The Central Cleavage of ?,?-Carotene – A Supramolecular Mimic of Enzymatic Catalysis

Abstract

The enzyme ?,?-carotene 15,15?-dioxygenase which cleaves ?,?-carotene to retinal (provitamin A) has been identified for the first time in chicken intestinal mucosa and subsequently sequenced and expressed in two different cell lines. To mimic this unusual metabolism a supramolecular receptor has been synthesized which binds ?,?-carotene with Ka = 8.3 × 106 M?1 and it was shown that the corresponding oxo-ruthenium complex catalyzes the selective cleavage of carotenoids.