Phytochemical Screening and Antioxidant Activity of Selected Estonian Galium Species.

The aim of the present study was to examine three different Galium species from the native population of Estonia, Galium verum, Galium aparine, and Galium mollugo, to characterise their non-volatile and volatile phytochemical composition and antioxidant activity. The main groups of bioactive compounds in the plants were quantified by colorimetric tests, showing high concentrations of polyphenols (up to 27.2 ± 1.5 mg GAE/g), flavonoids (up to 7.3 ± 0.5 mg QE/g) and iridoids (up to 40.8 ± 2.9 mg AE/g). The species were compared using HPLC-DAD-MS/MS, revealing some key differences in the phytochemical makeup of the extracts. The most abundant compound in the extracts of Galium verum blossoms and herb was found to be asperuloside, in Galium aparine herb, asperulosidic acid, and in Galium mollugo herb, chlorogenic acid. Additionally, the composition of volatile compounds was analysed by SPME-GC-MS. The degree of variability between the samples was high, but three volatiles, hexanal, anethole, and ß-caryophyllene, were quantified (≥1%) in all analysed samples. The antioxidative activity of all extracts was evaluated using the ORACFL method, demonstrating that the Galium species from Estonia all exhibit strong antioxidant capacity (up to 9.3 ± 1.2 mg TE/g). Out of the extracts studied, Galium verum blossoms contained the highest amounts of bioactives and had the strongest antioxidant capacity.

Extraction of bioactive compounds from Dipsacus fullonum leaves using deep eutectic solvents.

In this study, deep eutectic solvent (DES) based systems were evaluated for selective extraction and optimized for increased recovery of chlorogenic acid derivatives, flavone glycosides and iridoid glycosides from Dipsacus fullonum L. leaves. Bioactives from Dipsacus plants has shown great antioxidant and antimicrobial activities as well as effectiveness against several cancer strains and a source for anti-Borrelia compounds. Twelve different hydrophilic and hydrophobic DESs were tested to find the best solvent composition. Choline chloride and betaine were used as hydrogen bond acceptors (HBA) for the preparation of hydrophilic DESs and menthol for hydrophobic DESs. The tested hydrogen bond donors (HBD) were various organic acids and glycerol. The composition of most effective DES was optimized using the Box-Behnken design for each of the three main group of analytes from D. fullonum L. to evaluate possible selectivity and highest recovery. HPLC-DAD-MS was used to identify and quantify the main bioactive compounds extracted from plant material. The optimal extraction for highest overall recovery was achieved using a molar ratio of choline chloride and lactic acid of 1:2.4 with 35% water and 27 mL of the solvent per one gram of dry material. The optimized DES extract gave concentrations 1.8 to 2.2 times higher than traditional organic solvent extracts depending on the group of analytes.

Micellar electrokinetic chromatography method for the analysis of synthetic and phytocannabinoids.

Synthetic cannabinoids (SCs) are the largest group of illicit compounds currently monitored in Europe. Reliable analytical methods for the differentiation and quantification of SCs and phytocannabinoids (PCs) from plant-based products are needed to reduce possible public health risks. The objective of this research was to develop a new method for the detection of four SCs (JWH-018, JWH-073, JWH-200, JWH-250) and two PCs (THC, CBD) from plant materials by using micellar electrokinetic chromatography with UV-absorbance detection. A novel method with a water-based background electrolyte containing cholate micelles was developed and optimized using two sets of the Box-Behnken experimental design. The method enables the quantification of JWH-018, JWH-073, JWH-200, JWH-250, and detection of THC and CBD. The selectivity studies revealed that several plants that are prevalently used as carrier matrixes for SCs could be analyzed without an added sample purification procedure. A basic method validation was performed. The detection and quantification limits were 3.0 and 5.0 for SCs, and 3.7 and 6.2 mg/L for PCs. For all analytes, the method intra-day precision was under 8%, the inter-day precision under 13%, and recoveries up to 100%.

Extraction and Fractionation of Bioactives from Dipsacus fullonum L. Leaves and Evaluation of Their Anti-Borrelia Activity.

