Quantification Of Polyphenols Research Articles

Phytochemical screening and antioxidant activity of Vitex agnus-castus L.

Abstract This research is dedicated to investigating the antioxidant potential and phytochemical composition of three distinct extracts derived from Vitex agnus-castus L. These extracts, prepared through aqueous (EXA), ethanolic (EXE), and methanolic (EXM) maceration, were chosen based on prior assessments of total polyphenol content in extracts obtained from five solvents with differing polarities: water, methanol, ethanol, acetone, and butanol. The study initiated with a comprehensive phytochemical analysis focusing on the determination of total polyphenols and flavonoids. The quantification of total polyphenols was carried out using the Folin–Ciocalteu method, while the AlCl3 method was employed to assess flavonoids. In evaluating the in vitro antioxidant activity, we employed two well-established methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP). The preliminary tests, gauging the efficacy of solvents, demonstrated that the order of optimal solvent selection was as follows: aqueous, methanolic, ethanolic, butanolic, and acetone. Consequently, the first three solvents were chosen for the preparation of the extracts. The phytochemical analysis unveiled that EXA exhibited the highest total polyphenol content, with an impressive value of 126.84 ± 1.24 mg EAG/g extract, whereas EXE exhibited the lowest concentration of total polyphenols, measuring at 117.26 ± 0.18 mg EAG/g extract. In contrast, EXM showcased a notably high flavonoid content, registering at 33.65 ± 1.04 mg EQ/g extract, while EXA displayed a comparatively lower flavonoid content at 14.93 ± 0.14 mg EQ/g extract. When assessing antioxidant properties, EXA emerged as the most potent against both DPPH and FRAP, recording values of 78.94 ± 1.84 and 203.27 ± 0.17 μg/ml, respectively. In contrast, the ethanolic extract exhibited relatively lower antioxidant activity, with values of 204.16 ± 1.87 μg/ml for DPPH and 307.10 ± 1.15 μg/ml for FRAP.

Comparative Study of Antibacterial Activity of Cistus ladanifer L. Leaves Extracted by Ultrasound-Assisted Extraction and Maceration

Addressing infectious diseases poses a significant healthcare challenge due to the growing resistance of microorganisms to antibiotics. Consequently, extensive research efforts have been dedicated to identifying alternative molecules to antibiotics that can combat these infectious diseases. Notably, a wealth of bioactive compounds has been discovered in medicinal and aromatic plants, and their potential utility in the development of treatments for infectious diseases has been well-established. In this study, we employed two extraction methods, namely maceration and ultrasound-assisted extraction (UAE), and four different solvents with varying polarities to isolate bioactive compounds from Cistus ladanifer L. Subsequently, quantification of polyphenols was determined in all the extracted samples. Following this, we conducted both qualitative and quantitative assessments of the antibacterial activity of these extracts. Moreover, we delved into the mechanism of action of the most potent extract using scanning electron microscopy. The results revealed that methanol was the best solvent for extracting bioactive molecules and that UAE had a high extraction efficiency since it gave a higher yield of total polyphenols than the one acquired by maceration. Regarding the results of the disk diffusion assay, the extracts that were prepared by UAE were more effective against our bacterial strains than those extracted by maceration. Electron micrographs of damaged cells revealed that the methanolic extract obtained by UAE affected the integrity of the cell membrane. These outcomes have underscored the presence of active compounds within Cistus ladanifer L. that could serve as potential alternatives to antibiotics against some of the most pathogenic bacterial species.

Electrochemical sensor with electrohydrodynamic-printed microelectrodes for the detection of low concentration of tea polyphenols

The accurate quantification of tea polyphenols plays a crucial role in the quality inspection of tea and various food products. With the advantages of high sensitivity and selectivity, electrochemical method has gained widespread utilization in detecting tea polyphenols. The accuracy of electrochemical detection heavily relies on the dimensions of the microelectrodes utilized. In the present work, six microelectrode systems with varying diameters (70, 200, 300, 500, 800, and 1000 µm) were manufactured by electrohydrodynamic printing method and integrated into sensors to detect low concentration of tea polyphenols. The performances of sensors were evaluated in terms of detection limits, sensitivity, and linear range. The results demonstrated that sensors with minor microelectrodes exhibited superior detection limits and sensitivity. The sensor featuring a 70 µm microelectrode demonstrated a linear range of 1–70 μmol/L and a low detection limit of 0.22 μmol/L. Average recovery rates of sensors ranging from 95.2% to 105.0% were obtained in detecting tea polyphenols in green tea, confirming the remarkable potential for rapid and accurate detection of low concentration of tea polyphenols in real samples.

