Special Issue "Applications of Liquid Chromatography in Analysis of Pharmaceuticals and Natural Products"

A special issue of Pharmaceuticals (ISSN 1424-8247). This special issue belongs to the section "Natural Products".

Deadline for manuscript submissions: closed (20 September 2021).

Special Issue Editors

Prof. Dr. Jan Oszmianski
E-Mail Website
Guest Editor
Wrocław University of Environmental and Life Sciences, Department of Fruit, Vegetable and Nutraceutical Technology, Wroclaw, Poland
Interests: phenolic compounds; isolation and qualitative and quantitative determination of polyphenols; bioactive compounds; UV-VIS HPLC-MS-MS and SPE
Special Issues and Collections in MDPI journals
Dr. Sabina Lachowicz
E-Mail Website
Guest Editor
Wrocław University of Environmental and Life Sciences, Department of Fermentation and Cereals Technology, Wroclaw, Poland
Interests: antioxidant properties; anti-inflammatory properties; nutraceuticals and functional foods; bioactive compounds; polyphenolic compounds; carotenoid compounds; extraction; food analysis; food science and technology; medicinal plants; bioaccessibility and bioavailability
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

It is our pleasure to present this Special Issue of Pharmaceuticals, entitled “Applications of Liquid Chromatography in Analysis of Pharmaceuticals and Natural Products”. Plants produce a wide range of phytochemicals, which are secondary metabolites that confirm their identity and are used for the production of natural pharmaceuticals, among other things. The use of modern chromatographic techniques allows accurate quantitative and qualitative identification of the above-mentioned phytochemicals and their natural products. Liquid chromatography is one of the most efficient and robust specific techniques, due to the merits of convenience and strong separation ability, as well as a wide range of material applications for identification. Liquid chromatography is widely used for the analysis of plants, nutraceuticals, pharmaceuticals, natural product quality control, or quantitative determination of bioactive compounds. The most commonly used for the identification of different plant material and pharmaceuticals are the ultra- and high-performance liquid chromatography with UV-VIS, fluorescence, diode array, and equipped with mass spectrometry or tandem mass spectrometry detection methods. Therefore, for this Special Issue will publish work concerning the latest scientific news, insights, and advances in the field of innovation and applications of liquid chromatography in the analysis of phytochemicals and natural products. Original research articles, short communications, and critical review articles are welcome. The information presented will certainly arouse considerable interest among a large group of our readers from different disciplines and research fields.

Prof. Jan Oszmianski
Dr. Sabina Lachowicz
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Pharmaceuticals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Plant materials
  • Pharmaceuticals
  • Nutraceuticals
  • Product quality
  • Innovative methods
  • Food safety
  • Phytochemicals
  • Polyphenolic compounds
  • Isoprenoids
  • Bioactive compounds
  • Food chemistry
  • Natural products
  • Mass spectrometry
  • Extraction
  • LC-MS/MS techniques
  • HPLC-DAD-MS

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Published Papers (14 papers)

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Research

Article
Development, Characterization, and Stability Evaluation of the Anti-Cellulite Emgel Containing Herbal Extracts and Essential Oils
Pharmaceuticals 2021, 14(9), 842; https://doi.org/10.3390/ph14090842 - 25 Aug 2021
Viewed by 699
Abstract
Recently, the herbal compress was successfully developed and applied for cellulite treatment. The aim of this study was to formulate a more convenient dosage form of herbal application from the original formula. In addition, we aimed to characterize and evaluate the stability of [...] Read more.
