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Background: Studies have demonstrated that resveratrol exerts several pharmacological effects. However, the pharmacokinetic parameters are not completely established. Objectives: This study describes the plasma pharmacokinetics and tissue distribution of resveratrol after administration by different routes and doses in rats. Methods: A reliable, simple, and sensitive HPLC method using UV detection for the quantification of resveratrol in rat plasma and tissues was developed and validated. In addition, a pharmacokinetic analysis using non-compartmental and population modeling was performed. Results: The pharmacokinetic parameters of resveratrol after the administration of 5 mg/kg via i.v. bolus calculated by non-compartmental analysis were a constant of elimination (ke) of 0.09 h−1 ± 0.04, a half-life (t1/2) of 9.5 h ± 3.7, an apparent volume of distribution (Vd) of 5.8 L/kg ± 4.7, a clearance (Cl) of 0.39 L/h/Kg ± 0.26, and an area under the curve (AUC) of 6076 ng/h/mL ± 2959. The results obtained after the administration of 100 mg/kg p.o. were an elimination constant (ke) of 0.12 ± 0.07 h−1, a half-life (t1/2) of 7.9 ± 4.2 h, the apparent volume distribution (Vd) of 13.3 ± 3.3 L/kg, a clearance (Cl) of 1.76 ± 0.49 L/h/Kg ± 0.26, and an area under the curve (AUC) of 6519 ± 1592 ng/h/mL. For the tissue distribution analysis, 10 mg/kg of resveratrol was intravenously administered to rats and the molecule was quantified in the liver, lung, kidney, heart, stomach, spleen, adipose tissue, and brain of the animals. Conclusions: The population pharmacokinetic modeling showed that resveratrol has a two-compartment model in both routes of administration and has a higher volume of distribution when it is given orally. In addition, resveratrol showed a high brain concentration after iv administration, which indicates that this molecule is capable of crossing the blood–brain barrier of animals, a crucial capacity for its neuroprotective activity. [ABSTRACT FROM AUTHOR]

Introduction. The search for new promising sources of biologically active substances is one of the tasks of modern pharmacognosy. Among the huge variety of species of the genus Astragalus L., only a few of them have been studied. In addition, none of them is included in the current edition of the State Pharmacopoeia of the Russian Federation. In our opinion, the study of four species of this genus of Astragalus L. (A. dasyanthus, A. varius, A. testiculatus, A. henningii) growing in the Volga region is of interest.Aim. Study of the glycoside composition of flavonoids in the astragalus herb of four species (A. dasyanthus, A. varius, A. testiculatus, A. henningii) by HPLC-UV using external standards.Materials and methods. The material was samples of astragalus grass (A. dasyanthus, A. varius, A. testiculatus, A. henningii), collected on the territory of the Saratov region in accordance with the basic rules of collection and preparation and dried to an air-dry state. Aqueous-alcoholic extracts (1 : 50) were analyzed. Qualitative and quantitative analysis of flavonoid glycosides was carried out on an Agilent 1260 chromatograph (Agilent Technologies, USA) equipped with a diode array detector, manual sample injection (Agilent G1328C manual injector, Agilent Technologies USA) and an Agilent Open Lab CDS system for collecting and processing chromatographic data. The elution gradient was selected individually using 0.1 % phosphoric acid/acetonitrile solution as solvents. Compounds were identified by retention times and UV spectra of reference standards (RS). The quantitative content of each detected component was expressed in mg/g of dry raw material. All studies were repeated five times, the results were statistically processed using MS Exсel 2010.Results and discussion. The chromatographic profiles of aqueous-alcoholic extracts from the herbs of four types of astragalus were studied. Differences were found in both the qualitative composition and quantitative content of flavonoid glycosides in the grass of the analyzed species. The largest number of compounds was found in the herb of A. varius (6 compounds), 4 compounds were identified in the herb of A. dasyanthus and A. henningii, and 3 compounds were identified in the herb of A. testiculatus. The dominant components in the herb of A. henningii are orientin and rutin, in the herb of A. testiculatus and A. varius it is cynaroside, and in A. dasyanthus it is rutin.Conclusion. A HPLC-UV method was developed for determining the quantitative content of flavonoid glycosides in extracts from the herbs of four species of astragalus (A. dasyanthus, A. varius, A. testiculatus, A. henningii) and the chromatographic profiles of the analyzed samples were studied.

A simple, sensitive and quick HPLC method was developed for the determination of ketoprofen in cell culture media (EMEM, DMEM, RPMI). Separation was performed using a gradient on the C18 column with a mobile phase of acetonitrile and miliQ water acidified by 0.1 % (v/v) formic acid. The method was validated for parameters including linearity, accuracy, precision, limit of quantitation and limit of detection, as well as robustness. The response was found linear over the range of 3–100 μg/mL as demonstrated by the acquired value of correlation coefficient R2=0.9997. The described method is applicable for determination of various pharmacokinetic aspects of ketoprofen in vitro. [ABSTRACT FROM AUTHOR]

Foi empregada a técnica de extração por sorção em fase de tecido para a remoção simultânea de sulfametazina e sulfametoxazol em leite. Para tanto, procedeu-se ao revestimento de um tecido de algodão com uma solução sol-gel de polietilenoglicol, a fim de utilizá-lo como substrato no processo de adsorção. Os tecidos, revestido e não revestido, foram caracterizados por meio de energia dispersiva de raios-x e microscopia eletrônica de varredura, confirmando a eficácia do procedimento de revestimento. A quantificação dos analitos foi realizada por cromatografia líquida de alta eficiência com detecção ultravioleta, sendo o comprimento de onda utilizado de 267 nm. A fase móvel que apresentou melhor separação analítica e seletividade em relação aos analitos estudados diante da matriz complexa do leite foi composta por acetonitrila e água (30:70 v/v). Os resultados da avaliação da capacidade de remoção das sulfonamidas foram de 35,30 % ± 1,09 para sulfametazina e 42,79 % ± 1,68 para sulfametoxazol, evidenciando a eficácia do sistema adsorvente e da metodologia utilizada na extração e detecção desses compostos no leite.

Dispersive solid phase extraction/back–extraction of Ibuprofen using multi-walled carbon nanotubes as sorbent was studied. The effects of some factors on Ibuprofen extraction were investigated. pH of IP solution and temperature were more effective on IP adsorption than other investigated parameters. The obtained preconcentration factor was 11.43. A linear range of 10.31 – 206.28 mg/L (R2 = 0.997) was obtained for the HPLC method. The detection limit and relative standard deviation were 4.93 mg/l and 2.27%, respectively. Extraction and HPLC/UV determination of Ibuprofen in the human blood serum samples was carried out efficiently using the suggested procedure. The obtained results showed satisfactory selectivity and efficiency for the extraction of Ibuprofen molecules from the matrix of the Human blood serum samples. The suggested method is simple, efficient, fast, without usage of organic solvents, and low cost for separation, extraction, and determination of Ibuprofen molecules. [ABSTRACT FROM AUTHOR]

The present study was to develop and validate a rapid analytical method of high-performance liquid chromatography with UV (HPLC/UV) detection for the determination of levetiracetam (LEV) concentration in human serum and cerebrospinal fluid (CSF) samples. The newly developed method was used to measure LEV concentration in the serum/CSF of 29 patients with different types of epilepsy; 52% (group I, n = 15) were treated with LEV in monotherapy, 48% (group II, n = 14) were co-administered with other AEDs. Serum and CSF levels of LEV were correlated with patients dosage, concomitant AEDs, therapeutic effect, and adverse drug reactions (ADRs). The calibration curves for serum and CSF were linear in the range 0.5-100 and 0.5-50 mg/L, respectively, with a coefficient correlation (R) value > 0.998 in each case. The quantitation limit was 0.5 mg/L in serum and CSF. The validated method was found to be selective, precise, and accurate. Optimal Cssmin values according to International League Against Epilepsy (12-46 mg/L) were achieved in 40 and 50% of patients in group I and II, and did not correlate with treatment efficacy in 27 and 21% patients, respectively. The ratio of serum LEV to CSF concentration (Kp) after 2 h administration LEV ranged in group I from 0.31 to 0.92 and in group II from 0.18 to 0.65. These findings indicate that the developed simple and rapid HPLC/UV method may be useful for monitoring serum/CSF LEV concentrations in patients receiving standard doses.

