Ethyl Acetate Research Articles

Bioactive phenolic contents of Scorzonera ketzkhowelii Sosn. ex Grossh. (Asteraceae) with comprehensive in vitro and in silico studies

This study explores the antioxidant, anti-inflammatory, and anticholinesterase properties of extracts from the natural plant Scorzonera ketzkhowelii for the first time. Additionally, it focuses on isolating phenolic compounds from the ethyl acetate sub-extract, elucidating their structures, and investigating their in-silico bioactivities. Twelve phenolic compounds were isolated and characterized from the ethyl acetate sub-extracts, including hydrangenol (1), 4-hydroxybenzaldehyde (2), luteolin (3), esculin (4), 3-O-caffeoylquinic acid ethyl ester (5), 3-O-caffeoylquinic acid methyl ester (6), kaempferol 3-O-β-glucopyranoside (7), quercetin 3-O-α-arabinopyranoside (8), 3,5-di-O-caffeoylquinic acid ethyl ester (9), thunberginol F 7-O-β-D-glucopyranoside (10), hydrangeic acid 4′-O-β-D-glucopyranoside (11), and 3-O-caffeoylquinic acid (12). The ethyl acetate sub-extracts from both aerial and subaerial parts demonstrated exceptional radical scavenging activity. Moreover, all fractions exhibited potent inhibition against COX-I and COX-II enzymes, with notable inhibitory effects observed in the ethyl acetate and dichloromethane sub-extracts against AChE. Additionally, the inhibitory effects of these compounds were assessed against various biological targets, including TNFα, COX-I, COX-II, human CYP450, and hAChE, through molecular docking studies. According to the molecular docking and dynamics studies, compound 9 emerged as particularly noteworthy across all complexes, exhibiting stable binding modes and promising interactions with key residues involved in inhibition.

Biochemical and microbial characterization of a forest litter-based bio-fertilizer produced in batch culture by fermentation under different initial oxygen concentrations.

This work focused on the physico-chemical, biochemical and microbiological characterization of a new organic fertilizer based on fermented forest litter (FFL) mixed with agro-industrial by-products, on the culture realized in airtight glass bottle. Under strict anaerobiosis (0% initial oxygen concentration (IOC)), after a 16-day batch culture, the bottle-headspace analysis showed that the specific CO2 production rate was low (0.014 mL/h.g dry matter) compared to those reached under aerobic conditions (e.g. 0.464 mL/h.g dm at 21% IOC). Moreover, the culture displayed a slight fermented fruity odour, mainly due to ethanol and ethyl acetate detected in the headspace (335 µL and 58.6 µL accumulated, respectively). The FFL organic matter degradation followed by infrared spectroscopy and catabolic potential and diversity characterized by BIOLOG® EcoPlates were poor and pH dropped to 4.54. The microbiome's metabolism was oriented toward lactic fermentation with medium acidification, enrichment in lactic acid bacteria (LAB), depletion in fungi and absence of pathogens. By increasing IOC from 0 to 21%, the respirometric activity, and the catabolic potential and diversity increased. However, some enterobacteria were detected above 5% IOC. Ethanol and ethyl acetate decreased strongly with IOC, and aromatics and proteins contained in the solid matrix remained in the culture. This study showed the importance of oxygen on the final product. A 2% IOC was found to ensure an optimal balance between LAB development, preservation of functional catabolic diversity and bio-product free of microbial pathogens.

Development of a targeted LC-MS/MS method for the analysis of zero tolerance antimicrobials in buffalo meat

A simple, affordable, and efficient multiresidue analytical method was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to accurately identify and quantify a prioritized zero-tolerance antimicrobial residues in buffalo meat. Analyzing zero-tolerance antimicrobials such as chloramphenicol, metronidazole, and nitrofurans involves detecting even trace levels of residues in food products to safeguard consumer safety and public health. A modified QuEChERS method with 2-nitrobenzaldehyde derivatization using ethyl acetate was employed for the extraction of the antimicrobial compounds, followed by a suitable clean-up. Liquid chromatographic conditions were optimized on a reverse phase C18 analytical column over a runtime of 12 min, and the eluted analytes were observed in selected reaction monitoring mode (SRM). The method's performance was validated in accordance with Regulation (EU) 2019/1871 and Commission Implementing Regulation (EU) 2021/810 guidelines. The linearity of the calibration curves was > 0.99, and the mean recoveries of the analytes ranged from 81.92 % to 110 %. The intra-day and inter-day precisions were less than 9 %. The limits of detection (LOD) and limits of quantification (LOQ) were in the range of 0.04–0.11 µg/kg and 0.13–0.37 µg/kg, respectively. This is well below the MRLs set by the European Commission for zero-tolerance substances.

