Luiz Antonio d’Avila

Selective and cost effective protocol to separate bioactive triterpene acids from plant matrices using alkalinized ethanol: Application to leaves of Myrtaceae species

Background: Triterpenes as betulinic (BA), oleanolic (OA) and ursolic acids (UA) have increasingly gained therapeutic relevance due to their wide scope of pharmacological activities. To fit large-scale demands, exploitable sources of these compounds have to be found and simple, cost-effective methods to extract them developed. Leaf material represents the best plant sustainable raw material. To obtain triterpene acid-rich extracts from leaves of Eugenia, Psidium and Syzygium species (Myrtaceae) by directly treating the dry plant material with alkalinized hydrated ethanol. This procedure was adapted from earlier methods to effect depolymerization of the leaf cutin. Materials and Methods: Extracts were prepared by shaking the milled dry leaves in freshly prepared 2% NaOH in 95% EtOH solution (1:4 w/v) at room temperature for 6 h. Working up the product in acidic aqueous medium led to clear precipitates in which BA, OA and UA were quantified by gas chromatography. Results: Pigment-free and low-polyphenol content extracts (1.2–2.8%) containing 6–50% of total triterpene acids were obtained for the six species assayed. UA (7–20%) predominated in most extracts, but BA preponderated in Eugenia florida (39%). Carried out in parallel, n-hexane defatted leaves led to up to 9% enhancement of total acids in the extracts. The hydroalcoholate treatment of Myrtaceae species dry leaves proved to be a cost-effective and environmentally friendly method to obtain triterpene acids, providing them be resistant to alkaline medium. These combined techniques might be applicable to other plant species and tissues.

Análise comparativa da concentração industrial e de turnover da indústria farmacêutica no Brasil para os segmentos de medicamentos de marca e genéricos

Comparative analysis of the industrial concentration and turnover of the pharmaceutical industry in Brazil for the segments of mark and generic drugs - This paper analyzes the evolution of brand-name and generic drugs structure in Brazil since 1997. After the introduction of generic drugs it was not verified a significant decrease in the concentration of Brazilian pharmaceutical industry. The process of mergers and acquisitions in the 90?s enhanced the process of concentration in the international market. However, a non-expressive turnover can be demonstrated in both pharmaceutical and generic markets. At the same time, the entrance of the generic industry in Brazil explains the invigoration of the national industry. The mergers and acquisitions process in the pharmaceutical industry is quite intense in Europe and in the USA, although in Brazil it is still not significant.

Characterization of fuel detergent–dispersant additives by thermogravimetry

Detergent–dispersant additized gasoline helps to keep engines clean, inhibits the formation of gum and sludge in the combustion process, and reduces the emissions of contaminants to the atmosphere. In this study, a new procedure using thermogravimetry (TG), derived thermogravimetry (DTG), and differential scanning calorimetry (DSC) was developed to identify the presence of four commercial detergent–dispersant additives used in gasoline in Brazil using sealed aluminum pans with small holes and pinholes and an inert ambient. It was found that when pinholes of the same diameter were used, it was possible to distinguish the additives more accurately. The thermal decomposition temperatures of the active components of each additive were mainly identified by TG and DTG. The results indicate that the active components of additives T and Y are similar, but that their content is slightly different. They can be rapidly and easily distinguished from additives W and G, which allows their quantification by size-exclusion chromatography in real samples of Brazilian gasoline to which they may have been added.

Paclitaxel-loaded PLA/PEG/fluorescein anticancer agent prepared by Ugi reaction

ABSTRACT Two different fluorescent block copolymers of poly(lactic acid) (PLA) and polyethylene glycol (PEG) containing fluorescein grafted to the polymer chain were synthesized by Ugi four-component condensation (UFCC). The structure of these PEG–PLA copolymers was confirmed by 1H-NMR and fluorescence spectroscopy. Paclitaxel-loaded fluorescent microspheres (PCT-FMS1 and PCT-FMS2) were prepared from them by the single-emulsion solvent evaporation method. A kinetic study of drug release in vitro using high-performance liquid chromatography showed a prolonged and controlled release of paclitaxel. Anticancer activity of release medium against colorectal cancer cell line (Caco-2) was determined using the cell viability assay. Paclitaxel-loaded microspheres were able to inhibit cancer cell growth and colony formation. The main contribution of this work is to propose a new application for UFCC in the preparation of biomasked fluorescent drug delivery systems able to improve cancer treatment. GRAPHICAL ABSTRACT

Simultaneous analysis of esters and acylglycerols in biodiesel by high-performance liquid chromatography with refractive index detection

ABSTRACT Currently, gas chromatography (GC) is the most widely used analytical technique to verify the quality of biodiesel in relation to its glyceride and fatty acid methyl ester (FAME) contents, even though its use has some disadvantages, such as damage to the injector and column caused by the presence of trace levels of triacylglycerols in biodiesel, which means the column has to be replaced every 3 months; the need for the sample to be derivatized, which, while improving chromatographic separation, also increases analysis time; and the use of several imported standard solutions. The main aim of this work was to use high-performance liquid chromatography with refractive index detection (HPLC-RI) to simultaneously quantify the glyceride (mono, di, and triacylglycerol) and FAME contents of biodiesel. The proposed method showed satisfactory results when compared with those obtained by the reference method (GC), particularly when these results were within the working ranges of the reference method. The proposed method using HPLC-RI is therefore promising and could potentially be used instead of the reference method, since the results it yielded were statistically equivalent, with 95% confidence, to the results obtained by the reference method (GC) for the nine samples of commercial biodiesel analyzed in this study. GRAPHICAL ABSTRACT