Novel immonium type peptide coupling reagent: 5-(1H-benzotriazol-1-yloxy)-3,4-dihydro-l-methyl 2H-pyrrolium hexachloroantimonate (BDMP )

A novel immonium type coupling reagent, 5-(1H-benzotria-zol-1-yloxy )-3,4-dihydro-1-methyl 2H-pyrrolium hexachlo-roantimonate (BDMP) has been designed, synthesized and u-tilized to synthesize oligopeptides and biologically active pep-tide both in solution and solid phase with satisfactory yield, low racemization and fast reaction rate. The estimation of racemization and the influence of several reaction parameters were studied by HPLC method using the model reaction: Z-Gly-Phe-OH + Val-OMe·HCl→Z-Gly-D/L-Phe-Val-OMe. It was shown that the reactivity of BDMP was much higher and the racemization was much lower than those of HOBt-based 'onium' reagents, even though its analogues BOMI. To further verified the effectiveness of BDMP, Leu-enkephalin was synthesized both in solution and solid phase using BDMP as coupling reagent. The proposed mechanism was also speculated.

Application of an Organophosphorus Compound-DEPBT as Coupling Reagent in Liquid Phase Peptide Synthesis

DEPBT, a novel coupling reagent containing phosphorus, was used in synthesis of pentapeptide Boc-Ile-Asn-Met-Trp(For)-Gly.OMe by solution method.