Cysteinylated and glutathionylated precursors of sulfanylalkyl alcohols have been extensively studied in hop grape matrices, contrast to those aldehydes acetates. Here, cysteinylated adducts 3-sulfanylpentanal (Cys-3SPal G-3SPal), 3-sulfanylhexanal (Cys-3SHal G-3SHal), 3-sulfanylpentyl acetate (only Cys-3SPA), 3-sulfanylhexyl (Cys-3SHA G-3SHA) were first synthesized. Next, the occurrence these ...

Non-Saccharomyces yeasts have been used for many years due to their technological potential, particularly as a “booster” of wine fruity aroma in mixed fermentations with Saccharomyces cerevisiae. Recently, new application has emerged, bioprotection, which consists colonizing the environment context sulfite reduction wines. The chemical and sensory impact non-Saccharomyces yeast according differ...

The labial gland secretions from males of the bumblebee Bombus (Separatobombus) griseocollis De Geer, a bumblebee exhibiting perching behaviour, were analysed by gas chromatography/mass spectrometry (GC/MS) in the electron impact and positive ion chemical ionization mode. The major compound of the complex mixture of alkenols, acetates, hydrocarbons, wax type esters and steroids is tetradecyl ac...

Ester compounds are widely used in applications such as solvents, plasticizers, polymers, lubricants, cosmetics, medicinals, agrochemicals, soaps and other surface active agents, to mention a few. In many of these applications the simultaneous knowledge of the phase behavior and interfacial properties is an advantage for designing better products and improved processes. The van der Waals densit...

Protocols for selective acetylation of the hydroxyl groups of ginkgolide C have been developed. These acetylations have given rise to various ginkgolide C acetates and iso-ginkgolide C acetates, the latter having a rearranged skeleton resulting from translactonization. These acetyl derivatives, as well as ginkgolides A and B acetates have been investigated for their ability to bind to a cloned ...

A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which accepted C₅- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C₂)...

An SN2 reaction (NaI) of 1,7-di(methanesulfoxyl)heptadien-4-yl methoxy-(2-naphthyl)acetate and a tributyltin hydride reduction of 1,7-diiodo-4-yl methoxy-(2-naphthyl)acetate (2NMA) is crucial for determination of the absolute configuration of secondary alcohols.

The title compound, [Sn(C4H9)2(CH3COO)2], was synthesized in order to study the influence of large organic groups on the mol-ecular structure of diorganotin di-acetates. The title compound exhibits the same structure type as other diorganotin(IV) di-acetates characterized by an unsymmetrical bidentate bonding mode of the two acetate groups to tin. The influence of the t-butyl groups on this mol...

A highly efficient synthesis of a wide range of 2,5-disubstituted pyrazines from (Z)-β-haloenol acetates is described. The reactions are conducted under convenient conditions and provide products with excellent regioselectivity in moderate to excellent yields with a broad substrate scope, including a variety of aromatic and aliphatic haloenol acetates.

Glycosyl donors containing a double bond between C2 and C3 were designed by mimicking the reaction mechanism of lysozyme-initiated hydrolysis of mucopolysaccharides. It was found that, under various glycosylation conditions, the reactivities of 2,3-unsaturated glycosyl acetates were significantly higher, while those of the corresponding 2,3-unsaturated-4-keto glycosyl acetates were much lower t...