functional groups were also discussed.

495-500

Authors: Rajesh Kumar, Harish Sharma, M.C. Vishwakarma, S.K. Joshi, N.S. Bhandari and N.D. Kandpal

In the present study, removal efficiency (%) of Rubus ellipticus leaves (REL) as an adsorbent for the removal of Pb(II), Cu(II) and Cd(II) ions was investigated. Different parameters i.e., pH, contact time, temperature, adsorbent dose and initial metal ion concentration were investigated to obtain the optimum adsorption efficiency. At pH 4, a maximum adsorption was 84.6, 80.2 and 74.5 % for Pb(II), Cu(II) and Cd(II) ions, respectively. The maximum adsorption of all the three metal ions obtained at contact time (75 min), initial metal ion concentration (10 mg/L), temperature (25 ºC) and adsorbent dose (5.0 g). The equilibrium adsorption of Pb(II), Cu(II) and Cd(II) ions at different temperature was described by Langmuir, Freundlich and Temkin isotherms. The equilibrium data fitted well the Langmuir adsorption isotherm. Thermodynamic parameters like Gibb′s free energy (ΔGº), enthalpy (ΔHº) and entropy (ΔSº) were also calculated. The calculated parameters indicated that adsorption of Pb(II), Cu(II) and Cd(II) ions onto Rubus ellipticus leaves (REL) was spontaneous (ΔGº < 0), endothermic (ΔGº > 0). The feasibility of the process was evident from the positive value of ΔSº.

508-514

Authors: Vinay Kumar Chintalapudi, Ramya Krishna S.L. Kanamarlapudi, Useni Reddy Mallu and Sudhamani Muddada*

In the present study, initially Aspergillus niger was tested for biosorption of Pb(II) ions and then studied the effect of pretreatment for enhanced biosorption. It was found that the maximum biosorption potential was achieved with citric acid treatment (70.56 %) in comparison with the biomass without treatment (65.46 %) at a biosorbent dose of 20 mg/L, pH 4, 100 rpm, 37 ºC for 8 h. The optimized conditions for treated Aspergillus niger were determined by optimizing the biosorption parameters such as pH, temperature, biomass dose, incubation time and agitation speed. This study indicates that the citric acid treated Aspergillus niger is an effective biosorbent for removal of lead (II) at optimized conditions with the maximum biosorption potential of 83.6 % as compared to previous reported work. SEM-EDX and FTIR analysis showed the structural variations and the functional groups involved in lead biosorption, respectively. Biosorption kinetics showed that pseudo second order kinetic model as the better fit.

519-527

Authors: S.R. Kande, B.H. Zaware, G.G. Muley and A.B. Gambhire*

A series of SnO2/activated carbon (AC) nanomaterials were prepared by co-doping V(III), Cr(III), Mn(II), Fe(III), Co(III), Ni(II), Cu(II), Zn(II) with nitrogen and sulphur, separately by co-precipitation method, combined with surfactant incorporation method. The as-prepared sample were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Brunauer-Teller method (BET), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and Raman spectroscopy. The results showed that the phase composition, crystallite size, BET surface area and optical absorption of samples varied significantly with the nature dopants. The photocatalytic activities of these co-doped SnO2/AC catalysts were investigated by degradation rhodamine B in aqueous solution under solar-light illumination. The results showed an appreciable enhancement in the photoactivity of Fe/N/SnO2/AC as compared to other co-doped SnO2/AC because of smaller particle size, higher specific surface area, photogenerated carrier′s separation and solar light absorption. The degradation rate of rhodamine B dye reached 98 % in 30 min, which is about 10 times higher than that of pure SnO2.

539-542

Authors: S. Arthi, D. Sumalatha*, K. Susmitha, Manan Bhargavi and Alina Jyothi Joseph

A novel Schiff base [SAL-L=2-((2,3-dihydro-1H-inden-4-ylimino)methyl phenol] was synthesized and used as ligand for the synthesis of Ni(II) and Co(II) complexes. The structural characterization of ligand and its Ni(II) and Co(II) complexes was determined using various spectroscopic methods. Based on spectral studies, a square planar and octahedral geometry have been proposed for Ni(II) and Co(II) complexes, respectively. DNA binding properties of these metal complexes with calf-thymus DNA in tris-hydrochloride buffer (pH 7.2) were investigated using UV- visible absorption studies. The binding constants were in the order of 105 M-1 suggested a good binding affinity towards CT-DNA. The synthesized ligand is docked on TSPO protein showing good binding energy and found to be a potent inhibitor of cancer.

