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Study of Nα-benzoyl-L-argininate ethyl ester chloride, a model compound for pol...
Fonseca, A. C.; Jarmelo, S.; Silva, M. Ramos; Beja, A. M. Matos; Fausto, R.; Gil, M. H.; Simões, P. N.Poly(ester amide)s (PEAs) are lacking in structural and spectroscopic information. This paper reports a structural and spectroscopic characterization of Nα-benzoyl-L-argininate ethyl ester chloride (BAEEH+·Cl−), an important amino acid derivative and an adequate PEAs’ model compound. Crystals of BAEEH+·Cl− obtained by slow evaporation in an ethanol/water mixture were studied by different complementary technique...
FTIR spectroscopy structural analysis of the interaction between Lactobacillus ...
Gerbino, E.; Mobili, P.; Tymczyszyn, E.; Fausto, R.; Gómez-Zavaglia, A.FTIR spectroscopy was used to structurally characterize the interaction of S-layer proteins extracted from two strains of Lactobacillus kefir (the aggregating CIDCA 8348 and the non-aggregating JCM 5818) with metal ions (Cd+2, Zn+2, Pb+2 and Ni+2). The infrared spectra indicate that the metal/protein interaction occurs mainly through the carboxylate groups of the side chains of Asp and Glut residues, with some ...
FTIR spectroscopic and theoretical study of matrix-isolated (E)-1-(cyclopropyld...
Duarte, L.; Giuliano, B. M.; Reva, I.; Campos, Ana M. F. Oliveira; Fausto, R.Photochromic systems are important due to their industrial applications in variable optical transmission materials and optobioelectronic devices. For such applications, the organic photochromic compounds involved are usually incorporated in polymers, liquid crystalline materials, or other convenient host matrices [1, 2]. Herein, a photochromic compound, (E)-1-(cyclopropyldiazenyl)naphthalen-2-ol (show in Figure...
Sigmatropic rearrangements in 5-allyloxytetrazoles
Frija, L.; Reva, I. D.; Ismael, A.; Coelho, Daniela; Fausto, R.; Cristiano, Maria Lurdes SantosMechanisms of thermal isomerization of allyl tetrazolyl ethers derived from the carbocyclic allylic alcohols cyclohex-2-enol and 3-methylcyclohex-2-enol and from the natural terpene alcohol nerol were investigated. In the process of the syntheses of the three 1-aryl-5-allyloxytetrazoles, their rapid isomerization to the corresponding 1-aryl-4-allyltetrazol-5-ones occurred. The experiments showed that the imidat...
1H NMR Spectroscopic and Quantum Chemical Studies on a Poly(ester amide) Model ...
Fonseca, A. C.; Jarmelo, S.; Carvalho, R. A.; Fausto, R.; Gil, M. H.; Simões, P. N.The molecular structure of the l-arginine derivative, Nα-benzoyl-l-argininate ethyl ester chloride (BAEEH+·Cl−), was characterized by combining quantum chemical methods and 1H NMR spectroscopy. A conformational search on the potential energy surfaces of the three lowest-energy tautomers of BAEEH+ [A: R−N+H═(NH2)2; B: R−NH−C(═NH)N+H3; C: R−N+H2−C(═NH)NH2; R = C6H5C(═O)NH−CH(COOCH2CH3)CH2CH2CH2−] was carried out ...
Role of Guanidyl Moiety in the Insertion of Arginine and Nα-Benzoyl-l-argininat...
Fonseca, A. C.; Frías, M. A.; Bouchet, A. M.; Jarmelo, S.; Simões, P. N.; Fausto, R.; Gil, M. H.; Lairion, F.; Disalvo, E. A.Role of Guanidyl Moiety in the Insertion of Arginine and Nα-Benzoyl-l-argininate Ethyl Ester Chloride in Lipid Membranes AbstractFull Text HTMLHi-Res PDF[1247 KB]PDF w/ Links[216 KB]FiguresReferencesA. C. Fonseca‡, M. A. Frías†, A. M. Bouchet†, S. Jarmelo‡§, P. N. Simões‡, R. Fausto§, M. H. Gil‡, F. Lairion† and E. A. Disalvo*† Laboratory of Physical Chemistry of Lipid Membranes, Department of Analytical Che...
Conformational Space and Photochemistry of α-Terpinene
Marzec, K. M.; Reva, I.; Fausto, R.; Malek, K.; Proniewicz, L. M.α-Terpinene is a natural product that is isolated from a variety of plant sources and is used in the pharmaceutical and perfume industries. In the atmosphere, under the influence of sunlight, α-terpinene undergoes a series of photochemical transformations and contributes to the formation of the secondary organic aerosols. In the present work, α-terpinene has been isolated in low-temperature xenon and argon matr...
Tautomer Selective Photochemistry in 1-(Tetrazol-5-yl)ethanol
Ismael, A.; Cristiano, M. L. S.; Fausto, R.; Gómez-Zavaglia, A.A combined matrix isolation FTIR and theoretical DFT/B3LYP/6-311++G(d,p) study of the molecular structure and photochemistry of 1-(tetrazol-5-yl)ethanol [1-TE] was performed. The potential energy surface landscapes of the 1H and 2H tautomers of the compound were investigated and the theoretical results were used to help characterize the conformational mixture existing in equilibrium in the gas phase prior to de...
Molecular modeling of the interaction of novel hydroxy-and aminobisphosphonates...
Duarte, L. F.; Teixeira, Fátima C.; Fausto, R.Bisphosphonates (BPs) are a class of drugs widely used in the treatment of several metabolic bone disorders associated with increased bone resorption. Although BPs can directly inhibit the cellular activity of osteoclasts, their ability to adsorb on bone mineral is also an important factor in determining their potency and duration of action. In this study, we performed a molecular mechanics analysis of the mole...
Synthesis and structure of novel benzisothiazole-tetrazolyl derivatives for pot...
Frija, Luís M. T.; Fausto, R.; Loureiro, Rui M. S.; Cristiano, M. Lurdes S.http://www.sciencedirect.com/science/article/B6TGM-4V70NKX-1/2/ad205afe2d6f14b54072365e68e443a0
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