Polysubstituted Cyclopentene Benzamides and Dianthramide Alkaloids from Delphinium anthriscifolium Hance

Thirteen new benzamide alkaloids, delphiniumines A–M (1–13), together with one known analogue (14), were isolated from Delphinium anthriscifolium Hance. All of the structures were determined by spectroscopic and spectrometric analyses. Absolute configuration for 1 was established using experimental and calculated ECD data, as well as by X-ray crystallography analysis. Compound 1 possesses a previously undescribed polysubstituted cyclopentene carbon framework. Compound 2 was isolated as an artifact from 1 during the extraction process. Compound 7 is glycosylated with a β-D-glucose unit. Compound 13 bears a chlorine substituent. At a concentration of 10 μM, compounds 6, 8, and 10–12 suppressed LPS-induced NO production in RAW264.7 cells with inhibition rates ranging from 40.3% to 78.8%.