Introduction. Promising sources of biologically active compounds (BAS) are extracts obtained from various morphological parts of plants of the numerous genus Astragalus L. One of the main groups of BAS isolated from plants of this genus are flavonoids, saponins, and polysaccharides. Sufficiently studied are Astragalus membranaceus (Fisch.) Bunge) and Astragalus mongholicus Bge., whose extracts have a wide range of pharmacological activity. Expansion of the nomenclature of medicinal plant materials and the study of BAS groups that determine the main pharmacological effects are topical studies in pharmacognosy. From this point of view, little-studied species of Astragalus (Astragalus henningii (Stev.) Klok., Astragalus testiculatus Pall., Astragalus varius S.G. Gmel., Astragalus dasyanthus Pall.), massively growing in the Volga region, are of interest.Aim. Isolation and identification of 5 aglycones of flavonoids in hydrolysates of water-alcohol extracts from Astragalus herb: A. henningii, A. testiculatus, A.varius, A. dasyanthus by HPLC/UV.Materials and methods. The objects of the study were the herb of four types of Astragalus (A. henningii, A. testiculatus, A.varius, A. dasyanthus), harvested during the period of mass flowering in the Saratov region and dried to an air-dry state. To study the composition of phenolic compounds, extraction was carried out with 70 % ethanol in the ratio of raw material : extracting agent 1 : 10 by infusion for 7 days. Acid hydrolysis was carried out with hydrochloric acid 37 % with heating for 40 min. The resulting hydrolysates were analyzed on an Agilent 1260 chromatograph (Agilent Technologies, USA) with a diode array detector, manual sample injection (Agilent G1328C manual injector, Agilent Technologies, USA) and an Agilent OpenLab CDS chromatographic data collection and processing system using an individually selected elution gradient of the mobile phase (0.1 % solution of orthophosphoric acids/acetonitrile). Compounds in the hydrolysates were identified by the retention times and UV spectra of a mixture of reference standards (RS) of quercetin, isorhamnetin, luteolin, kaempferol, and apigenin.Results and discussion. An elution gradient was selected for one time determination of 5 aglycones of flavonoids with a single analysis time of 13 minutes. These conditions made it possible to identify compounds in the hydrolyzates of water-alcohol extracts of four types of Astragalus. Luteolin, quercetin and apigenin were found in hydrolyzates of A. henningii, A. testiculatus and A. varius; isorhamnetin and kaempferol were found in A. henningii and A. varius. None of the analyzed aglycones was found in the A. dasyanthus hydrolyzate.Conclusion. After preliminary selection of the optimal conditions for the chromatographic separation of a mixture of 5 aglycones of flavonoids, hydrolysates of four types of Astragalus were analyzed. The data obtained indicate the prospects for further study of the chemical composition of Astragalus and confirm the expediency of their use for obtaining of new herbal remedies.

The main objective of this work is to evaluate the species Pistacia atlantica by analyzing the chemical composition of the methanolic extract of the plant leaves; then by determining its content on phenolic compounds, flavonoids and condensed tannins; and finally by testing its antioxidant and inhibitory activities against some enzymes involved in several diseases. To identify phenolic compounds, a high-performance liquid chromatography analysis with ultraviolet detector was used; Folin--Ciocalteu tri-chloroaluminum and vanillin methods were carried out for phenolic compounds, flavonoids, and condensed tannins quantification, respectively. The antioxidant effect was tested by five different methods. Acetylcholinesterase, butyrylcholinesterase, α-glucosidase, and tyrosinase were used to evaluate the inhibitory power of the plant against those enzymes. The results indicated the presence of phenolic compounds in the extract, including phenolic acids and flavonoids. The total phenolic compounds, flavonoids, and condensed tannins contents obtained, respectively, were equal to 36.089 ± 0.047 mg equivalent of galic acid per gram, 0.775 ± 0.01 mg equivalent of quercetin per gram, and 5.44 ± 0.5 mg of equivalent catechin per gram of dry plant. High antioxidant activity was observed and it wasexpressed by IC50 ranging from 3.50 ± 0.05 to 11.11 ± 4.03 μg/ml and concentrations at absorbance 0.5 from 0.84 ± 0.08 to 54.57 ± 0.24 μg/ml values. Strong antidiabetic effect was recorded which far exceeds the effect of acarbose, and interesting anti-Alzheimer and anti-tyrosinase effects were noted. [ABSTRACT FROM AUTHOR]

This study aimed to develop microextraction in a packed syringe (MEPS) method for the determination of the three opiates in urine samples. Covalent organic framework-polypyrrole- cetyltrimethylammonium bromide (COF-PPy-CTAB) nanocomposite, as an appropriate and highly efficient adsorbent, was synthesized and applied to the MEPS process. The analytes were separated and extracted on the solid phase surface of the adsorbent through π stacking, hydrophobic, and host-guest interaction and then eluted by a desorbing solvent. After synthesizing the composite and using it in the syringe as a substrate for analyte adsorption, the parameters affecting the extraction of the analytes were optimized and the calibration curve was obtained according to the optimum conditions. The results were linear in the concentration range of 0.5–1000 μg L − 1 with a coefficient of determination greater than 0.9945. The limits of detection and quantification were obtained in the range of (0.1–1.0) and (0.5–5.0) μg L‒1, respectively. The precision of the work was obtained for a syringe in a day and between days and also syringe to syringe in the range of 4.4–6.1%, 6.5–8.1%, and 7.8–10.1%, respectively. The preconcentration factors of 17, 20, and 16 were obtained for codeine, papaverine, and naltrexone, respectively. Relative recoveries of the drugs from urine samples were in acceptable range of 94.4–100.6% for codeine, 99.3–103.1% for papaverine and 95.0–98.9% for naltrexone.

Abstract A vortex-assisted dispersive liquid–liquid microextraction (DLLME) method, mated to chemometrics and combined with HPLC/UV detection was optimized and validated for enrichment and determination of repaglinide in environmental samples using nateglinide as an internal standard (IS). A phosphate buffer (10 mM, pH 2.5): acetonitrile (45:55, v/v) was used as a mobile phase with a flow rate of 1 mL/min in an isocratic elution mode. Chemometrics-assisted optimization was performed using a quadratic integrated d-optimal design. The developed model assessed the statistical significance of the independent variables and their interactions to attain the optimum conditions revealing that extractant type, extractant volume and pH are the most influential factors. Optimization of the extraction procedures was performed with the aid of Design Expert 8® software, which suggested 58 different experiments. The optimal conditions were 30 µL of 1-octanol as extractant, 100 µL of acetonitrile as a disperser at pH 8. Under the optimized conditions, the method showed linearity over the range of 1–100 ng/mL with a limit of detection of 0.4 ng/mL. The accuracy, the intra- and inter-day precision were assessed, the %recoveries were found to be between 98.48 and 100.81% with %RSD lower than 1.3. Using chemometrics in method optimization helped achieve the maximum possible enrichment with the least effort, time, and reagents while considering all possible interactions between variables.

