SYNTHESIS AND BIOLOGICAL EVALUATION OF SOME NEW CHALCONES AS POTENTIAL CYTOTOXIC AGENTS

C. Kistayya*, N. G. Raghavendra Rao, A. Vasudev Rao, N. Srinath, B. Sanjeeva Nayak, Bhawatha Chawda

Chalcones, a group of compounds with two aromatic rings connected by a keto-vinyl chain, constitute an important class of naturally occurring flavonoids exhibiting a wide spectrum of biological activities. The presence of a reactive ?, ?-unsaturated keto functional group is partly responsible for their activity. The main objective present study is to synthesize and characterize some new chalcones of 4-bromoacetophenone by reaction with various aromatic and heteroaromatic aldehydes. The structure of the synthesized compounds were confirmed by means of IR, 1HNMR 13C NMR, mass spectra and by elemental analysis. To screen the synthesized chalcones for their cytotoxic activities. Total compounds (B2 to B25) were synthesized. All these compounds are new and the characteristic physical and spectral data was presented separately in detail. All the chalcones exhibited characteristic absorption bands in the IR spectra (cm-1 ), 1H NMR and 13C NMR spectra shows standard characteristic absorption bands. The chalcones (B1- B25) have been evaluated for their cytotoxicity against HT-29 (colon cancer), MCF-7 (breast cancer) and DU-145 (prostate cancer) cell lines. Methotrexate was used as the reference standard. The results clearly revealed that most of the compounds possessed cytotoxic activity as evidenced by the IC50 values. Of all the compounds tested against HT-29 cell lines, the compound B22 having a thienyl moiety in its structure showed maximum activity with a IC50 value of 42 µg/mL. This is followed by compounds, B15 having a bromofuran moiety (IC50 67 µg/mL), B5 having a difluoro phenyl moiety (IC50 68 µg/mL), B21 having a pyrrolyl moiety (IC50 73 µg/mL), B1 having a 4-methylphenyl moiety (IC50 76 µg/mL) and B6 having a dichlorophenyl moiety (IC50 80 µg/mL). From this study, it can be concluded that the chalcones were found to have more cytotoxic activities.