Validation of analytical procedures using HPLC‐ELSD to determine six sesquiterpene lactones in Eremanthus species

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, 10.0mg of powdered Eremanthus leaves was extracted with a 5mL MeOH/H2O (9:1v/v) solution containing scopoletin at 140 mu g/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 mu g/mL for all compounds with r(2)>0.9987. The limits of detection and quantitation ranged from 2.00 to 6.79 mu g/mL and from 6.00 to 20.40 mu g/mL, respectively. Assessing the robustness study, this method can be used in inter-laboratory studies. Using the HPLC-ELSD method, six sesquiterpene lactones including 4,5-dihydro-2,3-dihydroxy-15-deoxy-goyazensolide, goyazensolide, 4,5-dihydro-2,3-epoxy-15-deoxy-goyazensolide, centratherin, 4,5-dihydro-15-deoxy-goyazensolide and lychnofolide, were detected and quantified from distinct Eremanthus species, which were collected in different regions. Copyright (c) 2015 John Wiley & Sons, Ltd.