Metabolomic profiling and quantification of polyphenols from leaves of seven Acacia species by UHPLC-QTOF-ESI-MS

The genus Acacia (Fabaceae) comprises >1350 species and has been used in traditional medicine as infusions and decoctions to treat wounds, sores, headaches, diarrhea, and cough. The leaf methanolic extracts of seven Acacia species growing in Egypt namely: Acacia saligna, Acacia seyal, Acacia xanthophloea, Acacia tortilis subsp. raddiana., Acacia tortilis, Acacia laeta, Acacia albida were analyzed using UPLC-QTOF-ESI-MS. A total of 37 polyphenols were identified and discussed in detail. They included phenolic acids, flavonoids, and procyanidins, among which sixteen polyphenols were identified in Acacia for the first time. Folin-ciocalteau assay and ferric reducing antioxidant power, cupric reducing antioxidant capacity, 2,20 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) cation radical and the scavenging capacity against 2,2-diphenyl-1- picrylhydrazyl radical were performed to investigate the total phenolic content and the antioxidant activity of the Acacia extracts, respectively. Furthermore, the absolute quantification of eighteen polyphenols common to most of the species was performed using UPLC-MS. It was evident that the differences in the chemical composition among the species accounted for the difference in antioxidant activity which was in line together with the total phenolic content.

Quantification of Total Polyphenols, Total Flavonoids, and Evaluation of Antioxidant Activity of the Aerial Part of Distichochlamys orlowii K. Larsen & M.F. Newman

Distichochlamys orlowii K. Larsen & M.F. Newman is a type of ginger endemic to Vietnam with high values of usage. This study aims to evaluate the total phenolic content, total flavonoid content, and antioxidant effect of the aerial part of Distichochlamys orlowii. The medicinal samples were extracted by ultrasonic method with different solvents including methanol, ethanol, ethyl acetate, and dichloromethane. The total phenolic content was evaluated using the Folin-Ciocalteu reagent and the total flavonoid content was evaluated by the aluminum chloride colorimetric method. The in vitro antioxidant effects of extracts were investigated through free radical scavenging models with DPPH and ABTS. The obtained results showed that the ethanol extract contained the highest content of total phenolic content and total flavonoid content with values of 12.81 ± 0.05% and 19.52 ± 0.23%, respectively. Meanwhile, the methanol extract exhibited the strongest DPPH and ABTS free radical scavenging activities with IC50 values of 243.89 ± 5.98 µg/mL and 33.58 ± 3.14 µg/mL, accordingly. The IC50 values of positive controls were 7,88 ± 0,25 µg/mL for the former assay and 9,74 ± 0,36 µg/mL for the latter assay. This is the first report on the chemical composition and antioxidant activity of the extracts from the aerial part of Distichochlamys orlowii.
 
 
 