Lyme disease (LD) is a tick-borne bacterial disease that is caused by Borrelia burgdorferi. Although acute LD is treated with antibiotics, it can develop into relapsing chronic form caused by latent forms of B. burgdorferi. This leads to the search for phytochemicals against resistant LD. Therefore, this study aimed to evaluate the activity of Dipsacus fullonum L. leaves extract (DE) and its fractions against stationary phase B. burgdorferi in vitro. DE showed high activity against stationary phase B. burgdorferi (residual viability 19.8 ± 4.7%); however, it exhibited a noticeable cytotoxicity on NIH cells (viability 20.2 ± 5.2%). The iridoid-glycoside fraction showed a remarkable anti-Borrelia effect and reduced cytotoxicity. The iridoid-glycoside fraction was, therefore, further purified and showed to contain two main bioactives-sylvestrosides III and IV, that showed a considerable anti-Borrelia activity being the least toxic to murine fibroblast NIH/3T3 cells. Moreover, the concentration of sylvestrosides was about 15% of DE, endorsing the feasibility of purification of the compounds from D. fullonum L. leaves.

Capillary Electrophoresis as a Monitoring Tool for Flow Composition Determination.

Flow analysis is the science of performing quantitative analytical chemistry in flowing streams. Because of its efficiency and speed of analysis, capillary electrophoresis (CE) is a prospective method for the monitoring of a flow composition withdrawn from various processes (e.g., occurring in bioreactors, fermentations, enzymatic assays, and microdialysis samples). However, interfacing CE to a various flow of interest requires further study. In this paper, several ingenious approaches on interfacing flow from various chemical or bioprocesses to a capillary electrophoresis instrument are reviewed. Most of these interfaces can be described as computer-controlled autosamplers. Even though most of the described interfaces waste too many samples, many interesting and important applications of the devices are reported. However, the lack of commercially available devices prevents the wide application of CE for flow analysis. On the contrary, this fact opens up a potential avenue for future research in the field of flow sampling by CE.

Analysis of Total Phenols, Sugars, and Mineral Elements in Colored Tubers of Solanum tuberosum L.

The use of colored tubers of Solanum tuberosum L. is growing worldwide due to their health benefits and attractive color. The positive health effects of purple-fleshed tubers are a result of anthocyanins and various phenolic compounds. The aim of this study was to evaluate and compare variety Blue Congo and its cross-breeds of Desiree and Granola to yellow-fleshed tubers. The concentration of total phenols, anthocyanins, sugars, and mineral elements were evaluated in all tubers. The results showed differences between all tested materials, with largest differences in sugar content. Moreover, the results confirmed the preservation of health improving compounds of Blue Congo when cross-bred with yellow-fleshed tubers. The total phenolic content and anthocyanin concentrations of all analyzed tubers were above the comparison yellow ones.

Use of a newly-developed portable capillary electrophoresis analyser to detect drugs of abuse in oral fluid: A case study.

The aim of the current study was to develop and validate an analytical method to determine whether drugs of abuse (DOA) were present in oral fluid (OF) using a newly-developed, portable capillary electrophoresis (CE) instrument coupled to a deep ultra-violet fluorescence detector (FD). The performance of this portable CE-FD DOA analyser was tested at the Weekend Festival Baltic (Pärnu, Estonia) between 2016 and 2018 as well as on the roadside OF samples collected by the police. The study reported 128 analysed cases in which persons were allegedly found to have been under the influence of DOA. The samples were analysed for amphetamine (AMP), methamphetamine (METH), 3,4-methylenedioxy-methamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), cocaine (COC) and cocaethylene (COET). Subsequent toxicological reports revealed that 26% cases were negative, and 74% were positive. The most frequently detected and quantified DOA was MDMA (68 cases, 62%). A comparative study was conducted to validate the accuracy of using the CE-FD DOA analyser versus classic high-performance liquid chromatography coupled to mass spectrometry (HPLC-ESI-MS). Diagnostic statistics for CE-FD DOA were also evaluated and were higher than 99.5%. In addition, all zeta-scores were lower than 2 when both methods were compared, showing that the CE-FD analyser can be implemented as a reliable, sensitive and convenient tool for roadside and workplace testing for DOA.

Rapid and sensitive capillary electrophoresis method for the analysis of Ecstasy in an oral fluid.

