A kémiai szerkezet molekuláris felismerésre gyakorolt hatása

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Synthesis of carotenoid-monosaccharide conjugates via azide–alkyne click-reaction

Carotenoid pentynoates were coupled to protected and unprotected sugar azides via an azide-alkyne click-reaction using bis-triphenylphosphano-copper(I)-butyrate (C3H7COOCu(PPh3)2) complex. Protected sugars delivered the conjugates with excellent yields, whereas with unprotected ones amphipathic carotenoid-sugar derivatives were obtained in good or moderate yields in a simple wa

Palladium-Mediated Catalysis Leads to Intramolecular Narcissistic Self-Sorting on a Cavitand Platform

Palladium-catalyzed aminocarbonylation reactions have been used to directly convert a tetraiodocavitand intermediate into the corresponding carboxamides and 2-ketocarboxamides. When complex mixtures of the amine reactants are employed in competition experiments, no ‘mixed’ products possessing structurally different amide fragments are detected either by 1H or 13C NMR. Only highly symmetrical cavitands are sorted out of a large number of potentially feasible products, which represents a rare example of intramolecular, narcissistic self-sorting. The reactivity order of the amine reactants and the changes in the Gibbs energies calculated using the semiempirical PM6 model suggest that this self-sorting process is kinetically controlled

Study on the Synthesis, Antioxidant Properties, and Self-Assembly of Carotenoid-Flavonoid Conjugates

L

β-estradiol and ethinyl-estradiol contamination in the rivers of the Carpathian Basin

17 β - estradiol (E2) and 17 α - ethinyl estradiol (EE2), wh ich are environmental estrogens have been determined with LC - MS in freshwater. Their sensitive analysis needs derivatisation and therefore is very hard to ac hieve in multiresidue screening . We analysed samples from all the large and some small rivers (River Danube, Drava, Mur, Sava, Tisza and Zala) of the Carpathian Basin and from Lake Balaton. Freshwater was extracted on solid phase and derivatised using dansyl - chloride. Separation was per formed on a Kinetex XB - C18 column. Detection was achieved with a benchtop orbitrap mass spectrometer using targeted MS analysis for quantification. Limits of quantification were 0.05 ng/L (MS1) and 0.1 ng/L (MS/MS ) for E2, and 0.001 ng/L (MS1) and 0.2 ng/L (MS/MS ) for EE2. River samples contained n.d. - 5.2 ng/L E2 and n.d. - 0.68 ng/L EE2. Average levels of E2 and EE2 were 0.6 1 and 0.084 ng/L respectively in rivers, water courses and Lake Balaton together, but not counting city canal water . EE2 was less abunda nt, but it was still present in almost all of the samples. In b each water samples from Lake Balaton we measured 0.076 - 0.233 E2 and n.d. - 0.133 EE2. A relative high amount of EE2 was found in river Zala (0.68 ng/L) and in Hévíz - P áhoki canal (0.52 ng/L), whic h are both in the catchment area of Lake Balaton (Hungary)

Elevated Vascular Level of ortho-Tyrosine Contributes to the Impairment of Insulin-Induced Arterial Relaxation.

Previous studies have shown that in diabetes mellitus, insulin-induced relaxation of arteries is impaired and the level of ortho-tyrosine (o-Tyr), an oxidized amino acid is increased. Thus, we hypothesized that elevated vascular level of o-Tyr contributes to the impairment of insulin-induced vascular relaxation. Rats were fed with o-Tyr for 4 weeks. Insulin-induced vasomotor responses of isolated femoral artery were studied using wire myography. Vascular o-Tyr content was measured by HPLC, whereas immunoblot analyses were preformed to detect eNOS phosphorylation. Sustained oral supplementation of rats with o-Tyr increased the content of o-Tyr in the arterial wall and significantly reduced the relaxations to insulin. Sustained supplementation of cultured endothelial cells with o-Tyr increased the incorporation of o-Tyr and mitigated eNOS Ser (1 177) phosphorylation to insulin. Increasing arterial wall o-Tyr level attenuates insulin-induced relaxation - at least in part - by decreasing eNOS activation. Elevated level of o-Tyr could be an underlying mechanism for vasomotor dysfunction in diabetes mellitus