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The aim of this study was to discover the unique volatile compositional traits of retail milk from different production systems. Forty-four retail milk samples were analyzed, including organic milk (n = 10), conventional milk (n = 14) and pasture milk (n = 20) from winter (n = 22) and summer (n = 22). Proton transfer reaction quadrupole mass spectrometry (PTR-(Quad)MS) was utilized to obtain the mass-resolved fingerprints (76 masses per sample) of volatile organic compounds (VOCs). Principal component analysis (PCA) and analysis of variance (ANOVA) were performed to evaluate the differences between the groups. The production systems were characterized by six masses, while season showed larger differences, with twenty-two masses discriminating between the milks. For 2 masses, a significant interaction of systems and seasons was observed. The chemical formula of these VOC masses were tentatively identified by Proton Transfer Reaction Time-of-Flight Mass Spectrometric (PTR-(ToF)MS). These results illustrate that the type of feed is reflected in the VOC composition of milks. [ABSTRACT FROM AUTHOR]

Temporal developmental progression is highly coordinated in Caenorhabditis elegans. However, loss of nicotinamidase PNC-1 activity slows reproductive development, uncoupling it from its typical progression relative to the soma. Using LC/MS we demonstrate that pnc-1 mutants do not salvage the nicotinamide released by NAD+ consumers to resynthesize NAD+, resulting in a reduction in global NAD+ bioavailability. We manipulate NAD+ levels to demonstrate that a minor deficit in NAD+ availability is incompatible with a normal pace of gonad development. The NAD+deficit compromises NAD+ consumer activity, but we surprisingly found no functional link between consumer activity and reproductive development. As a result we turned to a comparative metabolomics approach to identify the cause of the developmental phenotype. We reveal widespread metabolic perturbations, and using complementary pharmacological and genetic approaches, we demonstrate that a glycolytic block accounts for the slow pace of reproductive development. Interestingly, mitochondria are protected from both the deficiency in NAD+ biosynthesis and the effects of reduced glycolytic output. We suggest that compensatory metabolic processes that maintain mitochondrial activity in the absence of efficient glycolysis are incompatible with the requirements for reproductive development, which requires high levels of cell division. In addition to demonstrating metabolic requirements for reproductive development, this work also has implications for understanding the mechanisms behind therapeutic interventions that target NAD+ salvage biosynthesis for the purposes of inhibiting tumor growth. [ABSTRACT FROM AUTHOR]

Environmentally benign conditions have been developed for the synthesis of 2-amino-4-(2-oxo-2 H -chromen-3-yl)thiophene-3-carbonitriles ( 3 ) starting from 3-acetyl-2 H -chromen-2-one ( 1 ) through the intermediacy of 2-(1-(2-oxo-2 H -chromen-3-yl)ethylidene)malononitrile ( 2 ) using the Knoevenagel condensation followed by the Gewald reaction. Alternatively, 3 could also be prepared in a one pot method by treating equimolar amounts of 1 , malononitrile, and elemental sulfur. The merits of this preparation are mild reaction conditions, easy work-up procedure, and good yields. [ABSTRACT FROM AUTHOR]

We have disclosed an efficient, one pot, novel multi-component approach for the synthesis of 5-aryl-[1,2,4]triazolidine-3-thiones from aldehyde, hydrazine hydrate, and trimethylsilyl isothiocyanate (TMSNCS) in the presence of catalytic amount of sulfamic acid. High yields, easy work-up procedure, no chromatographic separation, and novelty in multi-component strategy are the main merits of the present strategy. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of open chain, cyclic, and unsymmetrical dithioacetals from aryl/hetero-aryl/aliphatic aldehydes is described. The reaction is performed using graphene oxide (GO) as the catalyst under solvent-free and aerobic conditions. High chemoselectivity is observed in the reaction as aryl/alkyl ketones do not give thioketals under the condition. [ABSTRACT FROM AUTHOR]

A new and efficient protocol is described for the one-pot synthesis of benzimidazoles from a variety of aryl alcohols and 1,2-diaminoarenes. The yields were ranging from moderate to excellent. Moreover, the present method is utilizing alcohols instead of aldehydes and the reactions are carried out under solvent- and catalyst-free conditions, offering an environmentally benign process. [ABSTRACT FROM AUTHOR]

The development of an efficient synthetic method toward substituted 1,2-dihydropyridines from cinnamylideneacetophenones is reported. The key intermediates N -sulfonylazatrienes were synthesized through a TiCl 4 -mediated direct condensation of primary sulfonamides with the substituted ( E , E )-cinnamylideneacetophenones. The 6π-electrocyclization of these intermediates, catalyzed by a Lewis acid, selectively afforded the desired products in good yields. [ABSTRACT FROM AUTHOR]

An efficient protocol for the synthesis of highly functionalized 2-aminoindolizines and pyrido[3,2- a ]indolizines has been achieved via the reaction of N -RC(O)CH 2 -2-chloropyridinium bromides with 2-amino-1,1,3-tricyanopropene in the presence of Et 3 N. The reaction of N -allyl-2-chloropyridinium bromide with 2-amino-1,1,3-tricyanopropene in the presence of Et 3 N gives 3-[1-allylpyridin-2(1 Н )-ylidene]-2-aminoprop-1-ene-1,1,3-tricarbonitrile, which could be cyclized to give [2-amino-(2-amino-3-vinylindolizin-1-yl)methylene]malononitrile upon treatment with KOH–DMF. [ABSTRACT FROM AUTHOR]

The synthesis of medium-ring heterocycles remains a challenge largely due to unfavorable energetic factors. We are reporting syntheses of 7–9-member diaza heterocycles that go to completion in 5 min, require no solvents, and are quantitative with the only byproducts being acetone and water. The reaction products could be isolated in pure form by simply placing the mixture under vacuum. The reaction sequence possesses many of the hallmarks of a click reaction. [ABSTRACT FROM AUTHOR]