Synthesis and preliminary biological evaluation of beta-carotene and retinoic acid oxidation products.

Synthesis of the beta-carotene oxidation product, 2,3-dihydro-5,8-endoperoxy-beta-apo-carotene-13-one (1) was achieved in six steps starting from beta-ionone. Photo-oxygenation of all trans-retinoic acid (8) and 13-cis-retinoic acid (9) produced a mixture of 5S*,8S*-epidioxy-5,8-dihydroretinoic acid (10) and 13-cis-5S*,8S*-epidioxy-5,8-dihydroretinoic acid (11). Methylation of the crude photo-oxygenation mixture afforded the corresponding methyl esters 12 and 13, respectively, both of which underwent ready aerial oxidation yielding hitherto unknown oxidation products of retinoic acid identified as methyl 5S*,8S*-epidioxy-9,10beta-epoxy-5,8,9,10-tetrahydroretinoate (14) and methyl 13-cis-5S*,8S*-epidioxy-9,10beta-epoxy-5,8,9,10-tetrahydroretinoate (15).

The night vision threshold test is a better predictor of low serum vitamin A concentration than self-reported night blindness in pregnant urban Nepalese women.

This study was conducted to validate the night vision threshold test (NVTT) as an indicator of night blindness. A total of 1401 pregnant women from the National Maternity Hospital participated in this study. Women were queried about night blindness and took the NVTT using standardized procedures after 10 min of dark adaptation.

Cytotoxic constituents of Aspergillus terreus from the rhizosphere of Opuntia versicolor of the Sonoran Desert.

A novel cyclopentenedione, asterredione (1), two new terrecyclic acid A derivatives, (+)-5(6)-dihydro-6-methoxyterrecyclic acid A (2) and (+)-5(6)-dihydro-6-hydroxyterrecyclic acid A (3), and five known compounds, (+)-terrecyclic acid A (4), (-)-quadrone (5), betulinan A (6), asterriquinone D (7), and asterriquinone C-1 (8), were isolated from Aspergillus terreus occurring in the rhizosphere of Opuntia versicolor, using bioassay-guided fractionation. Acid-catalyzed reaction of 2 under mild conditions afforded 4, whereas under harsh conditions 2 yielded 5 and (-)-isoquadrone (9). Catalytic hydrogenation and methylation of 4 afforded 5(6)-dihydro-terrecyclic acid A (10) and (+)-terrecyclic acid A methyl ester (11), respectively.

Multinational study of major breast milk carotenoids of healthy mothers.

Background: Carotenoids in serum vary between countries and within populations with evidence suggesting a qualitative relationship to diet. Breast milk carotenoids furnish a source of vitamin A and potentially provide immunoprotection and other health benefits for infants. There have been numerous studies of milk carotenoid concentrations in undernourished populations; however, carotenoid concentrations have not previously been compared in populations of well-nourished mothers.