550-554

Authors: Suresh Kumar Patel, Dhananjay Singh* and Rahul Dev

Arsenic is a ubiquitous and short-term poisoning element, which affects living things. In this study, the removal of arsenic from Gomti river water, Lucknow, Uttar Pradesh integrated modified double slope solar still with activated adsorption bed has been applied. Arsenic contamination in Gomti river at five places were found in the river water in the range of 55.70 ppb to 681.60 ppb, which exceed the maximum permissible limit of 10 ppb as recommended by WHO. Maximum concentration of arsenic in water was found in Mohan Maekins (681.60 ppb). However, mean arsenic concentration in water followed the order: Gaughat (115.37 ppb) < Hanuman setu (297.80 ppb) < Barrage (302.62 ppb) < Kukrail (336.27 ppb) < Mohan Maekins (481.89 ppb). The amount of adsorbed arsenic was increased with increasing initial concentration of arsenic. The aim of this study is to develop a low-cost process for the removal of arsenic effectively including the production of potable water. After results, data were analyzed with ICP-MS method and also verified with Langmuir and Freundlich adsorption isotherm models.

561-564

Authors: Dileep Kumar M. Guruswamy and Shankar Jayarama*

(2E)-3-(2-Bromo-6-hydroxy-4-methoxyphenyl)-1-(naphthalene-2-yl)prop-2-en-1-one (d1) was synthesized by the Claisen-Schmidt condensation method and characterized by 1H NMR, 13C NMR spectral studies. The anti-inflammatory activity was conducted in Swiss albino rats for paw edema model. Edema was actuated with 1 % carrageenan to every one of the animals following 1 h of the oral medicines. Paw thickness was checked at t = 1, 2, 3, 4, 5 and 24 h. Stair climbing score and motility score were surveyed at t = 24 h. Compound d1 signicant decline in paw thickness at p < 0.001 diminished by 32 % in paw thickness. The compound d1 signicantly expanded the stair climbing and motility score. This study suggested that the compound d1 exhibits remarkable anti-inflammatory activity when compared with that of the standard drug

570-574

Authors: Annie Aureen Albert*, D.G. Harris Samuel, and V. Parthasarathy

CuO-PVA hybrid nanofluid was synthesized within PVA matrix by a simple wet chemical precipitation method. The influence of rate of addition of precursor (NaOH) on the structure, morphology and stability of CuO-PVA hybrid nanofluids were studied. The structure was confirmed by XRD and UV-visible spectroscopy. High resolution transmission microscopy (HRTEM) images revealed the formation of smaller particles for addition of precursor in solid form or rapid addition (RA), whereas slow addition of precursor (SA) resulted in uniform particle size. The selected area electron diffraction (SAED) pattern of sample SA shows rings with small bright spots indicating that the sample is nano crystalline. The SAED pattern of sample RA shows diffuse rings with lesser number of bright spots indicating that it is less crystalline. The stability studies indicate that both the samples were stable for more than one year.

580-586

Authors: Ranjit V. Gadhave* and Bhanudas S. Kuchekar

A new series of N-(benzo[d]thiazol-2-yl)-[1,2,4]triazolo[4,3-c]quinazoline-5-carboxamide derivatives were synthesized by condensation of [1,2,4]triazolo[4,3-c]quinazoline-5-carboxylate derivatives with substituted benzothiazoles. The chemical structures of the synthesized compounds were confirmed by FT-IR, MS and 1H NMR spectra. Designed triazoloquinazoline derivatives were docked with oxido-reductase enzyme (PDB Code 4h1j) and DNA gyrase enzyme (PDB Code 3g75). Based on high binding affinity score, the best compound were selected for synthesis and subjected to in vitro antioxidant and antibacterial activity. Compounds 7a and 7d were found to be most active compounds as antioxidant agent among this series when compared with ascorbic acid. Compounds 7a, 7d and 7f were found to be most active compounds as an antibacterial agents among this series when compared with ciprofloxacin against bacterial strains such as S. aureus (ATCC 25923), E. coli (ATCC 25922) and P. aeruginosa (ATCC 27853). Study revealed that the most active compounds after structural modifications can be exploited as lead molecules for other pharmacological activities such as anti-inflammatory, anticancer and antidepressant activities.

