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Golgi α-mannosidase: opposing structures of Drosophila melanogaster and novel h...
Drogalin, Artem; Monteiro, Luís S.; Alves, Maria José Chão; Castro, Tarsila GabrielThe search for Golgi a-mannosidase II (GMII) potent and specific inhibitors has been a focus of many studies for the past three decades since this enzyme is a key target for cancer treatment. a-Mannosidases, such as those from Drosophila melanogaster or Jack bean, have been used as functional models of the human Golgi a-mannosidase II (hGMII) because mammalian mannosidases are difficult to purify and characteri...
Concise synthesis of (S)-7-Hydroxy-5-aza-8a- epi - D -swainsonine from a d -ery...
Sousa, Cristina E.A.; Salgueiro, Daniela A.L.; Alves, Maria José ChãoA five-step synthesis of (S)-7-hydroxy-5-aza-8a-epi-D-swainsonine [(3S,4S,4aS,5S,6R)-octahydropyrrolo[1,2-b]pyridazine-3,4,5,6- tetraol] was accessed in good overall yield from readily available D-erythrosyl benzylidene acetal buta-1,3-diene. The key step of the reaction sequence is a full stereoselective Diels Alder cycloaddition between the diene and dienophile: diethyl azodicarboxylate (DEAD) or di-tert-buty...
Synthesis of novel sugar derived aziridines, as starting materials giving acces...
Sousa, Cristina E.A.; Alves, Maria José Chãod-Erythrosyl aziridines were obtained from d-erythrosyl triazoles either by photolysis or through diazirine intermediates. These were found to undergo rich, high yielding chemistry by reaction with protic acids (HCl, BiI3/H2O and trifluoroacetic acid) leading to two types of furanoid sugar α-amino acids, and polyhydroxylprolines. Based on experimental evidence, reaction mechanisms have been proposed for the syn...
Synthesis and bioactivity of new analogue of Bicyclic 1-Azafagomine
Akhundova, Fidan N.; Kurbanova, Malahat M.; Huseynzada, Alakbar E.; Alves, Maria José Chão; Sujayev, Afsun R.New (S)-(1,2,3,6-tetrahydropyridazin-3-yl)methanol was synthesized by Lewis acid catalyzed and self-assembled Diels-Alder (LACASA-DA) cycloaddition reaction using (S)-BINOL as a chiral inductor. The N-2 pyridazine position was protected, the hydroxyl group was carbonylated to form the new bicyclic structure. The protective group was removed and the double bond was dihydroxylated leading to the target compound. ...
Synthesis of New Iminosugar Derivatives Based on (S)-(1,2,3,6-Tetrahydropyridaz...
Axundova, F. N.; Kurbanova, M. M.; Huseynzada, A. E.; Alves, Maria José Chão(S)-(1,2,3,6-Tetrahydropyridazin-3-yl)methanol was synthesized in two steps by the Diels-Alder reaction of penta-2,4-dien-1-ol with diethyl azodicarboxylate in the presence of (S)-BINOL as chiral catalyst. The subsequent Boc-protection of the 2-position of the pyridazine ring, ring-closing carbonylation of the hydroxy group, and deprotection afforded a bicyclic iminosugar analog. The structure of the isolated c...
A short synthesis of (2 S,3 S,4 R )-Dihydroxyhomoprolines from d -Erythrose-Der...
Freitas, David S.; Noro, Jennifer Martins; Drogalin, Artem; Fernandes, Monica C. S.; Baptista, Antonio V. M.; Parente, Joana F. C.(2S,3S,4R)- Dihydroxyhomoprolines were obtained from a six- carbon- atom lactone intermediate obtained from D- erythrose in a short synthesis, by facile operational methodology, in very good overall yields.
(3S,4R)-3,4-Dihydroxy-N-alkyl-l-homoprolines: synthesis and computational mecha...
Freitas, David S.; Sousa, Cristina E. A.; Parente, Joana; Drogalim, Artem; Fortes, A. Gil; Cerqueira, Nuno M. F. S. A.; Rodríguez-Borges, José E.This is the first synthetic report of (3S,4R)-dihydroxy-N-alkyl-l-homoprolines described so far. 2,4-O-Benzylidene-d-erythrose was obtained from d-glucose with an improved yield, and then transformed into the title (3S,4R)-dihydroxy-N-alkyl-l-homoprolines, in a two-step strategy, with excellent overall yields. Hydrogenolysis of the benzyl group led to the NH congener. The synthesis of final products from 1,4-la...
Total Stereoselective Michael Addition of N- and S- Nucleophiles to a D-Erythro...
Rocha, Juliana F.; Freitas, David S.; Noro, Jennifer Martins; Silva Teixeira, Carla S.; Sousa, Cristina E. A.; Alves, Maria José ChãoThe synthesis of a 1,S-lactone 2,4-O-alkylidene-D-erythrose derivative was found to be a highly stereoselective template in Michael addition trough the reaction of a D-erythrosyl 1,5-lactone derivative with nitrogen and sulfur nucleophiles. The sulfur adducts formed are 1 (D-erythrose derivative):1 (nucleophile), and the nitrogen adducts are 1:2. Both were then treated under HCl to give 2,6-dideoxy-4-functional...
Styrene epoxidation over heterogeneous manganese(III) complexes
Kuzniarska-Biernacka, Iwona; Lisinska-Czekaj, A.; Czekaj, D.; Alves, Maria José Chão; Fonseca, A. M.; Neves, Isabel C.The manganes(III) complex functionalised with 2,3-dihydropyridazine has been encapsulated in the supercages of the NaY zeolite using two different procedures, flexible ligand and in situ complex. The parent zeolite and the encapsulated manganese(III) complexes were screened as catalysts for styrene oxidation by using t-BOOH as the oxygen source in acetonitrile. Under the optimized conditions, the catalysts exhi...
Exploiting the antiparasitic activity of naphthalimides derivatives
Silva, Anabela Cordeiro da; Alves, Maria José Chão; Thoo-Lin, Paul Kong; Baptista, Catarina; Noro, Jennifer Martins; Cristo, Gabriela; Gaspar, LuísA set of 1,8-naphtalimides derivatives were synthesized and tested against three protozoans that cause important human diseases: Leishmaniainfantum, Trypanosomabrucei and Trypanosomacruzi. Additionally, toxicity was determined by growth inhibition of THP-1 derived macrophages. The results suggest that chemical modifications in the carbon chain linking the naphthalimide and the substituting groups have different...