Thesis (M.Sc.)--Chulalongkorn University, 2002

The preliminarily biological activity results pointed out that the dichloromethane crude extract of Ardisia colorata Roxb. fruits exhibited high cytotoxic activity against brine shrimp Artemia salina as well as scavenged the DPPH radical. The chemical constituents investigation disclosed three pure compounds: 2,5-dihydroxy-3-undecyl-1,4-benzoquinone (embelin), stigmasterol and octadeca-9,12-dieonoic acid (linoleic acid), and four mixtures: a mixture of long chain alcohols, a mixture of stigmasteryl-3-O-palmitate and beta-sitosteryl-3-O-palmitate, a mixture containing alpha-amyrin, and a mixture of 1,3-dihydroxy-5-(heptadec-8,11-dienyl)benzene and 1,3-dihydroxy-5-(pentadec-8-enyl)benzene. Among isolated substances, embelin, the major component, exhibited the highest cytotoxic activity against brine shrimp, the highest scavenging effect on DPPH radical, moderate insect antifeedant activity, and gave positive tests for antimicrobial activity against Bacillus subtilis, enzymatic inhibitor on p-hydroxypyruvate dioxygenase. A mixture of 1,3-dihydroxy-5-(heptadec-8,11-dienyl)benzene and 1,3-dihydroxy-5-(pentadec-8-enyl)benzene displayed the growth inhibition effect on phytophatogenic fungi, Alternaria sp., by bioautographic method as well as showed insecticidal activity against Spodoptera litura. These two substances displayed strongly cytotoxic activity against the breast cancer cell and the small cell lung cancer.