Solvent Fractions Research Articles

A life cycle assessment model to evaluate the environmental sustainability of lignin-based polyols

Lignin-based polyols are expected to provide significant environmental benefits by offering new synthetic routes to various types of bio-resins for coating applications. Currently, no models evaluating lignin-based polyols are available in the literature, therefore, the present study introduces a new model to assess environmental impacts associated with the synthesis of lignin-based polyols and to evaluate their potential environmental advantages in bio-product manufacturing. The model follows the life cycle assessment methodology and is based on lignin-based polyols production at a pilot scale, beginning with kraft lignin extraction, followed by solvent fractionation. The results indicate that, compared to their petrochemical counterparts, lignin-based polyols demonstrate superior environmental performance under specific conditions, such as the use of bio-based solvents and an appropriate energy mix. Tetrahydrofuran and electricity consumption emerge as the primary hotspots contributing to environmental impact categories such as climate change, fossil resource use, and water use—identified as the main contributors to the overall environmental impact of lignin-based polyol production. An uncertainty analysis was conducted using Monte Carlo simulation. Based on the findings, producers can consider lignin-based polyols as a promising raw material if they replace tetrahydrofuran with its bio-based counterpart and adopt a renewable energy mix for production. This model can be easily extended by researchers and/or practitioners to further evaluate the environmental impacts of bio-products derived from lignin-based polyols. Moreover, the results of this study can guide policymakers in shaping bio-product policies, as lignin-based polyols show promise as a more sustainable chemical alternative.

Prosopis africana extract inhibits critical enzymes associated with hypertension in vitro and in cyclosporine-induced hypertensive rats

ObjectiveThis study evaluated the antihypertensive properties of leaf extracts of Prosopis africana (PA) in vitro and in hypertensive rats. MethodsEthanol (ELPA) and differential solvent fractions [ethyl-acetate (EAPA), butanol (BLPA), and aqueous (ALPA)] were prepared using standard protocols. Hypertension was induced in female albino Wistar rats intraperitoneally using cyclosporine (25 mg/kg/day) while extracts were administered via oral route. Forty female rats were grouped into 5 (n = 8). Group 1 received 2 ml distilled water, Group 2: (cyclosporine + 2 ml distilled water); Group 3: cyclosporine + captopril (10 mg/kg/day); Group 4: cyclosporine + 1000 mg/kg ELPA and Group 5: cyclosporine + 1500 mg/kg ELPA. The blood pressure of anesthetized rats was measured using LabScribe coupled to a Lab-Trax-4/24T, and the activities of angiotensin-converting enzyme (ACE), arginase, phosphodiesterase-5 (PDE-5), acetylcholinesterase (AChE) and adenosine deaminase (ADA) were evaluated using standard methods. ResultsAll the fractions exerted significantly (p < 0.05) higher ACE inhibitory effect (ELPA = 64.36 ± 0.50%; EAPA = 86.31 ± 0.60%; BLPA= 85.28 ± 2.30 % ; ALPA= 82.27 ± 2.10 % ) than the reference, lisinopril (40.22±0.50 % ); while the butanol fraction (67.05±0.40 % ) showed higher PDE-5 inhibition than the reference, sildenafil (23.06±0.70 % ). Administration of cyclosporine caused notable (p < 0.05) elevation of systolic/diastolic blood (131.00 ± 1.22/93.25 ± 1.49 mmHg) pressure plus elevated heart rate when in comparison with the normotensive rats (106.25 ± 1.65/85.25 ± 1.18 mmHg). Treatment of hypertensive rats with ELPA significantly reduced elevated activities of ACE, PDE-5, AChE, and arginase to values that are not significantly (p < 0.05) different from those of the rats treated with the reference drug. ConclusionThis result could validate the use of P. africana as an antihypertensive agent in folklore.

Comparative study on the physicochemical characteristics of lignin via sequential solvent fractionation of ethanol and Kraft lignin derived from poplar and their applications

The challenges in high value-added utilization of lignin own to its wide molecular weight distribution and complex physicochemical properties associated with it. How to narrow the molecular weight of lignin and elucidate the differences in physiochemical properties related to molecular weight of lignins is of crucial importance for lignin conversion processing. In this study, lab-made Kraft and ethanol lignins were fractionated into several narrower molecular weight distribution components through a designed solvent system. The yield, molecular weight distribution, structural characterization and their physicochemical properties of each fractionated lignin were analyzed comparatively. The results indicated that the yield of ethanol lignin is higher (8.44 %) than that of Kraft lignin (5.26 %). Kraft lignin shows lower molecular weight (Mw=2480 g/mol), higher hydroxyl content (4.29 mmol/g), and lower content of β-O-4 and β-5 bonds compared to ethanol lignin (Mw=3682 g/mol, 2.10 mmol/g). Meanwhile, the phenolic hydroxyl content in both ethanol and Kraft lignins increased with the decrease of molecular weight. Furthermore, ethanol lignin demonstrated higher antioxidant activity and much higher (65times) tensile strength of lignin-based polyurethane elastomer than that of Kraft lignin-based polyurethane elastomer.

