title: Anti-complement sesquiterpenes from Viola yedoensis.
abstract: Two new germacrane sesquiterpenes, yedoensins A (1) and B (2), together with 8 known ones (3-10) were isolated from the herb of Viola yedoensis. The structures of the new compounds were established by extensive spectroscopic means including 1D ((1)H and (13)C) and 2D NMR experiments (HSQC, HMBC, and NOESY) as well as HR-ESI-MS analysis. The absolute configurations of the known sesquiterpenes versicolactone B (3) and madolin W (6) were determined by a modified Mosher's method for the first time. The sesquiterpenes 1-3, and 5-9 exhibited anti-complement activity against the classical pathway (CP) and the alternative pathway (AP) with the CH50 and AP50 values ranging from 0.14 to 0.37mg/mL and 0.32 to 0.54mg/mL, respectively. Preliminary mechanism study using complement-depleted sera showed that yedoensin A (1) and versicolactone B (3) acted on C1q, C3 and C9, while madolin W (6), aristoyunnolin E (7) and madolin Y (9) interacted with C1q, C3, C5 and C9 components in the complement activation cascade.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Du
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, China. Electronic address: chengzhh@fudan.edu.cn.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, China. Electronic address: dfchen@shmu.edu.cn.
authors.forename: Daofeng
authors.initials: D
authors.lastname: Chen
mesh_terms: D000328:Adult; D000818:Animals; D003167:Complement Activation / Q000187:drug effects*; D051056:Complement Inactivating Agents / Q000737:chemistry* / Q000302:isolation & purification; D006168:Guinea Pigs; D006801:Humans; D015394:Molecular Structure; D011817:Rabbits; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification; D032413:Viola / Q000737:chemistry*
chemical_list: D051056:Complement Inactivating Agents; D012717:Sesquiterpenes; C050784:versicolactone B
keywords: Anti-complement; Mosher's method; Sesquiterpenes; Viola yedoensis