Simultaneous Determination of Four Marker Compounds in Lobelia chinensis Lour. Extract by HPLC-PDA

Lobelia chinensis Lour. (L. chinensis) has traditionally been used as a treatment for snake bites, high fever, jaundice, edema, and diarrhea, and modern studies have reported its anti-inflammatory, antioxidant, and antiviral activities. L. chinensis contains various compounds, such as flavonoids and coumarins, and its flavonoid components have been identified in many studies. In this study, a high-performance liquid chromatograph equipped with a photodiode array (PDA) detector and an Aegispak C18-L reverse-phase column (4.6 mm × 250 mm i.d., 5 μm) was used to simultaneously analyze four marker components in L. chinensis for standardization purposes. HPLC-PDA (detection at 340 nm), performed using a 0.1% formic acid-water/0.1% formic acid-acetonitrile gradient, separated the four marker compounds: luteolin-7-O-β-d-glucuronopyranosyl (1→2)-O-β-d-glucuronopyranoside, clerodendrin, chrysoeriol-7-O-diglucuronide, and diosmin. The developed analytical method showed excellent linearity values (r2 > 0.9991), limits of detection (LODs: 0.376–2.152 μg/mL), limits of quantification (LOQs: 1.147–6.521 μg/mL), intra- and inter-day precisions (RSD < 1.96%), and analyte recoveries (96.83–127.07%; RSD < 1.73%); thus, it was found to be suitable for the simultaneous analysis of these four marker compounds in L. chinensis.

Dicamba residues in sprayers: Phytotoxicity on non-dicamba tolerant soybean

ABSTRACT This study aimed to evaluate the dicamba residue after cleanout procedures in sprayers with different tank materials (fiberglass and polyethylene) and its effects on the symptomology of non-dicamba tolerant (DT) soybean. The experiment consisted of spraying rinsates collected during a cleanout of boom sprayers on non-DT soybean at the V3 stage. Once the dicamba solution was mixed in the sprayer tank and sprayed, four rinses were made, and for each rinse, a sample was collected. The dicamba residue analyses in each rinse solution were conducted in a completely randomized design with three replicates in a 2 × 4 factorial scheme, corresponding to two sprayer tank materials (fiberglass and polyethylene) and four rinses, using High-Performance Liquid Chromatograph (HPLC). The evaluation of the potential risk of injury on non-DT soybean caused by dicamba residue was conducted in a randomized block design with four replicates and a 2 × 4 + 1 factorial scheme, corresponding to two types of sprayer tank material (fiberglass and polyethylene), four rinses, and control (without application). The dicamba was effectively removed using at least three rinses regardless of spray tank material. Fiberglass tank sprayer retained more residue in the first rinsate, but similar to polyethylene tank sprayer in the following rinses. Plant height was reduced by spraying rinsates collected from the first rinse regardless of tank material. In contrast, visual estimation of injury and reduced yield were observed due to the rinsate application collected from the first and second rinses.

LC-QTOF/MS Untargeted Metabolomics of Sheep Milk under Cocoa Husks Enriched Diet

The aim of this work was to evaluate, by an untargeted metabolomics approach, changes of milk metabolites induced by the replacement of soybean hulls with cocoa husks in the ewes’ diet. Animals were fed with a soybean diet integrated with 50 or 100 g/d of cacao husks. Milk samples were analyzed by an ultra high performance liquid chromatograph coupled to a time of flight mass spectrometer (UHPLC-QTOF-MS) platform. Multivariate statistical analysis showed that the time of sampling profoundly affected metabolite levels, while differences between treatments were evident at the fourth week of sampling. Cocoa husks seem to induce level changes of milk metabolites implicated in the thyroid hormone metabolism and ubiquinol-10 biosynthesis.

Detection of falsified clopidogrel in the presence of excipients using voltammetry

There has been a recent surge in the amount of substandard and falsified clopidogrel. Pharmacopeial based assays using high performance liquid chromatograph and mass spectroscopy are widely used for measurement...

