ABSTRACT
Two new dimeric sterols, manadosterols A (1) and B (2), were isolated from the marine sponge Lissodendryx fibrosa collected in Indonesia. The two compounds are comprised of two sulfonated sterol cores connected through the respective side chains. Manadosterols A (1) and B (2) inhibited the Ubc13-Uev1A interaction with IC(50) values of 0.09 and 0.13 µM, respectively. They are the second and third natural compounds showing inhibitory activities against the Ubc13-Uev1A interaction and are more potent than leucettamol A (IC(50), 106 µM), the first such inhibitor, isolated from another marine sponge.
Subject(s)
Porifera/chemistry , Sterols/isolation & purification , Sterols/pharmacology , Animals , Drug Screening Assays, Antitumor , Indonesia , Inhibitory Concentration 50 , Marine Biology , Molecular Structure , Sphingolipids/pharmacology , Sterols/chemistryABSTRACT
Two reverse-prenylated indole alkaloids, deoxybrevianamide E and 6-hydroxydeoxybrevianamide E, are proposed as biosynthetic precursors for advanced metabolites isolated from the marine-derived Aspergillus sp. In order to uncover the role of the alkaloids in the biosynthetic pathway, the feeding experiments of the [(13)C](2)-[(15)N]-labeled deoxybrevianamide E and 6-hydroxydeoxybrevianamide E were performed to afford the metabolites, which were produced by oxidation and successive pinacol-type rearrangement of the isoprenyl units.
ABSTRACT
Notoamides O-R were isolated from a marine-derived Aspergillus sp. Notoamide O possesses a novel hemiacetal/hemiaminal ether functionality hitherto unknown among this family of prenylated indole alkaloids. The structure represents an unusual branch point for the oxidative modification of other members in the family of prenylated indole alkaloids in the biogenetic pathway.
Subject(s)
Aspergillus/chemistry , Indole Alkaloids/chemistry , Indole Alkaloids/isolation & purification , Animals , Bivalvia/microbiology , Marine Biology , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Oceans and Seas , PrenylationABSTRACT
Besides 12 known glycosides, five new steroidal glycosides have been isolated from the stems of Solanum sodomaeum L. (Solanaceae). The chemical structures of these five glycosides were determined on the basis of spectroscopic data as well as chemical evidence, and the structure of one known steroidal glycoside was corrected.