Study on Bioactive Components of Aromatic Cynanchum thesioides (Freyn) K. Schum by Solvent Fractionation.

This study evaluated the antioxidant activity of the methanol extract from aromatic Cynanchum thesioides (Freyn) K. Schum. by fractionating it with different solvents, aiming to provide theoretical evidence for the development of products related to aromatic Cynanchum thesioides (Freyn) K. Schum. The yield of the methanol extract was 13.33%, with the water fraction showing the highest yield, followed by n-hexane, n-butanol, dichloromethane, and ethyl acetate. Among these fractions, the ethyl acetate fraction showed the highest antioxidant activity, as indicated by total polyphenol content and ABTS radical scavenging activity. The DPPH radical scavenging activity, reducing power, and SOD-like activity measurements showed no significant difference between the ethyl acetate and n-butanol fractions, as both showed the highest radical scavenging activity. In the FRAP activity measurement, the n-butanol fraction ranked behind the ethyl acetate and dichloromethane fractions in terms of antioxidant activity. Although the ethyl acetate fraction showed the highest antioxidant activity, its yield was only 1.29%, making it unsuitable for product production considering productivity and economy. However, the n-butanol fraction showed overall high antioxidant activity and was approximately four times more abundant, with a yield of 5.80% compared to the ethyl acetate fraction. Consequently, considering both productivity and economy, the n-butanol fraction is considered suitable for product development and production.

Gas Chromatography-Mass Spectrometry and Fourier Transform Infrared Spectroscopy Analysis of Potential α-Glucosidase Inhibitors from Terminalia catappa Leaf Extracts

Aims: Postprandial hyperglyceamia is often caused by insulin insufficiency or cellular glucose uptake complications, and conventional treatments often yield undesirable side effects. The aim of the current work was to assess the α-glucosidase inhibitory activities of T. catappa leaf extracts and use spectroscopic techniques to partially characterize possible inhibitors. Study Design: Phytochemical screening, enzyme inhibition assay and spectrometric and spectroscopic characterization of bioactive compounds from leaf extract and fractions of T. catappa. Place and Duration of Study: The entire work was carried out at the Department of Applied Chemistry and Biochemistry, University for Development Studies, Ghana within nine months. Methodology: T. catappa leaf extract and fractions were qualitatively screened for phytochemicals and their biological activity assessed in α-glucosidase inhibition assay. The potential enzyme inhibitors were characterized by Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infrared (FT-IR) Spectroscopy. Results: Phytochemical screening of the extract and the various solvent fractions revealed the presence of alkaloids, flavonoids, saponins, flavanol glycosides, phenolics, and terpenoids. The α-glucosidase inhibition potential of the crude leaf extract was concentration-dependent with a half-maximal inhibitory concentration (IC50) of 337.5 µg/ml. Solvent fractions from the crude extract demonstrated α-glucosidase inhibitory activity with IC50 values ranging from 170.40 µg/ml for ethyl acetate (EtOAc) fraction to 71.90 µg/ml for n-hexane (n-Hex) fraction. Acarbose, the control drug, demonstrated significant α-glucosidase inhibition activity in a similar pattern with IC50 of 6.16 µg/ml. The enzyme inhibition kinetics parameters, specifically the Michaelis constant (KM) and Maximum reaction velocity (Vmax) values, suggested that the inhibition of α-glucosidase by T. catappa extract followed a competitive mode. GC-MS and FT-IR analysis of the n-Hexane fraction identified the compounds Eugenol, Urs-12-en-24-oic acid, 3-oxo-, methyl ester (+)-, phytol, trans-isoeugenol, α-amyrin, and squalene as the potential antidiabetic agents that might be responsible for reducing postprandial blood glucose levels. Conclusion: These findings show that T. catappa leaf extract contains α-glucosidase inhibitors and therefore serves as a valuable resource in the discovery of natural anti-diabetic agents.

