Linfuranones B and C, Furanone-Containing Polyketides from a Plant-Associated Sphaerimonospora mesophila.

Two new furanone-containing polyketides, linfuranones B and C, were isolated from a plant-associated actinomycete of the genus Sphaerimonospora. Their structures were determined by NMR and MS spectroscopic analyses, and the absolute configurations were established by anisotropic methods and chemical degradation approaches. In silico analysis of biosynthetic genes suggested that linfuranone B is generated from linfuranone C by oxidative cleavage of the polyketide chain. Linfuranones B and C induced preadipocyte differentiation into matured adipocytes at 20-40 µM without showing cytotoxicity.

Two new secondary metabolites from a fungus of the genus Robillarda.

Two new compounds, robillafuran and (+)-robillapyrone, were isolated from the culture extract of a fungal strain of Robillarda along with (+)-monascuspyrone. The absolute configuration of (+)-robillapyrone and (+)-monascuspyrone was determined by ECD calculation. These three compounds showed preadipocyte differentiation activity at 10-40 µM.

Hikiamides A-C, Cyclic Pentadepsipeptides from Fusarium sp. TAMA 456.

Three new cyclic pentadepsipeptides, hikiamides A-C (1-3), were isolated from the culture extract of Fusarium sp. TAMA 456. The structures were determined by spectroscopic analysis using NMR and MS, and the absolute configurations were established by using Marfey's method and chiral HPLC analysis. Hikiamides induced the differentiation of murine ST-13 preadipocytes into mature adipocytes at 2 µM and adiponectin mRNA expression (5- to 13-fold higher than control). They also induced PPAR-γ-dependent gene expression at a concentration from 0.63 to 10 µM in a gene reporter assay.