Synthesis and Evaluation of Habiterpenol Analogs.

Habiterpenol is a G2 checkpoint inhibitor isolated from the culture broth of Phytohabitans sp. 3787_5. Here, we report the synthesis of new habiterpenol analogs through the total synthesis process of habiterpenol and evaluating the analogs for G2 checkpoint inhibitory activity. We investigated two different synthetic approaches for total synthesis, with intramolecular conjugate addition and Ti(III)-mediated radical cyclization as key reactions. Although the former was unsuccessful, the latter reaction facilitated stereoselective total synthesis and determination of the absolute configuration of habiterpenol. The extension of these chemistries to a structure-activity relationship (SAR) study gave new habiterpenol analogs, which could not be derived from natural habiterpenol and only be synthesized by applying the total synthesis. Therefore, this study provides important insights into SAR studies of habiterpenol.

Scopranones with Two Atypical Scooplike Moieties Produced by Streptomyces sp. BYK-11038.

Three new compounds, designated scopranones A-C, were isolated from the culture broth of a soil isolate, Streptomyces sp. BYK-11038, and shown to be inhibitors of bone morphogenetic protein (BMP) induced alkaline phosphatase activity in a BMP receptor mutant cell line. The structures were elucidated using NMR and other spectral data. The scopranones have an unusual structure with two atypical scooplike moieties linked at the tails to form part of a unique 3-furanone ring.