Patent ID: 7030248

Claim:
A process for isolating substantially pure L-β-3-indolylalanine (L-β-3) from a source of amino acids including L-β-3, the process comprising: contacting a porous container containing a hydrophobic substance being attractive to aromatic amino acids and having substantially no attraction to aliphatic amino acids with an aqueous solution of the source of amino acids; agitating the aqueous solution and the porous container to allow a substantial portion of the L-β-3 to adsorb to the hydrophobic substance and thereby produce a first solution containing aliphatic amino acids; separating the porous container from the aqueous solution; contacting the porous container with an acidic solution to produce a second solution containing any L-phenylalanine and L-tyrosine displaced from the hydrophobic substance, wherein the acidic solution includes an acid selected from one or more of a group consisting of acetic acid, formic acid, propionic acid, butyric acid, isobutyric acid, and acids having a molecular weight no greater than 88.10 daltons and a K a in the range of 1.77×10 −4 and 1.34×10 −5 at 25° C.; separating the porous container from the second solution; and contacting the porous container with a basic solution to displace L-β-3 from the hydrophobic substance and thereby produce a third solution containing L-β-3 , wherein the basic solution includes a base selected from one or more of a group consisting of ammonia, short chain aliphatic primary, secondary or tertiary amines, trimethylamine, triethylamine, (CH 3 ) 2 NH (C 2 H 5 NH, CH 3 NH 2 , CH 2 CH 2 NH 2 and bases having a molecular weight no greater than 101.19 daltons and a K b in the range of 1.26×10 −3 and 1.8×10 −5 at 25° C.