Bio-active Me tabolites from the Brown Alga Dictoyota dichotoma.

[摘要] Air dried algal materials of Dictyota dichotoma were extracted with a mixture of organic solvents,followed by purification on silica gel, led to isolation of six pure metabolites. After establishing the chemicalstructures, their antimicrobial, cytotoxicity and antioxidant activities were assayed. Six compounds wereobtained. Compounds 1 and 2 are significantly potent against Klebsiella pneumonia and even higher than thatof the positive control, penicillin G. Compounds 3, 5 and 6 at a concentration of 50µg/ml showed comparableeffect with that of chloramphenicol. Compound 5 showed significant activity against Candida albicans (10-16mm) and Fusarium oxysporium (15- 19 mm). Dictyol (6) and the total extract showed strong cytotoxic activityagainst two cancer cell lines (MCF-7 and HepG-2). The total extract displayed antioxidant effect. Both totalextract and the isolated compounds showed potent antimicrobial effects compared with several referenceantibiotics. The measured activities of the total extract are mainly higher than those of the pure compounds,which could be due to other effective compound(s) or synergistic action between the isolated compounds.

[学科分类] 工程和技术（综合）

[关键词] Red Sea;Marine organisms;Cytotoxicity;Terpenoids;Antimicrobial.