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Background: Cannabis sativa is a psychoactive plant indigenous to Central and South Asia, traditionally used both for recreational and religious purposes, in addition to folk medicine. Cannabis is a rich source of natural compounds, the most important of which are commonly known as cannabinoids that cause a variety of effects through interaction with the endocannabinoid system. Materials and Methods: In this study, a high-performance liquid chromatography-ultraviolet/photodiode array (PDA) method was developed and validated for the analysis of 15 cannabinoids in cannabis plant materials and cannabis-based marketed products. These cannabinoids are cannabidivarinic acid, cannabidivarin, cannabidiolic acid, cannabigerolic acid, cannabigerol, cannabidiol, delta-9-tetrahydrocannabivarin, delta-9-tetrahydrocannabivarinic acid, cannabinol, delta-9-tetrahyrocannabinol, delta-8-tetrahyrocannabinol, cannabicyclol, cannabichromene, delta-9-tetrahyrocannabinolic acid A, and cannabichromenic acid. The separation was carried out using a reversed-phase Luna® C18(2) column and a mobile phase consisting of 75% acetonitrile and 0.1% formic acid in water. A PDA detector was used, and data were extracted at λ=220 nm. Principal component analysis of cannabis four varieties was performed. Results: The method was linear over the calibration range of 5-75 µg/mL with R2>0.999 for all cannabinoids. This method was sensitive and gave good baseline separation of all examined cannabinoids with limits of detection ranging between 0.2 and 1.6 µg/mL and limits of quantification ranging between 0.6 and 4.8 µg/mL. The average recoveries for all cannabinoids were between 81% and 104%. The measured repeatability and intermediate precisions (% relative standard deviation) in all varieties ranged from 0.35% to 9.84% and 1.11% to 5.26%, respectively. Conclusions: The proposed method is sensitive, selective, reproducible, and accurate. It can be applied for the simultaneous determination of these cannabinoids in the C. sativa biomass and cannabis-derived marketed products.
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A method for the determination of microcystins concentrations (MC-LR, MC-RR, MC-YR) in natural water samples was optimized using High Performance Liquid Chromatography with UV/PDA detection after Solid Phase Extraction. Solid Phase Extraction is needed to clean natural sample and concentrate pollutant. The method was validated by evaluation of specificity and repeatability. Average recoveries in ultra-pure grade water were better than 95% with Relative Standard Deviation values lower than 4%. Matrix interferences, as pH, conductivity and organic matter content, were tested. pH must be fixed between 6 and 8 to avoid under-estimation or over-estimation and conductivity did not interfere with the analytical method. Organic Matter content negatively impacted microcystins quantification unlike organic matter characteristics. It over-estimated the concenration by an average of 19%. Then, the developed method was applied to study the occurrence of microcystins in Pigeard pond (France). These results constitute the first report on the concentration levels and seasonal variations of microcystins in this resource water.
Assuntos
Microcistinas/análise , Poluentes Químicos da Água/análise , Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental , Extração em Fase SólidaRESUMO
ABSTRACT Operculina macrocarpa (L.) Urb., Convolvulaceae, is used by the population as a laxative. In this work we described the isolation of the three phenolic acids present in the hydroethanolic extract of the O. macrocarpa roots. The quantification of the caffeic, chlorogenic acids and of the new caffeic dimer in the hydroethanolic and infusion extracts was performed by high-performance liquid chromatography coupled photodiode array detector. These analyses showed the higher content of the chlorogenic, caffeic and the new 3,4'-dehydrodicaffeic acid in hydroethanolic and hydroethanolic extracts without resin in which infusion. The acid found in greater quantity is caffeic acid followed by the 3,4'-dehydrodicaffeic acid. The laxative activity was evaluated by different experimental models of intestinal transit with the hydroethanolic and infusion extracts, and the resin fraction, caffeic, chlorogenic and ferulic acids. The results showed all extracts and compounds tested had significant activity in the experimental model tested. These results obtained are essential for the future development of a pharmaceutical product with safety and efficacy.
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Over the years there has been a growing interest in the therapeutic potential for central nervous system pathologies of sigma receptor modulators. The widely studied PRE-084 and our compounds RC-33 and RC-34 are very potent and selective sigma 1 receptor agonists that could represent promising drug candidates for Amyotrophic Lateral Sclerosis (ALS). Herein, we develop and validate robust and easy-to-use reverse-phase chromatographic methods suitable for detecting and quantifying PRE-084, RC-33 and RC-34 in mouse blood, brain and spinal cord. An HPLC/UV/ESI-MS system was employed for analyzing PRE-084 and an HPLC/UV-PDA system for determining RC-33 and RC-34. Chromatographic separations were achieved on Waters Symmetry RP18 column (150 × 3.9 mm, 5 µm), eluting with water and acetonitrile (both containing 0.1% formic acid) in gradient conditions. The recovery of PRE-084, RC-33 and RC-34 was >95% in all the considered matrices. Their limits of quantitation and detection were also determined. Validation proved the methods be suitable for separating tested compounds from endogenous interferences, being characterized by good sensitivity, linearity, precision and accuracy. A preliminary central nervous system distribution study showed a high distribution of RC-33 in brain and spinal cord, with concentration values well above the determined limit of quantitation. The proposed methods will be used in future preclinical investigations.
