Synthesis and applications of chelating resin based on tamarind kernel powder

Gupta Vikal, Goyal Jyotsna, Virvadiya Chandresh and Kumari Sharda

TKP powder (obtained from the seeds of Tamarind plant) has been used for the preparation of new chelating resin. Tertiary amine derivative of TKP acts as a flocculent cum metal ion exchanger and can also be used as scavenger for harmful toxic metal ions from the effluents of mineral and metallurgical industries. Methionine was binded on the TKP backbone in dioxane medium. The resultant ion exchange resin has been used in removal of toxic metals from effluent of mineral and metallurgical industries.

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Novel Organotin(IV) Dithiocarbamate: Cytotoxicity Evaluation and the Toxicity Mechanism in Human Leukemia Cell Lines

Kamaludin Nurul Farahana, Awang Normah, Baba Ibrahim, Hamid Asmah and Chan Kok Meng

The organotin(IV) dithiocarbamate derivatives have good cytotoxicity potentials. However, their mechanisms of action against cancer cells and their effects towards normal human cells are still unclear. In this study, four novel organotin(IV) N-butyl-N-phenyldithiocarbamate compounds with the formula RSn[S2CNC4H9(C6H5)]n (for n = 2, R = C4H9, C6H5; for n = 3, R = C6H5) were synthesized to evaluate their cytotoxicity potential and to determine the mechanism of action of the most potential compound in human leukemia cell lines. The Jurkat E6.1, HL-60 and K562 cell lines were treated with all compounds for 24 h prior to assessment via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazholium bro-mide (MTT) assay. The genotoxicity of the compound was assessed via alkaline comet assay. Meanwhile, the dihidroethidium, N-acetyl-L-cysteine and tetramethylrhodamine ethyl ester assays were conducted to determine the role of the intracellular oxidative stress and the loss of mitochondrial membrane potential (∆ψm) respectively. The apoptotic pathway involved was determined via caspase activation assay. The percentage of untreated cells along with compounds treated cells was calculated using one-way ANOVA (analysis of variance). All compounds exhibited a strong cytotoxicity in the Jurkat E6.1, HL-60 and K562 cell lines with IC50 values in the ranges 0.40–1.30 µM, 0.23–6.90 µM, and 1.85–7.00 µM respectively. Compound 4 (triphenyltin(IV) N-butyl-N-phenyldithiocarbamate) demonstrated the induction of reactive oxygen species (ROS) excessively in K562 cells, probably causing oxidative damage to DNA. Subsequently, decreases in ∆ψm and the activation of caspase 9 suggested that the cells died via the intrinsic pathway of apoptosis. In conclusion, the organotin(IV) N-butyl-N-phenyldithiocarbamate compounds demonstrated a good toxicity against the human leukemia cell lines tested. The generation of ROS was suggested as an important factor in inducing DNA damage and disrupting the normal mitochondrial function, consequently causing apoptosis.

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Microwave Assisted Synthesis of 2-amino-6-(4-hydroxy-2-oxo-2h-substituted-chromen-3-yl)-4-(1-phenyl-3-(substituted phenyl)-1h-pyrazol-4-yl-pyridine-3-carbonitrile (TAB)

Jain Anamika and Sharma Bindiya

The heterocyclic compounds are very widely distributed in nature and are very essential to living organisms. A rapid, improved andmicrowave assisted eco-friendly convenient route, for the synthesis of 2-amino-6-(4-hydroxy-2-oxo-2H subs- tituted- chromen-3-yl) -4- (1-phenyl-3- (substituted phenyl 1H-pyrazol-4-yl-pyridine-3-carbonitrile (TAB) has been developed. Excellent yields, shorter reaction time andeasy workup are the major advantageous features of this green protocol. All the compounds synthesized were characterized by physical methods like melting point, thin layer chromatography, molecular weight, molecular formula and spectral analysis like FT-IR, mass spectra, 1H NMR and elemental analyses. Not only is direct microwave heating able to reduce chemical reaction times from hours to minutes, but it is also known to reduce side reactions, increase yields andimprove reproducibility.

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Assessment of a π nucleophilicity of some selected siloxydienes used in organo catalytic Vinylogous Mukaiyama Aldol (OVMA) Reaction: A Density functional theory study

Boruah Bhupen

Siloxydienes are generally used as nucleophiles for OVMA reaction with aldehyde. There are two nucleophilic sites in siloxydiene for electrophilic attack with respect to siloxy group namely β and γ carbon atom. In this study we use philicity index (ωk-) and local nucleophilicity index (Nk) to probe intramolecular reactivity of a set of siloxydienes with respect to β and γ carbon atom of the C=C bond. To compare the nucleophilicity of the selected siloxydienes and to predict intermolecular nucleophilicity trend, we use group philicity (ωg- ) group softness ( Sg ) and group nucleophilicity (Ng) with respect to the β and γ carbon atom of C=C bond. Although there have been many issues pertaining to Mullikan’s-based condensed Fukui function, use of group properties such as group philicity can overcome these to a large extent. Therefore, we intend to use group property for the study of intermolecular reactivity trend.

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Fly ash as a solid waste used for the removal of Cu(II) ions from aqueous solution

Sinha Chumki, Singha Biswajit and Mandal Sailendra Nath

The presence of toxic heavy metal ions discharged into the water bodies from different industries pose serious threat to living beings. Copper is one of the hazardous heavy metal used in different industries such as mining and smelting, plating, brass manufacture, petroleum refining, electroplating industries and Cu-based agrichemicals. It is released from these industries with various concentrations. Although copper is an essential metal for living beings at lower concentration but it is also potentially toxic at higher concentration. Present study reported the effect of various physico-chemical parameters for the removal of Cu(II) ions using fly ash. The optimum pH for adsorption was found to be 4.5. Kinetics data were best described by the pseudo-2nd-order model. The experimental data fitted well with Langmuir isotherm model. The mean sorption energy was calculated using Dubinin-Radushkevich isotherm model and it confirmed that the sorption process was chemical in nature.

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