Cloying contraceptive

A sugar-based pill has been lauded as the most promising candidate for a male contraceptive. In fertilisation, the sperm penetrates a sugary coating around the egg with the help of an enzyme called N-acetyl-beta- D-hexoaminidase (HEX). After several computer-aided drug design programmes, Joseph Hall, a biochemist from North Carolina University, US, identified 15 compounds that tie up HEX so that it cannot bind the sperm to the egg. Out of the 15, sugar was the best compound as it cut down HEX activity to 95 per cent. (New Scientist, March 9,1996, Vol 149, No 2020).