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Halogen Labeled Compounds (F, Br, At, Cl) *
Published in Garimella V. S. Rayudu, Lelio G. Colombetti, Radiotracers for Medical Applications, 2019
In view of the facts that: (1) ω-halofatty acids catabolize very rapidly and appear as free halide in the blood or as glycerides or phospholipids in the heart; (2) cr-halofatty acids inhibit enzymatic activation and are not extracted well in the heart, Stöcklin and Machulla et al.151, 295 synthesized a different fatty acid analog, 75Br-, 77Br-, and 82Br-15(p -bromophenyl)pentadecanoic acid for fatty acid metabolism. This carbon-bromine bond is expected to be relatively stable. In addition, the metabolic product from β- oxidation would result in brominated hippuric acid, which would be excreted rapidly through the kidney. The uptake of 77Br-(p -bromophenyl)pentadecanoic acid in the myocardium was quite comparable to that of 17-iodoheptadecanoic acid.
Miscellaneous Methods of Analysis
Published in Joseph Chamberlain, The Analysis of Drugs in Biological Fluids, 2018
Most workers, however, measured the ability of the drug to inhibit the enzyme by measuring the production of [3Ή |hippuric acid from the substrate [3H]hippurylglycylglycine. The hippuric acid can be readily extracted from the incubation system and the enzyme activity determined according to conventional methods.1274 The method was used for other ACE inhibitors, including enalaprilat and the active form of the prodrug, fosinopril.1276 Indeed, one feature of these methods is that only the active forms of the drugs are measured.
In Vitro Skin Metabolism
Published in Rhoda G. M. Wang, James B. Knaak, Howard I. Maibach, Health Risk Assessment, 2017
Robert L. Bronaugh, Steven W. Collier
Benzoic acid that was absorbed by skin was partially converted to the glycine conjugate hippuric acid (Table 4). The receptor fluid contained essentially all the hippuric acid formed, which was equal to 6.9% of the absorbed radioactivity. The lack of hippuric acid formation in the distilled water control cells confirmed the enzymatic nature of the conjugation reaction. PABA was substantially biotransformed in skin to acetyl-PABA by acetylation of the primary amino group. Although the receptor contained only about 20% of the absorbed PABA, 60.7% of this material was identified as the acetylated metabolite (Table 5).
Antioxidant-rich Terminalia catappa fruit exerts antihypertensive effect via modulation of angiotensin-1-converting enzyme activity and H2S/NO/cGMP signalling pathway in Wistar rats
Published in Biomarkers, 2023
Adeniyi A. Adebayo, Ayokunle O. Ademosun, Bukola C. Adedayo, Ganiyu Oboh
The kidney and plasma ACE activity was determined as described by Akinyemi et al. (2015). The amount of cleaved hippuric acid from hippuryl-histidyl-leucine was measured by the enzymatic method. Fifty microliters of the samples and 150 µL of 8.33 mM of hippuryl-histidyl-leucine (Bz-Gly-His-Leu) in 125 mM Tris-HCl buffer (pH 8.3) were incubated at 37 °C for 30 min. After incubation, the reaction was arrested by adding 250 µL of 1 M HCl. The Gly–His bond was then cleaved, and the hippuric acid produced by the reaction was extracted with 1.5 mL ethyl acetate. Next, the mixture was centrifuged to separate the ethyl acetate layer; then, 1 mL of the ethyl acetate layer was transferred to a clean test tube and evaporated. The residue was re-dissolved in distilled water, and its absorbance was measured at 228 nm.
A metabolomic study on the anti-depressive effects of two active components from Chrysanthemum morifolium
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Tong Liu, Ning Zhou, Ruihao Xu, Yangang Cao, Yanli Zhang, Zhen Liu, Xiaoke Zheng, Weisheng Feng
From the theories of TCM, depression is closely related to liver injury, and elevated blood ammonia levels may be one of the important causes of abnormalities in the liver [40]. The conjugation of glycine with phenylacetate to form phenylacetylglycine through acyl-CoA has been shown to be a new ammonia-lowering route [41]. After the administration of Chr/Nar/Api, the level of phenylacetylglycine increased. This indicated that Chr/Nar/Api could ameliorate liver injury in depressed mice by reducing the level of blood ammonia. Hippuric acid is also a metabolite of glycine [42]. Glycine is deceased in the liver periphery, and may serve as a clinical trait-marker for depression [43]. Glycine is currently a favoured therapeutic target for rapid anti-depressant action [44]. The levels of phenylacetylglycine and hippuric acid were significantly increased after the administration of Chr and its two active components, indicating that the level of total glycine had increased.
The Association between the Preservative Agents in Foods and the Risk of Breast Cancer
Published in Nutrition and Cancer, 2019
Fardin Javanmardi, Jamal Rahmani, Fatemeh Ghiasi, Hadi Hashemi Gahruie, Amin Mousavi Khaneghah
Food preservatives are often used in the food industry to preserve products against the growth of microorganisms and reduce deteriorative chemical reactions (10,43). Among them, benzoate is the first-line preservative approved by the FDA (Number: 7; ID code: 532-32-1) (44,45). Benzoic acid and its salt are widely used in many foodstuffs with pH ≤ 4.5 such as salad dressing, carbonated beverage, fruit juice, pickle, lime juice, and mayonnaise (12,46). Hippuric acid is a byproduct of the interaction of glycine and benzoate and excreted in urine (47). The elimination of hippurate can compensate for the high daily dietary intake of benzoate (48). The genotoxic, cytotoxic, and mutagenic properties of sodium and potassium benzoate were demonstrated in vitro studies for the genome of lymphocyte (49,50). The suggested mechanism is the inhibition of factors corresponding to DNA repair by benzoate salts (51). The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an adequate daily intake (ADI) of 0–5 mg/kg of body weight for benzoic acid and benzoate salts, benzyl acetate, benzyl alcohol, and benzaldehyde (52).