Development of a Photothermal Regenerative Plasmonic Platform as a Light-Controlled Interface.

This study introduces a novel plasmonic nanocomposite platform, where gold nanoparticles (AuNPs) are synthesized in situ within a polydimethylsiloxane (PDMS) film. The innovative fabrication process leverages ethyl acetate swelling to achieve a uniform distribution of AuNPs, eliminating the need for additional reagents. The resulting nanocomposite film exhibits exceptional photothermal conversion capabilities, efficiently converting absorbed light into heat and rapidly reaching high temperatures. Furthermore, the platform is biofunctionalized with the phosphotriesterase enzyme, not only enabling the degradation of organophosphate pesticides but also showcasing the potential for multifunctional applications. The platform's ability to be regenerated after use underscores its sustainability for repeated applications.

Prooxidant and anti-inflammatory potential of Garcinia xanthochymus fruit and its phytochemical characterisation by UHPLC-Q-Orbitrap HRMS

Pro-oxidants play a crucial role in cancer by causing oxidative stress that leads to apoptosis. The present study demonstrates the prooxidant and anti-inflammatory potential of ethyl acetate and methanolic extracts of Garcinia xanthochymus fruit. Oxidation of Trolox and NADH activity indicated the pro-oxidant capacity of the extracts. Significant decrease in cell viability in B16F10 and MDA-MB-231 cancer cell lines and significant increase in caspase 3 activity after treatment with extracts indicated pro-oxidant induced apoptosis. Pre-treatment with the extracts significantly inhibited ROS, reduced NO production, inhibited LPS-induced COX-2 and suppressed IL-6 and TNF-α expression. HRMS analysis showed the presence of compounds like biflavonoids, xanthones, phloroglucinols, benzophenones, etc. The fruit is rich in total phenolic and flavonoid contents, and have DPPH radical scavenging, ferric reducing antioxidant and metal chelating potential. This study report for the first time about the anticancer and anti-inflammatory properties of G. xanthochymus whole fruit.

GC-MS/HPLC Profiling and Sono-maceration Mediated Extraction of Osbeckia parvifolia Polyphenols: In Silico and In Vitro Analysis on Anti-Proliferative activity in Ovarian Cancer Cell Lines.

Osbeckia parvifolia, an endemic edible plant of Western Ghats, was investigated in the present study for its polyphenolic compounds, including content, constituents, extraction through an ultrasonic-assisted maceration technique and therapeutic potential in biomedical applications. The methanolic extract (OPM) exhibited an IC50 value of 1.25 µg/mL against 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals. Furthermore, the ethyl acetate and methanolic extracts also strongly inhibited 5-lipoxygenase, especially OPM (84.93%), which was comparable to standard curcumin. OPM also elicited cytotoxicity in SKOV3 ovarian cancer cells (93.80%), surpassing paclitaxel. Bio-accessibility analysis demonstrated that the release of phenolic compounds and antioxidant potential were very high (above 100%), revealing the possibility of synergistic efficacy of polyphenolic complexes in drug development. Gas Chromatography -Mass Spectrometry (GC-MS) analysis revealed 22 bioactive polyphenolic compounds in OPM, such as epicatechin, quercetin, and psoralidin. This was confirmed by High Performance Liquid Chromatography (HPLC) and High-Pressure Thin Layer Chromatography (HPTLC) analyses, which revealed a high quantity of catechin (37.45 mg/g). Molecular docking revealed the significant binding affinity of these proteins for the ovarian oncoproteins PI3K (-8.52 kcal/mol) and Casp-8 (-8.41 kcal/mol). Adsorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) profiling indicated the favorable pharmacokinetic properties of these compounds, supporting their candidacy in drug formulations against ovarian cancer.

