TBTU

IC50: Not available.

The utilization of new peptide coupling reagents in organic synthesis has greatly flourished the development of peptide synthesis. TBTU, 2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronoium hexafluorphosphate, serves as a typical peptide coupling reagent which has a relatively lower racemization. In normal condition, coupling reactions mediated by TETU take only six minutes to complete when HOBt is added. Moreover, racemization in this reaction could be reduced to insignificant levels. Due to these features, TBTU is regarded as one of the key reagents of choice in both manufactory and lab. [1]

In vitro: It was reported that during synthesis of the macrocyclic peptide cyclotheonamide B, TBTU played an important role in coupling steps. Studies showed that TBTU had been successfully used in several coupling reactions, for instance, this reagent was suitable for couplings involving proline nitrogen, and therefore served as a crucial reagent for the macrolactamization. Although TBTU normally proceeded with little racemization, to suppress the racemization completely, HOBt was also required. Thus, in a typical reaction system, TBTU was added into 0.5 mM solution of CH2Cl2, followed by addition of HOBt and pyridine. Finally, cyclopentapeptide was obtained with a yield of 61%. [1]

In vivo: So far, no in vivo data has been reported.

Clinical trial: So far, no clinical trial has been conducted.

Reference:
[1]Bastiaans HM, van der Baan JL and Ottenheijm HC.  Flexible and convergent total synthesis of cyclotheonamide B. J. Org. Chem. 1997; 62: 3880-9.

Occupational rhinitis and bronchial asthma due to TBTU and HBTU sensitization.[Pubmed:12968399]

J Investig Allergol Clin Immunol. 2003;13(2):133-4.

Exposure to an increasing amount of products in the work environment is leading to new cases of occupational asthma among workers. We report the case of a worker at a pharmaceutical plant who developed occupational rhinitis and bronchial asthma due to HBTU: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate and TBTU: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate sensitization, two chemical products widely used in peptide synthesis and coupling. Skin tests (prick test) with HBTU and TBTU solutions in PBS were positive at a concentration of 1 mg/ml. Skin tests with the same solutions in 10 atopic controls yielded a negative result. Nasal challenge tests with these products were positive with HBTU at a concentration of 0.01 mg/ml and TBTU at a concentration of 1 mg/ml. In both cases PNIF (peak nasal inspiratory flow) decreased by more than 60% and severe sneezing and rhinorrhea were induced. Nasal challenge tests performed on 10 atopic controls with TBTU and HBTU at a concentration of 1 mg/ml were negative. We conclude that the patient presents occupational rhinitis and bronchial asthma due to TBTU and HBTU; the operational mechanism is probably immunological IgE-mediated given the positive prick tests and nasal challenge with these products.