title: Bifunctionalized amphilectane diterpenes from the sponge Stylissa cf. massa.
abstract: Two new amphilectane-type diterpenes, 8-isocyanato-15-formamidoamphilect-11(20)-ene (1) and 8-isothiocyanato-15-formamidoamphilect-11(20)-ene (2), along with two known derivatives, 8-isocyano-15-formamidoamphilect-11(20)-ene (3) and 7-formamidoamphilect-11(20),15-diene (4), were isolated from the sponge Stylissa cf. massa. Diterpenes bearing two different isonitrile-related functionalities, as in 1-3, are rare. The coexistence of these compounds, all of which possess the identical carbon skeleton, in the same sponge specimen suggests interconversion among them. All the isolated compounds were tested for antimalarial activity. Compound 3 proved approximately 10 times more active than 1 and 2, indicating the importance of the isonitrile moiety to antimalarial activity versus the isocyanate and isothiocyanate groups, respectively. Compound 4, which contains only the formamide group, was inactive at the highest concentration tested.
authors.affiliation: Marine Natural Products Research Unit, Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand.
authors.forename: Naphatson
authors.initials: N
authors.lastname: Chanthathamrongsiri
authors.forename: Supreeya
authors.initials: S
authors.lastname: Yuenyongsawad
authors.forename: Chatchai
authors.initials: C
authors.lastname: Wattanapiromsakul
authors.forename: Anuchit
authors.initials: A
authors.lastname: Plubrukarn
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004224:Diterpenes / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010963:Plasmodium falciparum / Q000187:drug effects; D011161:Porifera / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: C573612:8-isocyanato-15-formamidoamphilect-11(20)-ene; C573613:8-isothiocyanato-15-formamidoamphilect-11(20)-ene; D000962:Antimalarials; D004224:Diterpenes