Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of ...

The tetra azophenylcalix[4]arene with ortho-ester group was applied for determination of transition metal ions using spectrophotometer. In this case, the derivatives with ortho-ester group turned out the complexing formation selectively with transition metal ions over alkali, alkaline earth metal ions. From those, this study used the molecular mechanic method MM+ and molecular dynamic simulatio...

Molecular cages with arylboronate ester caps at the vertices are described. The were obtained by metal-templated polycondensation reactions of a tris(2-formylpyridine oxime) ligand arylboronic acids. Suited templates triflate or triflimide salts ZnII, FeII, CoII, MnII. In products, metal ions coordinated internally to pyridyl and oximato N atoms adjacent boronate ester, resulting in an improved...

In previous studies, it was reported that a neighbouring equatorial ester group is essential for a good yield of nitrite-mediated triflate inversion, whereas with neighbouring benzyl ether groups or axial ester groups, mixtures are generally produced. In the present study, the origin of this difference was addressed. The ambident reactivity of the nitrite ion has been found to be the cause of t...

The surface behavior of a series of cholesteryl esters was studied in mixtures with a model phospholipid, 1-palmitoyl-2-oleoyl phosphatidylcholine. The cholesteryl esters were representative of the predominant forms occurring naturally and qualitative similarities in their phase behavior permits generalization of their surface properties. Quantitative differences, however, show that the availab...

acyl-CoA and cholesterol. This enzyme plays key roles in both intestinal absorption of cholesterolX) and cholesteryl ester accumulation in macrophagederived foam cells, which are prominent in atherosclerotic plaques2). In the course of the search for microbial metabolites which inhibit cholesteryl ester formation in macrophages, helminthosporol (1)3), helminthosporal-derived acid (2)4) and helm...

Novel biodegradable and pH-sensitive polymersomes prepared from poly(ethylene glycol) and poly(d,l-lactide) grafted poly(beta-amino ester) exhibit pH dependent permeability on hydrophilic solutes of which permeability is determined by the packing state of poly(d,l-lactide) membrane followed by ionization of poly(beta-amino ester) inducing loosely packed membrane formation from well-ordered pack...

Mixed anhydrides with penicillinic acids (III) were unstable and gave N-acyl, amides IV. Only III with butyrolactam was stable and reacted with alcohols to give esters V. All anhydrides with cephalosporinic acids (VIlI) yielded symmetric anhydrides IX. Alcoholysis of IX gave cephalosporinic ester X, while aminolysis yielded amide. Formation of postulated isomeric mixed anhydride with O-imino ca...

Marinobacter hydrocarbonoclasticus DSM 8798 has been reported to synthesize isoprenoid wax ester storage compounds when grown on phytol as the sole carbon source under limiting nitrogen and/or phosphorous conditions. We hypothesized that isoprenoid wax ester synthesis involves (i) activation of an isoprenoid fatty acid by a coenzyme A (CoA) synthetase and (ii) ester bond formation between an is...

A cell free system prepared from etiolated cucumber (Cucumis sativus, L) in tris-sucrose buffer is able to incorporate delta-aminolevulinic acid-4- (14)C into the two components of protochlorophyll: protochlorophyllide and protochlorophyllide ester. The activity is associated with the etioplasts. Optimal incorporation is obtained at pH 7.7. For the formation of protochlorphyllide ester, oxygen,...