0000000000696979

AUTHOR

André M. N. Silva

0000-0001-5554-7714

showing 5 related works from this author

Phytochemical characterization and biological activities of green tea (Camellia sinensis) produced in the Azores, Portugal

2021

Abstract Background Green tea is not only one of the most widely consumed beverages worldwide, but is also known for its health promoting and therapeutic effects. Green tea is cultivated in areas with high humidity and acidic soils in China, Indonesia and Japan. Those places have well-marked dry and rainy seasons. In opposite, Azores have a climate with constant average annual rainfall and, unlike eastern regions, relatively constant air humidity throughout the year. While a brand implemented on the Portuguese market, the quality of green tea produced in Azores must be guaranteed. Quality control measures based on phytochemical determination of the chemical composition and biological activi…

PhytochemistryChemistryDPPHTheaceaeFunctional foodGeneral EngineeringEpigallocatechin gallateTheanineNatural productchemistry.chemical_compoundOther systems of medicineEpicatechin gallatePhytochemicalMaceration (wine)General Earth and Planetary SciencesCamellia sinensisFood scienceGallic acidAntioxidantRZ201-999General Environmental ScienceCancer
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1,3-Dipolar cycloadditions with meso-tetraarylchlorins – site selectivity and mixed bisadducts

2017

The 1,3-dipolar cycloaddition reaction of meso-tetraarylporphyrins with nitrones gives isoxazolidine-fused chlorins. Depending on the substitution pattern on the meso-aryl groups and the nitrone, the chlorins can be obtained in high yields (up to 91%). Bacteriochlorin-type bisadducts are also obtained, although in low yield, from the reaction of meso-tetrakis(pentafluorophenyl)porphyrin with N-methyl, N-cyclohexyl or N-benzyl nitrone. The structure of a bis(N-benzyl isoxazolidine-fused) bacteriochlorin was determined by single-crystal X-ray diffraction and rationalized by DFT calculations. To further explore the nature of site selectivity in the formation of bisadducts, isomeric mixed bacte…

chemistry.chemical_classification010405 organic chemistryChemistrySite selectivityOrganic ChemistryAzomethine ylide010402 general chemistryPhotochemistry01 natural sciencesPorphyrinCycloaddition0104 chemical sciencesNitronechemistry.chemical_compoundDipoleSettore CHIM/03 - Chimica Generale E InorganicaComputational chemistryYield (chemistry)Organic Chemistry Frontiers
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The Influence of the Amide Linkage in the FeIII-Binding Properties of Catechol-Modified Rosamine Derivatives

2015

The two new fluorescent ligands RosCat1 and RosCat2 contain catechol receptors connected to rosamine platforms through an amide linkage and were synthesized by using microwave-assisted coupling reactions of carboxyl- or amine-substituted rosamines with the corresponding catechol units and subsequent deprotection. RosCat1 possesses a reverse amide, whereas RosCat2 has the usual oriented amide bond (HNCO vs. CONH, respectively). The ligands were characterized by means of NMR spectroscopy, mass-spectrometry, and DFT calculations and X-ray crystallography studies for RosCat1. The influence of the amide linkage on the photophysical properties of the fluorescent ligands was assessed in different …

chemistry.chemical_classificationligand designCatecholChemistryStereochemistryOrganic ChemistryChemistry (all)Quantum yieldGeneral ChemistryNuclear magnetic resonance spectroscopyamideCatalysisCoupling reactionCoordination complexCrystallographychemistry.chemical_compoundironSettore CHIM/03 - Chimica Generale E InorganicaAmidePeptide bondChelationcoordination modemass spectrometry
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CCDC 1402129: Experimental Crystal Structure Determination

2016

Related Article: Carla Queirós, Andreia Leite, Maria G. M. Couto, mLuís Cunha-Silva, Giampaolo Barone, Baltazar de Castro, Maria Rangel, André M. N. Silva, Ana M. G. Silva|2015|Chem.-Eur.J.|21|15692|doi:10.1002/chem.201502093

6-(Diethylamino)-9-(4-((23-dihydroxybenzyl)carbamoyl)phenyl)-NN-diethyl-3H-xanthen-3-iminium chloride chloroform solvateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1488184: Experimental Crystal Structure Determination

2017

Related Article: José Almeida, António Aguiar, Andreia Leite, André M. N. Silva, Luís Cunha-Silva, Baltazar de Castro, Maria Rangel, Giampaolo Barone, Augusto C. Tomé, Ana M. G. Silva|2017|Org.Chem.Front.|4|534|doi:10.1039/C6QO00771F

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters1124-dibenzyl-271520-tetrakis(pentafluorophenyl)-1023-dioxa-112427282930-hexaazaheptacyclo[19.5.1.136.1814.11619.0913.02226]triaconta-1(27)2468(29)14161820-nonaeneExperimental 3D Coordinates
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