4-Pyridoxolactone

4-Pyridoxolactone (β-Pyracin) is a pivotal substrate in the vitamin B6 degradation pathway I, primarily involved in the vitamin B6 metabolism mediated by soil microorganisms. It serves as the specific substrate for 4-pyridoxolactonase, undergoing zinc-dependent lactone ring hydrolysis catalyzed by this enzyme to produce 4-pyridoxic acid.