Alkaloids from the Tunicate Polycarpa aurata from Chuuk Atoll.
Two new alkaloids, polycarpine (1) and N,N-didesmethylgrossularine-1 (4), have been isolated from extracts of the ascidian Polycarpa aurata collected in Chuuk, Federated States of Micronesia. Three degradation products of 1 were also isolated. The structures of 1, 2, and 4 were determined by X-ray crystallography. The dimeric disulfide 1 inhibited the enzyme inosine monophosphate dehydrogenase, but the inhibition could be reversed by addition of excess dithiothreitol suggesting that 1 reacts with sulfhydryl groups on the enzyme.
Abas
Sayed A.
SA
Institute of Biochemistry and Cell Biology, Syntex Discovery Research, Palo Alto, California 94304.
Hossain
M. Bilayet
MB
van Der Helm
Dick
D
Schmitz
Francis J.
FJ
Laney
Maureen
M
Cabuslay
Ronnel
R
Schatzman
Randall C.
RC