Browsing by Author "Sequeira, Miguel M."
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- Chemical constituents of Euphorbia hyberna L. (Euphorbiaceae)Publication . Ferreira, Ana Margarida V. D.; Carvalho, Maria João; Sequeira, Miguel M.; Silva, Artur M. S.; Carvalho, Luís H. M.Chemical investigation of the aerial part and the roots of Euphorbia hyberna L. subs. hyberna. resulted in the isolation and identification of four triterpenoids (3�-O-octadecanoyllupeol (1), glut-5-en-3�-ol (2), 24-methylenecicloartan-3�-ol (3) and cicloart-23-ene-3�,25-diol (6)) along with the phenolic compounds ellagic acid (4) and 3,30 -di-O-methylellagic acid (7). Although these are all known compounds, this is the first report of their isolation from this plant. Their structures were elucidated on the basis of spectral methods, including 2D NMR experiences, and confirmed by comparing with the literature data.
- Extinctions of introduced game species on oceanic islands: curse for hunters or conservation opportunities?Publication . Rocha, Ricardo; Sequeira, Miguel M.; Douglas, Leo R.; Gouveia, Manuela; Jardim, Roberto; Jesus, José; Jones, Holly P.; Russo, Danilo
- Is there solid evidence of widespread landscape disturbance in the Azores before the arrival of the Portuguese?Publication . Elias, Rui B.; Connor, Simon E.; Góis-Marques, Carlos A.; Schaefer, Hanno; Silva, Luís; Sequeira, Miguel M.; Moura, Mónica; Borges, Paulo A. V.; Gabriel, Rosalina
- Jatrophane and lathyrane diterpenoids from Euphorbia hyberna LPublication . Ferreira, Ana Margarida V. D.; Carvalho, Luı́s H. M.; Carvalho, Maria João M.; Sequeira, Miguel M.; Silva, Artur M. S.A new diterpene tetraester, from the jatrophane family, and two new diterpene triesters, with a lathyrane skeleton, have been isolated from the chloroform extract of the roots of Euphorbia hyberna L. The structures of these compounds have been established by spectroscopic methods, including 2D NMR experiments.
- RAS gene polymorphisms, classical risk factors and the advent of coronary artery disease in the Portuguese populationPublication . Freitas, Ana I.; Mendonça, Isabel; Brión, Maria; Sequeira, Miguel M.; Reis, Roberto P.; Carracedo, Angel; Brehm, AntónioBackground: Several polymorphisms within the renin-angiotensin system cluster of genes have been associated with the advent of coronary artery disease (CAD) or related pathologies. We investigated the distribution of 5 of these polymorphisms in order to find any association with CAD development and distinguish if any of the biochemical and behavioural factors interact with genetic polymorphisms in the advent of the disease. Methods: ACE I/D (rs4340), ACE A11860G (rs4343), AT1R A1166C (rs5186), AGT T174M (rs4762) and AGT M235T (rs699) gene polymorphisms were PCR-RFLP analysed in 298 CAD patients and 510 controls from Portugal. Several biochemical and behavioural markers were obtained. Results: ACE I/D DD and ACE11860 GG genotypes are risk factors for CAD in this population. The simultaneous presence of ACE I/D I and ACE11860 A alleles corresponds to a significant trend towards a decrease in CAD incidence. We found several synergistic effects between the studied polymorphisms and classical risk factors such as hypertension, obesity, diabetes and dyslipidaemia: the presence of the DD genotype of ACE I/D (and also ACE11860 GG) increases the odds of developing CAD when associated to each one of these classical risk factors, particularly when considering the male and early onset CAD subgroup analysis; AGT235 TT also increases the CAD risk in the presence of hypertension and dyslipidaemia, and AT1R1166 interacts positively with hypertension, smoking and obesity. Conclusion: ACE polymorphisms were shown to play a major role in individual susceptibility to develop CAD. There is also a clear interaction between RAS predisposing genes and some biochemical/environmental risk factors in CAD onset, demonstrating a significant enhancement of classical markers particularly by ACE I/D and ACE11860.