Browsing by Issue Date, starting with "2011-06"
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- Antifungal activity of endemic Origanum virens from PortugalPublication . Soares, M.O.; Ferreira da Vinha, Ana; Lima, R.P.; Coutinho, F.; Catarino, P.Origanum virens is widely used in Portuguese, and Mediterranem, cuizin. Althout it is use as food condiment, it is also used in traditional medicin as antiseptic. The antifungal activity of Origanum virens essential oil on Candida albicans ATCC 10231 and physicchemical characterization of several extracts were evaluated.
- Antimicrobial activity of essential oil of Cymbopogon citratus (DC) Stapf. Poaceae-Gramineae from Angola in ATCC and multidrug resistant strainsPublication . Soares, M.O.; Ferreira da Vinha, Ana; Lima, R.P.; Coutinho, F.; Machado, M.; Catarino, P.Cymbopogon citratus (DC) Stapf. Poaceae-Gramineae (C. citratus) is an herb from India, which grows in several countries in tropical and sub-tropical, as the Republic of Angola, where tea is known as caxinde. This tea is consumed, as aromatic drink, as well as in traditional cuisine due to its lemon flavor. Cymbopogon citratus (DC) is widelly used in folk medicine, where infusions and decoctions, feature anti-spasmatic, carminatives and anti-hypertension properties. The essential oil of C. citratus is often applied, in pharmaceutical industry, as flavor and fragrance, and is also used as a source of new phytochemical molecules for the development of new pharmaceutical products.
- Successes and failures of DFT functionals in acid/base and redox reactions of organic and biochemical interestPublication . Silva, Pedro J.; Ramos, Maria JoãoThe performance of 18 different DFT functionals in the prediction of absolute and relative energies of organic and biochemical acid/base and redox reactions was evaluated, using MP2 extrapolated to the complete basis set limit and CCSD(T)/aug-cc-pVTZ energies as benchmark. Absolute reduction energies were predicted with relatively large average errors (2–4 kcal mol−1) except for the best functional, PBE0 (1.3 ± 1.2 kcal mol−1). The DFT predictions of relative reduction energies afforded mean unsigned errors (2.1 kcal mol−1 for the best functional, PBE0) which, although relatively large, are smaller than those obtained with MP2 with comparable basis sets (3.2 kcal mol−1). This relatively poor performance was mostly due to significant underprediction of the reduction energy of a model disulfide bridge, and overprediction of that of a model quinone, as eliminating these reaction from the test set enables most of the tested hybrid-GGA functionals (B3LYP, B3PW91, B97-1, BHHLYP, PBE0, PBE1PW91, X3LYP), though not meta-GGA or meta-hybrid-GGA functionals, to achieve small mean unsigned errors (<1.5 kcal mol−1). In the acid/base reaction test set, several hybrid-GGA and meta-hybrid-GGA functionals (BHHLYP, B97-1, B97-2, X3LYP, M06-2X, as well as the popular B3LYP) yielded small errors (0.8–1.5 kcal mol−1) in the computation of relative energies across the tested model reactions. For most of the proton transfers between different acid/base pairs (or electron transfer between redox pairs) tested we could find at least one functional with very high accuracy (error < 0.2 kcal mol−1). The reactions involving electron transfer between quinone (or disulfide) and other redox groups stand out as the clearest example of the shortcomings of DFT methods, as the best functionals are most often wrong by 1–3 kcal mol−1.
- Pharmaceutical approaches for optimizing oral anti-inflammatory delivery systemsPublication . Lopes, Carla Martins; Oliveira, R.; Silva, Ana CatarinaThe purpose of the present review is to compile the recent literature in the field of anti-inflammatory treatments, with special focus to the state-of-the-art on pharmaceutical approaches for optimizing oral administration. Attending to the drawbacks associated with the use of these types of drugs, the development of oral modulated release formulations is highly desirable in order to achieve improved therapeutic efficacy and patient compliance. Several technological systems and their advantages in modulated and targeted drug releases (gastroretention or colonic release) have been described: matrix systems, coated dosage forms, osmotic pressure based formulations, prodrugs, colloidal carriers, microparticles and other carriers. These new approaches seem to be promising and have been considered by pharmaceutical companies.
- Chronopharmaceutical delivery of anti-inflammatory drugsPublication . Barata, Pedro; Lopes, Carla MartinsThe human body follows 24 hours cycles called the circadian rhythm that affect many physiological and physiopathological processes. Chronotherapeutic diseases include asthma, cardiovascular diseases, cancer, rheumatoid arthritis and other algesia processes. Drugs behaviours in the human body are also strongly affected by circadian changes, especially in what concerns absorption and elimination. Anti-inflammatory drugs are excellent candidates to chronotherapeutical delivery. Chronotherapeutic products are able to synchronize drug delivery with circadian rhythms in order to enhance efficacy and reduce side effects. These products mainly offer pulsatile release that follow a sigmoid release profile with a combination of periods of lag time and periods of fast drug release. Many technologies, either single units or multiparticulate systems, have been suggested and some have been successfully marketed improving patients adherence and quality of life. This review aims to describe the circadian rhythms and their influences in therapeutics as well as the technologies that have been proposed to develop chronopharmaceutical dosage forms.