Excessive melanin formation has been linked to various skin disorders such as hyperpigmentation and cancer. Tyrosinase is the most prominent target for inhibitors of production. In this study, we investigated whether arbutin its prodrug, undecylenic acid ester, might inhibit phenoloxidase (PO), a tyrosinase-like enzyme. Molecular docking simulation results suggested that ester can bind substrat...

The cholesteryl ester content of plasma low density lipoproteins (LDL) in monkeys has previously been shown to be related to the rate of hepatic cholesterol secretion and cholesteryl ester content of newly secreted lipoproteins in the isolated perfused liver. In the present studies, African green monkeys were fed diets containing cholesterol and 40% of calories as either butter or safflower oil...

Cholesterol exists within the hepatocyte as free cholesterol and cholesteryl ester. The proportion of intrahepatic cholesterol in the free or ester forms is governed in part by the rate of cholesteryl ester formation by acyl-coenzyme A:cholesterol acyltransferase (ACAT) and cholesteryl ester hydrolysis by neutral cholesterol ester (CE) hydrolase. In other cell types both ACAT and CE hydrolase a...

This paper examines the impact of various nanoparticles on ester fluids with a special focus their usage towards power transformers. The precautionary measures to be considered nanofluids such as preparation methodologies an appropriate surfactant and its stability is well elucidated. electrical double layer (EDL) formation around diffusion in insulating fluid explained by different layers away...

Exogenous ATP markedly reduced 1-desamino-8-d-arginine vasopressin (dDAVP)-stimulated Ca2+ transport and cAMP accumulation in primary cultures of rabbit connecting tubule and cortical collecting duct cells. Similarly, ATP inhibited the stimulatory effect of 8-bromo-cAMP. At first sight, this is in agreement with the "classic" concept that dDAVP exerts its stimulatory effect via cAMP. However, d...

The formation of the important flavor compound 4-hydroxy-2,5-dimethyl-3[2H]-furanone (HDMF; Furaneol) from D-fructose-1,6-bisphosphate by the yeast Zygosaccharomyces rouxii was studied with regard to the identification of intermediates present in the culture medium. Addition of o-phenylenediamine, a trapping reagent for alpha-dicarbonyls, to the culture medium and subsequent analysis by high-pr...

The action of a bacterial acyltransferase similar in overall reaction mechanism to the plasma enzyme lecithin:cholesterol acyltransferase (LCAT) has been studied using normal plasma and lipoproteins and plasma from LCAT-deficient patients. The microbial enzyme (GCAT) catalyzed acyl transfer using phosphatidylcholine and cholesterol in all of the lipoprotein fractions, presumably because it has ...

IN a previous communication [Kendal & Stickland, 1937, 1] it was shown that if rabbit muscle is minced and thoroughly washed with water, and then extracted several times with dilute Na2HPO4, the later extracts (usually the 4th) contain much of the glycolytic enzyme system but are freer from coenzymes than extracts prepared by earlier methods. This was shown by the fact that on addition of boile...

Non-heme iron(II) complexes are widespread synthetic enzyme models, capable of conducting selective C-H oxidation with H₂O₂ in the presence of carboxylic acid additives. In the last years, structurally similar manganese(II) complexes have been shown to catalyze C-H oxidation with similarly high selectivity, and with much higher efficiency. In this mini-review, recent catalytic and mechanistic d...