Vancomycin (VAN) is a glycopeptide antibiotic, active against Gram-positive bacteria resistant to other antibiotics. VAN therefore needs to be monitored for maximum efficacy and minimum toxicity. ...Electrochemical sensors can be used for this purpose, using the direct electrochemical signal of VAN. Due to its molecular complexity and the need for analysis from complex matrices, the electrochemical detection of VAN requires the development of a complex electrochemical fingerprint (CEF), which covers a large variety of possible combinations of samples and interferents at concentrations of interest.
The objective of this study was to develop a CEF for VAN, involving a battery of tests and the elucidation of the mechanism of anodic oxidation of VAN, using high-performance liquid chromatography coupled with mass-spectrometric analysis of the products obtained after small-scale electrolysis.
A CEF for VAN was obtained, describing the electrochemical behavior of VAN at different commercially available screen-printed electrodes, with several electrolytes, considering successive analyses, after simple pretreatments, and examining both anodic and cathodic peaks. The concept was successfully applied to analysis of VAN in real samples and in the presence of some common interferents. Furthermore, a two-step combined electrochemical–chemical mechanism was proposed for the electrooxidation of VAN.
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•Therapeutic drug monitoring of vancomycin is needed for maximum efficacy.•A battery of tests with different commercially available SPEs was performed.•Both anodic and cathodic electrochemical analyses were performed.•A complex 3D electrochemical fingerprint for vancomycin was produced.•A mechanism for anodic oxidation of vancomycin was proposed.
species are often used in traditional medicine as anti-inflammatory, diuretic, wound-healing and antimicrobial agents. Still, the bioactive compounds and biological activities of some species have ...not been studied. The present work aimed to investigate the polyphenolic profile and the biological properties of
L. Salisb., a poorly explored medicinal plant. The hydroalcoholic extracts from aerial parts were evaluated for total phenolic content (TPC), total flavonoid content (TFC) and the polyphenolic compounds were investigated by HPLC-MS. The antioxidant potential in vitro was determined using DPPH and FRAP assays. Antibacterial and antifungal effects were evaluated by dilution assays and MIC, MBC and MFC were calculated. The results showed that
aerial parts contain an important amount of total phenolics (192.69 mg GAE/g) and flavonoids (151.41 mg RE/g), with chlorogenic acid and quercitrin as major constituents. The hydroalcoholic extracts showed promising antioxidant and antimicrobial potential, with potent antibacterial activity against
and important antifungal effect against
and
. The obtained results indicated that the aerial parts of
could be used as novel resource of phytochemicals in herbal preparations with antioxidant and antimicrobial activities.
Plant by-products can be valuable sources of polyphenol bioactive compounds. Walnut (
L.) is a very important tree nut rich in biologically active molecules, but its septum was scarcely researched. ...Experimental data indicated a hypoglycemic effect of septum extracts, with almost no details about its phytochemical composition. The main objectives of this study were: (1) to obtain walnut septum (WS) extracts with high content in bioactive compounds and antioxidant activity based on an original experimental design; (2) characterization of the phytochemical profile of the WS extracts using HPLC-MS/MS; (3) evaluation of the biological potential of the richest polyphenolic WS extract. The variables of the experimental design were: extraction method (maceration and Ultra-Turrax extraction), temperature, solvent (acetone and ethanol), and percentage of water in the solvent. The first quantifiable responses were: total phenolic content, total flavonoid content, condensed tannins, and ABTS antioxidant capacity. The phytochemical profile of lyophilized extracts obtained by Ultra-Turrax extraction (UTE), the most efficient method, was further determined by HPLC-MS/MS analysis of individual polyphenolic and phytosterols compounds. It is the first study to assay the detailed composition of WS in hydrophilic and lipophilic compounds. The biological potential of the richest polyphenolic WS extract was also evaluated by FRAP and DPPH antioxidant capacity and the inhibition of tyrosinase, an enzyme involved in the browning in fruits and vegetables, skin wrinkles and aging. Conclusion: The phytochemical profile of the analyzed extracts proves that WS can be a valuable source of biologically active compounds (polyphenols) for food and/or pharmaceutical industry and warrant the continuation of current research in further evaluating its bioactive potential.
