A novel process for the preparation of L-threo-dihydroxyphenylserine (Droxidopa) is described. It comprises of enantioselective hydrolysis of racemic (DL)-threo-N-acetyl-3-(3,4-methylenedioxyphenyl)-serine using commercially available L-amino acylase from Aspergillus sp. (EC 3.5.1.14) in the presence of cobalt ions, to obtain (L)-threo-3-(3,4-methylenedioxyphenyl)-serine followed by dealkylation to obtain Droxidopa. Protecting the amino group of (L)-threo-3-(3,4-methylenedioxyphenyl)-serine using either benzyloxycarbonyl or phthaloyl group before dealkylation followed by deprotection of the amino group results in obtaining Droxidopa in high yields and purity.

The present invention relates to methods for identifying, assessing, preventing, and treating metabolic disorders and modulating metabolic processes using PM20D1 and N-lipidated amino acids.

A method efficiently produces a compound containing an N-acyl-amino group by an enzymatic method. Specifically, a method of producing a compound containing an N-acyl-amino group includes producing the compound containing an N-acyl-amino group by reacting a compound containing an amino group with a compound containing a carboxyl group in the presence of an enzyme having an ability to bond a carboxyl group and an amino group in an ATP dependent manner to form an amide bond.

At least the presence of a starting material is detected by measuring glycine formed as a by-product along with a main product through a chemical reaction involving hippuric acid and/or methylhippuric acid as the starting material and catalyzed by a hydrolase. The hydrolase is an aminoacylase having an amino acid sequence of SEQ ID NO: 1 or a protein having the amino acid sequence of SEQ ID NO: 1 in which one or more amino acids are deleted, replaced, or added and having activity for hydrolysis of the hippuric acid and the methylhippuric acid.