Secondary metabolites of Penicillium thomii GTX-122 and their chemotaxonomic investigation

One new natural product ( 1 ) and nineteen known ( 2-20 ) compounds were isolated from the fungus Penicillium thomii GTX-122, which was derived from Aconitum hemsleyanum . Their structures were elucidated through comprehensive spectroscopic analysis, and the compounds were evaluated for bioactivity. Compounds 1 , 2 and 19 serve as diagnostic markers distinguishing P. thomii from other Penicillium species , while compounds 4 , 6 , 7 and 13 represent chemotaxonomic markers of the genus Penicillium . Notably, compounds 1 , 2 , and 19 show restricted distribution within Penicillium species , suggesting their potential use as distinctive chemotaxonomic markers for the identification of P. thomii strains. Bioactivity evaluation revealed that compound 10 exhibited potent herbicidal activity against Portulaca oleracea and strong antifungal activity against Alternaria panax (MIC = 8.00 μg/mL). Compounds 13 and 19 displayed significant inhibitory activity against Candida albicans and Staphylococcus aureus , respectively (MIC = 8.00 μg/mL each). The chemotaxonomic relevance of these compounds was discussed. Thus, this study not only enriches the secondary metabolite repertoire of P. thomii but also offers valuable data for chemotaxonomic studies of the genus Penicillium .