Divicine is an unstable aglycon metabolite of the fava bean
pyrimidine beta-
glucoside vicine.
Divicine has long been thought to be a mediator of an acute hemolytic crisis, known as
favism, in susceptible individuals who ingest fava beans (Vicia faba). However, a recent report has questioned the chemical identity of the
divicine that was used in most of the studies on
divicine hemotoxicity. The present study was undertaken to examine the hemolytic potential of synthetic
divicine.
Divicine was synthesized and its identity and purity were confirmed by HPLC, mass spectrometry, and NMR spectroscopy. The stability and redox behavior of
divicine, under physiological conditions, were examined by HPLC and cyclic voltammetry. The data indicate that
divicine is readily oxidized under aerobic conditions; however, it was sufficiently stable at pH 7.4 to permit its experimental manipulation. When 51Cr-labeled rat erythrocytes were exposed in vitro to the parent
glucoside,
vicine (5 mM), and then readministered to rats, no decrease in erythrocyte survival was observed. In contrast, erythrocyte survival was dramatically reduced by in vitro exposure to
divicine (1.5 mM). These data demonstrate that
divicine is a direct-acting hemolytic agent and thus may be a mediator of the hemolytic crisis induced by fava bean ingestion.