title: Five Pairs of Meroterpenoid Enantiomers from Rhododendron capitatum.
abstract: Chemical investigation on the aerial parts of Rhododendron capitatum resulted in the discovery of five enantiomeric pairs of new meroterpenoids, (+)-/(-)-rhodonoids C (1a and 1b), E (3a and 3b), F (4a and 4b), and (-)-/(+)-rhodonoids D (2a and 2b) and G (5a and 5b). These enantiomeric pairs existed as partial racemates in a plant and were obtained by chiral HPLC separation. Their structures with absolute configurations were assigned by spectroscopic data, single-crystal X-ray diffraction, and ECD analysis. Compounds 1a and 1b are the first pair of meromonoterpenes incorporating an unprecedented 6/6/6/5 ring system, and 1a showed antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro. Compounds 2a and 2b are the first examples of meromonoterpenes featuring a unique 6/6/5/5 ring system.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy and ‡State Key Laboratory of Medical Neurobiology, Fudan University , 826 Zhang Heng Road, Shanghai 201203, China.
authors.forename: Hai-Bing
authors.initials: HB
authors.lastname: Liao
authors.affiliation: Department of Pharmacognosy, School of Pharmacy and ‡State Key Laboratory of Medical Neurobiology, Fudan University , 826 Zhang Heng Road, Shanghai 201203, China.
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Huang
authors.affiliation: Department of Pharmacognosy, School of Pharmacy and ‡State Key Laboratory of Medical Neurobiology, Fudan University , 826 Zhang Heng Road, Shanghai 201203, China.
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Yu
authors.affiliation: Department of Pharmacognosy, School of Pharmacy and ‡State Key Laboratory of Medical Neurobiology, Fudan University , 826 Zhang Heng Road, Shanghai 201203, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Lei
authors.affiliation: Department of Pharmacognosy, School of Pharmacy and ‡State Key Laboratory of Medical Neurobiology, Fudan University , 826 Zhang Heng Road, Shanghai 201203, China.
authors.forename: Ai-Jun
authors.identifier: 0000-0002-4514-0846
authors.initials: AJ
authors.lastname: Hou
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D018259:Herpesvirus 1, Human / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D029793:Rhododendron / Q000737:chemistry*; D013237:Stereoisomerism; D013729:Terpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D013729:Terpenes