Relying on a professional synthesis team, BOC Sciences has realized the asymmetric synthesis of unnatural amino acids by utilizing the high homologation of natural amino acids.
Amino acids are the most basic substances of living proteins, and are closely related to the life activities of organisms. According to the way of existence, amino acids can be divided into two categories: natural amino acids and unnatural amino acids. Natural amino acids are amino acids that exist in nature, with a wide variety and a wide range of uses. Unnatural amino acids are artificially synthesized amino acids. Some unnatural amino acids have completely different structures from natural amino acids, while others introduce or convert some groups on the side chains of natural amino acids to modify their properties. Optically active unnatural amino acids are important constituent units of peptides, peptoids, and many drug molecules, as well as key intermediates in the synthesis of chiral drugs, chiral pesticides, and chiral additives. The introduction of unnatural amino acids into the peptide chain can effectively change the configuration and conformation of the peptide, thereby improving the biological activity, which is of great significance to the development of peptide drugs. Therefore, the development of efficient synthetic methods for the asymmetric synthesis of unnatural amino acids has aroused widespread interest among synthetic chemists.
In the synthesis of chiral amino acids, it is the most direct way to use chiral source compounds to react. Natural amino acids exist widely in nature, and most of them are enantiomers with high optical purity, which are cheap and easy to obtain, and are good sources for chiral synthesis. We use natural L-amino acids as synthetic raw materials, and use traditional or innovative organic synthesis methods to efficiently synthesize more advanced and useful non-natural L- or R-amino acids.
We can use proline and leucine with large side chain steric hindrance as chiral sources to synthesize chiral unnatural α-amino acids, and we can also use serine as chiral sources to synthesize β, β-disubstituted, β- hydroxyl or higher alpha-amino acids.
The conformation of α-cyclic amino acids is restrictive, which is conducive to the formation and stability of the biologically active conformation of the peptide. We can use the intermolecular ring closure of natural amino acid derivatives and dihalogenated alkanes to obtain unnatural α-cyclic amino acids in high yield.
We used the Arndt–Eistert reaction to convert optically active α-amino acids into β-amino acids containing one more carbon atom, and obtained high-purity conformationally stable chiral β-amino acid homologues.
Since aspartic acid, asparagine and their derivatives have the structure of β-amino acid and β-amide, we can also synthesize novel β-amino acids from aspartic acid, asparagine and their derivatives.