We report the preparation and antiparasitic activity in vitro and in vivo of a series of isoflavone derivatives related to genistein. These analogues retain the 5, 7- dihydroxyisoflavone core of genistein: direct genistein analogues (2-H isoflavones), 2- carboethoxy isoflavones, and the precursor deoxybenzoins were all evaluated. Excellent in vitro activity against Cryptosporidium parvum was observed for both classes of isoflavones ...