Recently, the herbal compress was successfully developed and applied for cellulite treatment. The aim of this study was to formulate a more convenient dosage form of herbal application from the original formula. In addition, we aimed to characterize and evaluate the stability of the developed dosage form. A gelled emulsion, or an “emgel,” incorporated with 0.1 wt% tea and coffee extracts (1:1 ratio) plus 5 wt% essential oils (mixed oil) was prepared. The caffeine content in the finished product obtained from tea and coffee extracts analyzed by HPLC was 48.1 ± 2.3 µg/g. The bio-active marker monoterpenes of mixed oil characterized by headspace GCMS were camphene 50.8 ± 1.8 µg/mg, camphor 251.0 ± 3.2 µg/mg, 3-carene 46.7 ± 1.8 µg/mg, α-citral 75.0 ± 2.1 µg/mg, β-citral 65.6 ± 1.3 µg/mg, limonene 36.8 ± 6.7 µg/mg, myrcene 53.3 ± 4.5 µg/mg, α-pinene 85.2 ± 0.6 µg/mg, β-pinene 88.4 ± 1.1 µg/mg, and terpinene-4-ol 104.3 ± 2.6 µg/mg. The stability study was carried out over a period of 3 months at 4, 25, and 50 °C. The caffeine content showed no significant changes and passed the acceptance criteria of ≥80% at all tested temperatures. However, monoterpenes showed their stability for only 2 months at 50 °C. Therefore, the shelf-life of the emgel was, consequently, calculated to be 31 months using the Q10 method. Thus, the anti-cellulite emgel was successfully formulated. The characterization methods and stability evaluation for caffeine and monoterpenes in an emgel matrix were also successfully developed and validated. Full article
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Article
RP-18 TLC Chromatographic and Computational Study of Skin Permeability of Steroids
Pharmaceuticals 2021, 14(7), 600; https://doi.org/10.3390/ph14070600 - 22 Jun 2021
Viewed by 626
Abstract
The skin permeability of steroids, as investigated in this study, is important because some of these compounds are, or could, be used in preparations applied topically. Several models of skin permeability, involving thin layer chromatographic and calculated descriptors, were generated and validated using [...] Read more.
The skin permeability of steroids, as investigated in this study, is important because some of these compounds are, or could, be used in preparations applied topically. Several models of skin permeability, involving thin layer chromatographic and calculated descriptors, were generated and validated using Kp reference values obtained in silico and then tested on a group of solutes whose experimental Kp values could be found (log Kpexp). The study established that the most applicable log Kp model is based on RP-18 thin layer chromatographic data (RM) and the calculated descriptors VM (molar volume) and PSA (polar surface area). Two less efficient, yet simple, equations based on PSA or VM combined with HD (H-donor count) can be used with caution for rapid, rough estimations of compounds’ skin permeability prior to their chemical synthesis. Full article
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Article
Capillary Liquid Chromatography for the Determination of Terpenes in Botanical Dietary Supplements
Pharmaceuticals 2021, 14(6), 580; https://doi.org/10.3390/ph14060580 - 17 Jun 2021
Viewed by 731
Abstract
Dietary supplements of botanical origin are increasingly consumed due to their content of plant constituents with potential benefits on health and wellness. Among those constituents, terpenes are gaining attention because of their diverse biological activities (anti-inflammatory, antibacterial, geroprotective, and others). While most of [...] Read more.
Dietary supplements of botanical origin are increasingly consumed due to their content of plant constituents with potential benefits on health and wellness. Among those constituents, terpenes are gaining attention because of their diverse biological activities (anti-inflammatory, antibacterial, geroprotective, and others). While most of the existing analytical methods have focused on establishing the terpenic fingerprint of some plants, typically by gas chromatography, methods capable of quantifying representative terpenes in herbal preparations and dietary supplements with combined high sensitivity and precision, simplicity, and high throughput are still necessary. In this study, we have explored the utility of capillary liquid chromatography (CapLC) with diode array detection (DAD) for the determination of different terpenes, namely limonene, linalool, farnesene, α-pinene, and myrcene. An innovative method is proposed that can be applied to quantify the targets at concentration levels as low as 0.006 mg per gram of sample with satisfactory precision, and a total analysis time <30 min per sample. The reliability of the proposed method has been tested by analyzing different dietary supplements of botanical origin, namely three green coffee extract-based products, two fat burnings containing Citrus aurantium (bitter orange), and an herbal preparation containing lime and leaves of orange trees. Full article
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Article
Quantification of 17 Endogenous and Exogenous Steroidal Hormones in Equine and Bovine Blood for Doping Control with UHPLC-MS/MS
Pharmaceuticals 2021, 14(5), 393; https://doi.org/10.3390/ph14050393 - 21 Apr 2021
Viewed by 443
Abstract
A simple and fast analytical method able to simultaneously identify and quantify 17 endogenous and exogenous steroidal hormones was developed in bovine and equine blood using UHPLC-MS/MS. A total amount of 500 µL of sample was deproteinized with 500 µL of a mixture [...] Read more.
