L-Leucine → L-Tyrosine

Participants

Reaction Steps

The papain-catalyzed synthesis of leucine and HMB co-oligomers was performed. Synthesis of leucine oligomers and HMB-leucine co-oligomers was initiated with leucine ethyl ester and HMB ethyl ester as the substrates. The overall synthesis and purification approach was similar to the one used in the case of methionine and HMB-methionine. Reaction rates similar to those obtained with methionine and tyrosine were achieved. Approximate oligomer yield was 58%. The freeze-dried oligomer precipitates were solubilized in DMSO. The solution concentration was brought to approximately 2 μg/μl The solution was mixed with 1:1 acetonitrile:water mixture containing 0.1% acetic acid. The total fluid volume entering the ESI-MS was maintained at 0.2 mL min.−1 The positive mass spectrum of the leucine oligomers is shown in FIG. 33A.

Provenance & Evidence