Xicoreone, a new isocoumarin derivative isolated from the endophytic fungus Penicillium sclerotigenum of Aconitum carmichaelii.

The endophytic fungus Penicillium sclerotigenum WTJ14A was isolated from Aconitum carmichaelii Debeaux, a well-known traditional Chinese medicine commonly referred to as aconite. From the aconite-derived endophytic fungus P. sclerotigenum WTJ14A, 15 compounds were isolated, including a new 7-carbonyl isocoumarin derivative, xicoreone (1). The structure of 1 was determined through comprehensive spectroscopic and spectrometric analyses. Subsequent bioactivity evaluation revealed that 1 possesses moderate antimicrobial activity, with MIC values of 16 μg/mL against Bacillus subtilis and 8 μg/mL against Candida albicans.