Embryo resorptions in mice induced by diterpene resin acids of Pinus ponderosa needles.

Ingestion of hexane extract of Pinus ponderosa needles causes reproductive failure in mice during the early stages of gestation. Virgin mice of the ICR strain were mated with males of proven fertility. The day the copulatory plug was observed was designated day 1 of gestation. Hexane extracts were administered daily via stomach tube at various concentrations and for various feeding periods. Implantation sites were stained by injections of pontamine sky blue dye on day 8 of gestation, fifteen minutes before sacrifice by cervical dislocation. Embryonic resorptions were observed in the uterus. The active components of the hexane extracts were isolated and identified as a mixture of diterpene resin acids. The diterpene resin acids are pimaric, isopimaric, sandaracopimaric, palustric/levopimaric, abietic, dehydroabietic and neoabietic acid.