A simple and fast analytical method able to simultaneously identify and quantify 17 endogenous and exogenous steroidal hormones was developed in bovine and equine blood using UHPLC-MS/MS. A total amount of 500 µL of sample was deproteinized with 500 µL of a mixture of methanol and zinc sulfate and evaporated. The mixture was reconstituted with 50 µL of a solution of 25% methanol and injected in the UHPLC-MS/MS triple quadrupole. The correlation coefficients of the calibration curves of the analyzed compounds were in the range of 0.9932–0.9999, and the limits of detection and quantification were in the range of 0.023–1.833 and 0.069–5.5 ppb, respectively. The developed method showed a high sensitivity and qualitative aspects allowing the detection and quantification of all steroids in equine and bovine blood. Moreover, the detection limit of testosterone (50 ppt) is half of the threshold admitted in plasma (100 ppt). Once validated, the method was used to quantify 17 steroid hormones in both bovine and equine blood samples. The primary endogenous compounds detected were corticosterone (range 0.28–0.60 ppb) and cortisol (range 0.44–10.00 ppb), followed by androstenedione, testosterone and 11-deoxycortisol. Full article
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Article
Development of a Rapid UHPLC-PDA Method for the Simultaneous Quantification of Flavonol Contents in Onions (Allium cepa L.)
Pharmaceuticals 2021, 14(4), 310; https://doi.org/10.3390/ph14040310 - 01 Apr 2021
Cited by 1 | Viewed by 423
Abstract
Onion, one of the most consumed vegetables in the world, is also known to contain high levels of antioxidant compounds, with protective effects against different degenerative pathologies. Specifically, onion is rich in flavonols, mainly quercetin derivatives, which are compounds with high antioxidant and [...] Read more.
Onion, one of the most consumed vegetables in the world, is also known to contain high levels of antioxidant compounds, with protective effects against different degenerative pathologies. Specifically, onion is rich in flavonols, mainly quercetin derivatives, which are compounds with high antioxidant and free radical scavenging power. For this reason, it is of the utmost importance to count on optimal analytical methods that allow for the determination and quantification of these compounds of interest. A rapid ultra-high performance liquid chromatography (UHPLC)-photo-diode array (PDA) method for the separation of the major flavonols in onions was developed using a Box–Behnken design in conjunction with multiresponse optimization on the basis of the desirability function. The conditions that provided a successful separation were 9.9% and 53.2% of phase B at the beginning and at the end of the gradient, respectively; 55 °C column working temperature; and 0.6 mL min−1 flow rate. The complete separation was achieved in less than 2.7 min with excellent chromatographic characteristics. The method was validated, and its high precision, low detection and quantification limits, good linearity, and robustness were confirmed. The correct applicability of the method improves the analysis of the raw material, increasing the quality of onions and its subproducts in terms of bioactive compounds and functional characteristics for consumers. Full article
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Article
Comprehensive and Rapid Quality Evaluation Method for the Ayurvedic Medicine Divya-Swasari-Vati Using Two Analytical Techniques: UPLC/QToF MS and HPLC–DAD
Pharmaceuticals 2021, 14(4), 297; https://doi.org/10.3390/ph14040297 - 27 Mar 2021
Cited by 1 | Viewed by 3350
Abstract
Divya-Swasari-Vati (DSV) is a calcium-containing herbal medicine formulated for the symptomatic control of respiratory illnesses observed in the current COVID-19 pandemic. DSV is an Ayurvedic medicine used for the treatment of chronic cough and inflammation. The formulation has shown its pharmacological effects against [...] Read more.