In the present study, a capillary electrophoresis method, with a native fluorescence detection for the quantification of three amphetamine derivatives, methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-methamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA) in an oral fluid is described. The reported CE method has made it possible to assess Ecstasy abuse in approximately 15 min, including a saliva sample collection, pretreatment procedures and capillary electrophoresis (CE) analysis. The proof of the principle that was demonstrated on a home-made lab scale instrument has had the potential to be easily translated onto a truly portable instrument for on-site measurements. The baseline CE separation of the three illegal drugs was achieved in 10 min, by applying an aqueous background electrolyte (BGE) that was composed of 40 mM phosphoric acid and 10 mM triethanolamine. The amphetamine derivatives were detected at their λex/λem maximum (280/326 nm) with LOD values of about 3 ng/mL for each amphetamine. The recovery of the compounds from the collection pad was about 40% of the LOQ concentrations and the inter-day precision was less than 6% for all of the analytes. The procedure was applied to a quantitation of oral fluid (OF) samples that were collected during the Baltic Weekend Music Festival that was held in Estonia.

In Situ Determination of Illegal Drugs in Oral Fluid by Portable Capillary Electrophoresis with Deep UV Excited Fluorescence Detection.

The present study demonstrates the potential of a portable capillary electrophoresis (CE) instrument, coupled to deep UV fluorescence detector (FD) with a 230-255 nm excitation wavelength range, for the determination of the abuse of illegal drugs in oral fluids in situ. CE was introduced in this study due its exceptional power of separation and resolution, short analysis time, and ability for miniaturization for on-site assessment of different substances. The deep UV fluorescence detector was equipped with five interchangeable emission filters, in the emission wavelength range from 278 to 600 nm, and was successfully employed for determination of natively fluorescing illegal drugs, such as cocaine, cocaethylene, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxeamphetamine (MDA), 3,4-methylenedioxy- N-ethylamphetamine (MDEA), para-methoxyamphetamine (PMA), para-methoxy- N-methylamphetamine (PMMA), amphetamine (AMP), methamphetamine (METH), tetrahydrocannabinol (THC) and cannabidiol (CBD). The developed FD showed impressive sensitivity. The instrumental detection limit was 0.5 µg/L for MDMA. It also showed broad linearity, up to 50 mg/L for MDMA. The noise CV% was 1.1% for an empty capillary and 0.6% for a capillary filled with acetonitrile. The portable CE-FD with developed electrophoretic methodologies was successfully utilized for the determination of illegal abuse of drugs during "Weekend" 2016 and 2017 Music Festivals (Estonia). Moreover, CE-FD can be employed for detection of other natively fluorescing compounds in the proposed range (e.g., for different phenolic compounds, BTEX, naphthalene derivatives, and others), significantly widening the applicability of developed CE-FD instrument.

Determination of γ-hydroxybutyric acid in saliva by capillary electrophoresis coupled with contactless conductivity and indirect UV absorbance detectors.

The aim of the current study was to optimise and validate the methodology for determination of γ-hydroxybutyric acid (GHB) in saliva by CE combined with a contactless conductivity detector (C(4)D) and indirect UV absorbance detection (λ(ABS) = 210 nm). The optimized BGE, consisting of 8.5 mM maleic acid, 17 mM arginine, 255 µM cetyltrimethylammonium bromide (CTAB), and 15% acetonitrile, was evaluated for the separation of GHB in saliva within 6 min. The performance characteristics of the CE-C(4)D-indirect UV methodology was validated. The instrument detection and quantification limits were 0.49 and 1.6 mg/L for C(4)D, and 5.1 mg/L and 17.0 mg/L for indirect UV, respectively. The linearity was obtained over the range from 2.5 to 400 mg/L for C(4)D and from 12.5 to 400 mg/L for indirect UV. The interday precisions were within 2.3-5.7% and intraday precisions were within 1.6-9.0% for C(4)D as well as 2.1-9.3%, 5.6-10.1% for indirect UV in spiked saliva, respectively. The recoveries were within 87.2-104.4%. The matrix effects were +53.2% for small concentrations up to 25 mg/L for C(4)D and +23.6% for concentrations up to 75 for mg/L for indirect UV detection. No matrix effects were observed for higher concentration levels. In conclusion, CE-C4D-indirect UV can offer a rapid, accurate, sensitive, and definitive method for the determination of GHB abuse in saliva samples as a forensic screening tool.