Spectrophotometric assay of ascorbic acid in pure solutions, blood plasma and urine with <i>peri</i>naphthindanetrione hydrate

Ridi, M. S. El; Moubasher, Radwan; Hassan, Z.

doi:10.1042/bj0490246

Cited by 5 publications

(2 citation statements)

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“…The amount of dihydroxy perinaphthindenone formed is first estimated photoelectrically and then spectrophotometrically using a 5-mm cell, and the ascorbic acid present calculated from this spectrophotometric method. [ 42 ]…”

Section: Important Photoprotective Phytoconstituentsmentioning

confidence: 99%

Phytoconstituents as photoprotective novel cosmetic formulations

2010

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Phytoconstituents are gaining popularity as ingredients in cosmetic formulations as they can protect the skin against exogenous and endogenous harmful agents and can help remedy many skin conditions. Exposure of skin to sunlight and other atmospheric conditions causes the production of reactive oxygen species, which can react with DNA, proteins, and fatty acids, causing oxidative damage and impairment of antioxidant system. Such injuries damage regulation pathways of skin and lead to photoaging and skin cancer development. The effects of aging include wrinkles, roughness, appearance of fine lines, lack of elasticity, and de- or hyperpigmentation marks. Herbal extracts act on these areas and produce healing, softening, rejuvenating, and sunscreen effects. We have selected a few photoprotective phytoconstituents, such as curcumin, resveratrol, tea polyphenols, silymarin, quercetin and ascorbic acid, and have discussed the considerations to be undertaken for the development of herbal cosmetic formulations that could reduce the occurrence of skin cancer and delay the process of photoaging. This article is aimed at providing specific and compiled knowledge for the successful preparation of photoprotective herbal cosmetic formulations.

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Section: Important Photoprotective Phytoconstituentsmentioning

confidence: 99%

Phytoconstituents as photoprotective novel cosmetic formulations

2010

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“…The average concentration of IXS, VMA, HVA, AA, and UA for two different urine samples obtained from the same healthy female was determined to be 170, 55, 87, 142, and 1,075 μM, respectively. Normal levels of such analytes in urine are 100−1000 μM for IXS, 50−1000 μM for VMA, 14−125 μM for HVA, and 150−200 μM for AA, i.e., the values estimated by CE-ECD fall in the normal range for healthy subjects. Therefore, sample staking was not mandatory for the simultaneous analysis of IXS, HVA, and VMA in the presence of UA, AA, and TRP since the LOD of such analytes was significantly lower than their normal physiological levels.…”

Section: Resultsmentioning

confidence: 99%

Electrophoretic Analysis of Biomarkers using Capillary Modification with Gold Nanoparticles Embedded in a Polycation and Boron Doped Diamond Electrode

2010

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Field-amplified sample stacking using a fused silica capillary coated with gold nanoparticles (AuNPs) embedded in poly(diallyl dimethylammonium) chloride (PDDA) has been investigated for the electrophoretic separation of indoxyl sulfate, homovanillic acid (HVA), and vanillylmandelic acid (VMA). AuNPs (27 nm) exhibit ionic and hydrophobic interactions, as well as hydrogen bonding with the PDDA network to form a stable layer on the internal wall of the capillary. This approach reverses electro-osmotic flow allowing for fast migration of the analytes while retarding other endogenous compounds including ascorbic acid, uric acid, catecholamines, and indoleamines. Notably, the two closely related biomarkers of clinical significance, HVA and VMA, displayed differential interaction with PDDA-AuNPs which enabled the separation of this pair. The detection limit of the three analytes obtained by using a boron doped diamond electrode was approximately 75 nM, which was significantly below their normal physiological levels in biological fluids. This combined separation and detection scheme was applied to the direct analysis of these analytes and other interfering chemicals including uric and ascorbic acids in urine samples without off-line sample treatment or preconcentration.

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Recent Advances in Nutrition and Metabolism

Goldsmith¹

1952

AMA Arch Intern Med

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Spectrophotometric assay of ascorbic acid in pure solutions, blood plasma and urine with perinaphthindanetrione hydrate

Cited by 5 publications

References 4 publications

Phytoconstituents as photoprotective novel cosmetic formulations

Phytoconstituents as photoprotective novel cosmetic formulations

Electrophoretic Analysis of Biomarkers using Capillary Modification with Gold Nanoparticles Embedded in a Polycation and Boron Doped Diamond Electrode

Recent Advances in Nutrition and Metabolism

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