EX VIVO PERMEATION STUDY OF NANOSTRUCTURED DOSAGE FORM CONTAINING MANGO SEED KERNEL EXTRACT USING FRANZ CELL

Background: mango seeds (Mangiferin indica L.) have the ability to inhibit P. acnes, S.aureus, and E. coli bacteria and inhibit inflammation, potentially for transdermal therapeutic dosage forms. The nano-emulsion dosage forms were prepared based on the SNEDDS system with nano-oil droplets containing mango seed extract. These dosage forms contributed to carrying the active ingredient deeply into the impact site, bringing the highest efficiency, but this needs to be proven. Thus, it is necessary to study the process to evaluate the permeability of these formulas to prove their availability improvement. Objectives: To assess the transdermal permeability and active substance release of nanostructured dosage forms by a validated procedure. Methods: an ex vivo experiment was designed by adding a sample to diffuse through Franz cells. In addition, to ensure the quality and effectiveness of preparations containing mango seeds, developing and validating a process for quantifying the total polyphenols in the preparation are extremely necessary. Total polyphenols were quantified by color complexing with Folin-Ciocalteu reagents, with maximum absorption at 765 nm. Results: the procedure had been validated according to the International Conference on Harmonization (ICH) on the criteria of specificity, system compatibility with RSD = 1.02%, linearity built on the concentration range of 10–50 µg/ml with R2 = 0.998, accuracy, precision with %recovery in the range of 97.73% to 102.56%. The results showed that more than 300 mg/g of polyphenol was released after 6 hours from the tested nanostructured dosage form, about 4.3 times as many as the total amount of polyphenols in the comparative cream. Conclusions: the quantification of polyphenols diffused through Franz cells helps evaluate the quality of the preparation. The procedure had been validated according to the International Conference on Harmonization (ICH) and could be applied to evaluate nanostructured dosage forms containing mango seed kernel.

Development and Validation of an HPLC-DAD Method for the Simultaneous Analysis of Phenolic Compounds

Phenolic compounds are natural substances that exhibit different functional bioactivities and provide health-protective actions against chronic illnesses. The vast potential of these compounds in health and other sectors demands the establishment of analytical procedures for their immediate and simultaneous analysis. In this study, a high-performance liquid chromatography with diode-array detection (HPLC-DAD) method was developed and validated for the simultaneous analysis of gallic acid, catechin, epicatechin, rutin hydrate, caffeic acid, syringic acid, ellagic acid, p-coumaric acid, trans-ferulic acid, myricetin, resveratrol, and quercetin. The chromatographic separation of the selected polyphenols was carried out in a reversed-phase Inertsil ODS-3 column (250mm x 4.5mm x 5µm) at a flow rate of 0.8 mL/min, injection volume of 20 µL, and column temperature of 30°C. The detection and quantification of phenolic compounds were done at specific wavelengths (254, 275, 305, and 325 nm) using gradient elution for 40 minutes, with acidified water and acetonitrile solution as mobile phase. Validation of the established analytical procedure showed that the coefficient of determination (R2 > 0.99), limit of detection (0.01 to 0.35 µg/mL), limit of quantitation (0.03 to 1.07 µg/mL), recovery values (98.33 to 101.12%), and repeatability (RSD < 5%) respectively indicated a linear, sensitive, accurate, and precise analytical method for the simultaneous chromatographic analysis of the 12 phenolic compounds. Overall, the developed HPLC-DAD procedure can offer adequate confidence for the identification and quantification of specific polyphenols and can be modified or updated for future analysis of phenolic compounds in different plant extracts.

Bioactivities and chemical profiling comparison and metabolomic variations of polyphenolics and steroidal glycoalkaloids in different parts of Solanum nigrum L.

Solanum nigrum L. is a traditional medicinal herb and edible plant. Many studies provide evidence that S. nigrum L. is a nutritious vegetable. Polyphenols and steroidal glycoalkaloids are the main components. This study aimed to systemically evaluate the phytochemical profile, quantification, and bioactivities of polyphenolics and glycoalkaloids in different parts of S. nigrum L. Total polyphenols (TPC) and total glycoalkaloids (TGK) were determined using the Folin-Ciocalteu and acid dye colorimetric methods, respectively. A total of 55 polyphenolic constituents (including 22 phenolic acids and 33 flavonoids) and 24 steroidal glycoalkaloids were identified from different parts using ultrahigh-performance liquid chromatography Q-exactive high-resolution mass spectrometry (UHPLC-QE-HRMS), of which 40 polyphenols (including 15 phenolic acids and 25 flavonoids) and one steroidal glycoalkaloid were characterised for the first time in S. nigrum L. Moreover, typical polyphenols and glycoalkaloids were determined using HPLC-UV and HPLC-evaporative light-scattering detector (ELSD), respectively. In addition, the TPC and TGK and their typical constituents were compared in different anatomical parts. Finally, the antioxidant capacities of polyphenolic extracts from different parts of S. nigrum L. were evaluated by ·OH, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric-reducing antioxidant power (FRAP) assay in vitro. In addition, the antitumour effects of TGK from different parts of S. nigrum L. on the proliferation of PC-3 cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Polyphenolic and glycoalkaloid extracts from different parts of S. nigrum L. showed different antioxidant and cytotoxic capacities in vitro. This is the first study to systematically differentiate between polyphenolic and glycoalkaloid profiles from different parts of S. nigrum L.