592-596

Authors: Ami Ansul Shah, Belina Xavier and D. Jayalakshmi*

The prospect of developing new approaches in the assembly of noble metal nanoparticles and its functions has been garnering intense interest among researchers in various fields. The green synthesis method is an evolving trend as it is environment benign and aids in large-scale formation of nanoparticles. The versatile properties of green synthesized gold nanoparticles (AuNPs) like surface plasmon resonance, stability and morphology are examined by UV-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), zeta potential (ZP) and high resolution transmission electron microscopy (HRTEM) studies at pH 7. Fourier transform-infrared (FT-IR) analysis confirms the pivotal role of anthocyanins and polyphenols in Fragaria ananassa (strawberry) fruit extract for the capping of AuNPs. The size of gold nanoparticles is in the range of 10 to 40 nm and they exhibit greater negative value of zeta potential. The catalytically active AuNPs follow the pseudo-first order kinetic model and takes 10 min for rapid degradation and adsorption of methylene blue dye from aqueous solution. These results confirm that Fragaria ananassa has a remarkable function in the plant-mediated synthesis of AuNPs and thus can emerge as a positive platform to convert water pollutants into harmless molecules.

602-606

Authors: Pham Thi Mai Huong*, Truong Anh Thu, Chu Qui Thuong, Tran Hong Con and Nguyen Thi Huong*

Tay Nguyen red mud abundantly found in Vietnam, is a waste product of alumina production formed during processing of bauxite. It is rich in aluminate, residual alkaline, and oxides, such as silicon, iron, and titanium oxides. Iron oxide, which constitutes 45-55 % of Tay Nguyen, is useful for Fe3O4 nanoparticles synthesis. In this study, a Fe3O4 nanoparticles were synthesized using Tay Nguyen by the chemical co-precipitation method, which required a non-oxidizing oxygen-free environment. Fe3O4 nanoparticles were characterized using X-ray diffraction, field emission scanning electron microscopy, Brunauer-Emmett-Teller analysis, and vibrating-sample magnetometry. Adsorption of hexavalent chromium by the nanocomposite was conducted under batch conditions. Pseudo-second-order equations were used to describe kinetic data of adsorption reactions; the equations were fitted to kinetic data as shown by the results. The isotherms of adsorption were also studied using the linear forms of the Langmuir and Freundlich equations. The Langmuir equation exhibited higher linear correlation with the experimental data than the Freundlich equation did. The maximum monolayer coverage, qmax at 297 K was 31.44 mg/g.

612-618

Authors: Rotimi A. Larayetan*, Yahaya Abdulrazaq and Omobola O. Okoh

Callistemon citrinus belong to the kingdom plantae, family Myrtaceae and genus Callistemon. It grows in Australia but has been naturalized in South Africa. It is used as traditional herb to combat both gastro-intestinal and respiratory diseases, pain, diseases caused by bacteria and fungi infection. About 500 g of the air-dried leaves were pulverized each month and subjected to hydro-distillation using a modified Clevenger apparatus. Hydro-distillation of the fresh leaves of C. citrinus gave a pale yellow volatile oil with a strong scenty fragrance, about 97 components were identified in the 12 treatments analyzed each month. The key components were pinocarvone (1.25-6.17 %), pinocarveol (0.10-9.56 %), α-terpineol (5.24-9.94 %), α-pinene (7.45-22.75 %), limonene (24.08) and eucalyptol (14.69-72.35 %). The compositional profile of the leaves of C. citrinus varied between (January-December). Treatments under investigation revealed markedly qualitatively and quantitatively differences. Antioxidant capacity of the volatile oil of C. citrinus leaves evaluated also demonstrated significance influence of seasonal variation on its activity. The most exigent activity for DPPH free radical scavenging was recorded in the month of September (spring) with an IC50 of 0.50 ± 0.04 mg mL-1, while the most paramount activity for the ABTS assay was 0.94 ± 0.02 mg mL-1 in January (summer).The lowest activity were observed in the June (winter) collection with IC50 of 1.45 ± 0.00 mg mL-1 and 2.19 ± 0.05 mg mL-1 for DPPH and ABTS assays, respectively. Results show that seasonal variations affected the chemical compositions, oil yield as well as antioxidant activities of the volatile oil of the leaves of (C. citrinus); therefore, it is important to consider such effects for industrial and therapeutic purposes.

