(+/-)-3,4-Dihydroxy-8,9-methylenedioxypterocarpan and derivatives: cytotoxic effect on human leukemia cell lines.

Naturally occurring pterocarpans 1a,b, pterocarpan 1c, isoflavane 2 and ortho-quinone 3 were synthesized in the racemic form and their cytotoxic effect was evaluated on the human leukemia cell lines K562 (resistant to oxidative stress), Lucena-1 (MDR phenotype) and HL-60. Ortho-quinone 3 (IC(50)=1.5 microM, 1.