Designing New Sport Supplements Based on Aronia melanocarpa and Bee Pollen to Enhance Antioxidant Capacity and Nutritional Value.

With a high number of athletes using sport supplements targeting different results, the need for complex, natural and effective formulations represents an actual reality, while nutrition dosing regimens aiming to sustain the health and performance of athletes are always challenging. In this context, the main goal of this study was to elaborate a novel and complex nutraceutical supplement based on multiple bioactive compounds extracted from Aronia melanocarpa and bee pollen, aiming to support physiological adaptations and to minimize the stress generated by intense physical activity in the case of professional or amateur athletes. Our proposed formulations are based on different combinations of Aronia and bee pollen (A1:P1, A1:P2 and A2:P1), offering personalized supplements designed to fulfill the individual requirements of different categories of athletes. The approximate composition, fatty acid profile, identification and quantification of individual polyphenols, along with the antioxidant capacity of raw biological materials and different formulations, was performed using spectrophotometric methods, GS-MS and HPLC-DAD-MS-ESI+. In terms of antioxidant capacity, our formulations based on different ratios of bee pollen and Aronia were able to act as complex and powerful antioxidant products, highlighted by the synergic or additional effect of the combinations. Overall, the most powerful synergism was obtained for the A1:P2 formulation.

Pentaclethra eetveldeana Leaves from Four Congo-Brazzaville Regions: Antioxidant Capacity, Anti-Inflammatory Activity and Proportional Accumulation of Phytochemicals.

Oxidative stress and inflammation play a key role in the occurrence of neurodegenerative diseases. Traditionally, Pentaclethra eetveldeana leaves are used in dementia treatment. Therefore, this study aimed to evaluate the antioxidant and anti-inflammatory activities as well as the phytochemical composition of Pentaclethra eetveldeana leaves from four Congo-Brazzaville regions. The 1.2-diphenyl-1-picrylhydrazyl radical-scavenging, β-carotene bleaching and molybdenum reduction assays were used to assess the antioxidant activity. The protein denaturation and erythrocyte membrane stabilization tests were used to analyze the anti-inflammatory activity. Phytochemical screening, the quantification of polyphenols by spectrophotometry, as well as the determination of extraction yields were carried out. It was found that the extracts reduced molybdenum; furthermore, compared to ascorbic acid, they showed better antiradical activity and inhibited lipid peroxidation. Moreover, globally, the membrane-stabilizing power of the aqueous extracts was superior or comparable to diclofenac, while the same extracts were less effective for the inhibition of denaturation. All of the aqueous extracts contained polyphenols, saponins, alkaloids, anthraquinones, reducing sugar and cardiotonic glycosides. The total polyphenols, tannins and proanthocyanidins are produced proportionally from one region to another. Finally, the leaves from Brazzaville and Boundji contain flavonols, while those from Makoua and Owando contain flavones. Thus, Pentaclethra eetveldeana leaves contribute to traditional dementia treatment through their antioxidant and anti-inflammatory properties.

Maturity Assessment of Different Table Grape Cultivars Grown at Six Different Altitudes in Lebanon.

