title: Crambescidin 826 and dehydrocrambine A: new polycyclic guanidine alkaloids from the marine sponge Monanchora sp. that inhibit HIV-1 fusion.
abstract: Two new polycyclic guanidine alkaloids, crambescidin 826 (1) and dehydrocrambine A (2), and the known compounds crambescidin 800 (3) and fromiamycalin (4) were isolated from the marine sponge Monanchora sp. The structures of 1 and 2 were elucidated by 2D NMR and mass spectrometry, and relative stereochemistry was established by analysis of coupling constants and ROESY spectra. The pentacyclic guanidine alkaloids 1, 3, and 4 inhibit HIV-1 envelope-mediated fusion in vitro with IC(50)'s of 1-3 microM, while compound 2, a tricyclic guanidine alkaloid, showed weaker inhibition, with an IC(50) of approximately 35 microM.
authors.affiliation: Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892-0820.
authors.forename: LengChee
authors.initials: L
authors.lastname: Chang
authors.forename: Noel F
authors.initials: NF
authors.lastname: Whittaker
authors.forename: Carole A
authors.initials: CA
authors.lastname: Bewley
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D019380:Anti-HIV Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006146:Guanidines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D019029:Palau; D011161:Porifera / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D019380:Anti-HIV Agents; D006146:Guanidines; D013141:Spiro Compounds; C482472:crambescidin 826; C482473:dehydrocrambine A