In this study, safranal as the main component of the pleasant aroma of saffron was extracted and analyzed by two liquid-phase microextraction based methods, namely ultrasound-assisted emulsification microextraction and solidified floating organic drop microextraction. These methods are fast, simple, low-cost, environmentally friendly and efficient procedures that have been developed for the determination of safranal from aqueous samples. Extracted safranal was determined by high pressure liquid chromatography and the performance of the above mentioned methods was compared accurately. A narrow neck glass tube was used for the simple and rapid collection of the low-density organic phase from the sample surface after its centrifugation. A dynamic range over 0.1 to 5 μg mL−1 of safranal and limit of detection of 20 ng mL−1 were obtained for ultrasound-assisted emulsification microextraction. In addition, the dynamic range for solidified floating organic drop microextraction was between 0.02 to 5 μg mL−1 as well as a limit of detection of 3 ng mL−1 was obtained. Furthermore, the enrichment factor and recovery percent were 38 and 101±4.6% in ultrasound-assisted emulsification microextraction besides 252 and 25.2 ± 5.8% in solidified floating organic drop microextraction.The applicability of the proposed methods was evaluated by the extraction and determination of safranal from different Iranian saffron samples and finally, the results were validated by the ISO 3632 procedure.

This research was aimed to evaluate the chemical composition by HPLC/UV, anti-inflammatory effect in vitro (hyaluronidase assay) and anti-ulcer activity in vivo against gastric ulcer. This anti-ulcer activity was explored in vivo on Wistar rats exposed to a gastric ulcer provoked with oral administration of HCl /ethanol (150 mM /60%) for one day after five days of oral treatment with 250 mg/kg of ethanolic extract of carob pods (EECp), to restore stomach ulceration. Several compounds of carob have been identified by HPLC/UV. This identification reveals the existence of phenolic compounds; flavonoids (chrysin, galangin, pinocembrin, quercetin, genistein, kaempferol, etc.) and phenolic acids (rosmarinic acid, caffeic acids, ferulic acid, etc.). Our extract showed strong inhibitory activity of hyaluronidase with (IC50 = 20.7 mg / ml). The results obtained indicated that administration of HCl /ethanol alone produced stomach ulceration in rats with very extensive and bleeding gastric lesions with 44.09% of percentage lesion and 362.26 mm² of lesions area in the stomach mucosa. However, pretreatement of rats with EECp revealed a spectacular inhibition of gastric mucosal damage (7.46%), a significant reduction in malondialdehyde (4.86 nmol/mL) and an increase in enzymes of oxidative status (superoxide dismutase, catalase and glutathione peroxidase). The present study results can attribute to carob an antioxidant, anti-inflammatory and anti-ulcer effects. [ABSTRACT FROM AUTHOR]

This study evaluated the in vitro radical scavenging activities of edible tree sprouts, particularly those of the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), hydroxyl radical, and singlet oxide radical, to assess their antioxidant activities. Additionally, stigmasterol (ST) and β-sitosterol (BS) were analyzed using HPLC/UV. The edible sprouts of Eleutherococcus senticosus (ESC) and Morus alba (MAB) exhibited the highest DPPH scavenging activity among other edible sprouts. A reverse-phase column was used in an isocratic elution system, after which UV detection was performed at 210 nm. ST and BS analyses indicated that ESC sprouts contained the highest amounts of ST (9.99 mg·g− 1 extract), whereas MAB sprouts contained the highest concentrations of BS (14.69 mg·g− 1 extract). In conclusion, the highest antioxidant activity was observed in the edible sprouts with the highest phytosterol content. Therefore, our findings provide a theoretical basis for the development of plant-based functional foods or supplements with antioxidant properties. [ABSTRACT FROM AUTHOR]

The current study was conducted to evaluate the protective effect of the ethanolic extract of Anacyclus valentinus (EEA) against hepatotoxicity resulting from exposure to cisplatin (CP) in male rats. In this study, a total of twenty four adult male Wistar rats were used and divided into four groups. The first group (G1) was the control group, the second group (G2) was exposed to CP (three doses of 7 mg/Kg body weight for 6 days; by intravenous injection), the third group (G3) received 200 mg/Kg EEA orally per day for a period of 28 days and the last group (G4) was exposed to CP and treated with 200 mg/Kg EEA. Thus, the levels of γ-GT, ALP, AST and ALT were significantly increased (p <0.01) due to exposure to CP and these enzymes levels were reversed in the CP group receiving EEA. Further, CP caused a significant decrease (p <0.001) in the activity of antioxidant enzymes (SOD, CAT and GSH-PX) with an increase in the level of MDA and NO. Besides, administration of EEA to rats (G4) restored the impaired activity of the antioxidant system with a decrease in MDA and NO. A significant increase (p <0.001) in markers of inflammation (TNF-α and PGE2) was observed in animals treated with CP; while the effect was diminished by EEA. In addition, histological study of the liver indicated that injection of CP to rats caused vascular congestion, microvacuolar steatosis, inflammatory reaction and chronic hepatitis; these changes were resolved by administration of EEA. In conclusion, EEA possessed a therapeutic effect against CP-induced hepatotoxicity in rats. [ABSTRACT FROM AUTHOR]

Favipiravir is a potential antiviral medication that has been recently licensed for Covid‐19 treatment. In this work, a gadolinium‐based magnetic ionic liquid was prepared and used as an extractant in dispersive liquid–liquid microextraction (DLLME) of favipiravir in human plasma. The high enriching ability of DLLME allowed the determination of favipiravir in real samples using HPLC/UV with sufficient sensitivity. The effects of several variables on extraction efficiency were investigated, including type of extractant, amount of extractant, type of disperser and disperser volume. The maximum enrichment was attained using 50 mg of the Gd‐magnetic ionic liquid (MIL) and 150 μl of tetrahydrofuran. The Gd‐based MIL could form a supramolecular assembly in the presence of tetrahydrofuran, which enhanced the extraction efficiency of favipiravir. The developed method was validated according to US Food and Drug Administration bioanalytical method validation guidelines. The coefficient of determination was 0.9999, for a linear concentration range of 25 to 1.0 × 105 ng/ml. The percentage recovery (accuracy) varied from 99.83 to 104.2%, with RSD values (precision) ranging from 4.07 to 11.84%. The total extraction time was about 12 min and the HPLC analysis time was 5 min. The method was simple, selective and sensitive for the determination of favipiravir in real human plasma. [ABSTRACT FROM AUTHOR]

