"Click" reaction mediated synthesis of costunolide and dehydrocostuslactone derivatives and evaluation of their cytotoxic activity.

As part of pharmacological-phytochemical integrated studies on medicinal plants from Indian flora, costunolide (1) and dehydrocostus lactone (2), were isolated as major phytochemicals from Saussurea lappa, a plant traditionally used in different Asian systems of medicine. A series of 1,4-disubstituted-1,2,3-triazoles conjugates were synthesized through diastereo selective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reactions. All these triazolyl derivatives (5a-5j) & (7a-7j) were well characterized using modern spectroscopic techniques and evaluated for their anticancer activity against a panel of five human cancerous celllines. The results indicated that all the analogs displayed moderate cytotoxic activity.