Research in upcoming field of molecular medicine and gene therapy are constantly utilizing DNA as target macromolecules. Hence, various classes of nucleic acid based drugs have evolved to a broad range of diseases including cancer and other genetic disorders. Carboline group of alkaloids are such a large group of natural and synthetic indole molecules, having myriad of proven therapeutic applications, including cancer and tumor treatment.Three sets of carboline derived compounds (C1-C7) were prepared by Pictet-Spengler cyclization. These tetrahydro b- and g-carbolines have CF3 group with an additional amino alkyl chains (a- or d-position) and guanidine alkyl chains (a-position), of varying length. Binding with DNA resulted in dramatic enhancement and quenching in the fluorescence emission. Gamma-carboline analogs showed maximum DNA binding followed by beta-carboline compounds with amino alkyl chain and least with guanidine alkyl chain compounds. It decreased with increasing chain length. The bindings were entropically driven being more with guanidine alkyl chain analogs. Site preference and mode of binding with partial intercalation and external binding was supported by FTIR and viscosity. Cytotoxic potencies of the compounds were tested on seven different cancer cell lines. The smallest alkyl chain analog attached to gamma position, C3, showed maximum cytotoxicity with GI50 6.2 µM, against HCT-116 causing apoptosis, followed by the guanidine alkyl chain compounds, but amino alkyl chain compounds to beta position showed poor cytotoxicity. These results may be of prospective use in a framework to design novel carboline derivatives as antitumor drugs for improved therapeutic applications in future.

Dr. Bhadra has completed her PhD from Indian Institute of Chemical Biology, Jadavpur and postdoctoral studies from the same Institute. She joined University of Kalyani in the year 2010. She has supervised many international & national research projects funded by DST, UGC and CSIR, Govt. of India. She has 07 ph.D awardees under her supervision. Dr. Bhadra has presented her papers in several national and international conferences both in India and abroad and has been recognized as best presenter for her work She has received many awards. She is currently life member of many professional societies