A vortex-assisted dispersive liquid–liquid microextraction (DLLME) method, mated to chemometrics and combined with HPLC/UV detection was optimized and validated for enrichment and determination of repaglinide in environmental samples using nateglinide as an internal standard (IS). A phosphate buffer (10 mM, pH 2.5): acetonitrile (45:55, v/v) was used as a mobile phase with a flow rate of 1 mL/min in an isocratic elution mode. Chemometrics-assisted optimization was performed using a quadratic integrated d-optimal design. The developed model assessed the statistical significance of the independent variables and their interactions to attain the optimum conditions revealing that extractant type, extractant volume and pH are the most influential factors. Optimization of the extraction procedures was performed with the aid of Design Expert 8® software, which suggested 58 different experiments. The optimal conditions were 30 µL of 1-octanol as extractant, 100 µL of acetonitrile as a disperser at pH 8. Under the optimized conditions, the method showed linearity over the range of 1–100 ng/mL with a limit of detection of 0.4 ng/mL. The accuracy, the intra- and inter-day precision were assessed, the %recoveries were found to be between 98.48 and 100.81% with %RSD lower than 1.3. Using chemometrics in method optimization helped achieve the maximum possible enrichment with the least effort, time, and reagents while considering all possible interactions between variables. [ABSTRACT FROM AUTHOR]

Background: The counteractive action of diabetes by plant polyphenols along with their utilization in the treatment of diabetic difficulties is of expanding significance from the epidemiological information with in vitro and in vivo examinations. Objectives: We assessed the antihyperglycemic impacts of methanolic (MeCV), aqueous (AqCV), ethyl acetate (EaCV) and n-hexane (NhCV) extracts of Cleome viscosa whole plant. Materials and Methods: Qualitative phytochemical analysis and antidiabetic activities by glucose diffusion, inhibitory movement of starch processing enzymes i.e. a-glucosidase and a-amylase, glucose uptake by yeast cell method and also the non-enzymatic action (glycosylation of Hb). The identification of polyphenols in bioactive extracts was categorized by using HPLC/UV. Results: To evaluate the comparative power of these extracts, the concentrations required for 50% and 100% inhibition of enzyme movement were resolved. Greatest enzyme inhibition was utilized to evaluate an inhibitor's relative viability. Results demonstrated that MeCV strongly diffused by glucose and inhibited both a-glucosidase and a-amylase enzyme movement and great impact on the glucose uptake by yeast cells and non-enzymatic glycosylation of Hb with equivalent intensity respectively than acarbose. While NhCV was showed less impact on glucose diffusion, a-glucosidase, a-amylase, glucose uptake by yeast cells and glycosylation of Hb. Gallic acid (2.45%), protocatechuic acid hexoside (0.83%), chlorogenic acid (0.77%), catechin (0.53%), quercetin (0.80%), p-hydroxybenzoic acid (0.78%), and p-coumaric (0.07%) were the main compounds of the MeCV. Conclusion: Based on our results we concluded that the MeCV firmly impacts on enzymatic and non-enzymatic activities due to rich content of polyphenols present in MeCV. [ABSTRACT FROM AUTHOR]

Nowadays bioanalytical techniques including liquid and gas chromatography combined with different types of detectors are largely introduced in a practice. They are largely used for detection and control of substances and for monitoring of the whole production process. The type of detector depends on necessary levels of detection, but also on the matrix where aimed compounds have to be determined. Herein are summarized data from the last ten years related to determination of six main prohibited substances sildenafil, tadalafil, vardenafil, dapoxetine, yohimbine and sibutramine as well as their derivatives in food supplements using high performance liquid chromatography combined with mass spectrometric or UV detection. All these compounds are in a large interest because they are introduced often in products freely distributed in the internet market. [ABSTRACT FROM AUTHOR]

Background: Is a pleasant-smelling perennial shrub that grows in many parts of the world, Rosmarinus officinalis a well known valuable herbal medicine which is widely used in pharmaceuticals and traditional medicine as a digestive, tonic, astringent, diuretic, diaphoretic and useful for urinary ailments. Objective: The objective of this study has, on the one hand, focused on the changes in hepatotoxicity induced by the chronic administration of ethyl alcohol according to a biochemical and histological experimental approach and, on the other hand, on the chemical composition which was determined. As well as, the hepato-protective effect of the ethanolic extract of Rosmarinus officinalis (EER), whether to restore or not the harmful alterations due to ethylism was evaluated. Method: The study included twenty-four male Wistar albino rats which were divided into four groups. The rats received ethanolic extraction of Rosmarinus officinalis orally at a dose of 200 mg/kg. Hepatotoxicity was induced orally with a daily dose of 05 mL of 20% alcoholic solution for 90 days. Results: The chemical characterization of the ethanolic extract of Rosmarinus officinalis (EER) by HPLC/UV shows the presence of polyphenolic compounds and numerous flavonoids, the main constituent of which is rosmarinic acid. It was noticed that the Ethanol caused an increase in liver function parameters (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglyceride and cholesterol, total bilirubin) compared to the control and oxidative stress through a significant decrease in antioxidant liver enzymes Superoxidase dismutase (9.39 U/mg), glutathione peroxidase (12.89 U/mg) and catalase (25.39 U/mg) and increased malondialdehyde levels. The histological study showed significant lesions in the liver. Conclusion: The disturbances in liver function, antioxidant status and structural damage to the liver caused by ethanol have been restored by the administration of the ethanolic extract of Rosmarinus officinalis which strongly justifies its therapeutic effect. [ABSTRACT FROM AUTHOR]

The purpose of the present work is searching for new sources of bioactive molecules from plants to use them in treating or controlling some health problems. The methanolic extracts of two endemic species in Algeria Lavandula antineae (very few studies on its biological effects) and Thymus algeriensis were analyzed by HPLC/UV then tested for their antioxidant effect by the DPPH and ABTS scavenging radical tests, FRAP test and CUPRAC test. The inhibitory power of these same extracts on acetylcholinesterase, butyrylcholinesterase and α-glucosidase was also evaluated. Phenolic acids and flavonoids were found in common in both extracts as 3-hydroxy-4-méthoxycinnamic acid, and quercetin. The results showed considerable antioxidant effects for both plants with minimal IC50 values equal to 10.77±1.14 µg/ml for L. antineae and 11.73±0.20 µg/ml for T. algeriensis. The minimal value of PR0.5 was recorded with L. antineae (10.57± 0.38 µg/ml) after the BHA. The two species are shown to be effective on acetylcholinesterase especially T. algeriensis. L. antineae exhibited a high inhibitory power against butyrylcholinesterase with 20.84±9.74 µg/ml IC50 value. The same plant showed more effective than Galantamine in inhibiting α-glucosidase with 168.61±7.60 µg/ml IC50 value. Interesting results were given by methanolic extract of both plants, which can be exploited in medicine and pharmaceutical domains as natural treatments for diseases like Alzheimer and diabetes type 2. [ABSTRACT FROM AUTHOR]

Background: Due to its flavoring and seasoning properties, Salvia officinalis has been widely used in the preparation of many foods. In folk medicine in Asia and Latin America, it has been used for the treatment of various types of disorders, including seizures, ulcers, rheumatism, inflammation, dizziness, and high blood sugar. Objective: The purpose of this study is to determine the chemical composition by HPLC/UV, antioxidant activity and lipid peroxidation; thus the, the anti-inflammatory effect of the ethanolic extract of Salvia officinalis (EES) on certain homeostatic parameters, inflammatory biomarkers and antioxidant status in Wistar rats subjected to inflammation induced by carrageenan. Method: Male rats (n = 24) were exposed to inflammation of the peritoneal by carrageenan (200 μL: 2%) and treated for 5 days with ethanolic extract of Salvia officinalis (EES) in order to repair the damage caused by inflammation on homeostasis, TNF-α and PGE2. Results: The results of scavenging of DPPH and lipoperoxidation of the extract, showed an IC50 of 29.69 ± 1.32 and 46.17 ± 1.51 μg/mL, respectively. The identification of EEC by HPLC shows the presence of polyphenolic acids (salvianolic acid, rosmarinic acid, caffeic acid, ferulic acid) and many flavonoids (Cirsimaritin, Catechin, Acacetin, kaempferol, pinocembrine, quercetin). Salvia extract contains 221.08 ± 2.36 mg EAG/g and 80.54 ± 1.3 mg EQ/g dry extract. Compared to the control group, carrageenan induced a substantial decrease (P<0.05) in antioxidant enzymes and a highly significant increase (P<0.05) in homeostatic parameters (blood sugar, CRP and fibrinogen), biomarkers of inflammation (TNF-α and PGE2) and malondialdehyde levels. Conclusion: The administration of Salvia extract corrects this perturbation where there is an improvement in antioxidant enzymes and a decrease in biomarkers of inflammation. Salvia officinalis has been able to repair carrageenin-induced perturbations homeostasis and inflammation markers in Wistar rats. [ABSTRACT FROM AUTHOR]

Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are considered as viable targets in the treatment of Alzheimer's disease and other dementias. However, since clinically used AChE or dual AChE/BuChE inhibitors only provide some symptomatic treatment and lose their therapeutic effectiveness over time, in the last years an intensive search for multi-target compounds has started, which address additional targets besides AChE and BuChE, like endocannabinoid degrading enzymes. For the evaluation of the AChE and BuChE inhibitory potency of the test compounds in such drug development projects, usually the traditional Ellman's method is used. Since this method has some analytical drawbacks, we have developed alternative robust HPLC/UV based assays using pyridin-2-ylmethyl acetate as substrate for AChE and benzoylcholine for BuChE. The enzyme products pyridin-2-ylmethanol and benzoic acid, respectively, were determined by reversed phase HPLC adding the ion pair reagent sodium octane-1-sulfonate to the mobile phase in case to the polar pyridine derivative. AChE from electric eel, human recombinant AChE and BuChE from equine serum were employed as enzymes. For method validation, the IC50-values of the known AChE and BuChE inhibitors physostigmine, rivastigmine and tacrine were measured. The obtained data were within the very wide range of the IC50-values given in the literature for these compounds. [ABSTRACT FROM AUTHOR]

Antibiotics are widely used in intensive care patients to treat severe infections. To avoid bacterial resistance or toxic side effects, the determination of serum concentration of ABs is advisable. Therefore, in this study, we developed and validated a simple and fast high‐performance liquid chromatography method with UV detection for the simultaneous determination of four β‐lactam ABs (meropenem, imipenem, ceftazidime, and piperacillin) and two coadministered substances (cilastatin and tazobactam) in human serum. Sample preparation required a simple protein precipitation by methanol. The separation of the ABs occurred within a timeframe of 17 min. For this purpose, we used a Kinetex F5 column with a linear gradient of acetonitrile and phosphate buffer (pH 6.9). The UV detector recorded two separate chromatograms at 220 and 295 nm simultaneously. Validation has demonstrated that the method is linear, accurate, and precise within the clinically relevant range for each substance. [ABSTRACT FROM AUTHOR]

A new, selective and sensitive HPLC method for the determination of lixivaptan, an oral selective vasopressin 2 (V2)-receptor antagonist, was investigated and validated. A Waters symmetry C18 column was used as a stationary phase in isocratic elution mode using a mobile phase composed of KH2PO4 (100 mM)-acetonitrile (40: 60, v/v) at a flow rate of 1.5 mL min-1. Diclofenac was used as the internal standard (IS). Lixivaptan and the IS were extracted from plasma by protein precipitation and were detected at 260 nm. Lixivaptan and diclofenac were eluted at 3.6 and 6.2 min, respectively. The developed method showed good linearity over the calibration range of 50 -1000 ng mL-1 with a lower limit of detection of 16.5 ng mL-1. The extraction percentage of lixivaptan in the mouse plasma was in the range of 88.88 - 114.43%, which indicates acceptable extraction. The aforementioned method was validated according to guidelines of the International Council on Harmonization (ICH). The intra- and inter-day coefficients of variation did not exceed 5.5%. This method was presented to be simple, sensitive, and accurate and was successfully adapted in a pharmacokinetic study of the profile of lixivaptan in mouse plasma. A mean maximum plasma concentration of lixivaptan of 113.82 ng mL-1 was achieved in 0.5 h after oral administration of a 10 mg kg-1 dose in mouse as determined using the developed method.

To discover new standard for the standardization of bulbs of Allium fistulosum (Chongbaek, Korean herbal name), twelve compounds (1–12) were isolated. Among them, a new HPLC/UV analysis method by selecting the five cinnamic acid amides (5–9) and two decursidate isomers (10 and 11), was fully validated. The developed analysis method showed sufficient reproducibility (< 2.58%) and accuracy (96.00–106.72%). Moreover, among compounds 5–11, only trans-isomers were verified from all four Chongbaek samples which produced in different regions, and this finding implied that the cis-forms were not originally nature compounds, thus, it led us to verify the conversion processes. The four trans-standard solutions and extracts of Chongbaek were converted to the cis- derivatives after 96 h of UV (254 nm) light exposure as 78.74% (6), 82.29% (8), and 63.99% (11) in solution and 82.38% (6), 62.91% (8), and 61.64% (11) in extracts. A verified analysis method using new indicators was developed for quality control of Chongbaek, as well as their stability control under UV light exposure. These results might be important for the industrial use of Chongbaek. [ABSTRACT FROM AUTHOR]

In the current paper, an HPLC/UV method was developed and validated for determination of wogonin in plasma. Considerable attention was paid to the preparation of standard samples and factors affecting drug distribution. A preparation procedure was devised to simulate the conditions the drug is expected to experience in vivo while pointing to the shortcomings of previously published methods. The method was validated according to the FDA regulations and showed to be highly efficient and capable of extracting the drug and IS from the plasma accurately and precisely within the specified range of 50–500 ng mL−1. Further, the standard sample preparation of this method can be used as a guideline for other methods, particularly when highly hydrophobic drugs with considerable protein binding are involved and could be valuable in the field of bioanalysis to improve the reliability of methods.

Due to the low absorptivity of bile acids, the aim of this study was to develop and validate a simple and sensitive HPLC/UV method for quantification of ursodeoxycholic acid (UDCA) in pharmaceutical formulations. Effective separation was achieved on C18 end-capped column, with gradient elution of a mobile phase composed of 0.001 M phosphate buffer (pH 2.8±0.5) - acetonitrile mix, at flow rate 1.5 mL min-1, UV detection at 200 nm and injection volumes were 50 μL. The proposed HPLC method was fully validated according to the ICH guidelines and it was found to be simple, accurate, precise and robust. [ABSTRACT FROM AUTHOR]

A novel method was developed for quantification of five major piperine derivatives（piperanine, piperine, chavicine, isopiperine, and isochavicine）in a hot water extract of long pepper fruit（LPE） using the relative molar sensitivity（RMS）based on the combination of HPLC/UV and 1H- quantitative NMR（1H-qNMR）. The RMSs of piperanine, chavicine, isopiperine, and isochavicine to piperine of which the absolute purity was determined by 1H-qNMR were calculated to be 0.3693, 1.138, 0.9164, and 1.277, respectively. The total amount of piperine derivatives in LPE was quantified by both 1H-qNMR and HPLC/UV based on the RMS using piperine as a single-reference material RMS method）. The relative difference in quantitation values of 1H-qNMR and calibration curve method from the RMS method was 2.01％ or less. The relative difference of the total cis-trans piperine isomers content between before and after photoirradiation in piperine solution was quantified to be 2.84％ by the RMS method. In addition, the interlaboratory difference of the RMS method was confirmed in the range of 0.600 to 4.00 g/g when analysis was performed on piperine derivatives in LPE containing tablets, while the total amount of piperine derivatives in the tablets was quantified at 606 g/g. Our proposed method is a reliable tool for determining the contents of piperine and the derivatives in LPE and processed foods containing LPE. [ABSTRACT FROM AUTHOR]