ISOLATION AND IDENTIFICATION OF EUPHORBIA TRIODONTA PLANT POLYPHENOLS BY CHROMATO-MASS SPECTROMETRY

The aim of this work is to study the composition of polyphenols contained in plants of Euphorbia triodontus Prokh., growing throughout the Republic of Uzbekistan, in particular the Ferghana Valley region, using a high-performance liquid chromatograph with a diode-matrix detector (HPLC-DAD) and a tandem chromato-mass spectrometer (HPLC – Q-TOF-MS/MS). The roots of the plant Euphorbia triodontus Prokh., growing on the territory of Uzbekistan, collected in the period after flowering, studied the polyphenolic composition. For the first time from this type of Euphorbia, the method of stepwise hydrophobic chromatography was used to isolate polyphenolic fractions. By HPLC, as a result of semi-preparative chromatography, 6 individual compounds were isolated from the fraction eluted with a 20% methanol solution in the amount of: E-20-1 – 7 mg, E-20-2 – 22 mg, E-20-3 – 14.2 mg, E-20-4 – 41 mg, E-20-5 – 11.4 mg and E-20-6 – 32 mg. As a result of mass spectrometric analyzes, it was established that the polyphenols isolated in an individual state consist of gallic acid and glucose linked by an ester bond: O-galloyl-β-D-glucose. The structure of individual compounds was determined: E-20-1 – 1-O-meta-trigalloyl-β-D-glucopyranosyl-(4-O-β-D)-1-O-meta-trigalloyl-β-D-glucose, E-20-2 – 1-O-meta-trihalloyl-β-D-glucose, E-20-3 – 1-O-meta-tetragalloyl-β-D-glucose, E-20-4 – 1-O-meta-trigalloyl-4-O-haloyl-β-D-glucose, E-20-5 – 2,3,6-tri-O-galloyl-β-D-glucose and E-20-6 – 1,2,3,4,6-penta-O-galloyl-β-D-glucose.

Standardization of an analytical method to quantify ochratoxin A in green coffee beans by high performance liquid chromatography

Nowadays, Brazil is the largest producer and exporter of coffee, also the second largest consumer of the beverage. The importance of ensuring food safety for consumers has influenced research to improve and monitor the final product quality. Coffee is a product that presents a high risk of fungal contamination, which can result in the presence of mycotoxins and poses risks to human and animal health. Therefore, this study aimed to standardize a chromatographic method to test and quantify ochratoxin A in 13 samples of green coffee beans. The green coffee beans were stored in sheds without temperature or humidity control. Samples were ground, and the analyte was extracted by a 3% methanol:sodium bicarbonate (1:2 v/v) solution. Ochratoxin A was quantified in a high performance liquid chromatograph. The method was validated by testing the selectivity, linearity, accuracy, limits of detection and quantification. The method presented robustness to the tested parameters and among the analyzed samples. Ochratoxin A was detected above the limit established by the legislation (75.19 µg kg-1) only in one sample. Overall, the storage of green coffee beans in these sheds was adequate, since 12 samples had a low content of ochratoxin A and they were within the limit established by legislation. Therefore, food safety was guaranteed without any severe mycotoxin contamination.

STRUCTURE OF POLYPHENOLS OF LEAVES TANNING SUMAC RHUS CORIARIA L.

The aim of this work is to study the composition and structural characteristics of the polyphenols of the tanning sumac Rhus coriaria L. of the Anacardiaceae family, growing in Uzbekistan, using a high-performance liquid chromatograph with a diode-matrix detector (HPLC-DAD) and a tandem temple mass-spectrometer (HPLC– Q-TOF-MS / MS). The phenolic compounds of the aerial part (leaves) of Rhus coriaria L. plants of the Anacardiaceae family were studied. For the first time, polyphenol fractions were isolated from tanning sumac leaves using stepwise hydrophobic chromatography. By HPLC, as a result of semi-preparative chromatography from the fraction eluted with 30% ethanol, 9 individual compounds were obtained, in the amount of: R-1 – 0.5 mg, R-2 – 0.8 mg, R-3 – 2.3 mg, R-4 – 12.6 mg, R-5 – 34.5 mg, R-6 – 15 mg, R-7 – 8 mg, R-8 – 7.1 mg, R-9 – 45.5 mg As a result of mass spectrometric analyzes and NMR spectroscopy for individual polyphenols, it was established that the polyphenols isolated in the individual state consist of gallic acid and glucose, interconnected by an ester bond: mono-, di-, tri-, tetra-, penta- , hexa-, hepta-, octa- and non-O-galloyl-β-D-glucose.