title: Potent inhibitors of histamine release, two novel triterpenoids from the Okinawan marine sponge Penares incrustans.
abstract: Two novel triterpenoids with an unusual 14-carboxyl group, penasterone [1] and acetylpenasterol [2], were isolated from the Okinawan marine sponge Penares incrustans. The structures of 1 and 2 were established mainly on the basis of nmr spectroscopic data. The relative stereochemistry of 1 was confirmed by single-crystal X-ray diffraction analysis. Compounds 1 and 2 potently inhibited histamine release from rat peritoneal mast cells induced by anti-IgE in a dose-dependent manner.
mesh_terms: D000818:Animals; D004205:Cromolyn Sodium / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects*; D007073:Immunoglobulin E / Q000276:immunology; D066298:In Vitro Techniques; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D011161:Porifera / Q000737:chemistry*; D051381:Rats; D014315:Triterpenes / Q000494:pharmacology*
chemical_list: D014315:Triterpenes; D007073:Immunoglobulin E; D004205:Cromolyn Sodium