Novel highly emissive non proteinogenic amino acids : synthesis of 1,3,4-thiadiazolyl asparagines and evaluation as fluorimetric chemosensors for biologically relevant transition metal cations

Highly emissive heterocyclic asparagine derivatives bearing a 1,3,4-thiadiazolyl unit at the side chain, functionalised with electron donor or acceptor groups, were synthesised and evaluated as amino acid based fluorimetric chemosensors for metal cations such as Cu2+, Zn2+, Co2+ and Ni2+. The results suggest that there is a strong interaction through the donor heteroatoms at the side chain of the various asparagine derivatives, with high sensitivity towards Cu2+ in a ligand-metal complex with 1:2 stoichiometry. Association constants and detection limits for Cu2+ were calculated. The photophysical and metal ion sensing properties of these asparagine derivatives confirm their potential as fluorimetric chemosensors and suggest that they can be suitable for incorporation into chemosensory peptidic frameworks.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/QUI/66250/2006 (FCOMP-01-0124-FEDER-007428

VOLTAMMETRIC BEHAVIOR OF BOVINE ERYTHROCYTE SUPEROXIDE-DISMUTASE

VOLTAMMETRIC BEHAVIOR OF BOVINE ERYTHROCYTE SUPEROXIDE-DISMUTASE WAS INVESTIGATED IN AQUEOUS SOLUTIO

REDOX CHEMISTRY OF SUPEROXIDE-DISMUTASE - CYCLIC VOLTAMMETRY OF WILD-TYPE ENZYMES AND MUTANTS ON FUNCTIONALLY RELEVANT RESIDUES

The reduction potential of human cuprozinc superoxide dismutase and of several of its functionally relevant mutants have been measured through cyclic voltammetry. The reduction potential of the bovine enzyme has been also measured and compared with literature values. The human enzyme has a slightly higher redox potential than the bovine isoenzyme (E-degrees = 0.36 +/- 0.01 and 0.32 +/- 0.01 V vs NHE, at pH 7.4, respectively). The redox properties of the bovine copper-cobalt derivative are very similar to those of the native protein. The pH dependence of the E-degrees value in the wild-type enzyme and its pH independence in the Asn- 1 24 mutant, which has an empty zinc binding site over the entire pH range, is ascribed to the uptake of a proton by His-63 upon reduction. A pK(a) value of 10.8 for this group is obtained from H-1 NMR titrations. It is proposed that also in the zinc-deprived derivative the copper-His-63 bond is broken upon reduction. Sizably negative reduction potentials were estimated for CN- and N3--inhibited enzymes. The values are below the reduction potential of dioxygen to superoxide

Dietary patterns and the risk of coronary heart disease among Jordanians: A caseecontrol study

Background and Aims Dietary pattern and lifestyle have been reported to be significant risk factors in the development of coronary heart diseases (CHD). The contribution degree of these dietary risk factors in CHD development in non-westernized countries is unclear. This study aimed to evaluate several dietary choices and their potential association with CHD. Methods and Results A case-control study was conducted at Prince Hamza Hospital, a referral center for coronary angiography in Amman, Jordan. Four-hundred patients referring for elective coronary angiography with clinical suspicion of coronary artery disease were enrolled. Data was collected using interview-based questionnaires. Dietary patterns were derived using Principal Component Analysis. Multivariate logistic regression was used to estimate the relationship between dietary choices and CHD. Three dietary patterns were identified. The "Healthy Dietary Pattern", which presented a diet rich in olive oil, fruits, vegetables, legumes, whole grains, fish, and low meat intake, was associated with a significant decrease in the odds of CHD (OR= 0.53 , 95% CI=0.28 –0.98 ). The “High-Fiber Pattern”, which is mainly composed of legumes and bulgur, significantly reduced the odd of CHD (OR= 0.55, 95% CI=0.27–0.92) for the fourth quartile compared to the first one. No significant association was found between CHD and the "Western Dietary Pattern", which is loaded with refined grains, sweets and deserts, sugary drinks, and deep fried foods. Conclusions The “Healthy Dietary Pattern” and the “High-Fiber Pattern” were associated with a decrease in odds of CHD among Jordanians