Kinetically controlled syntheses catalyzed by proteases in reverse micelles and separation of precursor dipeptides of RGD

The precursor dipeptides of RGD (Arg-Gly-Asp), N-CBZ-Arg-Gly-NH2 and CBZ-Gl y-Asp-NH2 were synthesized in reverse micellar system and organic solvent u sing several proteases in different forms under kinetical control. The synt hesis reaction conditions for CBZ-Arg-Gly-NH2 and CBZ-Gly-Asp-NH2 catalyzed by chymotrypsin in AOT/isooctane reverse micelles were optimized by examin ing the effects of several factors including water content, temperature, pH , and reaction time on the dipeptide yields. The best yields for the synthe ses of CBZ-Arg-Gly-NH2 and CBZ-Gly-Asp-NH2 were 87.3% and 80.8%, respective ly. The dipeptide products were separated from the reverse micelles by usin g a silica gel column. (C) 1999 Elsevier Science Inc. All rights reserved.