Table grapes are harvested based on well-known maturity indices that must be monitored after fruit veraison. The aim of this study was to assess these indices across multiple locations and environmental conditions, encompassing different table grape cultivars such as Black Pearl, Crimson Seedless, Superior Seedless, and Red Globe. For this reason, grape sampling was conducted across six distinct locations characterized by varying altitudes above sea level (m asl) and environmental conditions over the ripening season. The main maturity indices, including pH, sugar content, titratable acidity, berry firmness, and other parameters were monitored over the growing season. Moreover, the quantification of total polyphenols, total anthocyanins, and antioxidant activity was determined using spectrophotometric assays at harvesting. The study has examined the effect of the vineyard's location on grape quality and its interaction with the cultivar and environment. Crimson Seedless maintained a relatively high level of acidity with altitude near harvesting. Black Pearl exhibited a notable decline in both sugar content and berry firmness as elevation increased, whereas Red Globe demonstrated contrasting outcomes. The optimal maturity of Superior Seedless was observed at an elevation of 1000 m asl. Black Pearl and Crimson Seedless exhibited better adaptability to intermediate elevations (650 and 950 m asl), while Red Globe and Superior Seedless showed better adaptability to higher elevations (1000-1150 m asl). Among the studied cultivars, Black Pearl exhibited significantly higher levels of total polyphenols and anthocyanins, while close values were noticed between red and green cultivars.

A comprehensive assessment of phytochemicals from Phyla nodiflora (L.) Greene as a potential enzyme inhibitor, and their biological potential: An in-silico, in-vivo, and in-vitro approach

This work explored Phyla nodiflora (L.) Greene as a potential source of the bioactive medicinal agent. In this aspect, methanol (PN-M) and dichloromethane (PN-D) extracts were prepared from the whole plant and evaluated for phytochemical composition (total bioactive contents, UHPLC-MS analysis, and HPLC-PDA polyphenolic quantification), biological (antioxidant and enzyme inhibition) potential and in-vivo toxicity. The PN-M was found to contain higher phenolic (26.08 mg GAE/g extract) and flavonoid (50.25 mg QE/g extract) contents which might correlate to the higher radical scavenging (DPPH: 52.94 mg TE/g extract; ABTS: 72.11 mg TE/g extract) and reducing power (FRAP: 71.96 mg TE/g extract; CUPRAC: 142.65 mg TE/g extract) antioxidant potential, as well as AChE (4.33 mg GALAE/g extract), tyrosinase (125.36 mg KAE/g extract), and amylase (1.86 mmol ACAE/g extract) inhibition activity of this extract. In contrast, the PN-D extract was found to be most active for phosphomolybdenum (1.30 mg TE/ g extract) and metal chelation (54.84 mg EDTAE/g extract) assays in addition to BChE (4.70 mg GALAE/g extract) and glucosidase (0.62 mmol ACAE/g extract) enzyme inhibition activity. The PN-M extract on UHPLC-MS analysis revealed the tentative identification of 24 different secondary metabolites, most of which belonged to the flavonoid, glycoside, and terpenoid classes of phytochemicals. The polyphenolic composition of the extracts was appraised by HPLC-PDA. Seven phenolic compounds were identified in the extracts. PN-M was found to be rich in catechin (0.25 µg/extract) and 3-OH benzoic acid (0.64 µg/extract), while PN-D contained epicatechin (0.30 µg/extract), 3-OH-4-MeO benzaldehyde (0.21 µg/extract), and 2,3-Di-Meo benzoic acid (0.97 µg/extract) in higher amounts. The methanol extract was found to be non-toxic even at higher doses. Furthermore, the relationship between the phytochemicals and the tested enzymes was highlighted by molecular docking studies. In sum, this research showed that the studied extracts were effective as enzyme inhibitors and antioxidants, suggesting it would be worth investigating in more depth for further advanced studies to explore its pharmacological properties.

Comparison of Si-GA-PLS and Si-CARS-PLS build algorithms for quantitation of total polyphenols in black tea using the spectral analytical system.

The objective of the current study was to compare two machine learning approaches for the quantification of total polyphenols by choosing the optimal spectral intervals utilizing the synergy interval partial least squares (Si-PLS) model. To increase the resilience of built models, the genetic algorithm (GA) and competitive adaptive reweighted sampling (CARS) were applied to a subset of variables. The collected spectral data were divided into 19 sub-interval selections totaling 246 variables, yielding the lowest root mean square error of cross-validation (RMSECV). The performance of the model was evaluated using the correlation coefficient for calibration (RC ), prediction (RP ), RMSECV, root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) value. The Si-GA-PLS model produced the following results: PCs = 9; RC = 0.915; RMSECV = 1.39; RP = 0.8878; RMSEP = 1.62; and RPD = 2.32. The performance of the Si-CARS-PLS model was noted to be best at PCs = 10, while RC = 0.9723, RMSECV = 0.81, RP = 0.9114, RMSEP = 1.45 and RPD = 2.59. The build model's prediction ability was amended in the order PLS < Si-PLS < CARS-PLS when full spectroscopic data were used and Si-PLS < Si-GA-PLS < Si-CARS-PLS when interval selection was performed with the Si-PLS model. Finally, the developed method was successfully used to quantify total polyphenols in tea. © 2023 Society of Chemical Industry.