Divya-Swasari-Vati (DSV) is a calcium-containing herbal medicine formulated for the symptomatic control of respiratory illnesses observed in the current COVID-19 pandemic. DSV is an Ayurvedic medicine used for the treatment of chronic cough and inflammation. The formulation has shown its pharmacological effects against SARS-CoV-2 induced inflammation in the humanized zebrafish model. The present inventive research aimed to establish comprehensive quality parameters of the DSV formulation using validated chromatographic analytical tools. Exhaustive identification of signature marker compounds present in the plant ingredients was carried out using ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/QToF MS). This was followed by simultaneous estimation of selected marker components using rapid and reliable high-performance liquid chromatography (HPLC) analysis. Eleven marker components, namely gallic acid, protocatechuic acid, methyl gallate, ellagic acid, coumarin, cinnamic acid, glycyrrhizin, eugenol, 6-gingerol, piperine and glabridin, were selected out of seventy-four identified makers for the quantitative analysis in DSV formulation. Validation of the HPLC method was evaluated by its linearity, precision, and accuracy tests as per the International Council of Harmonization (ICH) guidelines. Calibration curves for the eleven marker compounds showed good linear regression (r2 > 0.999). The relative standard deviation (RSD) value of intraday and interday precision tests were within the prescribed limits. The accuracy test results ranged from 92.75% to 100.13%. Thus, the present inclusive approach is first of its kind employing multi-chromatographic platforms for identification and quantification of the marker components in DSV, which could be applied for routine standardization of DSV and other related formulations. Full article
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Article
Antioxidant and Antiproliferative Potentials of Ficus glumosa and Its Bioactive Polyphenol Metabolites
Pharmaceuticals 2021, 14(3), 266; https://doi.org/10.3390/ph14030266 - 15 Mar 2021
Viewed by 849
Abstract
Ficus glumosa Delile (Moraceae), a reputed plant that is used in herbal medicine, is of high medicinal and nutritional value in local communities primarily ascribed to its phytochemical profile. Currently, there are hardly any fine details on the chemical profiling and pharmacological evaluation [...] Read more.
Ficus glumosa Delile (Moraceae), a reputed plant that is used in herbal medicine, is of high medicinal and nutritional value in local communities primarily ascribed to its phytochemical profile. Currently, there are hardly any fine details on the chemical profiling and pharmacological evaluation of this species. In this study, the flavonoids and phenolics contents of the ethanol extracts and four extracted fractions (petroleum ether (PE), ethyl acetate (EA), n-butanol, and water) of the stem bark of Ficus glumosa were firstly quantified. Further, their antioxidant and antiproliferative potentials were also evaluated. The quantitative determination indicated that the EA and n-butanol fractions possessed the highest total flavonoids/phenolics levels of 274.05 ± 0.68 mg RE/g and 78.87 ± 0.97 mg GAE/g, respectively. Similarly, for the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric-reducing antioxidant power (FRAP) assays, the EA fraction exhibited high potency in both DPPH and ABTS+ scavenging activities with IC50 values of 0.23 ± 0.03 mg/mL, 0.22 ± 0.03 mg/mL, and FRAP potential of 2.81 ± 0.01 mg Fe2+/g, respectively. Furthermore, the EA fraction displayed high cytotoxicity against human lung (A549) and colon (HT-29) cancer cells. Additionally, the liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was employed in order to characterize the chemical constituents of the EA fraction of Ficus glumosa stem bark. Our findings revealed 16 compounds from the EA fraction that were possibly responsible for the strong antioxidant and anti-proliferative properties. This study provides edge-cutting background information on the exploitation of Ficus glumosa as a potential natural antioxidant and anti-cancer remedy. Full article
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Article
Metabolite Profiling of Methanolic Extract of Gardenia jaminoides by LC-MS/MS and GC-MS and Its Anti-Diabetic, and Anti-Oxidant Activities
Pharmaceuticals 2021, 14(2), 102; https://doi.org/10.3390/ph14020102 - 28 Jan 2021
Cited by 11 | Viewed by 1370
Abstract
In this study, the methanolic extract from seeds of Gardenia jasminoides exhibited strong antioxidant and enzyme inhibition activities with less toxicity to NIH3T3 and HepG2 cells at the concentration of 100 µg/mL. The antioxidant activities (DPPH and ABTS), α-amylase, and α-glucosidase inhibition activities [...] Read more.
