中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | N-methyl-L-threonine methyl ester | 95599-23-8 | C6H13NO3 | 147.174 |
L-苏氨酸 | L-threonine | 72-19-5 | C4H9NO3 | 119.12 |
O-叔丁基-N-甲基-L-苏氨酸 | H-(Me)Thr(t-Bu)-OH | 42417-72-1 | C9H19NO3 | 189.255 |
We report the full structural determination of the depsipeptide petriellin A. The absolute configuration of the amino acid residues, N-methyl isoleucine and N-methyl threonine, have been determined by a combination of HPLC and TLC comparison of synthetic Marfey’s derivatives and Marfey’s derivatives of the natural product hydrolysate. The configuration of the chiral centres in these two N-methylated residues was found to be the same as those of the common unmethylated l-amino acids.
Reaction of N-benzyloxycarbonyl derivatives of aliphatic amino acids, and threonine, aspartic, and glutamic acids whose side-chains were protected with the t-butyl group, gave the corresponding N-methylamino acid derivatives in good yields. The methionine derivative could be obtained by using only one mol of methyl iodide. Derivatives of threonine, and aspartic and glutamic acids whose side-chains were not protected could not be methylated. Analysis of the crude products of methylation in three cases showed that they contained 0–1% of racemized material.