title: Validation of analytical procedures using HPLC-ELSD to determine six sesquiterpene lactones in Eremanthus species.
abstract: Eremanthus species display sesquiterpene lactones with therapeutic potential. We are proposing the development of a new analytical method that has been completely validated to qualify Eremanthus species and its main lactones in raw material using HPLC-ELSD. For the sample preparation, 10.0 mg of powdered Eremanthus leaves was extracted with a 5 mL MeOH/H2 O (9:1 v/v) solution containing scopoletin at 140 µg/mL as the internal standard. For the separation of eight compounds, six of which were lactones, one internal (IS) and one secondary standard were performed utilizing monolithic columns with a nonlinear gradient. The selectivity, stability, precision and matrix effects parameters showed values of RSD of <10%. The six lactones and scopoletin (IS) were recovered with a proportion between 74 and 90% with accuracy represented by error at -25.41%. The linear dynamic range was obtained between 10.0 and 310.0 µg/mL for all compounds with r(2)  > 0.9987. The limits of detection and quantitation ranged from 2.00 to 6.79 µg/mL and from 6.00 to 20.40 µg/mL, respectively. Assessing the robustness study, this method can be used in inter-laboratory studies. Using the HPLC-ELSD method, six sesquiterpene lactones including 4β,5-dihydro-2',3'-dihydroxy-15-deoxy-goyazensolide, goyazensolide, 4β,5-dihydro-2',3'-epoxy-15-deoxy-goyazensolide, centratherin, 4β,5-dihydro-15-deoxy-goyazensolide and lychnofolide, were detected and quantified from distinct Eremanthus species, which were collected in different regions.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais e Sintéticos, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: João Paulo B
authors.initials: JP
authors.lastname: Sousa
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais e Sintéticos, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Elídia F
authors.initials: EF
authors.lastname: Nogueira
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais e Sintéticos, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Leandro S
authors.initials: LS
authors.lastname: Ferreira
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais e Sintéticos, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Norberto P
authors.initials: NP
authors.lastname: Lopes
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais e Sintéticos, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: João Luis C
authors.initials: JL
authors.lastname: Lopes
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007783:Lactones / Q000032:analysis*; D057230:Limit of Detection; D016014:Linear Models; D010936:Plant Extracts / Q000737:chemistry*; D015203:Reproducibility of Results; D012717:Sesquiterpenes / Q000032:analysis*
chemical_list: D007783:Lactones; D010936:Plant Extracts; D012717:Sesquiterpenes
keywords: Eremanthus; HPLC-ELSD; sesquiterpene lactones; standardization; validation