Secondary Metabolites with Anti-Inflammatory Activities from an Actinobacteria   Herbidospora daliensis .

Bioassay-guided fractionation of extracts derived from solid cultures of a Herbidospora   daliensis originating from Taiwan led to the isolation of five new compounds, for which we propose the name herbidosporadalins A-E ( 1 - 5 ), one isolated for the first time, herbidosporadalin F ( 6 ), together with two known compounds ( 7 & 8 ). Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR experiments with those of known analogues, and on the basis of HR-EI-MS mass spectrometry, their anti-inflammatory activities were also evaluated. Of these isolates, herbidosporadalin A ( 1 ), B ( 2 ), F ( 6 ) and G ( 8 ) showed NO inhibitory activity, with IC 50 values of 11.8 ± 0.9, 7.1 ± 2.9, 17.8 ± 1.7, and 13.3 ± 6.5 μM, stronger than the positive control quercetin (IC 50 = 36.8 ± 1.3 μM). To the best of our knowledge, this is the first report on 3,4-seco-friedelane metabolites ( 5 , 6 & 8 ) from the genus Herbidospora .