Tailoring efficient manganese bromide-based scintillator films with ethyl acetate assistance

Metal halide scintillators serve as a compelling substitute for traditional scintillators in X-ray detection and imaging due to their low-temperature fabrication process, high light yield and mechanical flexibility. Nevertheless, the spatial resolution and photoluminescence quantum yield (PLQY) of these films are hindered by the agglomeration and uneven distribution of metal halides crystal particles during the fabrication process. We introduce a modified fabrication approach for metal halide scintillator films involving an additional step of ethyl acetate (EA) treatment, resulting in the preparation of a smooth EA-treated (Ph4P)2MnBr4/Polydimethylsiloxane film. The carbonyl groups within EA interact with elements of the (Ph4P)2MnBr4 microcrystals powder, ensuring uniform dispersion and preventing agglomeration. The EA-treated composite film demonstrates a remarkable PLQY of approximately 95% and an impressive spatial resolution of 14 lp/mm, with enhanced stability under harsh environments. These characteristics ensure its suitability as a high-performance X-ray imaging scintillator.&#xD.

LC-MS/MS Profiling, Biological Activities and Molecular Docking Studiesof Simmondsia Chinensis Leaves.

This study aimed to assess the biological activities of Tunisian Simmondsia chinensis and characterize their potential bioactive compounds. Different extracts of S. chinensis were tested for their antioxidant, antibacterial, anti α-amylase, and anti-acetylcholinesterase activities through in vitro assays. The methanolic extract exhibited the highest levels of antioxidant activity and total phenolic content (976.03 GAE/g extract) compared to the other extracts. Additionally, it demonstrated a substantial anti-acetylcholinesterase activity (PI= 75%) and potent antibacterial property, particularly against Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, and Salmonella enterica. The IC50 values of ethyl acetate and methanolic extracts against α-amylase were 42 μg/mL and 40 μg/mL, respectively, indicating potent anti-diabetic effects. HPLC-ESI-MS/MS analyses identified flavonoids and lignans as the major phenolic compounds in the methanolic extract. To better comprehend the mechanisms behind inhibitory effects on α-amylase and acetylcholinesterase enzymes, a molecular docking study was conducted. Consequently, these findings indicate that S. chinensis is a highly valuable natural resource with potential industrial applications.

From parasitic life to health-promoting applications - A versatile goldmine discovered in nature's secret treasure chest: Orobanche nana

Studies evaluating the phytoconstituents and therapeutic potential of species belonging to Orobanche (Family Orobanchaceae) are rather limited. The present study was designed to evaluate the chemical composition, antioxidant, enzyme inhibition and cytotoxic properties of the aerial parts of Orobanche nana Noë ex Rchb. Extracts were prepared by sequential maceration in dichloromethane, ethyl acetate and ethanol and finally an aqueous extraction by infusion were performed. NMR and LC-DAD-MS analysis allowed the identification of different phytoconstituents including the characteristic compounds of Orobanche like verbascoside, poliumoside, orobanone and orobanchoside. The ethanol extract displayed the highest total phenolic (115.63 mg GAE/g) and flavonoids (16.53 mg RE/g) contents, antiradical (DPPH = 623.70 mg TE/g; ATBS = 843.50 mg TE/g) and ions reducing (Cu++ = 725.39; Fe+++ = 617.70) properties while the aqueous extract exerted the best chelating power (19.54 mg EDTAE/g). It was determined that EtOH and Water extracts applied to HepG2 cells decreased the levels of anti-apoptotic proteins p-NFκB, BCL-2 and BCL-XL, while increasing the levels of apoptotic proteins BAX and p-53, thus inhibiting cell survival. In addition, Orobanche nana played an active role in the rearrangement of overexpress MMPs that cause disruption of ECM homeostasis. We employed Network Pharmacology to investigate the mechanisms through which Orobanche nana's compounds impact Kidney and Liver diseases. These findings suggested that O. nana could be a promising source of bioactive molecules with potential therapeutic applications.

