New cytotoxic flavonoids from Cryptocarya infectoria

A new dihydrochalcone, two new dihydroflavanones and eight new biflavonoids have been isolated together with cryptocaryone from the cytotoxic methanol extract of Cryptocarya infectoria. The absolute structure of cryptocaryone was established by X-ray analysis of its 8-bromo derivative. The structure of the new compounds were elucidated by spectroscopic means and their abso lute stereochemistry was deduced from chemical correlation, circular dichro ism data and NOESY experiments. Several compounds displayed significant cyt otoxicity and cryptocaryone was shown to possess cytotoxicity towards multi -drug resistant K562-DOX cells. (C) 2001 Elsevier Science Ltd. All rights r eserved.