Semperivium Ruthenicum Koch Extract-Loaded Bio-Adhesive Formulation: A Novel Oral Antioxidant Delivery System for Oxidative Stress Reduction.

Periodontitis is a chronic inflammatory disease that affects the oral cavity and can ultimately lead to tooth loss. Oxidative stress has been identified as a key factor in the development of periodontitis. In recent years, natural polyphenols have gained attention for their anti-inflammatory and antioxidant effects. This study aims to evaluate the potential of a bio-adhesive patch loaded with Semperivium ruthenicum Koch extract, rich in polyphenols, as a novel oral antioxidant delivery system for reducing oxidative stress in periodontitis. The plant extracts were prepared by maceration and were subjected to HPLC analysis for the identification and quantification of polyphenols. The bio-adhesive patches were prepared using a solvent-casting technique and characterized for their technical characteristics and release kinetics. The patches demonstrated satisfactory technical characteristics and followed Korsmeyer-Peppas release kinetics, with the active ingredients diffusing non-Fickian from the polymer matrix as it eroded over time. The bio-adhesive strength of the patches was comparable to other similar formulations, suggesting that the obtained patches can be tested in vivo conditions. The results suggest that treating oral periodontitis with natural polyphenols may effectively scavenge free radicals and regulate cytokine activity, leading to a reduction in oxidative stress. The non-smoking group had a mean saliva antioxidant activity of 7.86 ± 0.66% while the smoking group had a mean value of 4.53 ± 0.15%. Furthermore, treating oral oxidative stress may also contribute to overall gut health, as studies have shown a correlation between oral and gut microbiomes. Therefore, the use of bio-adhesive patches containing polyphenols may provide a promising approach for the treatment of periodontitis and its associated complications.

Antioxidant and anti-inflammatory potentials of aerial and floral parts of Neurada procumbens extracts: In vitro and in vivo studies

Neurada procumbens (Neuradaceae) is an importent plant of the Cholistan desert and is traditionally been used for the treatment and control of diabetes, fever, inflammations and jaundice. The aim of the current project is to investigate the bioactive compounds, free radical scavenging capacity and the anti-inflammatory potential of Neurada procumbens separately for its aerial and floral parts in six different extracts. The phytochemical profile (total bioactive contents, HPLC polyphenolic quantification), anti-oxidant (DPPH and FRAP assays), anti-inflammatory (HRBC stabilization) activities of the Aqu, MetOH, n-But, EtAc, n-Hex, and DCM extracts from the aerial and floral parts of Neurada procumbens were quantified. Based on the current results, the aerial and floral parts of N. procumbens extracts have found to contain a significant amount of active metabolites including polyphenolic compounds such as 2,3 di MeO benzoic acid, p-coumaric acid, chlorogenic acid, quercetin dihydrate and t-ferrulic acid. The total phenolic and total flavonoid contents of the plant were found to range from 28.13 to 78.9 GAE mg/g of plant and 17.23 to 68.23 RE mg/g of plant, respectively. DCM and n-But extracts of floral part exhibited comparatively higher antioxidant potential in DPPH (IC50 < 100 μg/ml) and FRAP (IC50 < 55 μg/ml) assays compared to aerial part. The dichloromethane floral extract demonstrated impressive anti-inflammatory activity in the hemolytic red blood cell lysis assay, with 83 % protection of HRBC lysis at an IC50 of 469.6 µg/ml (p < 0.01). In vivo, a 300 mg/kg body weight of DCM floral extract reduced carrageenan-induced paw oedema by 8.51 ± 0.35 mm to 7.65 ± 0.38 mm, a highly significant difference (p < 0.001).The toxicity studies revealed that the floral-DCM dose extract was found to be safe up to 2000 mg/kg BW, while its lethal dose (LD50) was found to be 4472.13 mg/kg BW in rats. Due to quite low toxicity effects, the floral part of the plant could be recommended as a safe pharmacological agent for various therapeutic applications.

