Chromatographic fractionation of anti-sickling agents in Fagara xanthoxyloides.

Fractionation of an aqueous extract of root bark from Fagara xanthoxyloides by column chromatography on DEAE-A-50, utilizing an elution gradient of pH 7.5-5.0, yielded five fractions. All fractions reversed metabisulfite-induced sickling in vitro of erythrocytes homozygous for hemoglobin S. Only the fraction containing the least anti-sickling activity also contained alkaloids. Thin-layer chromatography on silica gel and aluminum oxide revealed further molecular heterogeneity within two of the fractions.