5-Chloro-1-[bis(dimethylamino)methylene]-1H-benzotriazolium 3-oxide hexafluorophosphate CAS NO.330645-87-9

A critical factor in the successful amide bond formation step during peptide synthesis is the selection of an appropriate activating or condensing rea…

A critical factor in the successful amide bond formation step during peptide synthesis is the selection of an appropriate activating or condensing reagent. We are pleased to report that a new coupling reagent with improved properties over traditional condensing agents is now available from Peptides International. This new reagent was developed by Luxembourg Industries in Israel (1) and performs as good or better than traditional reagents such as HBTU and PyBOP?. Reports indicate that HCTU shows improved peptide purity in the trial synthesis of Lys10-Phe3-Amide [K10-F3-Amide]. The synthesis utilized Rink Amide resin with standard Fmoc coupling protocols using 4 fold excess of amino acids and 8 fold excess of NMM in DMF. The crude peptide obtained after cleavage with Reagent K [TFA: H2O: thioanisole: ethanedithiol; phenol 85:5:5:2.5:2.5] yielded higher purity with HCTU (97%) when compared to PyBOP (85%). Also stability studies have shown that HCTU remained colorless throughout typical and long peptide synthesis times therefore the reagent is considered to be quite stable. In addition HCTU reagent is reported to be non-poisonous, non-corrosive and is not a dermal irritant.