In this study, the methanolic extract from seeds of Gardenia jasminoides exhibited strong antioxidant and enzyme inhibition activities with less toxicity to NIH3T3 and HepG2 cells at the concentration of 100 µg/mL. The antioxidant activities (DPPH and ABTS), α-amylase, and α-glucosidase inhibition activities were found higher in methanolic extract (MeOH-E) than H2O extract. Besides, 9.82 ± 0.62 µg and 6.42 ± 0.26 µg of MeOH-E were equivalent to 1 µg ascorbic acid for ABTS and DPPH scavenging, respectively while 9.02 ± 0.25 µg and 6.52 ± 0.15 µg of MeOH-E were equivalent to 1 µg of acarbose for inhibition of α-amylase and α-glucosidase respectively. Moreover, the cell assay revealed that the addition of MeOH-E (12.5 µg/mL) increased about 37% of glucose uptake in insulin resistant (IR) HepG2 as compared to untreated IR HepG2 cells. The LC- MS/MS and GC-MS analysis of MeOH-E revealed a total of 54 compounds including terpenoids, glycosides, fatty acid, phenolic acid derivatives. Among the identified compounds, chlorogenic acid and jasminoside A were found promising for anti-diabetic activity revealed by molecular docking study and these molecules are deserving further purification and molecular analysis. Full article
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Article
Simultaneous Determination of Isothiazolinones and Parabens in Cosmetic Products Using Solid-Phase Extraction and Ultra-High Performance Liquid Chromatography/Diode Array Detector
Pharmaceuticals 2020, 13(11), 412; https://doi.org/10.3390/ph13110412 - 22 Nov 2020
Viewed by 1080
Abstract
Isothiazolinones methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI), and parabens methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) are the most common synthetic preservatives. They are all known to be potential skin allergens that lead to contact dermatitis. Thus, the identification of these unsafe [...] Read more.
