Secondary metabolites isolated from Penicillium expansum and their chemotaxonomic value

Chemical investigation of the aconite-derived fungus Penicillium expansum WTJP1 led to the isolation of thirteen compounds, including six indole alkaloids (1–6), three quinoline alkaloids (7–9), two cyclopiane diterpenoids (10–11), a chroman derivative (12), and a naphthalenone (13). Among them, three compounds (2–4) were identified for the first time from the genus Penicillium, and six compounds (6, 9–13) have not previously been isolated from the species P. expansum. The chemotaxonomic significance of these compounds was discussed. Some of the isolated compounds showed limited distribution within the Penicillium fungi, which could serve as chemotaxonomic markers to facilitate strain identification of P. expansum. This work enriches the secondary metabolites of P. expansum and provides valuable information for chemotaxonomic studies on the genus Penicillium.