This study determined acteoside and its content in Abeliophyllum distichum via HPLC/UV and LC/ESI-MS to obtain insights into the potential use of this plant as an antioxidant agent. Moreover, 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (•OH), and O2− radical scavenging activity assays were performed to assess in vitro antioxidative activity. The DPPH, •OH, and O2− radical scavenging activities of A. distichum leaf EtOH extracts at a 250 μg/mL concentration were 88.32%, 94.48%, and 14.36%, respectively, whereas those of stem extracts at the same concentration were 88.15%, 88.99%, and 15.36%, respectively. The contents of acteoside in A. distichum leaves and stems were 162.11 and 29.68 mg/g, respectively. Acteoside was identified as the main antioxidant compound in A. distichum leaves, which resulted in DPPH, •OH, and O2− radical scavenging activities of 82.84%, 89.46%, and 30.31%, respectively, at a 25 μg/mL concentration. These results indicate that A. distichum leaves and stems containing the antioxidant acteoside can be used as natural ingredients for functional and nutritional supplements.

Quetiapine is an atypical antipsychotic used to treat schizophrenia. However, despite great interest for its chronic therapeutic use, quetiapine has some important side effects such as weight gain induction. The development of a quetiapine nanocarrier can potentially target the drug into central nervous system, resulting in a reduction of systemic side effects and improved patient treatment. In the present work, a simple liquid chromatography/ultraviolet detection (LC/UV) analytical method was developed and validated for quantification of total quetiapine content in lipid core nanocapsules as well as for determination of incorporation efficiency. An algorithm proposed by Oliveira et al. (2012) was applied to characterize the distribution of quetiapine in the pseudo-phases of the nanocarrier, leading to a better understanding of the quetiapine nanoparticles produced. The analytical methodology developed was specific, linear in the range of 0.5 to 100 µg mL−1 (r2 > 0,99), and accurate and precise (R.S.D < ±5%). The absolute recovery of quetiapine from the nanoparticles was approximately 98% with an incorporation efficiency of approximately 96%. The results indicated that quetiapine was present in a type III distribution according to the algorithm, and was mainly located in the core of the nanoparticle because of its logD in the formulation pH (6.86 ± 0.4).

The glutathione (GSH) conjugates, S-(1,2-dichlorovinyl)-glutathione (DCVG) and S-(1,2-dichlorovinyl)-L-cysteine (DCVC), have been implicated in kidney toxicity and kidney cancer from trichloroethylene (TCE) exposure. Considerable differences in blood and tissue levels of DCVG and DCVC have been reported, depending on whether HPLC/UV (High Performance Liquid Chromatography-Ultraviolet) or HPLC/MS (HPLC-Mass Spectrometry) was used. A side-by-side comparison of analytical results with HPLC/UV and HPLC/MS/MS (High Performance Liquid Chromatography-Tandem Mass Spectrometry) detection was undertaken to quantitatively compare estimates for DCVG and DCVG using rat and human tissues. For the HPLC method, DCVG and DCVC were initially derivatized with fluorodinitrobenzene (DNP). The results from the HPLC/UV method showed that derivatized-DCVC eluted at the solvent front and could not be quantified. Derivatized-DCVG, however, was quantified but significant interference was observed in all four control tissues (rat blood, liver, kidney; and human blood), resulting in average spike recoveries of 222–22,990%. In contrast, direct analysis of spiked tissues by HPLC/MS/MS resulted in recoveries of 82–127% and 89–117% for DCVG and DCVC, respectively. These differences in analytical results were further confirmed in tissues from TCE-treated rats, e.g. , DCVG levels in rat liver were 18,000 times higher by HPLC/UV as compared to HPLC/MS/MS. Fraction collection of the derivatized-DCVG peak (obtained with the HPLC-UV method), followed by peak identification via an HPLC/UV/Q-TOF/MS/MS method, identified DNP-derivatized endogenous glutamate as the primary interfering substance that contributed to and exaggerated recoveries of DCVG. Thus, estimates of DCVG based on the HPLC/UV methods are not reliable; they will over-estimate the formation of the GSH conjugates of TCE and will artifactually exaggerate the potential cancer risk in humans from TCE exposure. Therefore, it is recommended that any characterization of cancer risks from TCE exposure attributable to the GSH conjugates of TCE rely on results obtained with the more specific and reliable HPLC/MS/MS method. [ABSTRACT FROM AUTHOR]

Evodiae fructus (EF) has been used in China for thousands of years as an analgesic, antiemetic, anti-inflammatory and antidiarrheal drug. EF is a toxic drug and causes hepatotoxicity in humans. Although recent chronic toxicity studies performed on aqueous extract of EF has revealed that it can produce obvious cumulative hepatotoxicity, the mechanism behind this toxicity is still uncertain. In the present study, we investigated the influence of EF on oxidative stress, mitochondrial permeability transition, adenosine triphosphate (ATP), and cytochrome C release of hepatic mitochondria. Rats were divided into four groups and fed distilled water, 6, 12, 24 g/kg of aqueous extract of EF daily for 15 days. Evodiamine, rutaecarpine and evodine were quantified in the aqueous extract by high performance liquid chromatography with ultraviolet detection (HPLC/UV). The results showed that aqueous extract of EF could significantly (p < 0.05) decrease MnSOD levels to 56.50%, 46.77% and 19.67% of control group, GSH level was decreased to 74.24%, 53.97% and 47.91% of control group and MDA level was increased to 131.55%, 134.34% and 150.81% of control group in the 6, 12 and 24 g/kg groups, respectively; extract also induced mitochondria swelling, vacuolation, MPT pore opening and a significant decrease (p < 0.05) in mitochondrial potential, while ATP levels were significant decreased (p < 0.05) to 65.24%, 38.08% and 34.59% of control group in the 6, 12 and 24 g/kg groups, respectively, resulting in ATP depletion and CytC release, finally trigger cell death signaling, which are the partial hepatotoxicity mechanisms of EF.

Recently, a novel quantitative method using relative molar sensitivity (RMS) was applied to quantify the ingredients of drugs and foods. An important development in this regard can be observed in the Japanese Pharmacopoeia (JP) 18, where the quantification of perillaldehyde, an unstable compound, in crude drug "Perilla Herb," was revised to incorporate the RMS method. In this study, the primary objective was to improve the tester safety and reduce the amount of reagents used in the JP test. To achieve this, the quantification of three toxic Aconitum monoester alkaloids (AMAs) was explored using the RMS method, employing a single reference compound for all three targets. These AMAs, namely benzoylmesaconine hydrochloride, benzoylhypaconine hydrochloride, and 14-anisoylaconine hydrochloride, which are the quantitative compounds of Kampo extracts containing Aconite Root (AR), were quantified using the reference compound benzoic acid (BA). Reliable RMS values were obtained using both 1 H-quantitative NMR and HPLC/UV. Using the RMS of three AMAs relative to the BA, the AMA content (%) in commercial AMAs quantitative reagents were determined without analytical standards. Moreover, the quantitative values of AMAs using the RMS method and the calibration curve method using the three analytical standards were similar. Additionally, similar values were achieved for the three AMAs in the Kampo extracts containing AR using the RMS and the modified JP18 calibration curve methods. These results suggest that the RMS method is suitable for quantitative assays of the Kampo extracts containing AR and can serve as an alternative to the current method specified in the JP18.