Isothiazolinones methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI), and parabens methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) are the most common synthetic preservatives. They are all known to be potential skin allergens that lead to contact dermatitis. Thus, the identification of these unsafe chemicals in cosmetic products is of high importance. In the present study, solid-phase extraction (SPE) based on HyperSep reversed-phase C8/benzene sulfonic acid ion exchanger (HyperSep C8/BSAIE) and Sep-Pak C18 sorbents, and ultra-high performance liquid chromatography/diode array detector (UHPLC/DAD) were optimized for the simultaneous determination of MI, MCI, MP, EP, PP and BP in cosmetic products. HyperSep C8/BSAIE and UHPLC/DAD with the eluting solvent mixture (acetonitrile/methanol, 2:1, v/v) and detection wavelength (255 nm) were found to be the optimal conditions, respectively. The method illustrates the excellent linearity range (0.008–20 μg/mL) with coefficient of determination (R2, 0.997–0.999), limits of detection (LOD, 0.001–0.002 μg/mL), precision in terms of relative standard deviation (RSD < 3%, intra-day and <6%, inter-day) when examining a standard mixture at low (0.07 µg/mL), medium (3 µg/mL) and high (15 µg/mL) concentrations. A total of 31 cosmetic samples were studied, achieving concentrations (MI, not detected (nd)-0.89 µg/g), (MCI, nd-0.62 µg/g), (MP, nd-6.53 µg/g), (EP, nd-0.90 µg/g), (PP, nd-9.69 µg/g) and (BP, nd-17.80 µg/g). Recovery values ranged from 92.33 to 101.43% depending on the types of sample. To our knowledge, this is the first specific method which covers the theme and describes background amounts of such preservatives in cosmetics. Full article
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Article
Availability of Guanitoxin in Water Samples Containing Sphaerospermopsis torques-reginae Cells Submitted to Dissolution Tests
Pharmaceuticals 2020, 13(11), 402; https://doi.org/10.3390/ph13110402 - 19 Nov 2020
Cited by 2 | Viewed by 881
Abstract
Guanitoxin (GNT) is a potent neurotoxin produced by freshwater cyanobacteria that can cause the deaths of wild and domestic animals. Through reports of animal intoxication by cyanobacteria cells that produce GNT, this study aimed to investigate the bio-accessibility of GNT in simulated solutions [...] Read more.
Guanitoxin (GNT) is a potent neurotoxin produced by freshwater cyanobacteria that can cause the deaths of wild and domestic animals. Through reports of animal intoxication by cyanobacteria cells that produce GNT, this study aimed to investigate the bio-accessibility of GNT in simulated solutions of the gastrointestinal content in order to understand the process of toxicosis promoted by GNT in vivo. Dissolution tests were conducted with a mixture of Sphaerospermopsis torques-reginae (Cyanobacteria; Nostocales) cultures (30%) and gastrointestinal solutions with and without proteolytic enzymes (70%) at a temperature of 37 °C and rotation at 100 rpm for 2 h. The identification of GNT was performed by LC-QqQ-MS/MS through the transitions [M + H]+m/z 253 > 58 and [M + H]+m/z 253 > 159, which showed high concentrations of GNT in simulated gastric fluid solutions (p-value < 0.001) in comparison to simulated solutions of intestinal content. The gastric solution with pepsin promoted the stability of GNT (p-value < 0.05) compared to the simulated solution of gastric fluid at the same pH without the enzyme. However, the results showed that GNT is also available in intestinal fluids for a period of 2 h, and solutions containing the pancreatin enzyme influenced the bio-accessibility of the toxin more compared to the intestinal medium without enzyme (p-value < 0.05). Therefore, the bio-accessibility of the toxin must be considered both in the stomach and in the intestine, and may help in the diagnosis and prediction of exposure and risk in vivo through the oral ingestion of GNT-producing cyanobacteria cells. Full article
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Article
Application of High-Performance Liquid Chromatography for Simultaneous Determination of Tenofovir and Creatinine in Human Urine and Plasma Samples
Pharmaceuticals 2020, 13(11), 367; https://doi.org/10.3390/ph13110367 - 05 Nov 2020
Viewed by 686
Abstract
Tenofovir disoproxil fumarate is widely used in the therapy of human immunodeficiency virus and hepatitis B virus; however, a high concentration of the prodrug effects kidney function damage. To control the effectiveness of kidney functions in treated patients, the level of creatinine in [...] Read more.
