2-Hydroxy-luisol A, a New Quinone-derived Tetraol from a Marine Streptomyces sp and Oxidation Products of Luisol A

In addition to luisol A (1a), luisol B (2), and aloesaponarin II, the marine streptomycete B7617 produced a new derivative of la, 2-hydroxy-luisol A (1b). In an attempt to increase the biological activity, luisol A (1a) was oxidized and delivered with Jones reagent or by Swern oxidation the derivatives 3a/3b and 4a/4b, respectively, but none of these compounds showed antimicrobial or cytotoxic activities. All structure elucidations are based on 2D NMR analyses or were derived by comparison with published data.