RESEARCH ARTICLE s f t

Natural products from plants provide an important source of new drugs and potential pharmaceutical "lead " com-pounds. Natural products or natural product-derived drugs include 28 % of all new chemical entities launched between 1981 and 2002, and 24 % of them are semi-synthetic natural product analogues or synthetic compounds based on nat-ural product pharmacophores [1]. Furthermore, many anti-tumor agents in current clinical use are of natural origin, among them taxanes (docetaxel, paclitaxel), Vinca alkaloids (vindesine, vinblastine, vincristine), anthracyclines (idarubicin, daunorubicin, epirubicin), and others. Thus, there is a promising future for the use of natural products derived from plants as anti-tumor agents. Adenocarcinoma of the pancreas, the most common form of pancreatic cancer, is the fourth commonest cause of cancer-related mortality worldwide [2]. This cancer is often diagnosed at advanced stages and has a poor prognosis, with fewer than 6 % of those patients liv-ing as long as five years after diagnosis [2]. The basis of * Correspondence