Chemical and antiplatelet aggregative investigation of the leaves of Clausena excavata

Abstract A new carbazole alkaloid, clausine-L together with 11 known compounds, safrole, glutinol, 13 2 -hydroxy(13 2 - R )-pheophytin-a, methyl pheophobide-a, scopoletin, steroidal glycoside [β-sitosteryl glucoside +stigmasteryl glucoside], 2-methoxy-4-(2-propenyl)phenyl-β- d -glucoside, 2,6-dimethoxy-4-(2-propenyl)phenyl-β- d -glucoside, p -hydroxybenzoic acid, rutin and nicotiflorin were isolated and characterized from the leaves of Clausena excavata . Their structures were elucidated by spectroscopic methods and/or chemical transformation. Among them, safrole showed significant antiplatelet aggregative activity which was induced by arachidonic acid and collagen.