Fractionation of Kraft Lignin for Production of Alkyd Resins for Biobased Coatings with Oxidized Lignin Dispersants as a Co-Product.

A new valorization pathway based on solvent fractionation was applied to kraft lignin, a major by-stream of the pulping industry, to extract a soluble lignin intermediate featuring an improved structural homogeneity, a low molecular weight, and a high content of phenolic hydroxyl and carboxylic acid groups to serve as a substitute of the nonrenewable polyacids in the formulation of alkyd resins, a dominant material used in the production of anticorrosion surface coatings. Herein, softwood kraft lignin was mixed in a low-cost green solvent, aqueous ethanol, prepared at different ratios, at room temperature to generate a soluble fraction of a low M w of ≤2200 g mol-1 and an insoluble fraction of a high M w of ≥3950 g mol-1 of lignin. The best combination of yields and molecular weights of soluble lignin (16-36% yield, 1740-1890 g mol-1) was attained using 50-80 vol % ethanol in fractionation. Thus, these conditions were further employed at the pilot scale to demonstrate the scalability of this technology. Soluble lignin from pilot fractionation was used to produce an optimal alkyd resin formulation and thereafter an anticorrosion coating on the metal surface, both of which matched the target properties of industrial standards well (180 s Persoz hardness and 72 gloss units of coating, 100% adhesion of paint with no cracks or peeling in the cross-cut test, no corrosion after 120 h of the salt spray test). The insoluble solids from pilot fractionation could also be valorized by alkali-O2 oxidation into lignin-based dispersants for special carbon black pigments. Overall, this study presents a new, simple strategy to develop an efficient, scalable, low-cost, and green process for upgrading kraft lignin into phenolic intermediates for biobased alkyd resins to facilitate sustainable production of high-performance anticorrosion coatings.

Factors increasing the hydroxycinnamic acids extraction from dandelion roots

Aim – to study the influence of extraction factors on the extraction of hydroxycinnamic acids (HCAs) from dandelion roots. Material and methods. The object of the study was air-dried dandelion roots. The HCAs content was determined using Arnov's reagent by spectrophotometric method according to the pharmacopoeial method. The influence of the nature, volume fraction of organic solvents, composition of extraction mixtures, temperature, duration, extraction frequency, medicinal plant raw material and extractant ratio, and medicinal plant raw material particle size on the HCAs yield from dandelion roots during extraction was established. Methanol, ethanol, propanol-1, propanol-2, acetone, acetonitrile, dimethyl sulfoxide, propylene glycol-1,2, ethylene glycol, glycerol and their aqueous solutions in volume fractions of 20, 40, 60 and 80 % were used as extractants. A dispersion analysis of the influence of these factors on the yield of HCAs during extraction was performed. Results. Extraction conditions providing the maximum yield of HCAs in comparison with pharmacopoeial and literary methods were experimentally developed. The conditions include: extractant – 60 % propanol-1 or a mixture of 50 % propanol-1 and 10 % acetone; extraction temperature – 80 ˚C; extraction duration – 6 hours; medicinal plant raw material and extractant ratio – 1 to 25; extraction frequency – single and medicinal plant raw material particle size – 500 μm or less. It has been proven that the physicochemical characteristics of the extractants, their volume fractions in solutions and extraction parameters have a statistically significant effect on the yield of HCAs. Conclusions. A statistically significant effect of the studied extraction factors on the yield of HCAs from dandelion roots has been proven. The developed extraction method statistically significantly increases the yield of HCAs by an average of 30% to 2.5 times in comparison with pharmacopoeial and literary extraction methods.

Wound-Healing Activity of Solvent Fractions and Antiinflammatory Activity of Crude Extract and Solvent Fractions of Acokanthera schimperi Schweinf (Apocynaceae) Leaves in Mice Model

