Daiane Dias

Optimization of headspace solid-phase microextraction for analysis of β-caryophyllene in a nanoemulsion dosage form prepared with copaiba (Copaifera multijuga Hayne) oil

Recent studies have shown the anti-inflammatory activity of Copaiba oils may be addressed to the high content of β-caryophyllene, the most common sesquiterpene detected, especially in the Copaifera multijuga Hayne species. In the present study, nanoemulsions were proposed as a delivery system for copaiba oil in view to treat locally inflamed skin. This article describes the optimization and validation of a stability-indicating SPME-GC method, for β-caryophyllene analysis in the nanoemulsions produced by high pressure homogenization. SPME methods are performed with PDMS (polydimethylsiloxane) fiber (100 μm). Three SPME parameters were evaluated by a three-level-three-factor Box-Behnken factorial design as potentially affecting the technique efficiency. According to the results obtained, the best conditions to extract β-caryophyllene were: (i) sampling temperature of 45°C, (ii) sampling time of 20 min and (iii) no NaCl addition. Results coming from the forced degradation tests showed a reduction of β-caryophyllene peak area when both caryophyllene methanolic solution and nanoemulsions were exposed to acid hydrolysis, UV-A irradiation, oxidative (H(2)O(2)) and thermolitic (60°C) conditions. Such reduction occurred in lower extent in the nanoemulsions, suggesting a protective effect of the formulation to β-caryophyllene content. Since no degradation products were detected in the same retention time of β-caryophyllene, the specificity of the method was demonstrated. The method was linear in the range of 0.14-0.68 μg mL(-1) of β-caryophyllene (r(2)>0.999), and was also validated for precision (R.S.D.≤5.0%), accuracy (97.85-101.87%) and robustness. Finally, the method was applied to quantification of β-caryophyllene content in the developed formulations.

Recent Advances on the Synthesis of Chalcones with Antimicrobial Activities: A Brief Review

Abstract: The increasing resistance of bacteria and fungi to antimicrobial drugs has been a matter of concern in public health in the last decades. The continuing need for novel therapeutic compounds is still urgent regarding the number of new diseases and resistant strains of microorganisms. Chalcones are ketones , -unsaturated with one aromatic ring bonded to carbonyl and another aromatic ring bonded to an olefin function. Literature has already reported the antimicrobial potential of several chalcones against a wide range of fungal and bacterial strains, including resistant ones; clearly indicating that they are attractive target compounds for new antimicrobial drug development. Several studies have shown that the introduction of different functional groups is a strategy used to improve the biological activity of these compounds, moreover, the structure of chalcones can also be employed as an intermediate reaction, enabling different reactions and giving rise to new molecules. In this review, we describe recent advances on the synthesis of chalcones with antimicrobial activities.

Determination of β-caryophyllene skin permeation/retention from crude copaiba oil (Copaifera multijuga Hayne) and respective oil-based nanoemulsion using a novel HS-GC/MS method

Copaiba oil is largely used in the Amazonian region for the treatment of inflammation, and recent studies demonstrated that one of the major components of the oil, β-caryophyllene (CAR), is a potent anti-inflammatory. The nanoemulsification of this oleoresin, which has unctuous character, converts it in a more acceptable hydrophilic formulation and may improve CAR penetration through the skin due to the small droplet size and the high contact surface afforded by the nanoemulsions. This paper describes the validation of a novel, sensitive, practical and solvent free method that uses gas chromatography in headspace mode coupled with mass spectrometry to evaluate the skin permeation/retention of CAR from the crude copaiba oil and its nanoemulsion. Our results show that the bioanalytic method was fully validated, demonstrating linearity (r(2)>0.99), specificity (no peaks co-eluting with CAR retention time), precision (RSD<15%) and accuracy (recovery>90%) within the accepted parameters and that the copaiba oil nanoemulsion presented a better skin penetration compared to the crude oil, with CAR achieving the most profound layer of the skin, the dermis.

Synthesis of limonene β-amino alcohol derivatives in support of new antileishmanial therapies

A series of seven limonene beta-amino alcohol derivatives has been regioselectively synthesised in moderate to good yields. Two of these compounds were found to be significantly effective against in vitro cultures of the Leishmania (Viannia) braziliensis promastigote form in the micromolar range. The activities found for 3b and 3f were about 100-fold more potent than the standard drug, Pentamidine, in the same test, while limonene did not display any activity. This is the first report of antileishmanial activity by limonene beta-amino alcohol derivatives.

Recent advances on the green synthesis and antioxidant activities of pyrazoles.

Pyrazoles have a representative history in medicinal chemistry. These nucleuses, molecules of synthetic origin, constitute a group of nitrogen heterocyclic compounds. Available literature particularly shows a variety of pyrazoles with antioxidant effect. In this connection, this review describes the advances on the green synthesis of pyrazoles with antioxidant activity, mainly covering the data published over the last seven years (2008-2014).