title: (±)-Homocrepidine A, a Pair of Anti-inflammatory Enantiomeric Octahydroindolizine Alkaloid Dimers from Dendrobium crepidatum.
abstract: A pair of racemic indolizidine enantiomers, (±)-homocrepidine A (1), and a piperidine derivative, homocrepidine B (2), were isolated from Dendrobium crepidatum along with the known alkaloid crepidine (3). The racemic mixture of 1 was separated into a pair of enantiomers, (+)-1 and (-)-1, by HPLC using a chiral chromatographic substrate, which represents the first successful example of resolving indolizidine racemic mixtures. The absolute configurations of (+)-1 and (-)-1 were assigned from single-crystal X-ray diffraction data. The evaluation of anti-inflammatory activity with LPS-induced RAW 264.7 macrophages revealed that (+)-1 strongly inhibited the production of nitric oxide (IC50, 3.6 μM) and significantly decreased the expression of inducible nitric oxide synthase, while (-)-1 and (±)-1 only had moderate inhibitory effects (IC50, 22.8 and 14.7 μM). Compound 2 showed moderate anti-inflammatory activity (IC50, 27.6 μM).
authors.affiliation: Research Department of Pharmacognosy, China Pharmacaeutical University , Nanjing, 211198, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Research Department of Pharmacognosy, China Pharmacaeutical University , Nanjing, 211198, People's Republic of China.
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Research Department of Pharmacognosy, China Pharmacaeutical University , Nanjing, 211198, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Research Department of Pharmacognosy, China Pharmacaeutical University , Nanjing, 211198, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of National Medicine, Yunnan University of Traditional Chinese Medicine , Kunming, 650000, People's Republic of China.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Feng
authors.affiliation: Research Department of Pharmacognosy, China Pharmacaeutical University , Nanjing, 211198, People's Republic of China.
authors.forename: Mian
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Chengdu Biopurity Phytochemicals Ltd. , Chengdu, 611131, People's Republic of China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Xie
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D031667:Dendrobium / Q000737:chemistry*; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D054836:Indolizidines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008968:Molecular Conformation; D015394:Molecular Structure; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D010880:Piperidines; D018547:Plant Stems / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004365:Drugs, Chinese Herbal; D054836:Indolizidines; D008070:Lipopolysaccharides; D010880:Piperidines; C000608591:homocrepidine A; C000608592:homocrepidine B; D009569:Nitric Oxide