scholarly journals Preparation, properties and metabolism of 5,6-monoepoxy-3-dehydroetinal

1969 ◽  
Vol 111 (1) ◽  
pp. 23-26 ◽  
Author(s):  
A. Krishna Mallia ◽  
M. R. Lakshmanan ◽  
K. V. John ◽  
H. R. Cama
Keyword(s):  
Vitamin A ◽  
Rat Growth ◽  
Growth Assay ◽  
Biological Potency ◽  
Reduction And Oxidation

1. 5,6-Monoepoxy-3-dehydroretinal was synthesized from 3-dehydroretinyl acetate and characterized. 2. When fed to vitamin A-deficient rats, 5,6-monoepoxy-3-dehydroretinal was converted into 5,6-monoepoxy-3-dehydrovitamin A and stored in the liver. 3. It was demonstrated that the rat possesses the necessary enzymes for the reduction and oxidation of 5,6-monoepoxy-3-dehydroretinal to the corresponding alcohol and acid respectively. 4. The biological potency of the epoxy-3-dehydroretinal by the rat-growth assay (determined by USP XIV procedure) was 1·07% of that of vitamin A.

scholarly journals Preparation, properties and metabolism of retro-3-dehydroretinyl acetate

1968 ◽  
Vol 109 (2) ◽  
pp. 293-299 ◽  
Author(s):  
A. Krishna Mallia ◽  
M. R. Lakshmanan ◽  
K. V. John ◽  
H. R. Cama
Keyword(s):  
Small Intestine ◽  
Vitamin A ◽  
Hydrobromic Acid ◽  
The Body ◽  
Rat Intestine ◽  
Retinyl Acetate ◽  
Major Site ◽  
Rat Growth ◽  
Growth Assay ◽  
Biological Potency

1. Treatment of 3-dehydroretinyl acetate with aqueous hydrobromic acid resulted in the formation of retro-3-dehydroretinyl acetate, which, on alkaline hydrolysis, gave the corresponding alcohol. 2. retro-3-Dehydroretinyl acetate was isomerized to 3-dehydrovitamin A when fed to vitamin A-deficient rats. 3. When retro-3-dehydroretinyl acetate was administered orally, it was hydrolysed to retro-3-dehydroretinol in the rat intestine, isomerized to 3-dehydroretinol and esterified before being transported to the liver for storage. 4. When administered intraperitoneally, both 3-dehydrovitamin A and retro-3-dehydrovitamin A were accumulated in liver and other tissues, whereas after enterectomy 3-dehydrovitamin A was not detected anywhere in the body. 5. The small intestine was shown to be the major site of conversion of retro-3-dehydrovitamin A into 3-dehydrovitamin A. 6. The extent of conversion of retro-3-dehydroretinyl acetate into 3-dehydrovitamin A was much smaller than that of the conversion of retro-retinyl acetate into vitamin A. 7. The biological potency of retro-3-dehydroretinyl acetate, determined by the rat-growth assay, was 2·6% of that all-trans-retinyl acetate, when given orally.

scholarly journals The Biological Potency of Vitamin A in Whale Liver Oil and its Molecular Distillates

1950 ◽  
Vol 16 (2) ◽  
pp. 46-52 ◽  
Author(s):  
K. SABASI ◽  
A. NAKAYAMA ◽  
S. HIRAO ◽  
T. KINUMAKI
Keyword(s):  
Vitamin A ◽  
Biological Potency

ISOMERIZATION OF 11-cis VITAMIN A IN VIVO

1960 ◽  
Vol 38 (11) ◽  
pp. 1219-1222 ◽  
Author(s):  
D. W. Stainer ◽  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Intestinal Tract ◽  
Biological Potency ◽  
Oral Doses ◽  
Poor Absorption ◽  
Cis Isomer

Single oral doses of all-trans and 11-cis vitamin A acetate were given to young, vitamin A deficient rats and the proportion of cis isomer in the intestinal tract and liver measured. Some conversion of 11-cis to all-trans occurred in the stomach and intestine, and a mixture of the two isomers was absorbed and stored in the liver. The high proportion of cis isomer found in the liver stores 5 hours after a dose of 11-cis vitamin A disappeared completely in 23 days. Oral doses of both all-trans and 11-cis vitamin A produced greater liver stores than the same doses given subcutaneously. The relative biological potency of the 11-cis isomer was the same by either route, which indicated that the low potency of this isomer was not due only to poor absorption from the intestine.

