QM-HiFSA-Aided Structure Determination of Succinilenes A-D, New Triene Polyols from a Marine-Derived Streptomyces sp.

Based on profiles of secondary metabolites produced by marine bacteria obtained using LC/MS, succinilenes A-D (1-4), new triene polyols, were discovered from a culture of a Streptomyces strain SAK1, which was collected in the southern area of Jeju Island, Republic of Korea. The gross structures of 1-4 were primarily determined through analysis of NMR spectra. The double bond geometries of the succinilenes, which could not be established from conventional ¹H NMR spectra because of the highly overlapped olefinic signals, were successfully deciphered using the recently developed quantum-mechanics-driven ¹H iterative full spin analysis (QM-HiFSA). Succinilenes A-C (1-3) displayed inhibitory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO) production, indicating their anti-inflammatory significance. These three compounds (1-3) commonly bear a succinic acid moiety, although succinilene D (4), which did not inhibit NO production, does not have this moiety in its structure. The absolute configurations of succinilenes A-D (1-4) were established through J-based configuration analysis, the modified Mosher's method following methanolysis, and CD spectral analysis.

Separacenes A-D, novel polyene polyols from the marine actinomycete, Streptomyces sp.

Separacenes A-D (1-4), novel polyene polyols, were isolated from Streptomyces sp. collected from the southern area of Jeju Island, Korea. The chemical structures of 1-4 were established by NMR, mass, UV, and IR spectroscopy as well as the modified Mosher's method. Separacenes A-B (1-2), which share an identical planar structure but possess different relative configurations, bear tetraene units flanked by two diol moieties, whereas the stereoisomeric separacenes C-D (3-4) possess a triene moiety between two diol substructures. Separacenes A-D each contain a terminal olefinic methylene. Separacene A displayed inhibitory activity against Candida albicans isocitrate lyase and weak cytotoxicity against both the colon carcinoma cell line HCT-116 and the lung cancer cell line A549.