title: Quantitative determination of 20-hydroxyecdysone in methanolic extract of twigs from Vitex polygama Cham.
abstract: 20-Hydroxyecdysone (20E) is effective in stimulating protein synthesis, therefore, it has been largely used as anabolic agent in several commercial formulas. Phytochemical study of methanolic extract of twigs from Vitex polygama, used in traditional Brazilian medicine as emenagogue, yielded a large quantity of 20E. This finding led us to developing and validating a simple and reliable method to determine 20E in the surveyed extract. Chromatographic separation of 20E was achieved on a phenyl-hexyl-based column using reversed elution mode. Extract was cleaned-up by solid phase extraction employing C(18) cartridge, and an absolute recovery of 97% was acquired. External standard and standard addition calibration graphs were obtained and good linearity was accomplished (r>0.999 for both curves). The limit of quantification and detection were determined. The results for accuracy fell within the -5 to +7% range.
authors.affiliation: Departamento de Química, Universidade Federal de São Carlos, CP 676, 13560-970 São Carlos, SP, Brazil. marejor@uol.com.br
authors.forename: Margareth Borges Coutinho
authors.initials: MB
authors.lastname: Gallo
authors.forename: Flávio Luis
authors.initials: FL
authors.lastname: Beltrame
authors.forename: Paulo Cezar
authors.initials: PC
authors.lastname: Vieira
authors.forename: Quezia Bezerra
authors.initials: QB
authors.lastname: Cass
authors.forename: João Batista
authors.initials: JB
authors.lastname: Fernandes
authors.forename: Maria Fátima das Graças Fernandes
authors.initials: MF
authors.lastname: da Silva
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004441:Ecdysterone / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet; D020950:Vitex / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D004441:Ecdysterone; D000432:Methanol