Use of the cyclopropylcarbinyl test to detect a radical-like intermediate in penicillin biosynthesis
Abstract
Cyclisation of the cyclopropyl-containing substrates (6) and (7) by the enzyme isopenicillin N synthetase (IPNS) gave the bicyclic β-lactams (9) and (10), respectively; these products support the hypothesis that a carbon-centred free radical or equivalent iron–carbon bonded intermediate is involved in the carbon–sulphur bond formation.