The continuing search for antitumor agents from higher plants

Secondary metabolites and their semi-synthetic derivatives of plant origin continue to play an important role in anticancer drug discovery. In this short review, selected single chemical entity antineoplastic agents representing high structural diversity are described from higher plants that are currently in clinical trials as promising cancer chemotherapy drug candidates. In addition, the approaches taken toward the discovery of anticancer agents from tropical plants in the laboratory of the authors are summarized.