Two novel isocembrene derivatives have been isolated from the marine soft coral Sclerophytum capitalis and their structures determined by spectroscopic methods.Marine invertebrates have been shown to possess a wide variety of secondary metabolites including terpenes, alkaloids, and steroids.' The diversity of di-and tri-terpenes encountered in marine organisms is phenomenal., A soft coral of the genus Lohophj-tutn has been reported to contain an isocembrene (1) which could serve as a precursor of three novel diterpenes identified as cladiellin (2),4 ophirin (3),5 and eunicellin (4) isolated from the soft corals Cladiellu sp., Muricellu sp., and Ezrrzice/kz stricfci, respectively. Here we report the isolation and structures of two novel diterpenes-sclerophytin A and B from the soft coral Sderoplij~tum capitalis, which we believe are derived from a deacetylcladiellin intermediate. Sclerophytin A was found to be cytotoxic against the L1210 cell line at a concentration of 0.001 pg m1-l. Results and DiscussionA methanolic extract (40 1) of the coral on evaporation and lyophilization gave a residue which was triturated with hexane, chloroform, and finally with methanol. The hexane extract on repeated chromatography on silica gel 60 gave a group of fractions which were combined and evaporated to give sclerophytin B (6). Chromatography of the chloroform extract (2 x ) followed by h.p.1.c. gave sclerophytin A (5) as colourless needles, m.p. 187 "C. The ' H n.m.r. spectrum in CDCl, showed the presence of an exocyclic methylene [

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The whole plant of Ervatamia coronaria var. plena obtained from Thailand has afforded a new indole alkaloid 19S-heyneanine hydroxyindolenine whose structure was deduced through interpretation of spectral data. Nine known alkaloids, coronaridine, coronaridine hydroxyindolenine, voacangine, voacangine hydroxyindolenine, heyneanine, voacristine, 3-oxo-coronaridine, 3-oxo-voacangine,and voacristine hydroxyindolenine, and six common triterpenoids were also isolated. Coronaridine was the principal cytotoxic alkaloid obtained.

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A new naturaly occurring alkaloid has been isolated from the rpe fruits of Aegle marmelos and characterized as 0-methyihalfordinol (I). Alloimperatorin methyl ether, hitherto unknown in the genus Aegle, and 0-isopentenyihalfordinol, earlier detected in leaves, were also obtained.