Three new hasubanan-type alkaloids from the Stephania longa.

Three new hasubanan-type alkaloids, stephalonine Q (1), stephalonine R (2) and stephalonine S (3), together with four known alkaloids, isolonganone (4), eletefine (5), aurantiamide (6), N-cinnamoyltyramine (7), were isolated from the whole plant of Stephania longa. Their structures were identified by NMR, HR-ESI-MS, CD methods and x-ray crystallography, as well as by comparison with the literature data. All isolated compounds were evaluated for their antimicrobial activities against five bacteria in vitro. Compound 5 displayed inhibitory activity against only S. aureus, with an MIC value of 50 μg/mL. [ABSTRACT FROM AUTHOR]