Enzymatic conversion of all-trans-. beta. -carotene to retinal by a cytosolic enzyme from rabbit and rat intestinal mucosa

Journal Article · Fri Dec 01 00:00:00 EST 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.23.9124· OSTI ID:7138120

Lakshman, M R; Mychkovsky, I; Attlesey, M ^[1]

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1. Veterans Administration Medical Center, Washington, DC (USA)

Enzymatic conversion of all-trans-{beta}-carotene to retinal by a partially purified enzyme from rabbit and rat intestinal mucosa was demonstrated. The enzymatic product was characterized based on the following evidence: (i) the product gave rise to its O-ethyloxime by treatment with O-ethylhydroxylamine with an absorption maximum at 363 nm in ethanol characteristics of authentic retinal O-ethyloxime. High-pressure liquid chromatography (HPLC) of this derivative yielded a sharp peak with a retention time of 7.99 min corresponding to the authentic compound; (ii) the mass spectrum of the O-ethyloxime of the enzymatic product was identical to that of authentic retinal O-ethyloxime; (iii) the specific activity of the enzymatically formed ({sup 14}C)retinal O-ethyloxime remained constant even after repeated crystallization; (iv) the enzymatic product exhibited an absorption maximum at 370 nm in light petroleum characteristic of authentic retinal. This retinol was enzymatically esterified to retinyl palmitate by rat pancreatic esterase with a retention time of 10 min on HPLC corresponding to authentic retinyl palmitate. Thus, the enzymatic product of {beta}-carotene cleavage by the partially purified intestinal enzyme was unequivocally confirmed to be retinal.

• OSTI ID: 7138120
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 86:23; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON 14 COMPOUNDS
TRACER TECHNIQUES
CAROTENOIDS
ESTERIFICATION
VITAMIN A
BIOLOGICAL PATHWAYS
ABSORPTION SPECTROSCOPY
ESTERASES
INTESTINES
LIQUID COLUMN CHROMATOGRAPHY
MASS SPECTROSCOPY
MUCOUS MEMBRANES
RABBITS
RATS
ANIMALS
BODY
CHEMICAL REACTIONS
CHROMATOGRAPHY
DIGESTIVE SYSTEM
ENZYMES
GASTROINTESTINAL TRACT
HYDROCARBONS
HYDROLASES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANES
ORGANIC COMPOUNDS
ORGANS
PIGMENTS
RODENTS
SEPARATION PROCESSES
SPECTROSCOPY
TERPENES
VERTEBRATES
VITAMINS
550201* - Biochemistry- Tracer Techniques