α-Chymotrypsin-catalyzed (3 + 7) segment synthesis of the luteinizing hormone releasing hormone

Abstract The formation of the luteinizing hormone releasing hormone (LHRH) Glp-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH 2 ( 1 , from the segments Glp-His-Trp-OEt ( 2 ) and H-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH 2 ( 3 ) is catalyzed by α-chymotrypsin. A yield of 71% was achieved when the reaction was performed at -15°C in a solution which contained 38 vol % DMSO and was saturated with KCI.