Novel Cyclic Hexapeptides from Marine-Derived Fungus, Aspergillus sclerotiorumPT06-1.

Two novel cyclic hexapeptides containing both anthranilic acid and dehydroamino acid units, sclerotides A (1) and B (2), were isolated from the marine-derived halotolerant Aspergillus sclerotiorumPT06-1 in a nutrient-limited hypersaline medium. Both 1and 2are photointerconvertible and could be interconverted via a radical reaction initiated by direct photoisomerization. Both compounds showed moderate antifungal activity. Compound 2also showed weak cytotoxicity and antibacterial activity. [ABSTRACT FROM AUTHOR]