University of Lisbon

About: University of Lisbon is a education organization based out in Lisbon, Lisboa, Portugal. It is known for research contribution in the topics: Population & European union. The organization has 19122 authors who have published 48503 publications receiving 1102623 citations. The organization is also known as: Universidade de Lisboa & Lisbon University.

Increased homocysteine and S-adenosylhomocysteine concentrations and DNA hypomethylation in vascular disease

Abstract: Background: The pathogenic mechanism of homocysteine’s effect on cardiovascular risk is poorly understood. Recent studies show that DNA hypomethylation induced by increases in S -adenosylhomocysteine (AdoHcy), an intermediate of Hcy metabolism and a potent inhibitor of methyltransferases, may be involved in homocysteine-related pathology. Methods: We measured fasting plasma total Hcy (tHcy), AdoHcy, and S -adenosylmethionine (AdoMet) and methylation in leukocytes in 17 patients with vascular disease and in 15 healthy, age- and sex-matched controls. Results: Patient with vascular disease had significantly higher plasma tHcy and AdoHcy concentrations and significantly lower plasma AdoMet/AdoHcy ratios and genomic DNA methylation. AdoMet concentrations were not significantly different between the two groups. More than 50% of the patients fell into the highest quartiles of plasma tHcy, AdoHcy, and [3H]dCTP incorporation/μg of DNA (meaning the lowest quartile of DNA methylation status) and into the lowest quartile of the AdoMet/AdoHcy ratios of the control group. Plasma tHcy was significantly correlated with plasma AdoHcy and AdoMet/AdoHcy ratios (n = 32; P < 0.001). DNA methylation status was significantly correlated with plasma tHcy and AdoHcy (n = 32; P < 0.01) but not with plasma AdoMet/AdoHcy ratios. Conclusion: Global DNA methylation may be altered in vascular disease, with a concomitant increase in plasma tHcy and AdoHcy.

Construction of bispirooxindoles containing three quaternary stereocentres in a cascade using a single multifunctional organocatalyst

Abstract: Spirooxindoles are important structural motifs found in an array of bioactive compounds. Here a Michael–aldol domino reaction for the construction of bispirooxindoles is presented, creating four stereocentres, including three quaternary carbon centres. Novel multifunctional organocatalysts have been developed for this transformation.