In-tube solid-phase microextraction with a dummy molecularly imprinted monolithic capillary coupled to ultra-performance liquid chromatography-tandem mass spectrometry to determine cannabinoids in plasma samples.

A selective and sensitive method that uses automated in-tube solid-phase microextraction coupled to ultra-performance liquid chromatography-tandem mass spectrometry (in-tube SPME/UHPLC-MS/MS) was developed to determine cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC) in plasma samples. A new dummy molecularly imprinted monolithic capillary (MIP monolith) for in-tube SPME was prepared by in situ polymerization in a fused silica capillary; hydrogenated cannabidiol was employed as dummy template. Fourier Transform Infrared Spectroscopy (FTIR) confirmed that the synthesis reagents were incorporated into the polymer chain. On the basis of the microscopy images (scanning electron microscopy - SEM and transmission electron microscopy - TEM), the MIP monolithic phase presented larger pores than the non-imprinted monolithic phase (NIP monolith), as well as a skeleton comprising clusters consisting of microspheres. By optimizing the polymerization conditions, the MIP monolith specifically recognized CBD and Δ9-THC. The MIP monolith had CBD and Δ9-THC sorption capacity of 148.05 and 44.49 ng cm-3, respectively. The capillary was reused over fifty times without significant changes in its extraction efficiency. For both CBD and Δ9-THC, in-tube SPME/UHPLC-MS/MS presented linear range from 10 to 300 ng mL-1, precision with coefficient of variation (CV) values ranging from 0.2% to 19.1% (LLOQ), and accuracy with relative standard deviation (RSD) values spanning from -9.3% to 19.6% (LLOQ). The developed method was successfully applied to determine cannabinoid levels in plasma samples from volunteer patients in treatment with CBD.

New antifungal ent-labdane diterpenes against Candida glabrata produced by microbial transformation of ent-polyalthic acid.

Candida glabrata, the most common non-albicans Candida species and one of the primary causes of candidemia, exhibits decreased susceptibility to azoles and more recently to echinocandins. Polyalthic acid 1, a furan diterpene, has been shown promising biological potential and in this study ent-polyalthic acid derivatives with antifungal activity against Candida glabrata were produced by microbial transformation. Incubation of 1 with Aspergillus brasiliensis afforded two known (compounds 5 and 10) and eight new derivatives (compounds 2-4, 6-9 and 11). The most common reaction was hydroxylation, but isomerization of the double bond and acetylation were also detected. None of the tested compounds showed cytotoxicity against HeLa, MCF-7 and MCF-10A cell lines showing IC50 values ranging from 62.6 µM to > 500 µM. Compounds 1, 5, 6, 8 and 11 showed fungistatic effects (ranging from 34.1 µM to 39.5 µM) on C. glabrata at lower concentrations than fluconazole (163.2 µM). Compounds 1, 6 and 8 were more potent fungicides (ranging from 79.0 to 143.6 µM) than fluconazole, which showed fungicidal effect at concentrations higher than 163.2 µM. These results suggest that ent-polyalthic acid and some of its derivatives could be used as lead compounds to develop new antifungal agents.

Reliable Methods for Analyses of Volatile Compounds of Copaifera Oleoresins Combining Headspace and Gas Chromatography.

Two analytical methods were developed in this study for direct and fast chemical investigation of authentic Copaifera oleoresins (COR) and commercial products. Polydimethylsiloxane microfiber coupled to gas chromatography-mass spectrometry (HS-SPME-GC/MS) showed the best results for oleoresin qualitative analysis, setting the following extraction conditions: equilibrium time of 15 min, extraction time of 30 min, extraction temperature at 60 °C and constant stirring of 400 rpm. Sesquiterpenes α-copaene, ß-elemene, ß-caryophyllene and trans-α-bergamotene were found in all investigated samples. Quantitative analysis by gas chromatography coupled with flame ionization detector (GC-FID) measured the content of the four sesquiterpenes in all samples. Qualitative and quantitative results showed important differences between COR of distinct species and commercial products. Data regarding the volatile composition of C. oblongifolia and C. trapezifolia oleoresins were first presented in this study and two new analytical methods were reported for direct and fast qualitative and quantitative analysis of COR.