ИСТИНА

The invention relates to a method of enzy­matically separating optical isomers of a protected amino­ acid. According to the invention, a (non-sidechain-carboxyl)­ protected aminoacid is used having the general formula (I) HR1N-CR2- (CH) n-C (0) ZR3 wherein R1 is an amino-protective group or hydrogen; - R2 is a side chain; n is a number chosen from 0, 1, and 2; ZR3 is a carboxy-protective group where Z is chosen from 0 or NH; and R1 and R3 may be integrated, forming a heterocy­clic (non-sidechain-carboxyl)-protected ring, the ring backbone comprising 5 to 8 atoms; the (non-sidechain-carboxyl)-protected aminoacid having a mo­lecular weight of less than 1000 Dalton, said method comprising the steps of - contacting the (non-sidechain-carboxyl) -protected aminoacid (I) in the presence of water with an optionally partially pu­rified cell-free extract of a fungus containing an enzyme having at least one of an esterase and amidase activity yielding a mixture of (non-sidechain carboxyl) deprotected product and starting material; and - optionally separating the (non-sidechain carboxyl) depro­tected product and starting material.