International Journal of Chemical Research

144-152

Authors: SOMERSET V., BAKER P., IWUOHA E.

In this paper the results for the construction of a gold/mercaptobenzothiazole/polyaniline/ acetylcholinesterase/polyvinylacetate (Au/MBT/PANI/AChE/PVAc) thick-film biosensor for the determination of certain carbamate pesticide solutions in selected aqueous organic solvent solutions are reported. AChE biosensors are designed to complement the classical analytical methods of pesticide detection. The Au/MBT/PANI/AChE/PVAc electrocatalytic biosensor device was constructed by encapsulating acetylcholinesterase (AChE) enzyme in the PANI polymer composite, followed by the coating of poly(vinyl acetate) (PVAc) on top to secure the biosensor film from disintegration in the organic solvents evaluated. The electroactive substrate called acetylthiocholine (ATCh) was employed to provide the movement of electrons in the amperometric biosensor. The voltammetric results have shown that the current shifts more anodically as the Au/MBT/PANI/AChE/PVAc biosensor responded to successive acetylthiocholine (ATCh) substrate addition under anaerobic conditions in 0.1 M phosphate buffer, KCl (pH 7.2) solution and aqueous organic solvent solutions. For the Au/MBT/PANI/AChE/PVAc biosensor, various performance and stability parameters were evaluated. These factors include the optimal enzyme loading, effect of pH, long-term stability of the biosensor, temperature stability of the biosensor, the effect of polar organic solvents, and the effect of non-polar organic solvents on the amperometric behavior of the biosensor. The biosensor constructed in this study offered a reasonable linear range between 0.25 to 3.45 nM for the detection of carbofuran, aldicarb and dioxacarb pesticide solutions. The detection limits for the individual carbamate pesticides were 0.249 nM for carbofuran, followed by 1.209 nM for aldicarb and 1.572 nM for dioxacarb.

134-139

Authors: BELAIDI S., MELKEMI N., BOUZIDI D.

Molecular geometry, electronic structure, effect of the substitution and structure physical-chemical property relationship for 1,2- dithiole-3-thione derivatives, have been studied by molecular mechanics, PM3, Ab initio, DFT and QSAR method. In the present work, the calculated values, namely net charges, bond lengths, dipole moments, electron-affinities, heats of formation and QSAR properties, are reported and discussed in terms of the biological activity of 1,2-dithiole-3-thione derivatives.

122-125

Authors: TEWARI I.C., RAJESH SHUKLA, SUSHMA RANI

The present manuscript deals the kinetics and mechanism of the reaction between crotonic acid and ceric perchlorates. The order of the reaction with respect to Ce (IV) is unity but the rate is dependent on the initial concentration of the Ce (IV). The spectrophotometric investigation has been also carried out which negatived the intermediate complex formation. The main reaction species of Ce (IV) involved in rate determining step was the hydrated uncomplexed ceric ion which at higher initial concentration gets dimerises.

66-70

Authors: MISHRA K.K., MAYA SHUKLA

The reaction between mercaptosuccinic acid (TMA) and methylene blue (MB) was investigated in acidic medium using Cu (II) as catalyst. Two moles of substrate are oxidized by one mole of MB forming the corresponding disulphide and dihydromethylene blue. The order in MB is zero while order in TMA is unity. The rate shows a maximum on varying [H+] whereas it increases linearly on increasing [Cu (II)]. Electrolytes exert a diverse influence, which is attributed to environmental effect. The rate increases on increasing the dielectric constant of the medium but it remains unaffected on adding externally the disulphide and leucobase to the system. It is known that Zn (II)-pyrazole complex acts as a model for the enzyme, liver alcohol dehydrogenase (LADH) which regulates the function of liver 22.3-Methyl-1 phenyl-2-pryazoline-5-one (Pyrazolone) was also added to the system in a bid to investigate the effect of simultaneous ligation of catalyst on the rate and pyrazolone was found to retard the reaction.

74-82

Authors: DESHPANDE D.S., BAJPAI R., BAJPAI A.K.

