title: Conformational analysis of an anti-androgenic, (E,E)-8-hydroxygermacrene B, using NOESY and dynamic NMR spectroscopy.
abstract: (E,E)-8-Hydroxygermacrene B was prepared by ketone reduction of germacrone, a naturally occurring compound from Curcuma aeruginosa Roxb. with NaBH4 at low temperature (4 °C). This compound showed remarkable in vitro anti-androgenic activity (IC50 0.15±0.022 mM) applicable to male baldness treatments. NMR analysis at -50 °C indicated that there were four conformational isomers of (E,E)-8-hydroxygermacrene B in a ratio of 48:40:8:4. The major conformers were assigned by (1)H NMR and 2D-NOESY NMR spectroscopy as having methyl groups at C-10 and C-4 in up-down (UD) orientations (48% predominance) and UU (40%). (1)H NMR spectra implied another two minor conformers with these methyls having DU (8%) and DD (4%) orientations.
authors.affiliation: Bioscreening Unit, Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences and Center of Excellence for Innovation in Chemistry, Naresuan University, Phitsanulok 65000, Thailand.
authors.forename: Jukkarin
authors.initials: J
authors.lastname: Srivilai
authors.affiliation: Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences and Center of Excellence for Innovation in Chemistry, Naresuan University, Phitsanulok 65000, Thailand.
authors.forename: Nantaka
authors.initials: N
authors.lastname: Khorana
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences and Center of Excellence for Innovation in Chemistry, Naresuan University, Phitsanulok 65000, Thailand.
authors.forename: Neti
authors.initials: N
authors.lastname: Waranuch
authors.affiliation: Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
authors.forename: Nungruthai
authors.initials: N
authors.lastname: Suphrom
authors.affiliation: Bioscreening Unit, Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences and Center of Excellence for Innovation in Chemistry, Naresuan University, Phitsanulok 65000, Thailand. Electronic address: k_ingkaninan@yahoo.com.
authors.forename: Kornkanok
authors.initials: K
authors.lastname: Ingkaninan
mesh_terms: D000726:Androgen Antagonists / Q000737:chemistry*; D030024:Curcuma / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D008968:Molecular Conformation; D012015:Reference Standards; D027343:Rhizome / Q000737:chemistry; D045788:Sesquiterpenes, Germacrane / Q000737:chemistry*
chemical_list: C000595766:8-hydroxygermacrene B; D000726:Androgen Antagonists; D045788:Sesquiterpenes, Germacrane
keywords: (E,E)-8-Hydroxygermacrene B; Anti-androgen; Conformational analysis; Dynamic NMR spectroscopy; Sesquiterpenoids