Antibacterial Activity of Eight Medicinal Plants from the Traditional Pharmacopoeia of Niger.

The emergence of multidrug bacterial resistance poses a great public health problem and requires a constant search for new antibacterial agents. However, Niger's flora possesses several medicinal plants used in traditional medicine to cure infectious diseases and can be used as sources of bioactive ingredients. This current study was designed to evaluate the antibacterial activity of eight plants used in the traditional pharmacopeia of Niger. The extracts were prepared by maceration using ethanol, methanol, and distilled water. The obtained extracts were screened against Salmonella spp., Shigella spp., and Escherichia coli using the microdilution method coupled with a resazurin-based assay. Phytochemical screening was performed using colorimetry, while the quantification of total polyphenols, total flavonoids, and total tannins was determined by spectrophotometry. Out of the eight plants obtained, five named Cassia italica, Limeum pterocarpum, Phyllanthus pentandrus, Strychnos innocua, and Ximenia americanum exhibited antibacterial activity with MICs ranging from 500 μg/mL to 2000 μg/mL. Phytochemical screening showed the presence of alkaloids, saponosides, tannins, flavonoids, terpenes/sterols, quinones, and polyphenols. The ethanolic and methanolic extracts of X. americana contained important quantities of total polyphenols, with 43.59 ± 0.15 and 41.97 ± 0.02 mg EAG/100 mg of extract, respectively. These extracts showed the highest contents of total tannins at 46.49 g/L and 45.52 g/L, respectively. For total flavonoids, the highest content was obtained with the methanolic extract of P. pentandrus, with 3.12 ± 0.01 mg QE/100 mg of extract. These findings justify the uses of these plants in traditional medicine for the treatment of infectious diseases such as diarrhea and can be used as starting points for the development of phytodrugs against infectious diarrhea.

Impact of ultrasound-assisted extraction of polyphenols and caffeine from green tea leaves using high-performance thin-layer chromatography.

Tea is the most popular daily drink consumed globally, with a high concentration of caffeine and polyphenols. In this study, the effects of ultrasonic-assisted extraction and quantification of caffeine and polyphenols from green tea were investigated and optimized using 23 -full factorial design and high-performance thin-layer chromatography. Three parameters were optimized to maximize the concentration of caffeine and polyphenols extracted using ultrasound: crude drug-to-solvent ratio (1:10-1:5), temperature (20-40°C), and ultrasonication time (10-30 min). The optimal conditions achieved from the model for tea extraction were as follows: crude drug-to-solvent ratio, 0.199 g/ml; temperature, 39.9°C; and time, 29.9min; the extractive value was found to be 16.8%. Images from scanning electron microscopy showed that the matrix underwent a physical alteration and cell wall disintegration, which intensified and accelerated the extraction. This process might be simplified using sonication, which results in a higher extractive yield and a significant concentration of caffeine and polyphenols than the traditional approach, with a smaller quantity of solvent and faster analytical times. The result of high-performance thin-layer chromatography analysis proves a significant positive correlation between extractive value and caffeine and polyphenol concentrations.

Patterning (Electro)chemical Treatment-Free Electrodes with a 3D Printing Pen

A simple fabrication method to make electrochemical sensors is reported. The electrodes were fabricated with a commercial filament based on polylactic acid and carbon black (PLA/CB). They were engineered with a three-dimensional (3D) printing pen and poly(methyl methacrylate) template. The optimization parameters included the thickness and diameters of the electrodes. The electrode diameter was restricted by the 3D printing pen's nozzle dimension, and larger diameters generated small cracks on the electrode surface, compromising their analytical signal. The electrode thickness can increase the electrical resistance, affecting their electrochemical response. The fabrication showed reproducibility (RSD = 4%). The electrode surface was easily renewed by sanding the electrodes, making them reusable. Additionally, the proposed sensor provided comparable electrochemical responses over traditional glassy carbon electrodes. Moreover, no (electro)chemical surface treatment was required for sensing applications due to the compromise between the thickness and diameters of the electrodes, effectively translating the filaments' electrical properties to resulting materials. The electrodes' analytical performance was shown for organic and inorganic species, including paraquat, Pb2+, and caffeic acid. As proof of concept, the analytical applicability was demonstrated for total polyphenolic quantification in tea samples. Therefore, this work provides an alternative to fabricating miniaturized electrodes, bringing valuable insights into PLA/CB 3D-printed sensors and opening possibilities for designing electrode arrays. Moreover, the proposed electrodes are promising platforms for paper-based microfluidic systems.