Vitamin B2 (riboflavin) is a water-soluble essential vitamin. Nowadays an increased risk for riboflavin deficiency may be seen in people on special diets (diabetes mellitus), smokers or heavy alcohol drinkers. In the Czech diet the main sources of the vitamin intake are milk and dairy products followed by cereals and meat. Cereals are good source of this vitamin as it is widely and regularly consumed in different forms. Analyses of the vitamin B2 content in different types of cereal products (flours, breads, pastries, breakfast cereals, cooked pasta) of Czech origin using HPLC with reversed phase and UV detection were done. The vitamin B2 content of chosen cereal products decreased in this progression: enriched wholemeal breakfast cereals (the best source of the vitamin), enriched wheat flours, breads – rye and wholemeal wheat breads, whole wheat and spelt flours, wheat bread, cooked whole wheat and rye spaghetti, wheat and multigrain pastries and finally scoured wheat flours.

This paper describes the development of extraction and high-performance liquid chromatography with ultraviolet detection methods for the determination of boscalid, pyraclostrobin, and trifloxystrobin. The extraction method includes classical solid-liquid and liquid-liquid extraction methods. The fungicides and the internal standard were separated in less than 6.5 min on an ODS column with acetonitrile/water mobile phase at 1.5 mL min−1 flow rate and detected at 265 nm. The limit of detection and quantification were 0.0084 and 0.0280 mg kg−1 for boscalid; 0.0032 and 0.0106 mg kg−1 for pyraclostrobin; 0.0113 and 0.0377 mg kg−1 for trifloxystrobin. The reproducibility of the method was lower than 0.6 % and 0.7 % relative standard deviation in terms of retention time for within day and between days, respectively, lower than 1.4 % in terms of the ratio of peak areas for both within day and between days. The accuracy of the analysis method in terms of relative error was lower than 11 % at low, 8 % at medium and 1 % at high concentrations. The recoveries were between 99–106 % for boscalid, 70–82 % for pyraclostrobin and 52–64 % for trifloxystrobin. These developed methods were then applied for the determination of selected fungicides in dried grape and apricot samples. • Extraction and analysis methods were developed and applied to dried fruits. • Sample preparation included classical solid-liquid and liquid-liquid extractions. • Both methods do not require expensive and complex equipment. • The proposed methods are easy, simple, cheap and adequate for routine analysis. • Analysis method was accurate, reproducible and showed good linearity with low LOD. [ABSTRACT FROM AUTHOR]

Scented candles are known to release various volatile organic compounds (VOCs) including both pleasant aromas and toxic components both before lighting (off) and when lit (on). In this study, we explored the compositional changes of volatiles from scented candles under various settings to simulate indoor use. Carbonyl compounds and other VOCs emitted from six different candle types were analyzed under ‘on/off’ conditions. The six candle types investigated were: (1) Clean cotton (CT), (2) Floral (FL), (3) Kiwi melon (KW), (4) Strawberry (SB), (5) Vanilla (VN), and (6) Plain (PL). Although a large number of chemicals were released both before lighting and when lit, their profiles were noticeably distinguishable. Before lighting, various esters ( n = 30) showed the most dominant emissions. When lit, formaldehyde was found to have the highest emission concentration of 2098 ppb (SB), 1022 ppb (CT), and 925 ppb (PL). In most lit scented candles, there was a general tendency to show increased concentrations of low boiling point compounds. For some scented candle products, the emission of volatiles occurred strongly both before lighting and when lit. For instance, in terms of TVOC (ppbC), the highest concentrations were observed from the KW product with their values of 12,742 (on) and 2766 ppbC (off). As such, the results suggest that certain scented candle products should act as potent sources of VOC emission in indoor environment, regardless of conditions – whether being lit or not. [ABSTRACT FROM AUTHOR]

A new method for the determination of trace bisphenol A (BPA) and diethylstilbestrol (DES) in water samples has been developed by using three phase hollow fiber liquid-phase microextraction (HF-LPME) and an ionic liquid (IL, 1-Octyl-3-methylimidazolium hexafluorophosphate, [C8MIM][PF6]) as supported phase (IL-HF-LPME) combined with high performance liquid chromatography/ultraviolet spectrophotometry (HPLC/UV). The optimized microextraction conditions were as follows: [C8MIM][PF6] was used as the extraction solvent, pH 10 NaOH solution, 5 µL, as acceptor phase; 20 mL water sample with NaCl (5%, w/v) as donor phase and the extraction time was 30 min (stirring rate 200 rpm, 25°C). Under the optimal extraction conditions, the proposed method offered: good linearity range, 0.30–100 µg L−1, with correlation coefficients (r2) of 0.9996 and 0.9988; low detection limit, 0.20 and 0.05 µg L−1(S/N = 3) for BPA and DES, respectively; good reproducibility (relative standard deviation, RSD, 7.28% and 8.45%, respectively,n = 5); high enrichment factor, 850 and 624, respectively. The method was used to analyze real water samples, and satisfactory recoveries (75.4–99.2%) were obtained, which confirmed that the developed method was simple and environmentally friendly for the determination of BPA and DES in aquatic systems. Meanwhile, it was found that humic acid had no obvious influence on enrichment factor. [ABSTRACT FROM PUBLISHER]

ABSTRACT Introduction Quantitative 1H-NMR (qNMR) is a well-established method for quantitative analysis and purity tests. Applications have been reported in many areas, such as natural products, foods and beverages, metabolites, pharmaceuticals and agriculture. The characteristics of quantitative estimation without relying on special target reference substances make qNMR especially suitable for purity tests of chemical compounds and natural products. Ginsenosides are a special group of natural products drawing broad attention, and are considered to be the main bioactive principles behind the claims of ginsengs efficacy. The purity of ginsenosides is usually determined by conventional chromatographic methods, although these may not be ideal due to the response of detectors to discriminate between analytes and impurities and the long run times involved. Objective To establish a qNMR method for purity tests of six dammarane-type ginsenoside standards. Methods Several experimental parameters were optimised for the quantification, including relaxation delay (D1), the transmitter frequency offset (O1P) and power level for pre-saturation (PL9). The method was validated and the purity of the six ginsenoside standards was tested. Also, the results of the qNMR method were further validated by comparison with those of high performance liquid chromatography. Conclusion The qNMR method was rapid, specific and accurate, thus providing a practical and reliable protocol for the purity analysis of ginsenoside standards. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A new method for the determination of four endocrine disrupting compounds (EDCs) (bisphenol A, 17-β-estradiol, estrone and diethylstilbestrol) in water samples has been developed using polypropylene hollow-fiber-supported ionic liquid (IL, 1-Octyl-3-methylimidazolium hexafluorophosphate, [C8MIM][PF6]) microextraction [HF-liquid-phase microextraction (LPME)] combined with high-performance liquid chromatography (HPLC)/UV. This method was used to investigate pollutants in surface water, on the Neijiang River, located at Zhenjiang, Jiangsu Province. Several parameters (sample pH, volume of accepter phase, ionic strength) were investigated. Under the optimum extraction conditions (sample pH, 2.0; volume of extraction solvent, 2.5 μL; ionic strength, 2.57) the proposed method offered: good linearity range, 0.15-100 μg L-1, with the correlation coefficients (r2) of 0.9996, 0.9994, 0.9990 and 0.9984, respectively; low limits of detection, 0.03, 0.05, 0.10, 0.05 μg L-1 (S/N = 3) for bisphenol A, 17-β-estradiol, estrone and diethylstilbestrol, respectively; good reproducibility (relative standard deviation (RSD), 8.41, 7.61, 9.00, 7.22%, respectively, n = 5); satisfactory recoveries (80.2-107.1%, n = 5); and high enrichment factors, 5,240, 3,693, 2,425 and 2,086, were achieved, for the four chemicals, respectively. Using the proposed HF-LPME, among 15 sampling sites along Neijiang River, bisphenol A, diethylstilbestrol and 17-β-estradiol were detected in some sites, all of which were the near suburban sampling sites. The results indicate that the role of municipal sewage is an important source of EDC contamination. [ABSTRACT FROM AUTHOR]