Bioavailability of tryptophan in selected foods by rat growth assay

1989 ◽  
Vol 39 (1) ◽  
pp. 85-91 ◽  
Author(s):  
F. E. McDonough ◽  
C. E. Bodwell ◽  
P. A. Wells ◽  
J. A. Kamalu
Keyword(s):  
Rat Growth ◽  
Growth Assay

EVALUATION OF PROTEIN IN FOODS: III. A STUDY OF BACTERIOLOGICAL METHODS

1959 ◽  
Vol 37 (11) ◽  
pp. 1351-1360 ◽  
Author(s):  
C. G. Rogers ◽  
J. M. McLaughlan ◽  
D. G. Chapman
Keyword(s):  
Amino Acid ◽  
Protein Quality ◽  
Animal Origin ◽  
Rat Growth ◽  
Amino Acid Requirements ◽  
Growth Assay ◽  
Assay Methods ◽  
Limiting Amino Acid ◽  
Egg Powder

Bacteriological methods for the determination of protein quality were evaluated by comparison with protein efficiency ratio (P.E.R.) values determined by a standardized rat growth assay. Enzyme or acid hydrolyzates of foods were used as the source of amino acids with hydrolyzed whole egg powder as the reference standard. With Streptococcus faecalis A.T.C.C. 9790 autolysis occurred in media containing hydrolyzates of proteins deficient in lysine, and was largely responsible for results which did not agree with P.E.R. values. In methods employing Leuconostoc mesenteroides P-60 A.T.C.C. 8042, growth was influenced only by the most limiting amino acid relative to the requirements of the test organism.Results with enzyme hydrolyzates correlated poorly with P.E.R. values, whereas, with acid hydrolyzates, a good correlation was obtained for cereal proteins. A difference in amino acid requirements was largely responsible for the lack of agreement between the P.E.R. assay and methods employing L. mesenteroides, particularly for legumes and foods of animal origin. It was concluded that bacteriological assay methods which have been proposed for protein evaluation are unsatisfactory as screening procedures for the evaluation of protein in foods.

ESTIMATION OF THE BIOLOGICAL POTENCY OF VARIOUS FORMS OF VITAMIN A

1961 ◽  
Vol 39 (11) ◽  
pp. 1687-1693 ◽  
Author(s):  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Antimony Trichloride ◽  
Vaginal Smear ◽  
Biological Potency ◽  
Liver Storage

The low biological potency of 9-cis and 9,13-di-cis vitamin A, heretofore measured by growth and liver storage assays, has been confirmed by vaginal smear assays. Appreciable quantities of these isomers in pharmaceuticals would lead to overestimation of biological potency by the U.S.P. XV or the antimony trichloride methods. In an extensive series of assays the U.S.P. method accurately estimated the biological potency of most oil-soluble, water-dispersed, and dry, stabilized samples of vitamin A. The antimony trichloride method did not accurately estimate biological potency but, for many samples, correction of these values in accordance with their maleic values was not justified. Water-dispersed and dry, stabilized samples of vitamin A were not better utilized than oil solutions of the vitamin.

ISOMERIZATION OF 11-cis VITAMIN A IN VIVO

1960 ◽  
Vol 38 (1) ◽  
pp. 1219-1222 ◽  
Author(s):  
D. W. Stainer ◽  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Intestinal Tract ◽  
Biological Potency ◽  
Oral Doses ◽  
Poor Absorption ◽  
Cis Isomer

Single oral doses of all-trans and 11-cis vitamin A acetate were given to young, vitamin A deficient rats and the proportion of cis isomer in the intestinal tract and liver measured. Some conversion of 11-cis to all-trans occurred in the stomach and intestine, and a mixture of the two isomers was absorbed and stored in the liver. The high proportion of cis isomer found in the liver stores 5 hours after a dose of 11-cis vitamin A disappeared completely in 23 days. Oral doses of both all-trans and 11-cis vitamin A produced greater liver stores than the same doses given subcutaneously. The relative biological potency of the 11-cis isomer was the same by either route, which indicated that the low potency of this isomer was not due only to poor absorption from the intestine.

scholarly journals Studies on the relative biopotencies and intestinal absorption of different apo-β-carotenoids in rats and chickens

1976 ◽  
Vol 158 (2) ◽  
pp. 377-383 ◽  
Author(s):  
R V Sharma ◽  
S N Mathur ◽  
J Ganguly
Keyword(s):  
Retinoic Acid ◽  
Methyl Ester ◽  
Vitamin A ◽  
Intestinal Absorption ◽  
Free Acid ◽  
Beta Carotene ◽  
Weight Basis ◽  
Molar Basis ◽  
Growth Assay ◽  
Liver Storage

1. The biopotencies relative to beta-carotene of several apocarotenoids, such as 8′-, 10′- and 12′-apo-beta-carotenal and methyl 8′-apo-beta-carotenoate, were investigated in rats, on a molar basis, by both curative-growth assay and liver-storage tests. 2. In the curative-growth assays, on a molar basis the biopotencies of 8′-, 10′- and 12′-apo-beta-carotenal and methyl 8′-apo-beta-carotenoate were 72, 78, 72 and 53% respectively, whereas on a weight basis the corresponding values were 93, 111, 111 and 63%, with respect to beta-carotene taken as 100%. In terms of yield of vitamin A, these values were much lower in the liver-storage tests. 3. When 8′-apo-beta-carotenal was fed, the unchanged aldehyde together with small amounts of the corresponding alcohol and larger proportions of the acid rapidly appeared in the tissues of both rats and chickens. The 8′-apocarotenol, 8′-apocarotenoic acid and its methyl ester were absorbed unchanged. The free acid disappeared most rapidly from the tissues, but its methyl ester persisted in the tissues longest. 4. On the basis of these observations it is suggested that most of an apocarotenal is oxidized to the corresponding acid, which, in turn, is mostly degraded to retinoic acid, with small proportions of it being attacked by the dioxygenase system giving retinal.

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