627-633

Authors: Anurag Geete*, B.D. Shrivastava and Ashutosh Mishra

In present investigation, seven copper(II) complexes were synthesized using various aniline dithiocarbamate. The synthesized Cu(II) complexes were studied for different structural and chemical parameters using XRD, EXAFS and XANES. The output obtained from X-ray studies was synthesized using Athena and Origin 6.0 software. The results of the investigation were used in determining the structures of the synthesized complexes. The particle size of the synthesized complexes ranged between 46.7 and 125.3 nm. The lattice constant of Cu(II) complexes was found 3.61-3.62 Å.

641-645

Authors: E. Jayanthi*, M. Anusuya, R. Anusuya, K. Thenmozhi, A. Nagaveni and N.S.P. Bhuvanesh

A new ruthenium arsine complex was prepared by reacting equimolar ratio of [RuBr3(AsPh3)3] and 2-benzoyl pyridine. It was characterized by microanalysis, FT-IR and single crystal X-ray diffraction studies. X-ray diffraction data showed the distorted octahedral geometry of the complex. The pyridine nitrogen and carbonyl oxygen of the ligand coordinated with the metal center. Antioxidant activity of the complex was analyzed using different assays, which manifested significant activity. It has been found that a newly synthesized complex possessed better antioxidant activity than the ligand and precursor complex.

653-658

Authors: S. Anandhi, D. Keerthika, M. Leo Edward and V. Jaisankar*

In present work, polyindole-Nb2O5 nanocomposite was synthesized and characterized by various analytical methods. Niobium oxide nanoparticles were prepared by sol gel method. Polyindole and Nb2O5 nanocomposites was prepared by chemical polymerization method and the morphology of Nb2O5 nanoparticles, polyindole and the nanocomposite was studied by SEM. The chemical structure of Nb2O5 nanoparticle, polyindole and the nanocomposite was characterized by UV-visible, FTIR and NMR spectroscopic techniques. Elemental composition and chemical character was analyzed by the use of EDAX technique. The X-ray powder diffraction technique was used to determine the degree of crystallinity and crystallite sizes. Thermal analysis such as TGA and DSC showed that the conducting polymers in the nanocomposites were stable even at high temperatures.

665-677

Authors: R. Suganthi Devi and N. Kumaraguru*

To enhance the application of metalosurfactants in the field of drug delivery, it is essential to acquire the role of surfactants in terms of micellization, hydrophobicity, interaction with nucleic acids, reactive changes with abnormal cells and pathogenic organisms. A new class of two ruthenium(II) metallosurfactant complexes [Ru(DMP)2(CA)Cl](ClO4) (1) and [Ru(DMP)2(CA)2](ClO4)2 (2), where DMP = 2,9-dimethyl[1,10]phenanthroline) and CA = cetyl amine were synthesized and characterized. The critical micelle concentration (CMC) and the thermodynamic parameters of micellization were determined and the variations suggest the expression of hydrophobic interaction in these complexes. The binding affinity of ruthenium(II) metallosurfactant complexes with CT-DNA has been investigated by spectroscopic and viscosity magnitudes. The outcomes expose that the complexes associate with CT-DNA through intercalation mode. Subsequently the complexes were taken for in vitro anticancer and antimicrobial inhibition study against human cervical cancer cell lines (HeLa) and pathogenic microorganisms and found that the complexes exhibited remarkable inhibitory action. The cytotoxic nature of the complexes towards, HeLa cells, was adopted by MTT assay and apoptosis were examined by AO/EB (acridine orange/ethidium bromide) and tryphanblue staining methods showing that complexes affected the viability of the cells significantly.

