Arun B Barua

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A reversed-phase gradient high-performance liquid chromatographic (HPLC) procedure, which utilizes gradient elution and detection by a photodiode-array detector, has been developed to analyze simultaneously very polar retinoids, such as 4-oxo-retinoyl-beta-glucuronide, retinoyl beta-glucuronide and 4-oxo-retinoic acid; polar retinoids, such as retinoic acid(More)
We examined the differentiation activity of retinoyl beta-D-glucuronide, a biologically active physiological metabolite of vitamin A, using the human promyelocytic leukemic cell line HL-60, which can be induced to differentiate with retinoic acid. Retinoyl beta-D-glucuronide (1 microM) inhibited HL-60 cell proliferation by 55-75%, inhibited tritiated(More)
Retinoids induce the promyelocytic cell line, HL-60, to differentiate along the granulocytic pathway in vitro. A number of water-soluble and nitrogen-containing retinoids were synthesized in our laboratory [retinoyl-glucose (RAGL), retinyl-glucose (ROGL), retinoyl-adenosine (RADS), retinoyl-adenine (RAD), retinoyl-beta-glucuronide (beta RAG), and(More)
N-(4-Hydroxyphenyl) retinamide (4HPR) and retinoyl beta-glucuronide (RAG) are two derivatives of all-trans retinoic acid (RA) that show properties both similar to as well as different from their parent compound, RA. Both retinoids possess the important property of showing much-reduced toxicity relative to RA while maintaining significant biological(More)
The complex of microsomal UDP-glucuronosyl transferases (UGT; EC of rat liver catalyzes the formation of retinoyl beta-glucuronide (RAG) from retinoic acid (RA) and retinyl beta-glucuronide (ROG) from retinol (ROL) in the presence of UDP-glucuronic acid (UDPGA). The relative rates of formation of beta-glucuronides in noninduced microsomes were:(More)
A short, simple extraction procedure and a sensitive reversed-phase high-performance liquid chromatographic assay, which utilizes isocratic elution and detection either by a photodiode-array detector or by two detectors set at 300 and 450 nm, have been developed to measure retinol, tocopherols and several carotenoids in human serum simultaneously. By(More)
The purpose of these studies was to compare directly the percutaneous absorption,excretion and metabolism of all-trans-retinoyl beta-glucuronide (RAG), a nontoxic retinoid, with all-trans-retinoic acid (RA) in the rat. Previously, it was demonstrated that topical treatment of human acne with either RAG or RA in cream resulted in a significant reduction of(More)
The occurrence of retinoyl beta-glucuronide and retinoic acid as normal endogenous components of vitamin A reserve in human blood has been demonstrated. Use of high-performance liquid chromatography, coupled with a sensitive detector and integrator, has enabled us to quantitate nanogram quantities of the two retinoids. Serum concentrations of retinoyl(More)
Increased intake of fruits and vegetables is associated with reduced risk of cancer and other chronic diseases. Epoxycarotenoids are widely distributed in nature and constitute major dietary carotenoids in a number of fruits and vegetables. Previous studies have shown that beta-carotene 5,6-epoxide was absorbed well by humans, and was much more active than(More)
Retinoids are unstable compounds being readily oxidized and/or isomerized to altered compounds, especially in the presence of oxidants including air, light, and excessive heat. They are labile toward strong acids and solvents that have dissolved oxygen or peroxides. In this review, procedures for handling and storage of retinoids and biological samples(More)