A new diterpenoid alkaloid with antimicrobial activity from Aconitum brachypodum Diels.

A new C20‐denudatine‐type diterpenoid alkaloid (DA) 11S‐aconicarnine D (1) and fifteen known DAs were isolated from the lateral roots of Aconitum brachypodum Diels. Their structures were identified on the basis of extensive spectroscopic analyses, NMR calculations and DP4+ analysis. The antimicrobial activities of compound 1 was evaluated, compound 1 exhibited potent antimicrobial activity against Alternaria panax and Fusarium solani with MICs of 2.00 and 16.00 μg/mL (Nystatin, 1.00 μg/mL), respectively.