Identification and biological activity of a novel natural prostaglandin, 5,6-dihydro-prostaglandin E3.

A novel natural E-prostaglandin was detected by HPLC among the endogenous prostaglandins extracted from ram seminal vesicles. The corresponding precursor - all-cis-eicosa-8, 11, 14, 17-tetraenoic acid was isolated from bovine liver lipids and the preparative biosynthesis with the microsomal fraction of ram seminal vesicles was performed. The isolated product was purified by HPLC and identified by GC-MS as 5,6-dihydro-PGE3. The results of in vitro tests demonstrate that 5,6-dihydro-PGE3 is 14 times less active uterine stimulant than PGE1, at the same time retaining 75% of the anti-aggregatory potency of PGE1. Thus, 5,6-dihydro-PGE3 meets the requirements of a selective antithrombotic agent more than PGE1.