Over the last decade, concerns have been raised about potential respiratory health effects associated with occupational exposure to the flavoring additives diacetyl and 2,3-pentanedione. Both of these diketones are also natural components of many foods and beverages, including roasted coffee. To date, there are no published studies characterizing workplace exposures to these diketones during co...

Almost all enzymes capable of decarboxylating pyruvate have been shown to catalyze DPT’-dependent condensation reactions yielding acyloins such as AMC (l-7). Recent work of Schweet and coworkers (8) has demonstrated that in animal tissues these condensations are due to the activity of pyruvic oxidase. Purified preparations of pyruvic oxidase from pigeon breast muscle have the same ratio of acyl...

Many animal species change their behavior according to their stage of development. However, the mechanisms involved in translating their developmental stage into the modifications of the neuronal circuits that underlie these behavioral changes remain unknown. Here we show that Caenorhabditis elegans changes its olfactory preferences during development. Larvae exhibit a weak chemotactic response...

In our research, new bis-α, β-unsaturated carbonyl compounds (Z2-Z4) were prepared via Claisen- Schmidt reaction, by the condensation of 2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine (Z1) with different appropriate benzaldehyde, like (benzaldehyde, m-nitro benzaldehyde and o-chloro benzaldehyde) using 10% aqueous sodium hydroxide as a base. A simple efficient method has been applied for synthes...

abstract: kefir is fermented milk that has a unique flavor because of acetaldehyde, diacetyl, acetoin and ethanol. the aim of this study was to evaluate flavor and aroma compounds present in kefir. two types of starter (christian hansen and sacco) and three levels of temperatures (30, 33 and 35oc) were used for the preparation of kefir samples. the samples were analyzed for acetaldehyde, diacet...

A highly regio-, chemo-, diastereo- and enantioselective organocatalytic [4 + 1] annulation of 2-halo-1,3-dicarbonyl compounds with Morita-Baylis-Hillman adducts catalyzed by commercially available, low cost quinidine for the preparation of synthetically unique and medicinally multi-functionalized isoxazoline N-oxides with three stereogenic centers including adjacent quaternary and tertiary ste...

Patients suffering from pulmonary tuberculosis were investigated for the levels of isoniazid (INH) and its metabolites viz. acetyl-INH, mono and diacetyl hydrazines and ammonia. It was observed that 50% of the patients are slow inactivators of INH and almost all show an increase in circulating levels of NH3 at 6 hrs. Mono and diacetyl hydrazine levels in blood and urine were detectable in all t...