Ch. Srinivas

INDIUM TRICHLORIDE CATALYZED CHEMOSELECTIVE CONVERSION OF ALDEHYDES TO GEM-DIACETATES*

ABSTRACT Aldehydes are chemoselectively converted into the corresponding gem-diacetates at ambient temperature in high to quantitative yields using a catalytic amount of indium (III) chloride. The deprotection of the resulting gem-diacetates is achieved using the same catalyst in the presence of water. *IICT Communication No. 4628.

First stereoselective total synthesis and anticancer activity of new amide alkaloids of roots of pepper.

The first stereoselective total synthesis of new natural amide alkaloids 1-3 have been achieved from commercially available starting materials. Wittig olefination, Sharpless asymmetric dihydroxylation, epoxidation, a trans regioselective opening of 2,3-epoxy alcohol, Horner-Wadsworth-Emmons (HWE) olefination and amide coupling are the key steps. The amide alkaloids 1-3 are evaluated for their anticancer activity against colon (HT-29), breast (MCF-7) and lung (A-549) human cancer cell lines for the first time.

Zinc-mediated Barbier reactions of pyrrole and indoles: a new method for the alkylation of pyrrole and indoles

Abstract Pyrrole and indoles react smoothly with alkyl halides such as allyl bromide, prenyl bromide, crotyl bromide and propargyl bromide in the presence of zinc metal in THF to afford the corresponding 3- and 2-alkyl pyrrole and 3-alkyl indole derivatives in good yields with high regioselectivity.

An efficient approach for the synthesis of the hexahydroazepine segment of balanol

An efficient approach for the synthesis of the hexahydroazepine segment of balanol is described in seven steps in a highly stereoselective manner starting from (S)-2,3-O-isopropylidine glyceraldehyde.

Effect of Benzothiazole based conjugates in causing apoptosis by Regulating p53, PTEN and MAP Kinase proteins affecting miR-195a and miR-101-1

BackgroundHepatocellular carcinoma (HCC) accounts for majority of liver cancers and is the leading cause of cancer related death in Asia. Like any other cancer, HCC develops when there is a mutation to the cellular machinery that causes the cell to replicate at a higher rate and results in the loss of apoptosis. Therefore, a delicate balance between the expression of various genes involved in proliferation and apoptosis decide the ultimate fate of the cell to undergo rapid proliferation (cancer) or cell death.ResultsThe benzothiazole based compounds exhibited effective cytotoxicity at 4 μM concentration and have shown G1 cell cycle arrest with decrease in levels of G1 cell cycle proteins such as cyclin D1 and Skp2. Involvement of tumour suppressor proteins such as PTEN and p53 was studied. Interestingly these compounds displayed decrease in the phosphorylated forms of AKT, p38 MAPK and ERK1/2 which play a vital role in cell proliferation. Compounds have exhibited strong and significant effect on the expression of micro RNAs such as miR-195a & miR-101-1 which regulate hepatic cell proliferation.ConclusionsThe cell cycle arrest and apoptotic inducing nature of these compounds was revealed by FACS, BrdU cell proliferation and tunel assays. Compounds affected both tumour suppressor proteins as well as proteins that are involved in active cell proliferation. Micro RNAs whose target is Cyclin D1 such as miR-195a and miR-101-1 that is required for growth of hepatoma cells was drastically affected. These compounds caused apoptosis by activating caspase-3 and PARP.

Phenyl Sulphonyl Acetaldehyde Diethyl Acetal: A New Robust 1,2-Diol Protective Group

Abstract A simple preparation of a novel resilient protective group for 1,2-diols is described herein which is remarkably stable in the presence of extremely harsh basic conditions as well as acidic media. The title reagents versatility is detailed with numerous examples. #IICT Communication No.: 4583.

Bromoacetone: A New Protective Group For 1,2-Diols Cleavable with Zinc

Abstract Bromoacetone has been utilized for the first time as an excellent protective group for 1,2-diols that can be cleaved under neutral conditions viz., refluxing in Zn - MeOH.