The ever increasing use of polymers in our day to day life has given rise to quest for developing polymeric materials suitable for various applications. The content work aims to synthesize a novel semi-IPN in the form of hydrogel comprising of polyvinyl alcohol (PVA) and acrylonitrile (AN), in various proportions, by redox polymerization method in the presence of N, N'-methylene-bis-acrylamide (MBA) as a crosslinker and potassium persulphate (KPS) as initiator. Structure formation of the gel matrix has been confirmed by FTIR spectrophotometry. Phase morphology of the semi-IPNs in various proportions has been studied with scanning electron microscopy and X-ray diffraction technique has been utilized to detect the crystalline and amorphous characteristics of the synthesized gels. Water sorption capacity of the specimens have also been studied. IR spectra of the synthesized semi-IPN confirms the formation of a physical gel with polymer chains held to each other via hydrogen bonding. Their SEM images show single phase morphology with a less rough surface indicating a better compatibility of the two polymers. The XRD patterns of synthesized gels indicate that the crystallinity in the membrane is mainly due to PVA and swelling studies proves the approach to be beneficial for various bioengineering and bioindustrial applications.

99-104

Authors: AZIZ-UR-REHMAN, WAJEEHA TANVEER, MUHAMMAD ATHAR ABBASI, SUMBAL AFROZ, KHALID MOHAMMED KHAN, MUHAMMAD ASHRAF, IFTIKHAR AFZAL

In the present study, a series of N-substituted sulfonamides have been synthesized. The reaction of benzene sulfonyl chloride (1) with O-anisidine (2) yielded N-(2-methoxyphenyl) benzenesulfonamide (3), which on bromination with bromine in the presence of acetic acid gave N-(4,5-dibromo-methoxyphenyl)benzenesulfonamide (6). The two products (3) and (6) further on treatment with alkyl halides/acyl halide in the presence of sodium hydride yielded thirteen different N-substituted sulfonamides. The compounds were characterized by IR, EIMS and 1H-NMR and screened against acetyl cholinesterase, butyryl cholinesterase and lipoxygenase enzymes. The results revealed that N-butyl-N-(4, 5-dibromo-2-methoxyphenyl)benzene sulfonamide (6d) and N-pentyl-N-(4,5-dibromo-2-methoxyphenyl)benzenesulfonamide (6e) exhibited good inhibitory potential against lipoxygenase.

110-117

Authors: SURESH S., SUDHAKAR K., PREMALATHA M.

From the industrial revolution to the present, energy consumption has lead to a substantial rise in atmospheric greenhouse gases. The burning of fossil fuels accounts for about 80% of the rise of atmospheric carbon-dioxide (CO2), since the pre-industrial era, to its current level of 390 ppm. The increase in CO2 is already causing changes in the climate such as global warming. The “micro-algae based technology” (Biological carbon sequestration) is a new, might be the most promising, environmentally friendly and cost-effective means of reducing CO2 emissions in the energy sector. The most common microalgae species are Spirulina sp., Chlorella spa., Haematococcus spa. and Dunaliella spa., etc. This technology, have more important characteristics apart from carbon sequestration such as high biomass yield per unit of light and area. In this context, paper has focused the underlying issues in CO2 sequestration from algae based on geography, photosynthetic light, productivity and application of algal biomass. for conditions prevailing in India.

49-55

Authors: JIE CHAO, JIAN-NING LIU, YAN-CHUN TANG, SHOU-JUN XIAO

We have shown previously that oligonucleotide conjugated hirulog (bivalirudin) has a higher inhibitory activity against thrombin compared with hirulog. The negative charged oligonucleotide was considered to be responsible for the additive activity. To further investigate the related effect of oligonucleotide, the oligonucleotide conjugated hirulog18 was prepared in the present work and the activity of the conjugate against thrombin was measured. Hirulog18, a peptide lack of two N-terminal amino acid residues of hirulog, has little inhibitory activity against thrombin compared with hirulog. The conjugate oligonucleotide-hiruglog18 was successfully synthesized using click chemistry and validated by MALDI-MS and gel electrophoresis. The activity of the conjugate against thrombin was measured by the chromogenic assay using Chromozym TH as substrate. It was found surprisingly that oligonucleotide-hirulog18 had an inhibitory effect better than hirulog18 and hirulog. Strong negative charged heparin was used to study the binding mode between oligonucleotide-hirulog18 and thrombin. The results suggested that the negative charged oligonucleotide could be helpful for the conjugate’s binding to the anion-binding exosite of thrombin via the Coulomb force. The highly inhibitory effect of the oligonucleotide-hirulog18 conjugate against thrombin may present a new strategy to generate a novel class of direct thrombin inhibitors.