Determination of antipsychotic drugs in oral fluid using dried saliva spots by gas chromatography-tandem mass spectrometry.

The present work describes the optimization and validation of an analytical method for the determination of six antipsychotic drugs (chlorpromazine, levomepromazine, cyamemazine, clozapine, haloperidol, and quetiapine) in oral fluid samples after solvent extraction from dried saliva spots, by gas chromatography coupled to tandem mass spectrometry. The method was fully validated, and the included parameters were selectivity, linearity, limits of quantification, precision and accuracy, stability, and recovery. The method was linear for all compounds from 10 to 400 ng/mL, except for haloperidol (5-100 ng/mL), presenting coefficients of determination higher than 0.99. Inter- and intra-day precision and accuracy were in conformity with the criteria usually seen in bioanalytical method validation; i.e., coefficients of variation were lower than 15% and an accuracy of 15% or better for all studied drugs. The recoveries obtained with this miniaturized technique ranged from 63 to 97%. The herein described method is the first to be reported using the dried saliva spots approach for the analysis of these antypshychotic drugs, proving great sensitivity apart from its simple and fast procedure. The method was considered a good alternative to the conventional techniques to be applied in clinical and toxicological analyses, even more taking into account the extremely low sample volume used (50 µL). Graphical abstract.

Determination of amphetamine-type stimulants in urine samples using microextraction by packed sorbent and gas chromatography-mass spectrometry.

The aim of this work was the development, optimization and full validation of a method applying microextraction by packed sorbent (MEPS) coupled to gas chromatography-mass spectrometry (GC-MS) to determine amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxyethylmethamphetamine (MDMA), 3,4-methylenedioxy-N-methyl-α-ethylfenilethylamine (MBDB), and 3,4-methylenedioxy-N-ethylamphetamine (MDE) in urine samples. Using 200 µL of sample, the MEPS procedure was optimized concerning type of sorbent, sample dilution, number of strokes, activation of the ion exchange mechanism and composition of both washing and elution solvents. The method was fully validated according to the Food and Drug Administration and the Scientific Working Group of Forensic Toxicology guidelines for the validation of bioanalytical methods. The studied parameters included selectivity, calibration model and linearity, limits of detection and quantification, precision, accuracy, stability, dilution integrity and recoveries. Linearity was obtained in the range of 25-1000 ng/mL for MAMP, MBDB and MDE, 35-1000 ng/mL for AMP and MDMA, and 50-1000 ng/mL for MDA, with coefficients of determination (R2) >0.99 for all analytes. Both intra- and inter-day precision and accuracy were adequate, and coefficients of variation lower than 15% and mean relative errors (RE) within a range of ±15% of the theoretical concentrations were obtained for all compounds under study. Analyte recoveries ranged from 19 to 71%, allowing LLOQs ≤50 ng/mL.

Antibacterial and antioxidant activity of Portuguese Lavandula luisieri (Rozeira) Rivas-Martinez and its relation with their chemical composition.

Lavandula luisieri (Rozeira) Rivas-Martinez is an endemic aromatic Labiatae the Iberian Peninsula, common in semi-arid regions of southern Portugal and southwestern Spain, that produces an active antibacterial essential oil from the leaves and flowers. This work presents the study of the chemical variation in various stages of growth of leaves and flowers of L. luisieri. It has been found that the essential oils are mainly constituted by 1,8-cineol, camphor, linalool and trans-α-necrodil acetate. It was also studied the total phenol content and the antioxidant activity on leaves and flowers. The ethanol extraction from de leaves contents the highest total phenol, important factor for the antioxidant activity of the plant, extract. It has been studied too, the antibacterial activity against Escherichia coli, Salmonella spp. and Staphylococcus aureus. In accordance with the obtained results, the antibacterial activities stand out against Staphylococcus, of the oil of L. luisieri (leaves and flowers).

Synergistic antibacterial activity of the essential oil of aguaribay (Schinus molle L.).

Schinus molle L. (aguaribay, aroeira-falsa, "molle", family Anacardiaceae), a native of South America, produces an active antibacterial essential oil extracted from the leaves and fruits. This work reports a complete study of its chemical composition and determines the antibacterial activity of Schinus molle L. essential oil and its main components. The results showed that the crude extract essential oil has a potent antibacterial effect on Staphylococcus aureus ATCC 25923, a strong/moderate effect on Escherichia coli ATCC 25922 and moderate/weak one on Pseudomonas aeruginosa ATCC 27853.

From labdanes to drimanes. Degradation of the side chain of dihydrozamoranic acid.

A new route for the degradation of the saturated side chain of dihydrozamoranic acid has been devised, giving an advanced intermediate, compound 14, useful for the synthesis of insect antifeedants such as warburganal and polygodial.