公开(公告)号：JPH02174650A

公开(公告)日：1990-07-06

申请号：JP32620088

申请日：1988-12-26

Applicant: TOSOH CORP

Inventor： SHIOKAWA YUTAKA ,  KUNISAWA YUKIO ,  HARADA TSUNEO

IPC: A23L27/30 ,  C07K1/00 ,  C07K5/06 ,  C07K5/075

Abstract: PURPOSE:To prepare a granular dipeptide sweetener having high purity and excellent fluidity and solubility by spray-drying a slurry of a dipeptide sweetener without using a crushing operation, granulating the dried product and, as necessary, further drying the granules. CONSTITUTION:A slurry liquid containing crystals of an alpha-L-aspartyl-L- phenylalanine lower alkyl ester is spray-dried to obtain a dried product having extremely poor fluidity and containing a large amount of fusiform fine powder of

公开(公告)号：JPH01165559A

公开(公告)日：1989-06-29

申请号：JP32286387

申请日：1987-12-22

Applicant: TOSOH CORP

Inventor： SHIOKAWA YUTAKA

IPC: C07B55/00 ,  C07B31/00 ,  C07C67/00 ,  C07C227/00 ,  C07C227/14 ,  C07C227/36 ,  C07C229/00

Abstract: PURPOSE:To racemize the title compound useful as a synthetic raw material for peptide rapidly and efficiently without adding another catalyst such as acid, by selectively racemizing an optically active alpha-amino acid ester in a polar solvent in the presence of peptide or a derivative thereof. CONSTITUTION:An optically active alpha-amino acid ester is selectively racemized in a polar solvent (e.g., ketone or methyl isobutyl ketone) in the presence of peptide or a derivative thereof (e.g., N-benzyloxycarbonyl-L-aspartyl-L- phenylalanine or an aliphatic lower alkyl ester thereof). The amount of the peptide or the derivative thereof added is >=about 0. 1mol, preferably about 0.5-about 5 mol based on 1 mol optically active alpha-amino acid ester. The racemization is carried out under heating at about 40-200 deg.C, preferably 90 deg.C-200 deg.C.