Kambappa Vinaya

The normal female reproductive hormone estrogen has been linked with increased risk of breast and many other forms of cancer. This is largely due to metabolic conversion of estrogens into highly reactive catechol estrogen quinones which can interact with DNA and cause a variety of DNA adducts and lesions. Detection and analysis of these adducts and their associated cellular responses involve complex chemical, enzymatic, and LC-MS based methods, which are both laborious and require specialized expertise and instrumentation. Herein, we show that using a biotin-labeled estradiol allows immunodetection of estrogen-induced DNA adducts by slot blot and single-cell molecular combing and proximity ligation assays. The biotinylated and unlabeled estradiols induced similar levels of DNA single and double strand breaks as measured by comet assays. Using biotinylated estrogen, we further show that estrogens are able to activate the Fanconi anemia-BRCA tumor suppressor pathway and cause DNA strand breaks and oxidatively modified DNA bases as well as gross chromosomal aberrations. Utilization of biotin-labeled estrogens could be a powerful tool to detect estrogen adducts and associated DNA damage, and to track estrogen adduct-induced cellular responses and carcinogenic mechanisms in cultured cells. The techniques presented here allow simple and rapid detection and quantitation of estrogen adducts by slot blot as well as direct visualization on the DNA strand and could pave the way for developing new treatments to protect the genome from the effects of reactive estrogen metabolites.

A simple and convenient procedure for the synthesis of nitriles by dehydration of aldoximes using a PCC (pyridiniumchlorochromate) has been developed. A variety of aromatic, heteroaromatic, and aliphatic aldoximes are converted. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the full spectral details.

Abstract: A series of novel 3-(2-chloroethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one aliphatic/ aromatic/ heterocyclic amine derivatives were synthesized in good yield. The synthesized compounds were characterized by 1H-NMR, FTIR and elemental analysis. All the synthesized compounds were screened for their in vitro antibacterial activity by agar well diffusion and micro dilution method against standard strains of Gram-Positive (Bacillus Subtilis MTCC 121 and Staphylococcus epidermidis 435), and Gram-negative (Xanthomonas Campestris 7903 and Pseudomonas aeruginosa MTCC 7908) bacteria. Compounds with substituted heterocyclic piperazine moiety showed good activity. In particular, compound 6i showed two fold better activity compared to the standard drug Strepyomycin sulphate.

A series of novel 2‐(4‐(2,4‐dimethoxybenzoyl)phenoxy)‐1‐(4‐(3‐(piperidin‐4‐yl)propyl) piperidin‐1‐yl)ethanone derivatives 9(a–e) and 10(a–g) were synthesized and characterized by ¹H NMR, IR, mass spectral, and elemental analysis. These novel compounds were evaluated for their antileukemic activity against two human leukemic cell lines (K562 and CEM) by using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazoliumbromide assay. Some of the tested compounds showed good antiproliferative activity with IC₅₀ values ranging from 1.6 to 8.0 μm. Compound 9c, 9e, and 10f with an electron‐withdrawing halogen substituent at the para position on the phenyl ring showed excellent in vitro potency against tested human leukemia cells (K562 and CEM).

A series of novel 2-methyl-3-(2-(piperazin-1-yl)ethyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one sulfonamide and carboxamide derivatives were synthesized in good yield. The synthesized compounds were characterized by 1H-NMR, FTIR and elemental analysis. All the synthesised compounds were screened for their in vitro antimicrobial activity by agar well diffusion and micro dilution method against standard strains of Gram-positive (Bacillus subtilis MTCC 121, Staphylococcus epidermidis 435), and Gram-negative (Xanthomonas campestris 7903 and Pseudomonas aeruginosa MTCC 7908) bacteria. Compound 7a and compound 8d with dichloro substitution among sulphonamide and carboxamide series respectively showed potent inhibitory activity.

To explore the anticancer effect associated with the piperidine framework, several (substituted phenyl) {4‐[3‐(piperidin‐4‐yl)propyl]piperidin‐1‐yl} methanone derivatives 3(a–i) were synthesized. Variation in the functional group at N‐terminal of the piperidine led to a set of compounds bearing amide moiety. Their chemical structures were confirmed by ¹H NMR, IR and mass spectra analysis. Among these, compounds 3a, 3d and 3e were endowed with antiproliferative activity. The most active compound among this series was 3a with nitro and fluoro substitution on the phenyl ring of aryl carboxamide moiety, which inhibited the growth of human leukemia cells (K562 and Reh) at low concentration. Comparison with other derivative (3h) results shown by LDH assay, cell cycle analysis and DNA fragmentation suggested that 3a is more potent to induce apoptosis.

Fexofenadine is a selective H₁-histamine receptor antagonist, which is an attractive alternative treatment for allergy symptoms. An efficient and environmentally friendly synthetic approach for the preparation of fexofenadine was developed from commercially available cumene. The method involves the Friedel–Craft's reaction, substitution, reduction, bromination, and the Grignard reaction.

A novel, efficient Fe/CaCl₂ system is revealed for the reduction of nitroarenes and reductive cleavage of azo compounds by catalytic transfer hydrogenation (CTH). The selective reduction of nitro compounds in the presence of sensitive functional groups including halides, carbonyl, hydroxyl, aldehyde, methyl, methoxy, acetyl, nitrile, and ester substituents with an excellent yields is reported. The simple experimental procedure and easy purification make the protocol advantageous.