(3) The dipeptide Boc-His (Trt) -Aib-OH is adopted, so that racemization of amino acid can be better avoided compared with dipeptide protected by Boc on Fmoc or His, the stability is better, the reaction monitoring is facilitated, and the condition that other groups of a side chain need to be protected in advance is avoided
Then, in February 2025, FDA removed semaglutide from its shortage list, giving some pharmacies, called 503A pharmacies, until April 22, 2025, to stop dispensing exact copies of semaglutide, and others, so-called 503B pharmacies, until May 22, 2025
27:45 - Dustin Introduction The crew welcomes Dustin to the conversation, who has a background in exercise physiology and strength conditioning
1) for 5-6 cycles
Patent CN113801233A discloses coupling Boc-modified semaglutide propeptide with Fmoc compound (such as Fmoc-His-Aib or Fmoc-His-Aib-Glu), removing Boc-linked tertiary butyl protected side chain, removing Fmoc, and removing tertiary butyl to obtain semaglutide, which has many steps, and requires frequent deprotection (3 times of deprotection) to cause racemization of some amino acids, especially racemization of terminal His and introduction of other impurities with incomplete Fmoc removal, thereby causing great difficulty in subsequent purification