Dual Functionality of Papaya Leaf Extracts: Anti-Coronavirus Activity and Anti-Inflammation Mechanism.

Papaya leaves have been used as food and traditional herbs for the treatment of cancer, diabetes, asthma, and virus infections, but the active principle has not been understood. We hypothesized that the anti-inflammatory activity could be the predominant underlying principle. To test this, we extracted papaya leaf juice with different organic solvents and found that the ethyl acetate (EA) fraction showed the most outstanding anti-inflammatory activity by suppressing the production of nitric oxide (NO, IC50 = 24.94 ± 2.4 μg/mL) and the expression of pro-inflammatory enzymes, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2), and cytokines including interleukins (IL-1β and IL-6), and a tumor necrosis factor (TNF-α) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Transcriptomic analysis and Western blot results revealed its anti-inflammatory mechanisms were through the MAPK signaling pathway by inhibiting the phosphorylation of ERK1/2, JNKs, and p38 and the prevention of the cell surface expression of TLR4. Furthermore, we discovered that the EA fraction could inhibit the replication of alpha-coronavirus (HCoV-229E) and beta-coronavirus (HCoV-OC43 and SARS-CoV-2) and might be able to prevent cytokine storms caused by the coronavirus infection. From HPLC-QTOF-MS data, we found that the predominant phytochemicals that existed in the EA fraction were quercetin and kaempferol glycosides and carpaine. Counter-intuitively, further fractionation resulted in a loss of activity, suggesting that the synergistic effect of different components in the EA fraction contribute to the overall potent activity. Taken together, our results provide preliminary evidence for papaya leaf as a potential anti-inflammatory and anti-coronavirus agent, warranting further study for its use for human health promotion.

Endophytic Penicillium oxalicum AUMC 14898 from Opuntia ficus-indica: A Novel Source of Tannic Acid Inhibiting Virulence and Quorum Sensing of Extensively Drug-Resistant Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a harmful pathogen that causes a variety of acute and chronic infections through quorum sensing (QS) mechanisms. The increasing resistance of this bacterium to numerous antibiotics has created a demand for new medications that specifically target QS. Endophytes can be the source of compounds with antibacterial properties. This research is the first to examine tannic acid (TA) produced by endophytic fungus as a potential biotherapeutic agent. A novel endophytic fungal isolate identified as Penicillium oxalicum was derived from the cladodes of Opuntia ficus-indica (L.). The species identification for this isolate was confirmed through sequencing of the internal transcribed spacer region. The metabolites from the culture of this isolate were extracted using ethyl acetate, then separated and characterized using chromatographic methods. This led to the acquisition of TA, a compound that shows strong anti-QS and excellent antibacterial effects against extensively drug-resistant P. aeruginosa strains. Furthermore, it was shown that treating P. aeruginosa with the obtained TA reduced the secretion of virulence factors controlled by QS in a dose-dependent manner, indicating that TA inhibited the QS characteristics of P. aeruginosa. Simultaneously, TA significantly inhibited the expression of genes associated with QS, including rhlR/I, lasR/I, and pqsR. In addition, in silico virtual molecular docking showed that TA could efficiently bind to QS receptor proteins. Our results showed that P. oxalicum could be a new source of TA for the treatment of infections caused by extensively drug-resistant P. aeruginosa.

Cleistocalyx nervosum var. paniala mitigates oxidative stress and inflammation induced by PM10 soluble extract in trophoblast cells via miR-146a-5p