Tenofovir disoproxil fumarate is widely used in the therapy of human immunodeficiency virus and hepatitis B virus; however, a high concentration of the prodrug effects kidney function damage. To control the effectiveness of kidney functions in treated patients, the level of creatinine in the body must be controlled. This work describes a simple, fast, and “plastic-waste” reducing method for the simultaneous determination of tenofovir and creatinine in human urine and plasma. In both assays, only 50 µL of body fluid was required. The tests were carried out by reversed phase high-performance liquid chromatography with UV detection. In urine samples, the limits of detection for tenofovir and creatinine were 4 µg mL−1 and 0.03 µmol mL−1, respectively. In plasma samples, the limits of detection were 0.15 µg mL−1 for tenofovir and 0.0003 µmol mL−1 for creatinine. The method was applied for the determination of tenofovir and creatinine in human urine and plasma samples. The biggest advantage of the elaborated method is the possibility to determine tenofovir and creatinine in one analytical run in both urine and plasma sample collected from HIV and HBV patients. The possibility to reduce the level of laboratory waste in a sample preparation protocol is in the mainstream of a new trend of analytical chemistry which is based on green chemistry. Full article
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Article
Determination of Very Low Concentration of Bisphenol A in Toys and Baby Pacifiers Using Dispersive Liquid–Liquid Microextraction by In Situ Ionic Liquid Formation and High-Performance Liquid Chromatography
Pharmaceuticals 2020, 13(10), 301; https://doi.org/10.3390/ph13100301 - 12 Oct 2020
Cited by 3 | Viewed by 882
Abstract
Bisphenol A (BPA) is a chemical compound used in the manufacturing of plastics and resins whose presence in the body in low concentrations can cause serious health problems. Due to this, there is a growing interest in the scientific community to develop analytical [...] Read more.
Bisphenol A (BPA) is a chemical compound used in the manufacturing of plastics and resins whose presence in the body in low concentrations can cause serious health problems. Due to this, there is a growing interest in the scientific community to develop analytical methods that allow quantifying trace concentrations of BPA in different types of samples. The determination of this compound in toys made of plastics that can be manipulated by children leads to an extra concern, because it is possible for BPA to enter the body by introducing these toys into the mouth. This work presents a novel procedure to the quickly and easily quantification of trace levels of BPA in samples of toys and pacifiers according to the current demanding regulations. The determination of very low levels of BPA was carried out by ionic liquid dispersive liquid–liquid microextraction (IL-DLLME) followed by high-performance liquid chromatography (HPLC). The formation in situ of the ionic liquid (IL) 1-octyl-3-methylimidazolium bis((trifluoromethane)sulfonyl)imide ([C8MIm] [NTf2]), was achieved by mixing 1-octyl-3-methylimidazolium chloride ([C8MIm]Cl) and lithium bis(trifluoromethanesulfonyl)imide ([NTf2]Li) aqueous solutions, reaching an instant dispersion whose cloud of microdrops allows the total extraction of BPA in the IL from aqueous solutions. After centrifugation, BPA concentration in the sedimented phase was determined by HPLC. The optimal experimental conditions for the microextraction and determination of BPA in the IL were studied. The total extraction was achieved at pH 4, heating the sample at 30 °C for 5 min, using 100 µL of IL precursor volume, and spinning after the formation of dispersion at 3000 rpm for 10 min. The enrichment factor (EF) and detection limit (LOD) reached with the procedure were 299 and 0.19 µg L−1, respectively. The relative standard deviation for ten replications at the 0.5 µg L−1 level was 5.2%. Recovery studies showed a mean value for BPA recovery percentage in the samples of 99%. Additionally, a hybrid model was applied to characterize the extraction kinetics. This simple, low cost and fast method simplifies traditional microextraction techniques, representing an outstanding alternative. Full article
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Article
Fragaria viridis Fruit Metabolites: Variation of LC-MS Profile and Antioxidant Potential during Ripening and Storage
Pharmaceuticals 2020, 13(9), 262; https://doi.org/10.3390/ph13090262 - 22 Sep 2020
Cited by 8 | Viewed by 1163
Abstract
Fragaria viridis Weston or creamy strawberry is one of the less-known species of the Fragaria genus (Rosaceae family) with a wide distribution in Eurasia and is still in the shadow of more popular relatives F. ananassa (garden strawberry) or F. vesca (wild strawberry). [...] Read more.
