ALL-TRANS-RETINOYL BETA-GLUCURONIDE - NEW PROCEDURE FOR CHEMICAL SYNTHESIS AND ITS METABOLISM IN VITAMIN-A-DEFICIENT RATS

All-trans-retinoyl beta-glucuronide (RAG) was chemically synthesized i n high yields (up to 79%) by a new procedure involving the reaction of the tetrabutylammonium salt of glucuronic acid with all-trans-retinoi c acid (RA) via the imidazole or triazole derivative. When RAG was fed orally to vitamin A-deficient rats, RA was identified as the major me tabolite in the serum within hours of administration of RAG. Very litt le or no RAG was detected in the serum. Thus RAG, which was not apprec iably hydrolysed to RA in vitamin A-sufficient rats [Barua and Olson ( 1987) Biochem J. 263, 403-409], was rapidly converted into RA in vitam in A-deficient rats.