title: Minor constituents from the tubers of Gymnadenia conopsea.
abstract: Four new minor constituents including two cyclodipeptides (1 and 2) and two cyclopentene derivatives (3 and 4), together with four known cyclodipeptides, have been isolated from an ethanolic extract of the tubers of Gymnadenia conopsea. Their structures including absolute configurations were determined by spectroscopic data interpretation combined with chemical methods. Among them, compound 1 contains an abnormal S-(4''-hydroxybenzyl)cysteine residue, 3 and 4 possess [(4-methylcyclopentyl)methyl]benzene and (4-hydroxymethylcyclopentyl)benzene carbon skeletons, respectively, both of which are first found from the natural source.
authors.affiliation: Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Jia-Chen
authors.initials: JC
authors.lastname: Zi
authors.forename: Sheng
authors.initials: S
authors.lastname: Lin
authors.forename: Cheng-Gen
authors.initials: CG
authors.lastname: Zhu
authors.forename: Yong-Chun
authors.initials: YC
authors.lastname: Yang
authors.forename: Jian-Gong
authors.initials: JG
authors.lastname: Shi
mesh_terms: D003517:Cyclopentanes / Q000737:chemistry / Q000302:isolation & purification*; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D029595:Orchidaceae / Q000737:chemistry; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*; D035281:Plant Tubers / Q000737:chemistry
chemical_list: D003517:Cyclopentanes; D004365:Drugs, Chinese Herbal; D010456:Peptides, Cyclic