Fragaria viridis Weston or creamy strawberry is one of the less-known species of the Fragaria genus (Rosaceae family) with a wide distribution in Eurasia and is still in the shadow of more popular relatives F. ananassa (garden strawberry) or F. vesca (wild strawberry). Importantly, there is a lack of scientific knowledge on F. viridis compounds, their stability in the postharvest period, and bioactivity. In this study, metabolites of F. viridis fruits in three ripening stages were characterized with high-performance liquid chromatography with photodiode array and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PAD-ESI-tQ-MS). In total, 95 compounds of various groups including carbohydrates, organic acids, phenolics, and triterpenes, were identified for the first time. The quantitative content of the compounds varied differently during the ripening progress; some of them increased (anthocyanins, organic acids, and carbohydrates), while others demonstrated a decrease (ellagitannins, flavonols, etc.). The most abundant secondary metabolites of F. viridis fruits were ellagitannins (5.97–7.54 mg/g of fresh weight), with agrimoniin (1.41–2.63 mg/g) and lambertianin C (1.20–1.86 mg/g) as major components. Antioxidant properties estimated by in vitro assays (2,2-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (ABTS), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC)) showed good antioxidant potential in all ripening stages of F. viridis fruits. The pilot human experiment on the effect of F. viridis fruit consumption on the serum total antioxidant capacity confirmed the effectiveness of this kind of strawberry. Postharvest storage of ripe fruits at 4 °C and 20 °C lead to declining content in the majority of compounds particularly ascorbic acid, ellagitannins, and flavonols, with the most significant loss at room temperature storage. These results suggest that F. viridis fruits are a prospective source of numerous metabolites that have potential health benefits. Full article
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Article
Profile and Content of Phenolic Compounds in Leaves, Flowers, Roots, and Stalks of Sanguisorba officinalis L. Determined with the LC-DAD-ESI-QTOF-MS/MS Analysis and Their In Vitro Antioxidant, Antidiabetic, Antiproliferative Potency
Pharmaceuticals 2020, 13(8), 191; https://doi.org/10.3390/ph13080191 - 12 Aug 2020
Cited by 3 | Viewed by 1434
Abstract
The aim of this study was to accurately determine the profile of polyphenols using the highly sensitive LC-DAD-ESI-QTOF-MS/MS technique and to determine in vitro antioxidant activity, the ability of inhibition of α-amylase, α-glucoamylase, and pancreatic lipase activity, and antiproliferative activity in leaves, flowers, [...] Read more.
The aim of this study was to accurately determine the profile of polyphenols using the highly sensitive LC-DAD-ESI-QTOF-MS/MS technique and to determine in vitro antioxidant activity, the ability of inhibition of α-amylase, α-glucoamylase, and pancreatic lipase activity, and antiproliferative activity in leaves, flowers, roots, and stalks of medical plant Sanguisorba officinalis L. The results of the analysis of the morphological parts indicated the presence of 130 polyphenols, including 62 that were detected in S. officinalis L. for the first time. The prevailing group was tannins, with contents ranging from 66.4% of total polyphenols in the flowers to 43.3% in the stalks. The highest content of polyphenols was identified in the flowers and reached 14,444.97 mg/100 g d.b., while the lowest was noted in the stalks and reached 4606.33 mg/100 g d.b. In turn, the highest values of the antiradical and reducing capacities were determined in the leaves and reached 6.63 and 0.30 mmol TE/g d.b, respectively. In turn, a high ability to inhibit activities of α-amylase and α-glucoamylase was noted in the flowers, while a high ability to inhibit the activity of pancreatic lipase was demonstrated in the leaves of S. officinalis L. In addition, the leaves and the flowers showed the most effective antiproliferative properties in pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, bladder cancer, and T-cell leukemia cells, whereas the weakest activity was noted in the stalks. Thus, the best dietetic material to be used when composing functional foods were the leaves and the flowers of S. officinalis L., while the roots and the stalks were equally valuable plant materials. Full article
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