NEW DITERPENOIDS OF RABDOSIA MACROCALYX: THE STRUCTURE OF MACROCALIN A AND MACROCALIN B

From the dried powder of leaves of Rabdosia macrocalyx (Dunn) Hara three constituents were isolated, two of them were new diterpenoids, to which the names Macrocalin A and Macrocalin B were suggested. By means of spectral analysis combined with preparation of derivatives the structures of these two diterpenoids were determined. Macrocalin A and B were shown to have cytotoxicity in vitro against cultures of Hela cells