683-689

Authors: Blassan Samuel* and Madhvesh Pathak

A new class of moisture stable heteroleptic titanium(IV) complexes, synthesized from 8-hydroxyquinoline of the type [(Q)2Ti(2-O-5-X-C6H3CH2NC6H4R] (3a-j), was prepared by reacting the antecedent molecule [(Q2)Ti(OiPr)2] (2) with various 2-hydroxy-N-phenyl-benzylamine analogues in 1:1 molar ratios in dry toluene (where, HQ = 8-hydroxyquinoline; iPr = isopropyl; R = H, 4-CH3, 4-OCH3, 2-Cl, 4-Cl, 2-Br, 4-Br; X= H, Br). Moisture sensitive study disclosed that these new metal complexes were unreacted for 72 h. Mass spectral data were employed for proving the mono-nuclearity of the new derivatives. Thermal decomposition pattern of the new derivatives was explained by thermogravimetric analyses. Elemental analyses data are in concordance with their expected values. The hexa-coordinated way of titanium-ligand linkage is further proved through NMR, FTIR, and UV-visible spectral studies. The cytotoxic efficiency of new complexes was tested against MDA-MB-231 human breast carcinoma cell line. Complex 3a exhibited the highest cytotoxic potential of 0.039 μM in comparison to all its analogues of this series by employing cisplatin as the standard.

697-702

Authors: Dohyun Moon, Sunghwan Jeon, Keon Sang Ryoo and Jong-Ha Choi*

The crystal structure of 3,14-dimethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane-2-(nitric acid), C20H40N4·2(NO2OH) had been determined using synchrotron radiation at 220 K. The compound crystallized in the space group P21/n of the monoclinic system with two mononuclear formula units in a cell of dimensions a = 9.1930(18), b = 10.120(2), c = 12.979(3) Å and β = 101.06(3)º. The asymmetric unit contains half a centrosymmetric macrocycle and one nitric acid molecule. There were two molecules in the unit cell. In structure of macrocycle, C-C and N-C bond lengths were in the range 1.5198(19) to 1.5367(18) Å and 1.4744(16) to 1.4986 (16) Å, respectively. The NO2OH group has one longer N-O bond of 1.3441(18) Å and two shorter N-O bond of 1.2509(19) Å and 1.2510(19) Å, and O-N-O angles of 126.31(14)º, 117.98(14)º and 115.71(14)º. The N-H···O and N-H···N hydrogen bonds interconnect macrocycle (C20H40N4) with nitric acid molecules while two O-H···O hydrogen bonds link the nitric acid molecule to neighboring nitric acid molecule each other. The molecule was stabilized by forming intermolecular N-H···O, N-H−N and O-H···O hydrogen bonds. Hirshfeld surface analysis by 3D molecular surface contours and 2D fingerprint plots have been used to analyze intermolecular interactions present in the crystal.

706-726

Authors: Ashutosh Kumar*, Anjali Pandey and Anil Mishra*

In this paper, a complete quantum chemical calculation has been done to describe the relevant structural aspects of novel 2,3-bis[(1-methyl-1H-imidazole-2-yl)sulfanyl]quinoxaline with combination of DFT/B3LYP method 6-311++G(d,p) basis set in gas phase and in solvent phase. The molecular structure was examined by using IR, 1H & 13C NMR and UV-visible techniques and solvent effect on spectroscopic properties are also discussed. The vibrational assignments are analyzed by PED using Gauss View 5.0 and VEDA 4.0 program. The 1H NMR and 13C NMR chemical shifts are calculated using the gauge-independent atomic orbital method (GIAO method) in gas phase and in solvents (water, DMSO and chloroform). The UV spectrum is calculated by using TD-DFT/6-311++G(d,p) method in gas phase and in solvent (water, DMSO and chloroform) using IEF-PCM model. With the help of theoretical calculations chemical activities, electrophilic/nucleophilic nature and sites in the molecule, molecular and chemical properties that cannot be obtained by experimental way are obtained. Accordingly, molecular electrostatic potential (MESP), hardness (η)/softness (S) parameters, net charges analyses are investigated to gain electrophilic and nucleophilic nature. Also the sites in molecule and Fukui function analysis are discussed. The dipole moment (μ), polarizability (αtot), anisotropic polarizability (Δα) and first-order hyperpolarizability (βtot) of the title compound are reported and results shows that the material is capable to generate non-linear effect (NLO). The in silico study of all the biological and ADMET properties of title molecule are also discussed and compared with reference drug ciprofloxacin antibiotics. The title molecule and reference drug ciprofloxacin docked with biotin carboxylase enzyme (PDB ID: 2V59) of E. coli and aminoglycoside phosphotransferase APH(2")IVA (PDB ID: 4DFU) of Enterococcus casseliflavus receptor with the help of Molegro molecular viewer 2.5 program and binding affinity (ΔG) were determined by ParDock server.