BackgroundIn Ethiopia, Acokanthera schimperi is frequently used to treat wounds and other conditions. Nothing has been published to date on the anti-inflammatory properties of A. schimperi leaves or the wound-healing effects of solvent fractions, despite a report on the crude extract's ability to heal wounds being available in the literature. PurposeTherefore, this experiment has been initiated to look into the solvent fractions' ability to heal wounds and the anti-inflammatory properties of the A. schimperi leaf 80% methanol extract and its fractions in mice. Study designThe experimental study design was conducted to evaluate wound healing and the anti-inflammatory properties of the A. schimperi leaf 80% methanol extract and its fractions in mice. MethodsThe plant's leaf crude extract was fractionated using ethyl acetate, chloroform, and distilled water. The resulting fractions were then combined with a simple ointment base to make an ointment at 5% and 10% w/w. Next, using excision and incision wound models, the ointments' ability to promote wound healing was assessed. The excision model was utilised to estimate wound contraction and epithelization time, whereas the incision model was utilised to measure tensile strength. By dissolving 1% carrageenan in 0.9% saline (w/v) and giving oral dosages of the crude extract and solvent fractions (100, 200, and 400 mg/kg), the anti-inflammatory efficacy of the leaves was assessed concurrently with a carrageenan-induced hind paw edema model. ResultsSignificant wound healing activity was seen in both models in wounds treated with 5% and 10% (w/w) solvent fraction ointment, as shown by higher tissue breaking strength (with 51.38% maximum effect by 10% (w/w) ethyl acetate fraction ointment), shorter epithelization times (within 15.92 days by ethyl acetate fraction ointment 10%), and increased wound contraction (99.40% by ethyl acetate fraction ointment 10%). The extract (hydromethanolic) and solvent fractions also showed notable dose-related decreases in inflammation. ConclusionThe study's findings supported A. schimperi's traditional use as a wound healing agent by showing that the solvent fractions of the plant's leaves promoted wound healing, at least in part, through their anti-inflammatory effect.

Vieta–Lucas polynomials-based collocation simulation to analyze the solvent fraction factor in active and passive control flow induced by torsional motion

The present research explores the Boger fluid flow past a stretching cylinder with torsional motion in the presence of the magnetic field. It is assumed that the cylinder rotates continuously around its axis and that the starting point's position along the axis correlates with the cylinder wall's expansion rate. Additionally, the consequence of active and passive control of nanoparticles, activation energy, thermophoresis, and Brownian motion effects are considered. Similarity variables transform the governing partial differential equations into non-dimensional ordinary differential equations (ODEs). Furthermore, the Vieta–Lucas polynomials-based collocation method (V-LPBCM) is employed to solve the resulting ODEs. The V-LPBCM outcomes of Nusselt and Sherwood numbers are compared with Runge–Kutta Fehlberg's fourth-fifth-order scheme for validation purposes. The impact of various dimensionless parameters on the different profiles is depicted in the graphical representation. The increase in values of the magnetic parameter, the ratio of relaxation time, and the Reynolds number decline the velocity profile. The velocity profile increases as the values of the solvent fraction parameter rise. The thermal profile increases as the heat source/sink, and thermophoretic parameters rise. The increase in values of activation energy parameter increases the thermal profile.

Harnessing anti-infective efficacy of Cinnamomum verum in synergy with β-lactam and fluoroquinolones drugs to combat virulence and biofilms of Pseudomonas aeruginosa PAO1

Multidrug resistance (MDR) Gram-negative bacteria are increasingly resistant to multiple antibiotics, posing a serious challenge to infection control and treatment. Combining plant-derived bioactives with antibiotics offers a promising approach to overcome the challenges posed by MDR pathogens like Pseudomonas aeruginosa. This study investigated the synergistic effects of Cinnamomum verum with beta-lactam and fluoroquinolones against P. aeruginosa PAO1. The ethyl acetate fraction of C. verum (CVEF) was obtained through fractionation in organic solvents with progressively higher polarity. The interaction of CVEF with selected antibiotics was assessed by checkerboard synergy assay. The effects of synergistic combinations on pyocyanin, pyoverdine, protease, EPS production, and biofilm development were measured using spectroscopic assays. CVEF combined with cefepime, ceftazidime, and levofloxacin significantly enhanced antibacterial efficacy with FICIs between 0.156 and 0.5. The most active combinations i.e., CVEF-cefepime and CVEF-ceftazidime inhibited viable cell count of growth by 3.6 and 4.2 log10 CFU/ml respectively. The combination also inhibited virulence factors (>75 %) and biofilms (>80 %) at lower 1/2 × FICs. The viable count of biofilm cells was also reduced from 6.4 to 3.3 and 3.6 log10 CFU/ml. Membrane permeability was decreased by 60.34 % and biofilm cell viability by 22.53–38.44 %. Key phytochemicals analyzed by GC/MS and LC/MS/MS, include cinnamaldehyde, trans-chlorogenic acid, quercetin, and quercetin 3′-O-glucuronide. In molecular docking investigations, quercetin 3′-O-glucuronide had the highest binding affinity with quorum sensing (QS) and biofilm-associated protein. The findings suggest CVEF, in combination with antibiotics, effectively targets resistance phenotypes of P. aeruginosa, impairing growth, virulence, and biofilms. This supports further research into natural compounds alongside antibiotics to treat drug-resistant infections.