Air pollution poses a significant global concern, notably impacting pregnancy outcomes through mechanisms such as DNA damage, oxidative stress, inflammation, and altered miRNA expression, all of which can adversely affect trophoblast functions. Cleistocalyx nervosum var. paniala, known for its abundance of anthocyanins with diverse biological activities including anti-mutagenic, antioxidant, and anti-inflammatory properties, is the focus of this study examining its effect on Particulate Matter 10 (PM10) soluble extract-induced trophoblast cell dysfunction via miRNA expression. The study involved the extraction of C. nervosum fruit using 70% ethanol, followed by fractionation with hexane, dichloromethane, and ethyl acetate. Subsequent testing for total phenolics, flavonoids, anthocyanins, and antioxidant activity revealed the ethyl acetate fraction (CN-EtOAcF) as possessing the highest phenolic and anthocyanin content along with potent antioxidant activity, prompting its selection for further investigation. In vitro studies on HTR-8/SVneo cells demonstrated that 5–10 µg/mL PM10 soluble extract exposure inhibited cell proliferation, migration, invasion, and induced apoptosis. However, pretreatment with 20–80 µg/mL CN-EtOAcF followed by 5 µg/mL PM10 soluble extract exposure exhibited protective effects against PM10 soluble extract-induced damage, including inflammation inhibition and intracellular ROS suppression. Notably, CN-EtOAcF down-regulated PM10-induced miR-146a-5p expression, with SOX5 identified as a potential target. Overall, CN-EtOAcF demonstrated the potential to protect against PM10-induced harm in trophoblast cells, suggesting its possible application in future therapeutic approaches.

2,4-Di-Tert-Butylphenol of Streptomyces luridiscabiei MMS-10 Inhibits Biofilm Forming Cariogenic Streptococcus mutans ULSP-2.

Dental caries is a common chronic infectious disease of the oral cavity that affects the overall oral health of the individual. Cariogenic bacteria have long been recognized for their role in developing chronic dental infections. Drug-resistant bacteria represent a global challenge to effective pathogen control in caries. The present study aimed to isolate and identify soil actinomycetes for their antibacterial and anti-biofilm activities against antibiotic-resistant and biofilm-forming cariogenic bacteria. Thirteen caries bacteria isolated from infected tooth samples were evaluated for antibiotic resistance and biofilm formation. The isolate ULSP-2 showed the highest antibiotic resistance score (0.714) and was found to be a strong biofilm producer when tested by congo red agar and microtiter plate assays. The bacterium was identified as Streptococcus mutans based on morphological, biochemical, and molecular characterization. The effect of ethyl acetate extracts from 20 soil actinomycetes on the growth and biofilm formation ability of S. mutans was evaluated. The MMS-10 extract strongly inhibited growth (18.5 ± 0.5mm) and biofilm formation (56.46 ± 0.32%) of S. mutans at 100µg/mL. The isolate MMS-10 was identified at the molecular level as Streptomyces luridiscabiei. Based on FTIR, NMR, and GC-MS analysis, the purified MMS-10 extract was characterized and identified as 2,4-Di-tert-butylphenol. The metabolite's physiological, physicochemical, and pharmacokinetic properties were analyzed using the Swiss ADME web server and found to satisfy the criteria of drug-likenessof a molecule. The study revealed the significance of soil actinomycetes in controlling growth and biofilm formation in cariogenic S. mutans.

Separation and purification of ethyl acetate from its reaction mass: proposal for downstream distillation sequence and validation

ABSTRACT This work has performed simulation and experimentation of separating the reaction mixture of the ethyl acetate manufacture by Fischer esterification. Assuming stoichiometric proportion of reactants, mixture with equilibrium composition was subjected to separation. Simulation in the Aspen plus environment using RadFrac module with EQ model was performed. To obtain a range of parameters and variables, sensitivity analysis was performed. Economic analysis was also performed. Experimentation was done to verify the results of simulation using distillation and extractive distillation to obtain the streams with highest purity and unreacted reactants were separated into pure form. A complete flowsheet for separation and purification is suggested.

Phytochemical and antimicrobial evaluation of Miconia burchellii Triana (Melastomataceae).

Four novel triterpenoid saponins, 1α,3β,23-trihydroxy-olean-12-en-28-oic acid 28-O-β-glycopyranoside ester (1), 1α,3β,23-trihydroxy-urs-12-en-28-oic acid 28-O-β-glycopyranoside ester (2), 3-O-β-galloyl-1α,23-dihydroxy-olean-12-en-28-oic acid 28-O-β-glycopyranoside ester (3) and 3-O-β-galloyl-1α,23-dihydroxy-urs-12-en-28-oic acid 28-O-β-glycopyranoside ester (4) and two new pentacyclic triterpenoids, 3-O-β-trans-p-coumaroyl-1α-hydroxy-urs-12-en-28-oic acid (5) and 3-O-β-cis-p-coumaroyl-1α-hydroxy-urs-12-en-28-oic acid (6), together with six known compounds were isolated from the ethanolic extracts of Miconia burchellii leaves and stem bark. Their structures were established by HR-MS, 1D and 2D NMR and comparison with literature data. Additionally, the antimicrobial activity of the leaves and stem bark extracts and fractions was evaluated using the micro broth dilution technique. The crude extract, the ethyl acetate and methanol fractions of the stem bark were the most active against the tested bacteria, showing growth inhibition of both Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa). To the best of our knowledge, this is the first study to report on the antimicrobial activity of M. burchellii.