Extraction methods and compositions of polyphenols in Shanxi aged vinegar

The extraction, purification, qualification, and quantification of polyphenols (PPs) in vinegar are challenging owing to the complex matrix of vinegar and the specific physicochemical and structural properties of PPs. This study aimed to develop a simple, efficient, low-cost method for enriching and purifying vinegar PPs. The enrichment and purification effects of five solid phase extraction (SPE) columns and five macroporous adsorption resins (MARs) for PPs were compared. The results show that SPE columns were more effective in purifying vinegar PPs than MARs. Among them, the Strata-XA column showed a higher recovery (78.469 ± 0.949%), yield (80.808 ± 2.146%), and purity (86.629 ± 0.978%) than other columns. In total, 48 PPs were identified and quantified using SPE and gas chromatography-mass spectrometry from the SPE column extracts; phenolic acids, such as 4-hydroxyphenyllactic acid, vanillic acid, 4-hydroxycinnamic acid, 4-hydroxybenzoic acid, protocatechuic acid, and 3-(4-Hydroxy-3-methoxyphenyl) propionic acid, occupy a major position in SAV. Furthermore, considering the potential applications of PPs, the concentrates were characterized based on their bioactive properties. They exhibited high total PP, flavonoid, and melanoidin contents and excellent anti-glycosylation and antioxidant activities. These results indicate that the established methodology is a high-efficiency, rapid-extraction, and environment-friendly method for separating and purifying PPs, with broad application prospects in the food, chemical, and cosmetic industries.

Glucose adsorption capacity and inhibitory potential of Pseudocedrela kotschyi (Schweinf.) Harms (Meliaceae) leaf extracts against α-amylase: a comparative study over three months

Objective(s): The aim of this study was to evaluate the antidiabetic potential of Pseudocedrela kotschyi leaf decoction by making a comparison between extracts harvested over three months.&#x0D; Design: This study is done through a few experiences. After the quantification of total polyphenols by folin-Ciocalteu reagent method, the antioxidant activities were tested with ABTS, DPPH and FRAP essays. Then, the glucose oxidase kit was used to determine the glucose adsorption capacity of the extracts. At last, dinitrosalicylic acid method served to evaluate the α-amylase inhibitory activity of the extracts.&#x0D; Results: As results the leaves extracts of Pseudocedrela kotschyi showed a polyphenol content of 39,97 ± 3,63 mg EAG/g DE for October, 74,2 ± 11,64 for November and 59,45 ± 7,024 for December. For total flavonoids, the content was 4,86 ± 0,29 mg QE/g DE (October) 5,68 ± 0,39 mg QE/g DE (November) and 5,548 ± 0,19 mg QE/g DE (December). In addition, the antioxidant activity was correlated with the phenolic content (r = -0.65 for DPPH IC50, r = -0.84 for ABTS IC50 and r = 0.97 for FRAP). Besides, the extracts exhibited a strong α-amylase inhibitory activity (IC50 = 0,272 mg DE/mL for October, 0,097 mg DE/mL for November and 0,101 mg DE/mL for December) and had a high capacity to adsorb glucose (over 219,98 ±2,54mmol/g DE for a 30mM glucose solution for November).&#x0D; Conclusion: Pseudocedrela kotschyi leaf decoction has the ability to inhibit α-amylase activity and adsorb glucose in glucose concentrated solution. So it possess a high antidiabetic potential.&#x0D; Keywords: Glucose adsorption, α-amylase, Pseudocedrela kotschyi, antioxidant activity.