In vivo evaluation of anti-diarrheal activity of hydroalcoholic extract and solvent fractions of the leaf of Leucas deflexa Hook.f (Lamiaceae) in rodents

The emergence of antibiotic-resistant bacteria has intensified the search for novel antidiarrheal drug. Plant-derived extracts offer promising alternatives due to their ability to modulate gut motility and enhance water absorption. The leaves of Leucas deflexa Hook.f., a plant native to Ethiopia, have been traditionally utilized in the treatment of diarrheal diseases. Nonetheless, its traditional application has yet to be scientifically confirmed. Hence, the aim of the present study was to evaluate antidiarrheal activity of the crude extract and fractions of the leaf of Leucas deflexa Hook.f (Lamiaceae). Healthy Swiss albino mice were randomly divided into five groups per experimental model: castor oil-induced diarrhea, gastrointestinal motility, and anti-enteropooling assays. The control group received distilled water (10ml/kg), while the positive control was treated with loperamide (3mg/kg). The remaining groups were administered various dosages (LD100, LD200, and LD400 mg/kg) of a hydroalcoholic extract or its fractions from Leucas deflexa Hook.f. The crude extract and chloroform fraction substantially (P<0.001) delayed the onset of diarrhea, reduced fecal frequency, and decreased total fecal weight at all administered doses compared to the negative control. The butanol and aqueous fractions exhibited a substantial antidiarrheal effect at doses of 200mg/kg and 400mg/kg, respectively. All treatments, including the crude extract, chloroform, butanol, and aqueous fractions, substantially (P<0.001) reduced the volume and weight of intestinal contents at various doses. Additionally, the chloroform, aqueous fraction, and crude extract at doses of 100, 200, and 400mg/kg substantially inhibited gastrointestinal motility compared to the negative control. The results of this study corroborate the traditional use of Leucas deflexa leaves in the treatment of diarrhea. These findings give a scientific justification for further exploration of the underlying mechanisms and potential therapeutic applications of this plant extract.

Brine shrimp lethality and antioxidant property of &lt;i&gt;Lagenaria breviflora&lt;/i&gt; (Benth.) Roberty fruit crude extract and fractions

Background: Oxidative injury plays a pivotal impact in the development of human diseases, and it is a major component of the pathophysiology of several inflammation-linked human medical disorders. Objective: The focus of this study was to evaluate the cytotoxicity and antioxidant potential of the fruit of Lagenaria breviflora (Benth.) Roberty (LB). Methods: The antioxidant capacity of L. breviflora's crude and solvent fractions was assessed using standard techniques by measuring the total phenolic content, total flavonoid content, and DPPH radical scavenging activity. The data we0re analyzed using One-way ANOVA, and Dunnett's Multiple Comparison was used to establish the threshold. Results: The total flavonoid contents of fruit methanol extract, LB hexane, chloroform, and ethyl acetate fractions were 32.00 ± 0.94, 224.32 ±0.05, 224.06 ±0.14, and 2615.67 ± 13.20 mg gallic acid equivalent/g of extract, respectively. In contrast, the total phenolic contents were 5218.83 ± 3.18, 2615.67 ± 13.20, and 4553.00 ± 24.27 mg gallic acid equivalent/g of extract, respectively. The crude extract of LB, hexane fraction, chloroform, and ethyl acetate fraction displayed IC50 values of 242.57 ± 8.90, 262.91 ± 6.49, 96.17 ± 2.74, and 221.45 ± 0.83 μg/mL, respectively, for their ability to scavenge DPPH radicals. Ascorbic acid and rutin had IC50 values of 2.76 ± 0.01 and 20.6 ± 9.26 μg/mL, respectively. Conclusions: Fruit from L. breviflora (LB) exhibited strong antioxidant potential, which may have resulted from the fruit's phenolic and flavonoid content. This demonstrates the reason this herb is used in traditional medicine. Keywords: Oxidative stress, brine shrimp lethality assay, total phenolic contents, total flavonoid contents, DPPH, Lagenaria breviflora fruit.

