Lasiodiplactone A, a novel lactone from the mangrove endophytic fungus Lasiodiplodia theobromae ZJ-HQ1

Lasiodiplactone A (1), an unprecedented lactone, was obtained from the mangrove endophytic fungus Lasiodiplodia theobromae ZJ-HQ1. The structure of 1 was established by analysis of NMR spectroscopic data and electronic circular dichroism (ECD) spectra. Lasiodiplactone A (1) was the first example of lactone that possesses a unique tetracyclic system (12/6/6/5) of RAL(12) (12-membered beta-resorcylic acid lactone) with a pyran ring and a furan ring. A possible biogenetic pathway for 1 was proposed. Compound 1 showed anti-inflammatory activity by inhibiting nitric oxide (NO) production in lipopolysaccharide activated in RAW264.7 cells with IC50 value of 23.5 mu M and exhibited potential a-glucosidase inhibitory activity with IC50 values of 29.4 mu M.