Sirtris muscles up

As many companies do, Sirtris Pharmaceuticals Inc. has been using a less than perfect compound to provide proof of principle for its foundational idea: that activating sirtuins will be useful for treating aging-related diseases. Last week, the company announced the discovery of structurally distinct and significantly more potent compounds.

The sirtuin class of histone deacetylase enzymes has been linked to longevity in yeast and other lower eukaryotes. The genes encoding sirtuins are distinguished from other aging-related genes in that they are anti-aging genes; their activation extends life span...