Metastasis represents the most important cause of breast cancer-associated mortality. Even for early diagnosed stages, the risk of metastasis is significantly high and predicts a grim outcome for the ...patient. Nowadays, efforts are made for identifying blood-based biomarkers that could reliably distinguish patients with highly metastatic cancers in order to ensure a closer follow-up and a more personalized therapeutic method. Exosomes are nano vesicles secreted by cancer cells that can transport miRNAs, proteins, and other molecules and deliver them to recipient cells all over the body. Through this transfer, cancer cells modulate their microenvironment and facilitate the formation of the pre-metastatic niche, leading to sustained progression. Exosomal miRNAs have been extensively studied due to their promising potential as prognosis biomarkers for metastatic breast cancer. In this review, we tried to depict an overview of the existing literature regarding exosomal miRNAs that are already validated as potential biomarkers, and which could be immediately available for the clinic. Moreover, in the last section, we highlighted several miRNAs that have proven their function in preclinical studies and could be considered for clinical validation. Considering the lack of standard methods for evaluating exosomal miRNA, we also discussed the challenges and the technical aspects underlying this issue.
This study was designed to examine the in vitro antioxidant and antimicrobial activities and to characterize the polyphenolic composition of the ethanolic extracts of Hyssopus officinalis, Ocimum ...basilicum and Teucrium chamaedrys. Qualitative and quantitative analysis of the major phenolic compounds were conducted using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). The total polyphenols, caffeic acid derivatives and flavonoids content was spectrophotometrically determined. The phenolic profile showed the presence of phenolic acid derivatives (caftaric, gentisic, caffeic, p-coumaric, chlorogenic and ferulic acids), flavonoid glycosides (rutin, isoquercitrin and quercitrin) and free flavonoid aglycons (luteolin, quercetin), in different concentrations. DPPH radical scavenging assay, Trolox equivalent antioxidant capacity (TEAC) method, hemoglobin ascorbate peroxidase activity inhibition (HAPX) assay, and electron paramagnetic resonance (EPR) radicals detection were employed, revealing several aspects of the antioxidant activities of these species. The antimicrobial tests were performed using the disk diffusion assay. These extracts contained a large amount of the polyphenolic compounds (77.72, 175.57, and 243.65 mg/g, respectively), and they showed a good antioxidant activity, as witnessed by a number of methods. T. chamaedrys had a high antimicrobial activity. Besides their antioxidant activity, the antimicrobial effect of these extracts confirms the biological activities of these herbal medicinal products.
The aim of this work was to study the chemical composition of Allium obliquum L., A. senescens L. subsp. montanum (Fries) Holub, and A. schoenoprasum L. subsp. schoenoprasum. Sulphur-containing ...compounds analysis was performed by an LC-MS method, the identification and quantification of polyphenolic compounds through a HPLC-UV-MS method, and the presence of five sterols was simultaneously assessed by HPLC-MS-MS. Alliin was identified only in A. obliquum and A. senescens subsp. montanum extracts, whilst allicin was present in all extracts, with higher amounts in A. schoenoprasum and A. obliquum. The pattern of phenol carboxylic acids shows the presence of p-coumaric and ferulic acids in all species. Isoquercitrin was identified in A. obliquum and A. schoenoprasum, and rutin in A. senescens subsp. montanum and A. schoenoprasum. Luteolin and apigenin were identified only in A. obliquum. All three species contain glycosides of kaempferol and quercetol. β-Sitosterol and campesterol were identified in all species. The results obtained showed significant differences in the composition of the three Allium species.
Walnut (
L.) septum represents an interesting bioactive compound source by-product. In our study, a rich phenolic walnut septum extract, previously selected, was further examined. The tocopherol ...content determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed higher amounts of α-tocopherol compared to γ- and δ-tocopherols. Moreover, several biological activities were investigated. The in vitro inhibiting assessment against acetylcholinesterase, α-glucosidase, or lipase attested a real management potential in diabetes or obesity. The extract demonstrated very strong antimicrobial potential against
and
. It also revealed moderate (36.08%) and strong (43.27%) antimutagenic inhibitory effects against TA 98 and TA 100 strains. The cytotoxicity of the extract was assessed on cancerous (A549, T47D-KBluc, MCF-7) and normal (human gingival fibroblasts (HGF)) cell lines. Flow cytometry measurements confirmed the cytotoxicity of the extract in the cancerous cell lines. Additionally, the extract demonstrated antioxidant activity on all four cell types, as well as anti-inflammatory activity by lowering the inflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-1 β (IL-1β)) evaluated in HGF cells. To the best of our knowledge, most of the cellular model analyses were performed for the first time in this matrix. The results prove that walnut septum may be a potential phytochemical source for pharmaceutical and food industry.
