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Salmonella Kentucky is commonly found in poultry and rarely associated with human disease. However, a multidrug-resistant (MDR) S. Kentucky clone [sequence type (ST)198] has been increasingly reported globally in humans and animals. Our aim here was to assess if the recently reported increase of S. Kentucky in poultry in Spain was associated with the ST198 clone and to characterize this MDR clone and its distribution in Spain. Sixty-sixisolates retrieved from turkey, laying hen and broiler in 2011–2017 were subjected to whole-genomesequencing to assess their sequence type, genetic relatedness, and presence of antimicrobial resistance genes (ARGs), plasmid replicons and virulence factors. Thirteen strains were further analysed using long-readsequencing technologies to characterize the genetic background associated with ARGs. All isolates belonged to the ST198 clone and were grouped in three clades associated with the presence of a specific point mutation in the gyrA gene, their geographical origin and isolation year. All strains carried between one and 16 ARGs whose presence correlated with the resistance phenotype to between two and eight antimicrobials. The ARGs were located in the Salmonella genomic island (SGI-1) and in some cases (blaSHV-12, catA1, cmlA1, dfrA and multiple aminoglycoside-resistancegenes) in IncHI2/IncI1 plasmids, some of which were consistently detected in different years/farms in certain regions, suggesting they could persist over time. Our results indicate that the MDR S. Kentucky ST198 is present in all investigated poultry hosts in Spain, and that certain strains also carry additional plasmid-mediatedARGs, thus increasing its potential public health significance.

The Diels‐Alder reaction of 1‐aminovinylphosphonate esters has been studied for the first time as a suitable procedure leading to quaternary carbocyclic α‐aminophosphonates. The reaction is influenced by steric effects at the phosphonate functionality (bulky groups hinder the reaction) and electronic effects at the amino group (electron‐withdrawing substituents increase the reaction rate). The exo/endo ratio is constant, and no influence of the solvent is observed. The experimental results have been rationalized by DFT methods., This work was supported by the Ministerio de Economía y Competitividad (grants CTQ2013–40855-R to C.C. and CTQ2016–76155-R to P.M.) and the Gobierno de Aragón–FEDER (Biological and Computational Chemistry Group E34_R17 and Amino acids and Peptides Group E19_17R). M.M.J.-A. thanks the Gobierno de Aragón-FSE for predoctoral grant.

Two distinct series of the 3-amino-1, 5-benzoxathiepin scaffold, derived from L-cysteine, were synthesized and evaluated for their anti-proliferative activity in the breast cancer MDA-MB-231 and MCF-7 cells, and in the ovarian carcinoma SKOV-3 cell line. (3R)-Amino-3, 4-dihydro-2H-1, 5-benzoxathiepin [(R)-10] was diversified into two forms: (a) by incorporating different amino acids at its position 3, through an amide bond; and (b) by construction of the purine ring to give 6-chloro-9-[2-(3, 4-dihydro-2H-1, 5-benzoxathiepin-(3R)-yl)]-9H-purine [(R)-28]. Nevertheless, when the introduction of iodine was tried at position 2 of the purine ring of (R)-28, 2-{[2-(6-chloro-2-iodo-9H-purin-9-yl) prop-2-en-1-yl] thio} phenol (34) was obtained. Compound 34 shows activity against cancer cells. Interestingly, 34 inhibits mammosphere formation at the micromolar range, demonstrating activity against cancer stem cells. Although further studies of its targets and mechanism of action are needed, these findings support the therapeutic potential of this compound in cancer.

Using a combined chemical/chiral chromatographic approach we synthesized an N-protected derivative of (R)-c(3)Val, a severely conformationally restricted C-alpha-tetrasubstituted alpha-amino acid characterized by a C-beta,C-beta-dimethylated cyclopropane system. A set of terminally protected derivatives and model peptides (to the heptamer level), containing one or two (R)-c(3)Val residues in combination with either Aib or Gly residues, was prepared by solution methods. A detailed solution and crystal-state conformational investigation, based on Fourier transform infrared (FTIR) absorption, H-1-NMR, and x-ray diffraction techniques, performed in comparison with a similar study on related derivatives and peptides rich in (alphaMe)Val, the prototype of C-alpha-tetrasubstituted alpha-amino acids of this subfamily, allowed us to conclude the following: (a) c(3)Val is a good beta-bend and helix former, although less efficient than (alphaMe)Val. (b) The relationship between alpha-carbon chirality and screw sense of the folded structure formed is the same as that of (alphaMe) Val, i.e., the (R)-enantiomer has a strong left-handed bias. (c) c(3)Val seems more prone than (alphaMe)Val to fold into a gamma-bend conformation. The conformational propensities of C-beta,C-beta-disubstituted Ac(3)c residues are also discussed in comparison with those of the parent cyclopropane residue.

We have synthesized by solution methods and characterized the lipopeptaibol metabolite LP237-F8 extracted from the fungus Tolypocladium geodes and five selected analogues with the Etn --> Aib or Etn --> Nva replacement at position 8 and/or a triple Gln --> Glu(OMe) replacement at positions 516, and 9 (Etn = Calpha-ethylnorvaline, Aib = alpha-aminoisobutyric acid, Nva = norvaline). Conformation analysis, performed by FT-IR absorption, NMR, and CD techniques, strongly supports the view that the six terminally blocked decapeptides are highly helical in solution. Helix topology and amphiphilic character are responsible for their remarkable membrane activity. At position 8 the combination of high hydrophobicity and Ca tetrasubstitution, as in the Etn-containing LP237-F8 metabolite, has a positive effect on membrane interaction.

This report describes the synthesis of enantiomerically pure (S)- and (R)--vinylalanines and (S)- and (R)--ethynylalanines, four quaternary - amino acids, using a straightforward synthetic route and starting from (S)- and (R)-N-Boc-N,O-isopropylidene--methylserinals. (C) 1999 Elsevier Science Ltd.

General procedures for the synthesis of six series of 3-substituted pentane-2,4-diones are described. The diones were used as intermediates in the preparation of pyrazoles, isoxazoles, and coordination complexes whose mesogenic properties have been studied. Nematic and smectic phases have been obtained in a number of cases, and the relationship between molecular structure and mesogenic properties has been explored. © 1995 American Chemical Society.

High and complementary diastereoselectivities were obtained in the asymmetric Diels-Alder reactions of chiral (E)-2-cyanocinnamates with butadiene when (S)-ethyl lactate and (R)-pantolactone were used as chiral auxiliaries in the presence of TiCl4. The most selective reactions allowed the synthesis of the cycloadducts 2a and 3b, whose absolute configurations were assigned by an X-ray diffraction study of diastereoisomer 3b. The hydrolysis and subsequent hydrogenation of the stereoisomers gave the corresponding enantiomeric cyanocarboxylic acids. From these products the four 1-amino-2-phenyl-1-cyclohexanecarboxylic acids were synthesized in enantiomerically pure form following a protocol with stereocontrolled and stereodivergent transformations.