Selectivity in the extraction of 2-quinolone alkaloids with supercritical CO2

Abstract

This work describes the conditions for selective extraction of the alkaloids in Andreadoxa flava (Kallunki). The experiments were performed in a pilot plant SFE 500, in the following conditions. Extractor pressures 206.8 × 105, 241.3 × 105, 275.8 × 105 and 310.3 × 105 Pascal and pressures of 137.9 × 105, 69.0 × 10 5 and 55.2 × 105 Pascal for separators 6, 7 and 8 respectively. The temperatures were 40°C in the extractor and 20°C in the separators. The samples, extracted from A. flava leaves, were analysed by 1H NMR and GC/FID as well as by comparison with standards. This procedure allowed the identification for the first time of the 2-quinolone alkaloid 8-methoxy-N-methyl-flindersine in A. flava leaves of the. In addition, zanthophylline, 5-methoxyalmene and 8-methoxyflindersine were identified as the main alkaloids in leaves. Under the best conditions for zanthophylline extraction it was possible to obtain a purity of 79.4% while with other phytochemical technique 55.5% was obtained.