No abstract

The first general methodology for the gram-scale preparation of previously overlooked beta-(hetero)aryl-alpha-nitro-alpha,beta-enals (3) is reported. Condensation of (hetero)aromatic aldehydes with 2-nitroethanol gave the E-isomers of uncommon beta-(hetero)aryl-alpha-hydroxymethyl-alpha,beta-unsatured-nitroalkenes (2), as determined by NOE and X-ray studies. alpha-Nitro-alpha,beta-enals 3 were subsequently obtained by hypervalent iodine oxidation of 2 as E-Z-mixtures in solid form. They showed varied stability and solvent-dependent thermal-promoted and photopromoted E-Z interconversion. Starting with furfural, experimental conditions were developed to prepare the corresponding nitroenal 3a enriched in either the E or the Z isomer: E-3a/Z-3a approximately 90/10 and 20/80, respectively. In contrast with other structurally related compounds, nitroenals 3 have their (hetero)aryl-vinyl unit and their formyl and nitro groups all in a planar arrangement, both in solid form and in solution; accordingly, they are colored compounds with predicted high dipole moments. As deduced from solution-NMR and X-ray data, the C=C and the C=O double bonds in 3 are exclusively s- cis-oriented; this disposition corresponds in fact to the DFT-computed most stable conformer.

The aim of this study was to synthesize three nitro substituted chalcones and to evaluate their anti-inflammatory activity in the model of carrageenan induced edema in rats. The nitro chalcone were prepared by aldol condensation using of mechanical agitation and environmentally friendly solvents with 72-73% yields in approximately 2h. The three structures were evaluated on biological activity at dose of 200mg/kg and they showed anti-inflammatory protective effect by both oral and intraperitoneal administration, this effect was time dependent.

In recent years, the fermented milk product kefir has been intensively studied because of its health benefits. Here, we evaluated the microbial consortia of two kefir samples, from Escarcega, Campeche, and Campeche (México). We considered a functional comparison between both samples, including fungal and bacterial inhibition; second, we applied shotgun metagenomics to assess the structure and functional diversity of the communities of microorganisms. These two samples exhibited antagonisms against bacterial and fungal pathogens. Bioactive polyketides and nonribosomal peptides were identified by LC‐HRMS analysis. We also observed a high bacterial diversity and an abundance of Actinobacteria in both kefir samples, and a greater abundance of Saccharomyces species in kefir of Escarcega than in the Campeche kefir. When the prophage compositions were evaluated, the Campeche sample showed a higher diversity of prophage sequences. In Escarcega, we observed a prevalence of prophage families that infect Enterobacteria and Lactobacillus. The sequences associated with secondary metabolites, such as plipastatin, fengycin, and bacillaene, and also bacteriocins like helveticin and zoocin, were also found in different proportions, with greater diversity in the Escarcega sample. The analyses described in this work open the opportunity to understand the microbial diversity in kefir samples from two distant localities.

Key indicatorsSingle-crystal X-ray study T = 296 K Mean '(C±C) = 0.006 A Ê R factor = 0.058 wR factor = 0.167 Data-to-parameter ratio = 22.2 For details of how these key indicators were automatically derived from the article, seeThe crystal structure of the title compound, C 13 H 15 NOS, is very similar to that of the corresponding oxazolopyridin-5one. However, a signi®cant participation of a tautomeric thio± enolic form is observed, as re¯ected by the short NÐC( S) bond length of 1.328 (4) A Ê .