Chemical Constituents from a Soil-Derived Actinomycete, Actinomadura miaoliensis BCRC 16873, and Their Inhibitory Activities on Lipopolysaccharide-Induced Tumor Necrosis Factor Production

An investigation on the secondary metabolites from the BuOH extract of the fermentation broth of the thermotolerant polyester-degrading actinomycete Actinomadura miaoliensis BCRC 16873 was carried out. One previously undescribed -pyrone (=pyran-2-one) derivative, designated as miaolienone (1), and a new butanolide, miaolinolide (2), together with 13 known compounds, 315, were obtained. Their structures were established on the basis of extensive 1D- and 2D-NMR analyses in combination with HR-MS experiments. In addition, the isolated compounds 115 were evaluated for the inhibitory effects of the isolates on the production of tumor necrosis factor (TNF-) induced by lipopolysaccharide (LPS). Among the isolates, 1 and 2 significantly inhibited TNF- production in U937 cells in vitro, and the IC50 values were 0.59 and 0.76M, respectively. Compounds 35 displayed moderate inhibitory activities on LPS-induced TNF- production.