Metabolism of three active analogues of the male antifertility agent alpha-chlorohydrin in the rat.

1. Two ketal derivatives of alpha-chlorohydrin, which possess male antifertility activity, have been synthesized labelled with 36Cl. Both are metabolized by the rat to beta-chloroacetic acid. 2. Neither derivative inhibited the glycolytic enzymes glyceraldehyde 3-phosphate dehydrogenase and triosephosphate isomerase. 3. The epoxide glycidol is metabolized to beta-chlorolactic acid, presumably by first being converted to alpha-chlorohydrin. 4. It is proposed that the male antifertility actions of these three analogues is due to their biotransformation to alpha-chlorohydrin, which is then metabolized within mature sperm to a compound which is an inhibitor of glycolysis.