The occurrence of estrone and estriol in Trichostrongylus colubriformis (Nematoda).

Mammalian sex steroids and cholesterol were isolated from the lipid extract of the zooparasitic nematode Trichostrongylus colubriformis. In addition to the previously identified sex steroids progesterone and testosterone, estrone and estriol were detected and isolated from the mixture. The steroids were analyzed by thin-layer, gas-liquid and high-performance liquid chromatography, and their structures confirmed by proton nuclear magnetic resonance and mass spectroscopy.