Understanding and enhancing the phase stability of fast pyrolysis oils through ternary phase diagrams

Fast pyrolysis oils (FPOs), derived from various biomass feedstocks, hold promise as carbon–neutral fuels. However, their industrial use is hindered due to phase separations during storage, transportation, and co-processing, with limited understanding of the root causes that drive this phenomenon. This study aims to elucidate the kinetic stability of FPO by developing ternary phase diagrams and exploring the effects of the temperature and addition of organic solvents on the aging. The phase stability of FPO was found to be determined by the fraction of pyrolytic lignin (PL), mixed solvent (MS), and water. Even at 25 °C, phase separations could consistently occur when the PL content exceeded 56 wt% or the MS content fell below 28 wt%. Heating the FPO to 50 °C–80 °C led to a decrease in the water-soluble content and an increase in the water-insoluble content, while the water content remained relatively unchanged, indicating the transition of the water-soluble content to the water-insoluble content was closely related to FPO phase separation during aging at elevated temperatures. Moreover, the solvents could slow the aging of the FPO in the order of 2-propanol > ethanol > methanol > ethylene glycol > glycerol. Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR-spectroscopy) analysis further revealed changes in both the chemical compositions and polymerizations during aging, in which alcohols were identified as effective inhibiters to slow the aging. These new findings provide promising pathways to controlling the FPO phase stability through solvent selections and will advance the adoptions of FPOs.

Antimalarial potentials of Solanum dasyphyllum fractions against Plasmodium berghei infected mice

BackgroundThe leaves of Solanum dasyphyllum are commonly utilized in the management of fever in traditional medicine, yet scientific evidence supporting their antimalarial effectiveness is lacking. ObjectiveThis study aimed to assess the antioxidant properties of solvent fractions derived from these leaves, alongside investigating antimalarial potential against Plasmodium berghei in mice. MethodsAntioxidant activity was evaluated through total phenolic content determination, DPPH radical scavenging, and Ferric ion reducing antioxidant power assay. The fractions were tested against Plasmodium berghei (NK65) in 4-day suppressive, prophylaxis, and curative models, with mice orally administered 1 % Tween 80 (control), Solanum dasyphyllum hexane fraction (SdHXF), Solanum dasyphyllum dichloromethane fraction (SdDMF), Solanum dasyphyllum ethyl-acetate fraction (SdEAF), and Solanum dasyphyllum aqueous fraction (SdAQF) (each at 125 mg/kg), and chloroquine (10 mg/kg). IC50 values were determined via linear regression analysis, and antimalarial study results were statistically analyzed using one-way ANOVA followed by Duncan multiple range tests, considering significance at P value < 0.05. ResultsThe SdHXF (60.4 %), SdDMF (56.8 %), SdEAF (86.4 %), and SdAQF (94.8 %) exhibited notable percentage chemosuppression compared to the control in the 4-day suppressive test. In the prophylaxis test, SdEAF (80.6 %) and SdAQF (80.0 %) demonstrated similar percentage chemosuppression. In the curative test, the mean survival time significantly increased in SdHXF (30.2 ± 1.3 days), SdDMF (30.8 ± 3.2 days), SdEAF (31.4 ± 2.3 days), and SdAQF (30.1 ± 2.0 days) compared to the control (10.3 ± 0.1 days). The antioxidant activity of the fractions increased with concentration; however, it was lower than that of the positive controls (gallic acid and ascorbic acid). ConclusionThese results suggest that the fractions possess potent antiplasmodial activity against Plasmodium berghei, particularly in the mid-polar fractions, indicating the potential of the plant as a source of novel antimalarial agents.

Phytochemical Composition, Antioxidant, Anti-Helicobacter pylori, and Enzyme Inhibitory Evaluations of Cleistocalyx operculatus Flower Bud and Leaf Fractions.

Six solvent fractions isolated from flower bud and leaf ethanolic extracts of Cleistocalyx operculatus were analyzed for their phytochemical contents, including phenolics, flavonoids, saponins, tannins, and alkaloids. Antioxidant activities were measured using the ABTS, DPPH, and FRAP assays. The results showed that the flower bud aqueous fraction (BAF) and the leaf aqueous fraction (LAF) rich in phenolic content (768.18 and 490.74 mg GAE/g dry extract, respectively) exhibited significantly higher antioxidant activities than the other fractions. The flower bud hexane fraction (BHF) had remarkably high flavonoid and saponin contents (134.77 mg QE/g and 153.33 mg OA/g dry extract, respectively), followed by that of the leaf hexane fraction (LHF) (76.54 mg QE/g and 88.25 mg OA/g dry extract, respectively). The BHF and LHF were found to have extremely high antibacterial activity against two H. pylori strains, ATCC 51932 and 43504 (MICs of 125 µg/mL). Interestingly, DMC (2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone) isolated from the BHF displayed greater antibacterial activity against the bacterial strains (MICs of 25-50 µg/mL) than those of the fractions. In addition, DMC presented potent inhibitory effects on H. pylori urease (IC50 of 3.2 µg/mL) and α-amylase (IC50 of 83.80 µg/mL), but no inhibition against α-glucosidase. It was also demonstrated that DMC showed pronounced inhibitory effects on the urease activity and biofilm formation of H. pylori, and could increase the membrane permeability of the bacterial cells. Scanning electron micrographs depicted that the BHF and DMC had strong effects on the cell shape and significantly induced the distortion and damage of the cell membrane. The fractions and DMC showed no significant toxicity to four tested human cell lines. Efforts to reduce antibiotic use indicate the need for further studies of the flower buds and DMC as potential products to prevent or treat gastric H. pylori infections.

