Chemistry of Indole Alkaloids Related to the Corynanthe-Type from Uncaria, Nauclea and Mitragyna Plants

A number of monoterpenoid indole and oxindole alkaloids have been isolated from botanical sources, and many of them have been found to possess significant pharmacological activities and are utilized as key lead compounds in new drug development. In this review, the recent results of our phytochemical and synthetic studies of indole alkaloids having the Corynanthe-type related skeleton from genera Uncaria, Nauclea, and Mitragyna, which are classified under tribe Cinchoneae, family Rubiaceae, are described.