Investigating the Inhibitory Effect of Sargassum natans and Sargassum fluitans Extracts on Iron Corrosion in 1.00 mol L−1 HCl Solution

This study deals with the efficacy of extracts of Sargassum natans and Sargassum fluitans, an invasive brown algae present in Guadeloupe, as novel and environmentally friendly corrosion inhibitors for iron in 1 mol L−1 hydrochloric acid solutions. Six different Sargassum extracts (SE) were obtained using Soxhlet extraction with ethyl acetate, acetone, and ethanol, respectively, as solvents; cold successive maceration with chloroform and methanol, respectively; and microwave-assisted extraction with water. Subsequent electrochemical analysis showed that extracts from ethanol and ethyl acetate exhibited remarkable inhibition efficiencies of, respectively, 72.6% and 70.2%, but the better one was the extract of the cold maceration from chloroform with an inhibition efficiency of 92.0%. These findings allow us to focus on the chloroform extract (SEd) in order to see the change happening during the corrosion process via SEM and EDX analyses. Also, NMR analysis was conducted to identify the main chemicals responsible for the anticorrosion effect. The successful demonstration of the corrosion inhibitor effectiveness of extracts of Sargassum natans and fluitans suggests a potentially valuable use for this invasive biomass. These encouraging results warrant further investigation to identify and elucidate the active inhibitors in these extracts to deepen our understanding of their mechanisms for corrosion prevention and potentially expand their utility as an environmentally conscious approach to corrosion control.

A New Megastigmane Nor-sesquiterpene Isolated from Pourouma Guianensis by High-Performance Countercurrent Chromatography

Introduction: Pourouma guianensis (Urticaceae) is widespread throughout Brazil and is commonly known as “mapati”. Terpenes are common in Urticaceae species. However, few studies have reported the isolation and characterisation of these compounds in Pourouma genus. Method: The aim of this study was to separate substances from stem barks of P. guianensis using a high-performance countercurrent chromatography gradient elution method. The dichloromethane extract of the P. guianensis stem bark was submitted to silica gel column chromatography, yielding three fractions. Fraction 3 was submitted to a gradient elution system in high-performance countercurrent chromatography using two solvent systems, hexane/ethyl acetate/methanol/water (1:2:x:1, x=1.0 and 1.5). Six compounds were isolated. Results: A new megastigmane nor-sesquiterpene named 2-acetyl-4,7-epoxy-3-oxy-5,5,9- trimethylhexahydrocoumaran (1) was obtained together with five known terpenes: vomifoliol (2), 2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid (3), 3-β-D-arabinopyranoside-19-hydroxyurs-12-en- 28-oic acid (4), arjunolic acid (5), and tormentic acid (6). Fractions 1 and 2 were purified by binary gradient elution from hexane to ethyl acetate. Conclusion: This process isolated three known compounds: friedelin (7) and 3β-friedelanol (8) from fraction 1, and β-sitosterol (9) from fraction 2. Gradient elution in countercurrent chromatography was a suitable alternative, exploiting variations in the partition coefficient between substances with small structural differences.