Phenolic Contents and Antioxidant Properties of Bauhinia rufescens, Ocimum basilicum and Salvadora persica, Used as Medicinal Plants in Chad

The plants Bauhinia rufescens, Ocimum basilicum and Salvadora persica are well known in traditional African medicine, and particularly in traditional Chadian medicine. They are commonly used to treat infectious diseases, inflammatory diseases, fevers, gastroenteritis and other medical conditions. The aim of this study was to perform a phytochemical screening to determine the antioxidant properties of different extracts and fractions from the three plants. Ethanolic extracts and solvent fractions were prepared and analyzed for total phenolic content (TPC), total flavonoid content (TFC) and total tannin content (TTC). LC-MS and an online screening HPLC-ABTS system identified phytochemicals with antioxidant activities. DPPH and ABTS reduction methods were used to test the extracts and fractions for their antioxidant potential. The results showed that the TPC of O. basilicum was higher than that of B. rufescens, ranging from 64.70 ± 5.2 to 411.16 ± 8.11 mgGAE/g DW. B. rufescens extracts and fractions, on the other hand, showed higher TFC, ranging from 69.5 ± 5.3 to 408.26 ± 8.42 mgQE/g DW, and higher TTC, ranging from 4.57 ± 2.45 to 62.19 ± 4.7 mgTAE/g DW. The maximum TPC, TFC and TTC in both plants were recorded in the ethyl acetate fractions. S. persica extracts and fractions showed a very low quantity of TPC, TFC and TTC. Based on LC-MS and HPLC-ABTS analysis, rosmarinic acid was identified as the major component in the extracts and all fractions of O. basilicum, and epicatechin, procyanidin B and quercetin were found in B. rufescens. S. persica did not exhibit specific substances with antioxidant activity and was therefore not considered for further assays. DPPH and ABTS results showed that ethyl acetate fractions of B. rufescens and O. basilicum have the strongest antioxidant activities. This study indicates that B. rufescens and O. basilicum are good sources of phytochemicals with antioxidant properties, suitable for medicinal use in Chadian communities. Additionally, the antioxidant-rich extracts from these plants hold significant potential for cosmetic development, enhancing skin health and protecting against oxidative-stress-induced damage.

Chemical composition and physiological bioactivities of Stiefia multicaulis (Vahl) Soják Vahl grown in Palestine

Background: Herbal products encompass a wide range of natural substances that show great potential as therapeutic materials. Consequently, there has been a substantial investigation into the therapeutic potential of numerous plant species in recent times. The present study sought to determine the components and assess the antioxidant, antilipase, α-amylase, and α-glycosidase enzyme inhibitory activities of Stiefia multicaulis (Vahl) Soják Vahl hexane, acetone, methanol, and aqueous fractions. Methods: Standard pharmacopeia methods were used to conduct screenings for both quantitative and qualitative phytoconstituents. The lipase, α-amylase, and α-glycosidase enzyme inhibitory activities were assessed using established reference methods. In addition, the antioxidant activity was assessed using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: The screening methods of pharmacopeias revealed that S. multicaulis contains a wide range of secondary metabolites, especially tannins. However, the most potent antioxidant, antilipase, α-glucosidase, and α-amylase inhibitory activities were acetone fraction, hexane, methanol, and aqueous S. multicaulis fractions, respectively. Conclusion: The current study outcomes are the first on the α-amylase, lipase, α-glucosidase inhibitory activities of S. multicaulis four solvent fractions. Further investigations are needed to assess the in vivo potential of these plant fractions in animal models.

