Cherkupally Sanjeeva Reddy

Synthesis and in vitro study of methylene-bis-tetrahydro[1,3]thiazolo[4,5-c]isoxazoles as potential nematicidal agents

A series of methylene-bis-tetrahydro[1,3]thiazolo[4,5-c]isoxazoles 6 were synthesized by the reaction of chalcone derivative of methylene-bis-thiazolidinone 5 with hydroxylamine hydrochloride. The chemical structures of newly synthesized compounds were elucidated by IR, 1H, 13C NMR, MS and elemental analyses. The compounds 6a-g were evaluated for their nematicidal activity against Ditylenchus myceliophagus and Caenorhabditis elegans, compound 6e and 6f showed appreciable nematicidal activity. Further the compounds 6a-g were screened for their antifungal activity against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185) and Trichophyton mentagrophytes (IFO 40996). The compounds 6b and 6f displayed notable antifungal activity against all the microorganisms employed. The activity of these two compounds is almost equal to the standard. It is also interesting to note that the compounds 6b, 6f and 6g showed activity towards C. albicans at the concentration of 3.75 microM, which is less than the concentration of the standard Amphotericin B.

Synthesis, antimicrobial and nematicidal evaluation of a new class of triazolo[4,3- c ]quinazolinylthiazolidinones

In an attempt to find a new class of antimicrobial and nematicidal agents, a series of 2-aryl/heteryl-3-(5-phenyl[1,2,4]triazolo[4,3-c]quinazolin-3-yl)-1,3-thiazolidin-4-ones 5a-k was prepared by one-pot three-component reaction, involving 5-phenyl[1,2,4]triazolo[4,3-c]quinazolin-3-amine 4, aryl/heteroaryl aldehydes and thioglycolic acid, and characterized by physicochemical as well as spectral means. All the newly synthesized compounds 5a–k were tested in vitro for their antimicrobial activity against three representative Gram-positive (Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus), Gram-negative (Proteusvulgaris, Salmonella typhimurium, Escherichia coli) bacteria and four fungal strains (Candida albicans, Aspergillus fumigatus, Trichophyton rubrum, Trichophyton mentagrophytes). These compounds 5a–k, were also evaluated for their nematicidal activity against two nematodes (Ditylenchus myceliophagus, Caenorhabditis elegans). Except phenyl substituted, all the ten aryl/heteroaryl substituted compounds 5b–k showed significant antimicrobial and nematicidal properties against tested microorganisms. Particularly, compounds 5b, 5c, 5g, 5h, 5j and 5k containing electron-withdrawing substituents like chlorophenyl, nitrophenyl, furyl and 1,3-benzodioxole exhibited promising activity comparable to employed standards Ampicillin, Amphotericin B and Levamisole, and emerged as potent antimicrobial and nematicidal agents.

Aquachlororuthenium(III) complex catalysis in the oxidation of malonic and methylmalonic acids by bromate in perchloric acid medium. Study of induction period and evaluation of individual kinetic parameters

AbstractThe kinetics and mechanism of an aquachlororuthenium(III) complex catalyzed oxidation of malonic and methylmalonic acids by bromate in aqueous acetic acid medium containing perchloric acid and mercury(II) is reported here. The reaction shows an induction period (τ0), whose duration is inversely proportional to [substrate]0 and [catalyst]0, and temperature; however, independent of [bromate]0. After induction, the reaction exhibits first order each in [bromate] and [catalyst], less than unit order in [substrate] and an inverse fractional order in [HClO4]. The reaction also shows an inverse solvent isotope effect

Synthesis and biological study of novel methylene-bis-chalcones and substituted methylene-bis-pyrimidines/pyrimidinones

{(k_{D_{2}O}/k_{H_{2}O} = 0.72 \pm 0.05.)}

Synthesis and Evaluation of Novel Bis[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles as Potent Antimicrobial Agents

The observed rate law is interpreted by a mechanism involving the oxidation of RuIII to RuV by BrV (Kf), followed by complex formation (Kc) between the RuV and enol form (Ken) of the substrate in 1:1 ratio, which decomposes (kd) into products in the rate-determining step with regeneration of RuIII. The observed induction period is interpreted as the time-lag in building-up of the reactive intermediate(s). The reaction constants (Kf, Kc, Ken and kd) involved in the mechanism proposed have been evaluated and τ0 has been correlated in terms of initial concentrations of substrate and catalyst as: 1/τ0 = Q(X-1)[Sa]0(x-1) = Q′(Z-1)[Ru(III)]0(z-1).