title: Natural nitric oxide (NO) inhibitors from the rhizomes of Curcuma phaeocaulis.
abstract: An exploration we carried out for isolating nitric oxide (NO) inhibitors from the rhizomes of Curcuma phaeocaulis afforded one new salvialane-type sesquiterpene, phasalvione (1), two novel nor-sesquiterpenes, phaeocaudione (2) and phaeocauone (3), one aromatic acid 3-methyl-4-(3-oxo-butyl)-benzoic acid (4), two γ-elemene-type sesquiterpenes, 8β(H)-elema-1,3,7(11)-trien-8,12-lactam (5) and 8β-methoxy-isogermafurenolide (6), one eudesmane-type sesquiterpene, phaeusmane I (7), and one cyclic diarylheptanoid, phaeoheptanoxide (8). Their structures were established based on extensive spectroscopic analysis. The absolute configurations of compounds 1 and 2 were assigned using the circular dichroism data of the [Rh2(OCOCF3)4] complex, and the absolute configuration of 1 was further established by single crystal X-ray crystallography. It is noteworthy that compounds 5–7 were racemates analyzed by chiral HPLC. Furthermore, the inhibitory effects of the isolated compounds on nitric oxide production in LPS-activated macrophages were evaluated. Compounds 1, 3 and 4 showed strong inhibitory activities on NO production with IC50 values of 7.46 ± 0.69, 2.35 ± 0.17 and 3.49 ± 0.31 μM, respectively. A plausible biosynthetic pathway for 1–4 in C. phaeocaulis was also discussed.
authors.affiliation: School of Chinese Materia Medica and Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China. fengqiu20070118@163.com.
authors.forename: Jiang-Hao
authors.initials: JH
authors.lastname: Ma
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
authors.forename: Su-Yu
authors.initials: SY
authors.lastname: Gao
authors.forename: Li-Qin
authors.initials: LQ
authors.lastname: Ding
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Chen
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
mesh_terms: D000818:Animals; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D018360:Crystallography, X-Ray; D030024:Curcuma / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008968:Molecular Conformation; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D066244:Proton Magnetic Resonance Spectroscopy; D000067996:RAW 264.7 Cells; D027343:Rhizome / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D010936:Plant Extracts; D009569:Nitric Oxide