Bioassay-guided isolation and structure elucidation of anti-mycobacterium tuberculosis compounds from Galatella grimmii (Regel & Schmalh.) Sennikov

BackgroundGalatella is a genus in the family Asteraceae, represented by 35-45 species. Considering the high effectiveness of the ethyl acetate (EtOAc) fraction of G. grimmii against Mycobacterium tuberculosis (MIC = 0.5 µg/mL), a bioassay-directed fractionation of this extract was carried out.MethodsThe methanolic extract of the aerial parts of G. grimmii was obtained using maceration, then it was suspended in water and partitioned with petroleum ether, dichloromethane (CH2Cl2), EtOAc, and n-butanol (n-BuOH), successively. The most potent fraction (EtOAc), was selected for further isolation by Sephadex LH–20 and semi-preparative HPLC to obtain active compounds.ResultsFractionation of the EtOAc solvent fraction resulted in the characterization of five compounds, among them, compounds 1 and 2 showed the highest anti-mycobacterial effects with MICs of 0.062 and 1.00 µg/mL against H37Rv M. tuberculosis, respectively, which were higher than those of rifampin (MIC of 1.25 µg/mL) and isoniazid (MIC of 0.31 µg/mL), as positive controls. Also, compound 1 ​​inhibited all tested strains of drug-resistant Mycobacterium (MDR and XDR). Notably, the isolated compounds have been reported for the first time from G. grimmii.ConclusionDue to the potent anti-mycobacterial effect of isolated compounds from G. grimmii, this study could pave the way for developing a novel class of natural anti-tuberculosis compounds.

Antiplasmodial activities of n-hexane and water fractions of Dennettia tripetala leaf extract in Wistar rats

Many people die from malaria, a global health crisis. Most global malaria cases and deaths occur in sub-Saharan Africa. The rising resistance of Plasmodium spp. to antimalarial medications is hindering efforts to eradicate the illness. This study tested Dennettia tripetala leaf extract, N-hexane, and water fractions for antimalarial activity in rats. We used standard methods to screen Dennettia tripetala solvent (N-hexane and water) for phytochemical components. We tested the antimalarial potential of rats using Peters' 4-day suppressive, Rane's curative, and prophylactic tests. After conducting an exhaustive investigation, it was discovered that both fractions contained varying amounts of flavonoids, alkaloids, terpenoids, and saponins. There was a significant amount of antimalarial activity demonstrated by both fractions across all test models (P&lt;0.05). Compared to the water fraction, Dennettia tripetala's n-hexane fraction was highly chemosuppressive and curative. Dennettia tripetala n-hexane has chemoprophylactic, curative, and chemosuppressive effects. The curative effect was 62.3% to 72.4%, and the chemosuppressive effect was 51.2% to 88.5%. Chemoprophylactic activity was 32.1%–61.2%. At 250–1500 mg/kg, Combretum nigricans butanol suppressed 40.3%, 54.1%, and 69.1%, respectively. Therapeutic effects were 26.2%, 36.9%, and 34.5%, while chemoprophylaxis was 48.4%, 70.0%, and 87.4%. Both Dennettia tripetala solvent fractions have antimalarial activity, suggesting they may be effective in different malaria therapy stages.

In vitro and in vivo pharmacological evaluation of polygonum persicaria l.

The present study was designed to investigate the in vitro antioxidant, cytotoxic, anthelmintic and in vivo analgesic, anti-diarrheal, hypoglycemic and CNS anti-depressant properties of different solvent fractions of methanol extract of leaf and flower of Polygonum persicaria L., a notable medicinal plant in Bangladesh. The crude methanol extracts were partitioned separately to petroleum-ether, carbon tetrachloride, chloroform and aqueous fractions. In DPPH scavenging assay for antioxidant test, the aqueous fraction of flower extract showed maximum antioxidant activity with IC50 of 0.60 μg/ml. Most of the fractions revealed prominent lethality (LC50) against brine shrimp nauplii. The test samples also exhibited dose-dependent anthelmintic activity against Pheretima posthuma. The leaf extract and flower extract (200-and 400 mg/kg b.w.) can decrease the painful sensation in mice. Leaf extracts and flower extracts displayed 57.69 and 50% reduction of diarrhea induced by castor oil in mice, respectively. The plant samples exhibited hypoglycemic effect and CNS anti-depressant effect in mice. Based on the possibility of bioactivity, the plant can be thoroughly examined to determine its potential efficacy and to support its traditional uses. Bangladesh J. Bot. 53(3): 475-485, 2024 (September)