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Hasan R, Begum R, Huq AO, Rahman N, Akter S, Khan SH, Islam F. Development of normal phase HPLC based method for the determination of retinyl palmitate in fortified edible oils. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2023. [DOI: 10.1080/10942912.2022.2151618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Rakibul Hasan
- Department of Food Technology and Nutritional Science, Mawlana Bhashani Science and Technology University, Santosh, Bangladesh
- Department of Public Health Nutrition, Primeasia University, Banani, Bangladesh
| | - Rokeya Begum
- Department of Food Technology and Nutritional Science, Mawlana Bhashani Science and Technology University, Santosh, Bangladesh
| | - A.K. Obidul Huq
- Department of Food Technology and Nutritional Science, Mawlana Bhashani Science and Technology University, Santosh, Bangladesh
| | - Nannur Rahman
- Department of Food Technology and Nutritional Science, Mawlana Bhashani Science and Technology University, Santosh, Bangladesh
| | - Shamoli Akter
- Department of Food Technology and Nutritional Science, Mawlana Bhashani Science and Technology University, Santosh, Bangladesh
| | - Shahinul Haque Khan
- Department of Chemistry, Bangladesh University of Health Sciences (BUHS), Bangladesh
| | - Faridul Islam
- Institute of Food Science and Technology, Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
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Bolze CS, Helbling RE, Owen RL, Pearson AR, Pompidor G, Dworkowski F, Fuchs MR, Furrer J, Golczak M, Palczewski K, Cascella M, Stocker A. Human cellular retinaldehyde-binding protein has secondary thermal 9-cis-retinal isomerase activity. J Am Chem Soc 2013; 136:137-46. [PMID: 24328211 DOI: 10.1021/ja411366w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cellular retinaldehyde-binding protein (CRALBP) chaperones 11-cis-retinal to convert opsin receptor molecules into photosensitive retinoid pigments of the eye. We report a thermal secondary isomerase activity of CRALBP when bound to 9-cis-retinal. UV/vis and (1)H NMR spectroscopy were used to characterize the product as 9,13-dicis-retinal. The X-ray structure of the CRALBP mutant R234W:9-cis-retinal complex at 1.9 Å resolution revealed a niche in the binding pocket for 9-cis-aldehyde different from that reported for 11-cis-retinal. Combined computational, kinetic, and structural data lead us to propose an isomerization mechanism catalyzed by a network of buried waters. Our findings highlight a specific role of water molecules in both CRALBP-assisted specificity toward 9-cis-retinal and its thermal isomerase activity yielding 9,13-dicis-retinal. Kinetic data from two point mutants of CRALBP support an essential role of Glu202 as the initial proton donor in this isomerization reaction.
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Affiliation(s)
- Christin S Bolze
- Department of Chemistry and Biochemistry, and ‡Graduate School for Cellular and Biomedical Sciences, University of Bern , Freiestrasse 3, 3012 Bern, Switzerland
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Reepmeyer JC, Brower JF, Ye H. Separation and detection of the isomeric equine conjugated estrogens, equilin sulfate and Δ8,9-dehydroestrone sulfate, by liquid chromatography–electrospray-mass spectrometry using carbon-coated zirconia and porous graphitic carbon stationary phases. J Chromatogr A 2005; 1083:42-51. [PMID: 16078686 DOI: 10.1016/j.chroma.2005.05.092] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Equilin-3-sulfate and delta8,9-dehydroestrone-3-sulfate are two isomers found in equine conjugated estrogens that differ in structure only by the position of a double bond in the steroid B-ring. These geometric isomers were not resolved on a C18 column during the analysis of conjugated estrogen drug products by LC-MS using acetonitrile-ammonium acetate buffer as the mobile phase. While no separations of these two isomers were observed on C18 or other alkyl-bonded silica based phases using a variety of mobile phase conditions, partial separations were achieved on phenyl bonded silica phases with a resolution of 1.5 on a diphenyl phase, and baseline separations were readily achieved on two carbonaceous phases with resolutions routinely exceeding three on graphitic carbon-coated zirconia (Zr-CARB) and resolutions as high as 19 on porous graphitic carbon (Hypercarb). An examination of a selected few conjugated estrogens in the complex drug substance by LC-MS on Hypercarb is presented.
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Affiliation(s)
- John C Reepmeyer
- US Food and Drug Administration, Division of Pharmaceutical Analysis, St. Louis, MO 63101, USA.
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Fávaro RMD, Iha MH, Bianchi MDLP. Liquid chromatographic determination of geometrical retinol isomers and carotene in enteral feeding formulas. J Chromatogr A 2003; 1021:125-32. [PMID: 14735981 DOI: 10.1016/j.chroma.2003.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The objective of the present study was to evaluate a practical method for separation and determination of geometrical retinol isomers and carotene in enteral feeding formulas and to analyze 17 samples of commercial formulas. By using a normal-phase HPLC column and a mobile phase consisting of 1-octanol in n-hexane, seven isomers of retinol were separated and identified from the standard solution after photolysis. For evaluation of Vitamin A activity in these formulas, simultaneous determination of total carotene was performed. The data about linearity, recovery, accuracy and precision showed the reliability of analytical procedures. In the unsaponifiable portion of samples of commercial formulas, six retinol isomers were identified: (E)-retinol; (Z)-13; (Z)-9; (Z,Z)-9,13; (Z,Z)-11,13 and (Z)-7-retinol. (Z)-13/(E)-retinol ratios ranged between 3 and 37%. The range of total Z/(E)-retinol isomers fell between 5 and 42%. Despite the high concentration of Z-isomers observed in various commercial enteral feeding formulas, none of the samples presented Vitamin A activity below 90% of that specified on the label.
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Affiliation(s)
- Rosa Maria Duarte Fávaro
- Seção de Bromatologia e Química, Laboratório de Ribeirão Preto, Instituto Adolfo Lutz, Rua Minas 877, Ribeirão Preto 14085-410, SP, Brazil.
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Gillespie NB, Wise KJ, Ren L, Stuart JA, Marcy DL, Hillebrecht J, Li Q, Ramos L, Jordan K, Fyvie S, Birge RR. Characterization of the Branched-Photocycle Intermediates P and Q of Bacteriorhodopsin. J Phys Chem B 2002. [DOI: 10.1021/jp021221p] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nathan B. Gillespie
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Kevin J. Wise
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Lei Ren
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Jeffrey A. Stuart
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Duane L. Marcy
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Jason Hillebrecht
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Qun Li
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Lavoisier Ramos
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Kevin Jordan
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Sean Fyvie
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Robert R. Birge
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, and W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
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Gundersen TE, Blomhoff R. Qualitative and quantitative liquid chromatographic determination of natural retinoids in biological samples. J Chromatogr A 2001; 935:13-43. [PMID: 11762772 DOI: 10.1016/s0021-9673(01)01043-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Liquid chromatography continues to be the preferred method for determining retinoids in biological samples. The highly unstable nature of retinoids and the real possibility of artifacts or erroneous results have led to the development of rapid and highly automated protocols for retinoid extraction, separation and detection. Due to strong light absorbance in the ultraviolet region, UV detectors still predominate although mass spectrometric detection is gaining increased popularity. This paper reviews recent advances and provides major guidelines for using liquid chromatography to identify and quantify retinoids in biological samples.
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Affiliation(s)
- T E Gundersen
- Institute for Nutrition Research, Faculty of Medicine, University of Oslo, Blindern, Norway.
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