24 documents found, page 1 of 3
Conventional vs. microwave- or mechanically-assisted synthesis of dihomooxacali...
Santos Miranda, Alexandre; Marcos, Paula M.; J.R., Ascenso; Robalo, M. Paula; Bonifácio, Vasco D. B.; Berberan-Santos, Mario; Hickey, NealDirect O-alkylation of p-tert-butyldihomooxacalix[4]arene (1) with N-(bromopropyl)- or N-(bromoethyl)phthalimides and K2CO3 in acetonitrile was conducted under conventional heating (reflux) and using microwave irradiation and ball milling methodologies. The reactions afforded mono- and mainly distal di-substituted derivatives in the cone conformation, in a total of eight compounds. They were isolated by column ...
Laccases: versatile biocatalysts for the synthesis of heterocyclic cores
Sousa, Ana Catarina; Martins, Lígia O.; Robalo, M. PaulaLaccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formati...
Half-sandwich Ru(p-cymene) compounds with diphosphanes: In Vitro and In Vivo ev...
Lenis Rojas, Oscar; Robalo, M. Paula; Tomaz, Ana Isabel; Fernandes, Alexandra; Roma-Rodrigues, Catarina; Gonçalves Teixeira, Ricardo; Marques, FernandaRuthenium(II) complexes are currently considered attractive alternatives to the widely used platinum-based drugs. We present herein the synthesis and characterization of half-sandwich ruthenium compounds formulated as [Ru(p-cymene)(L)Cl]-[CF3SO3] (L = 1,1-bis(methylenediphenylphosphano)ethylene, 1; L = 1,1-bis(diphenylphosphano)ethylene, 2), which were characterized by elemental analysis, mass spectrometry, H-1...
Wasteful azo dyes as a source of biologically active building blocks
Fernandes, Ana; Pinto, Bruna; Bonardo, Lorenzo; Royo, Beatriz; Robalo, M. Paula; Martins, Lígia O.In this work, an environment-friendly enzymatic strategy was developed for the valorisation of dye-containing wastewaters. We set up biocatalytic processes for the conversion of azo dyes representative of the main classes used in the textile industry into valuable aromatic compounds: aromatic amines, phenoxazinones, phenazines, and naphthoquinones. First, purified preparations of PpAzoR azoreductase efficiently...
Donor functionalized iron(II) N-Heterocyclic carbene complexes in transfer hydr...
Lopes, Rita; Raya-Baron, Alvaro; Robalo, M. Paula; S. Vinagreiro, Carolina; Barroso, Sonia; Romão, Maria João; Fernandez, Ignacio; Pereira, Mariette M.Two piano-stool iron(II) complexes bearing N-heterocyclic carbene ligands outfitted with acetamide- and amine-pendant arms [Cp*Fe(NHC(R))(CO)I] {Cp* = eta(5)-tetramethylcyclopentadienyl; R = CH2CONEt2(3), (CH2)(2)NEt2(4)}, have been prepared and fully characterized. Their catalytic activity in transfer hydrogenation (TH) of ketones usingiPrOH as a hydrogen source and catalytic amounts of base (LiOtBu) has been ...
On the performance and recyclability of a green composite based on AESO resin
Seabra, Cláudio P.; Sousa, Ana Catarina; Bragança, Ivo; Silva, Carlos; Robalo, M. Paula; Loja, Amélia; Martins, PauloThe aims and objectives of this paper are two-fold: first to investigate the production of a green composite manufactured with renewable materials (i.e., jute fabric as reinforcement, acrylate epoxidase soybean oil (AESO) as matrix and sisal particles (SP) as filler), by the wet layup method; second, to propose a recycling procedure to recover the individual materials and reuse them in the production of a secon...
Novel "ruthenium cyclopentadienyl" - peptide conjugate complexes against human ...
Machado, João Franco; Machuqueiro, Miguel; Marques, Fernanda; Robalo, M. Paula; Piedade, M. Fatima M.; Garcia, M. Helena; Correia, João D. G.In this work we explored the possibility of improving the selectivity of a cytotoxic Ru complex [RuCp(PPh3)(2,2'-bipy)][CF3SO3] (where Cp = eta(5)-cyclopentadienyl) TM34 towards FGFR(+) breast cancer cells. Molecular dynamics (MD) simulations of TM34 in a phosphatidylcholine membrane model pinpointed the cyclopentadienyl group as a favorable derivatization position for the peptide conjugation approach. Three ne...
Supercritical CO2 extraction of spent coffee grounds. Influence of co-solvents ...
Coelho, Jose; Filipe, Rui; Robalo, M. Paula; Boyadzhieva, Stanislava; Cholakov, Georgi; Stateva, RoumianaSpent coffee grounds (SCGs) were extracted with supercritical CO2 at temperatures of 313 K and 333 K, pressures up to 50.0 MPa and different scCO(2) flow rates. The addition of co-solvents isopropanol, ethanol and ethyl lactate decreased the time to achieve the maximum oil yield, to half of that with pure CO2. Analysis of the extracted oils by NMR, showed that caffeine content was (0.56-3.96) % and DUFA and MUF...
Ruthenium carboranyl complexes with 2,2 '-bipyridine derivatives for potential ...
Gonçalves Teixeira, Ricardo; Marques, Fernanda; Robalo, M. Paula; Fontrodona, Xavier; Garcia, M. Helena; Geninatti Crich, Simonetta; Vinas, ClaraRuthenium complexes of carboranyl ligands offer the possibility of dual action (chemo + radiotherapy) that might result in significant clinical benefits. In that frame, we describe herein the development of ruthenium-carboranyl complexes bearing bipyridyl derivatives with the general formula [3-CO-3,3-{kappa(2)-4,4 '-R-2-2,2 '-bipy}-closo-3,1,2-RuC2B9H11] (R = CH3,RuCB1or R = CH2OH,RuCB2). Both compounds crysta...
Synthesis of Substituted 4-Arylamine-1,2-naphthoquinones in One-Pot Reactions U...
Sousa, Ana Catarina; Santos, Iolanda; Piedade, M. Fatima M.; Martins, Lígia O.; Robalo, M. PaulaAn efficient and environmentally benign biocatalytic strategy for the synthesis of substituted 4-arylamino-1,2-naphthoquinones was developed, through a cross-coupling reaction in which the 1,2-naphthoquinone nucleus, formed in the biocatalytic process mediated by CotA-laccase from Bacillus subtilis, is the key synthetic intermediate. Electrochemical data and kinetic parameters were determined revealing a signif...