LC-ESI-MS determination of quassinoids isobrucein B and neosergeolide in Picrolemma sprucei stem infusions

Abstract

Infusions of the stems of Picrolemma sprucei (pseudonym: P. pseudocoffea) are used in the Amazon regions of Peru, Brazil and French Guiana as antimalarials among other uses. They contain the bitter quassinoids isobrucein B (1) and neosergeolide (2) that have important antimalarial and toxic properties among others. In this study, an LC-(+)-ESI-MS/MS method was developed and applied to the determination of 1 and 2 in a common remedy prepared by infusing 1 g of dry, powdered stems of P. sprucei in 1 L of boiling water. Isolated 1 and 2 were used in calibration ranges of 0.25 to 5 μg mL-1 and 0.5 to 10 μg mL-1, respectively, with the internal standard phloroglucinol at 4.0 μg mL-1. Good linearity, precision and accuracy were observed for both compounds. The concentrations of 1 and 2 in the stem infusions were found to be 60.1 and 774 μg L-1, respectively. ©2009 Sociedade Brasileira de Química.