Spirobacillenes A and B, unusual spiro-cyclopentenones from Lysinibacillus fusiformis KMC003.

Two previously unreported spiro-cyclopentenones, spirobacillenes A (1) and B (2), were isolated from the 24 h broth culture of Lysinibacillus fusiformis KMC003 derived from acidic coal-mine drainage. The structures of 1 and 2 were elucidated by analyses of the NMR, HRFABMS, single-crystal X-ray diffraction crystallography, and circular dichroism (CD) spectral data. Compound 1 possessed moderate inhibitory activity against the production of nitric oxide (NO) and reactive oxygen species (ROS).