1.
Biosci Biotechnol Biochem
; 64(1): 206-9, 2000 Jan.
Article
in English
| MEDLINE
| ID: mdl-10766510
ABSTRACT
L-tryptophan is a very important precursor of niacin in mammals. Food preparation in which proteins are exposed to an alkali and/or high temperature for a long period generate appreciable amounts of D-amino acids from racemization. The efficiency of D-tryptophan as niacin was thus investigated by using weanling rats. The availability of D-tryptophan was almost the same as that in L-tryptophan as the precursor of niacin and was 1/6 as active as niacin.