Abstract: This work was dedicated to the development of a simple and direct multivariate UV spectrophotometric method for the simultaneous determination of three antiemetic drugs (ondansetron, dexamethasone and aprepitant) in a new organogel formulation developed for their simultaneous transdermal administration. This method that does not require separation of the drugs and sophisticated instrument will permit to control quality of this new transdermal form both during the optimization step and for a further routine control of this preparation at the pharmacy department of the hospital. Hence, a partial least squares regression model using the spectral data record from 260 to 288nm and 5 components, has firstly been validated thanks to the evaluation of the REP% (under 7.9%) and secondly using an accuracy profile approach (acceptance limit of ±10%). Thereby, the method allows the quantitation of the drugs in the ranges (5–15mgL−1), (4–8mgL−1) and (20–50mgL−1) for ondansetron, dexamethasone and aprepitant, respectively. An HPLC/UV reference method has also been developed. Optimal separation (2.52

Highlights: [•] A pressurized hot water extraction (PHWE) method was developed for chrysanthemum. [•] PHWE conditions were optimised and the method provided high extraction efficiency. [•] HPLC profiling of PHWE extracts and principal component analysis (PCA) were done. [•] Fingerprinting of chrysanthemum attributes, e.g., species and origin, was achieved. [•] PHWE/HPLC/PCA provides an economical and effective food quality control method. [Copyright &y& Elsevier]

The chemical compound thymoquinone (THQ) isolated fromNigella sativaseed oil has multiple therapeutic potentials. A simple and rapid reversed-phase high-performance liquid chromatography assay was developed to determine the concentration of THQ in rabbit plasma. The procedure involved extraction of the compound and thymol (internal standard) from the plasma using acetonitrile and methanol. The extract was injected onto Waters 5 µm Atlantis dC-18 Bond pack column (10 μ, 150 × 3.9 mm 1.d.). The mobile phase consisted of methanol and 10 mM KH2PO4buffer in the ratio of 90:10 (v/v, pH = 4.6), which was delivered using isocratic flow at a rate of 0.9 mL/min. THQ and the internal standard were monitored using UV detection at 254 nm with a total run time of 7 min. The method was found to be linear (r2 > 0.997), precise (CVs = 3.69–12.63%) and accurate (recovery = 88–107.77%) in the concentration range of 0.5–50 µg/mL. The limits of detection and quantitation of the method were 0.134 and 0.408 µg/mL, respectively. The within and between-day coefficients of variation were less than 7%. The method has been successfully used to measure THQ plasma concentrations in a rabbit model following an intravenous administration of the drug. [ABSTRACT FROM PUBLISHER]

ABSTRACT Only one kind of synthesized alkaloid, piperlonguminine, was used to understand the interference of the other alkaloids in pharmacokinetic study using HPLC/UV in rat plasma after oral administration. Compared with the previous report, it was clarified that mixed alkaloids such as piperine and the other extract from Piper longum Linn did not interfere with the results. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This study reports the first quantification study of pseudohypericin (PsHyp) and hypericin (Hyp) inHypericum undulatumSchousb. ex Willdin vitrocultures developed by a Portuguese company. Both compounds were quantified by high-performance liquid chromatography and their levels were compared with those in commercial samples ofHypericum perforatum. PsHyp was found to be the major naphthodianthrone ofH. undulatum,with an average ratio of 3.73:1 compared to Hyp. Significant statistical differences were found between the content of Hyp and PsHyp inH. undulatumregenerated shoots compared toin vivosamples. The mean concentration of total Hyps varied from 178.41 to 358.93 µg g−1dry extract inH. undulatumregenerated shoots, which is on average two to three times less than naphthodianthrone levels found inH. undulatum in vivoandH. perforatumcommercial samples. However, none of the analysed samples presented the levels of Hyps required by the European and United States Pharmacopoeias. [ABSTRACT FROM PUBLISHER]

Abstract: The plasma exposure of (−)-epigallocatechin gallate (EGCg) is typically assessed following administration of EGCg at doses equivalent to the consumption of at least 10 cups of green tea in one sitting. This study determines the plasma concentrations of EGCg in mice following administration of a dose reflecting typical consumption of one standard green tea beverage. Swiss Outbred mice were orally administered 0.76mg/kg EGCg, and using a validated HPLC method, the C max of un-conjugated and total EGCg was determined to be 31.5±3.3 and 34.3±2.0nM, respectively (mean±s.d., n =3–5). The area under the plasma concentration versus time curve for un-conjugated and total EGCg was 114.3±4.1 and 116.4±4.1nM·h, respectively (mean±s.d., n =3–5). To minimise potential ex vivo plasma degradation, a novel stabilizing solution of 20mM ascorbic acid (AA) and 13mM tris[2-carboxyethyl]phosphine hydrochloride (TCEP) was employed. Comparative evaluation of the efficacy of the 20mM AA and 13mM TCEP stabilizing solution to the commonly used stabilizing solution of 114mM AA and 0.13mM Na2EDTA, indicated that the AA/TCEP solution provided significantly greater (p <0.05) protection to EGCg than the AA/Na2EDTA stabilizing solution. Overall, this study demonstrates that plasma concentrations of EGCg are in the low nM range following oral administration to mice at a dose reflecting the consumption of a standard green tea beverage. In addition, a novel stabilizing solution has been identified which may be useful in stabilizing plasma samples obtained from pharmacokinetic studies. [Copyright &y& Elsevier]

Abstract: In the present work, the applicability of hollow fiber-based liquid phase microextraction (HF-LPME) was evaluated for the extraction and preconcentration of valerenic acid prior to its determination by reversed-phase HPLC/UV. The target drug was extracted from 5.0mL of aqueous solution with pH 3.5 into an organic extracting solvent (dihexyl ether) impregnated in the pores of a hollow fiber and finally back extracted into 10μL of aqueous solution with pH 9.5 located inside the lumen of the hollow fiber. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME, including pH of the donor and acceptor phases, type of organic phase, ionic strength, the volume ratio of donor to acceptor phase, stirring rate and extraction time were studied and optimized. Under the optimized conditions, enrichment factor up to 446 was achieved and the relative standard deviation (RSD) of the method was 4.36% (n =9). The linear range was 7.5–850μgL−1 with correlation coefficient (r 2 =0.999), detection limits was 2.5μgL−1 and the LOQ was 7.5μgL−1. The proposed method was evaluated by extraction and determination of valerenic acid in some Iranian wild species of Valerianaceae. [Copyright &y& Elsevier]