Oxidative stress has been incriminated in the physiopathology of many diseases, such as diabetes, cancer, atherosclerosis, and cardiovascular and neurodegenerative diseases. There is a great interest ...in developing new antioxidants that could be useful for preventing and treating conditions for which oxidative stress is suggested as the root cause. The thiazolidine-2,4-dione derivatives have been reported to possess various pharmacological activities and the phenol moiety is known as a pharmacophore in many naturally occurring and synthetic antioxidants. Twelve new phenolic derivatives of thiazolidine-2,4-dione were synthesized and physicochemically characterized. The antioxidant capacity of the synthesized compounds was assessed through several in vitro antiradical, electron transfer, and Fe
chelation assays. The top polyphenolic compounds
and
acted as potent antiradical and electron donors, with activity comparable to the reference antioxidants used. The ferrous ion chelation capacity of the newly synthesized compounds was modest. Several quantum descriptors were calculated in order to evaluate their influence on the antioxidant and antiradical properties of the compounds and the chemoselectivity of the radical generation reactions has been evaluated. The correlation with the energetic level of the frontier orbitals partially explained the antioxidant activity, whereas a better correlation was found while evaluating the O-H bond dissociation energy of the phenolic groups.
This study was performed to evaluate the phenolic profile, antioxidant and diuretic effects of black cumin and lady-in-a-mist seeds. In the phenolic profile, differences between the two species are ...significant. Qualitative and quantitative analyses of the phenolic compounds were performed using a HPLC-UV/MS method. Hyperoside was the only identified flavonoid glycoside (1.08 ± 0.01 μg∙g-1 dw plant material), in the N. damascena extract. Regarding the flavonol profile, kaempferol was identified before the hydrolysis, only in the N. sativa extract (6.06 ± 0.02 μg∙g-1 dw plant material) and quercetin only in N. damascena seeds (14.35 ± 0.02 μg∙g-1 dw plant material). The antioxidant potential of the two species was tested through several electron transfer assays, which indicated, excepting for the FRAP assay, N. damascena as exhibiting a higher free radical scavenging activity. The diuretic activity of the two extracts was tested using a rat-experimental model on acute diuresis. Administration of the ethanolic extract of N. sativa (100 mg∙kg-1) resulted in a significant increase in urine volume, although less than found with the reference drug; in addition N. damascena extract did not present a diuretic effect. In reference to the elimination of Na+, K+ and uric acid, the black cumin extract exhibited a higher natriuretic than kaluretic effect and a similar uricosuric effect with control and N. damascena. For N. damascena, the Na+/K+ ratio was sub unitary, but not due to an increasing of the kaluretic effect, but mostly to a decrease of Na+ excretion.
Many herbal products have a long history of use, but there are increasing concerns over product efficacy, safety and quality in the wake of recent cases exposing discrepancies between labeling and ...constituents. When it comes to St. John's wort (Hypericum perforatum L.) herbal products, there is limited oversight, frequent off-label use and insufficient monitoring of adverse drug reactions. In this study, we use amplicon metabarcoding (AMB) to authenticate 78 H. perforatum herbal products and evaluate its ability to detect substitution compared to standard methods using thin-layer chromatography (TLC) and high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Hypericum perforatum was detected in 68% of the products using AMB. Furthermore, AMB detected incongruence between constituent species and those listed on the label in all products. Neither TLC nor HPLC-MS could be used to unambiguously identify H. perforatum. They are accurate methods for authenticating presence of the target compounds, but have limited efficiency in detecting infrageneric substitution and do not yield any information on other plant ingredients in the products. Random post-marketing AMB of herbal products by regulatory agencies could raise awareness among consumers of substitution and would provide an incentive to manufacturers to increase quality control from raw ingredients to commercialized products.
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