BOC Sciences specially develops methylation-modified amino acid technology to help researchers in the research of amino acids, peptides, and proteins.
Amino acids are the basic building blocks of proteins and peptides, and one of the basic building blocks of life. The 20 natural amino acids found in nature are all in the L-configuration, and their sources are limited. With the increasing application and continuous improvement of production technology, mass production of optically pure amino acids has been realized.
Optically pure N-methyl-α-amino acid is an important part of many natural products with physiological activity, and plays an important role in obtaining information on the backbone structure and physiological activity of peptide molecules. N-methylation can reduce the number of isomers formed by limiting the flexibility of the peptide molecular backbone. This structural modification affects the interaction of the peptide with the receptor and also significantly enhances its biological activity compared to non-N-methylated peptides. At the same time, peptides and their analogs containing N-methylated amino acids are more resistant to degradation by proteases. N-methylated amino acids are also commonly used as tools for conformational studies of amino acids, peptides, and their derivatives.
Optically pure β-methylated amino acids exist in the structure of some active natural products and in the pathway of primary metabolism, and play a vital role in the important activities of natural products.
Methylated amino acids can serve as multifunctional synthetic building blocks for the construction of active peptides and natural products. Therefore, the synthesis of methylated amino acids is very important. We developed efficient and suitable amino acid methylation structural modification strategies to synthesize different types of α- or β-methylated amino acids and their derivatives.
(1) Iodomethane method
Under alkaline conditions, use methyl iodide as a methylating reagent to carry out the N-methylation reaction of amino acids. Alkalis used include silver oxide (Ag2O), sodium hydride (NaH), potassium carbonate (K2CO3). The silver oxide-methyl iodide method is only suitable for the N-methylation of amino acids with one amino group and one carboxyl group, and it is only used in small-scale laboratories. This method affords the corresponding methyl ester. Subsequent saponification demethylation is required. The sodium hydride-methyl iodide method is suitable for selective N-methylation of Z or Boc protected amino acids. Subsequent separation and purification by column chromatography is required. The potassium carbonate-iodomethane method is suitable for the N-methylation of Bts-protected amino acids.
(2) Dimethyl sulfate method
N-methylation of unprotected or Boc-protected amino acids was performed using dimethyl sulfate.
A carbonyl compound (aldehyde or ketone) is used to react with an amine to generate an imine intermediate, and then undergo a reductive amination reaction to finally obtain an N-methylated amino acid.
Reaction of unprotected amino acids with aldehydes and reducing agents such as triethylsilane yields N-methylated amino acids. An oxazolidinone intermediate is formed during the reaction. This method is not suitable for amino acids with basic side chains.
Metabolic engineering, synthetic biology and enzyme engineering are used to carry out β-methylation biosynthesis of amino acids.