title: Two new eremophilanolides from Xanthium sibiricum.
abstract: Two new eremophilanolides, sibiriolides A (1) and B (2), were isolated from the aerial parts of Xanthium sibiricum. The structures of the new compounds were identified as 4S,5R,7R,8R, 11R-2-oxo-1(10)-eremophilen-12,8-olide (1) and 4S,5R,7R,8R,11S-2-oxo-1(10)-eremophilen-12,8-olide (2) by HREIMS and NMR spectroscopic techniques in combination with X-ray crystallographic analysis and CD measurements.
authors.affiliation: Institute of Traditional Chinese Medicine & Natural Products, Jinan University, Guangzhou 510632, PR China.
authors.forename: Xiao-Qi
authors.initials: XQ
authors.lastname: Zhang
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Ye
authors.forename: Ren-Wang
authors.initials: RW
authors.lastname: Jiang
authors.forename: Zhi-Qi
authors.initials: ZQ
authors.lastname: Yin
authors.forename: Shou-Xun
authors.initials: SX
authors.lastname: Zhao
authors.forename: Thomas C W
authors.initials: TC
authors.lastname: Mak
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Yao
mesh_terms: D002681:China; D018360:Crystallography, X-Ray; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification*; D013058:Mass Spectrometry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009904:Optical Rotation; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D031210:Xanthium / Q000737:chemistry*
chemical_list: D007783:Lactones; D010936:Plant Extracts; D012717:Sesquiterpenes