Pyrazino-bis-steroids, including cephalostatins isolated from the marine worm Cephalodiscus glichristi, ritterazines isolated from the tunicate Ritterella tokioka as well as their artifical anlogues, are a group of complex steroid - alkaloid hybrids. These compounds not only possess the unique structural characteristics. but also potent antitumor biological activites. Since the first natural pyrazino - bis - steroids, cephalostatin 1 was reported in 1988,many new natural and unnatural analogues successively have appeared in the scientific literature. This review deals with the structure and synthesis of pyrazino - bis -steroids and covers the literature published in 1988 to 1998.

Key words: PYRAZINE P, STEROIDS, ALKALOID, ANTINEOPLASTIC ACTIVITY