Enzymatic cyclization of 1,N6-etheno-nicotinamide adenine dinucleotide

The ADP-ribosyl cyclase from Aplysia californica catalyzed the transformation of 1,N6-etheno-nicotinamide-adenine dinucleotide (2) into a novel cyclic nucleotide, 3. The newly formed glycosyl linkage is attached onto the N-1 position of the etheno-adenine ring corresponding to the N-7 position of the adenine nucleus. This alternative mode of cyclization gives more versatility in the biosynthesis of novel analogs of cADPR (1).