Antifungal Potential of Struchium sparganophora (Antsbush): A Promising Candidate for Treating Candidiasis and Cryptococcosis

Aims: The incidence of Candidiasis and Cryptococcosis, and the emergence of acquired antifungal resistance have increased rapidly. This study aimed to evaluate the effectiveness of S. sparganophora leaf extracts against C. albicans and C. neoformans; and to determine whether there was any difference between the antifungal effects of S. sparganophora leaf extracts and two conventional antifungal agents (AFAs). Study Design: Experiment-based study. Place and Duration of Study: S. sparganophora leaves was obtained from a site in Kimbia, Berbice River, Guyana; identified by the Biodiversity Centre and tested at the Main Laboratory at the College of Medical Sciences, University of Guyana during January- August 2023. Methodology: Dried pulverised leaves were macerated using different solvents and concentrated using a rotary evaporator. Sterile filter paper discs were soaked in different concentrations of the various extracts. Antifungal discs were placed on Sabouraud’s Dextrose Agar plates seeded with fungi. All plates were incubated and zones of inhibitions (ZOIs) were measured and expressed as mean ± SD. Results: S. sparganophora leaf extracts showed large ZOI especially at the 100 mg/ml concentrations against all organisms tested. The largest ZOI was seen for the hexane extract against C. neoformans (35.5±5 mm) and C. Albicans In-House B (18.5±3.5 mm) at 100 mg/ml concentrations. No ZOI was observed against the AFA fluconazole by C. albicans In-House B, while large ZOI were observed with the hexane and ethyl acetate extracts at 100 mg/ml concentrations. Statistical analysis showed correlation between the ZOI and concentrations, ZOI and solvent extract, and ZOI and type of fungi. Conclusion: In conclusion, S. sparganophora leaf extracts have great antifungal activity and in some cases showed greater activity when compared to conventional AFAs.

Enhanced Biological Potential and Phytochemical Profiling of Phoenix Dactylifera Leaves (Deglet Nour and Alig) by Kombucha Fermentation: Focus on Polyphenols, Antioxidant, Antidiabetic, and Cytotoxic Activities.

The date palm, scientifically known as Phoenix dactylifera, is an important cultural and economic source of wealth in southern Tunisia. It produces considerable agricultural waste, including palm leaves, the disposal of which is often a challenge. Our study addresses the sustainable conversion of date palm leaves into a valuable product through kombucha fermentation, focusing on two widely used varieties in Tunisia: Deglet Nour and Alig. HPLC-RI analysis showed a significant difference in the fermentation process between the treated samples, which is reflected in the highest sugar consumption and metabolite production in Alig palm. Unfermented and fermented date palm leaves were sequentially extracted with solvents of increasing polarity to evaluate their chemical composition and bioactivity. The results showed that kombucha fermentation significantly increased the total phenolic content, with the highest amounts in the ethyl acetate fraction. In terms of antioxidant activity, the ethyl acetate extracts showed a high percentage inhibitory activity (82.76%) against the DPPH radical found in fermented Palm Alig, which also exhibited the most important antidiabetic capacity (resulting in an IC50 value of 20 µg/mL). The chemical analyses resulted in the detection of 19 compounds by HPLC-DAD and 50 volatiles by GC-MS, which are mainly found in kombucha extracts.

Epicatechin Isolated from Litchi chinensis Sonn. (Litchi) Fruit Peel Ethyl Acetate Extract Modulated Glucose Uptake in Chang Cells and Suppressed ROS Production in RAW 264.7 Macrophages.

Bioactive flavonoid epicatechin has been reported in the peel of litchi fruit but isolated from its hydroalcoholic extracts. This study isolated epicatechin with cellular glucose uptake modulatory and ROS production inhibitory properties from the ethyl acetate (EtOAc) extract using a bioassay-guided approach. The fruit peel was defatted with hexane and sequentially extracted using dichloromethane (DCM), EtOAc, methanol (MeOH) and water. In vitro phytochemical models, namely antioxidant (Fe3+ reducing, radical scavenging and anti-linoleic acid peroxidative) and glycaemic control (α-glucosidase and α-amylase inhibitory and glucose uptake modulatory), were employed for the bioassay-guided isolation, while the isolated compound was characterised using NMR and mass spectrometry and assessed for dose-dependent inhibition of α-glucosidase and lipopolysaccharide (LPS)-induced cellular ROS production, as well as modulation of cellular glucose uptake. Relative to the other extracts, the EtOAc extract had appreciable phenol and flavonoid contents, which perhaps influenced its potent anti-lipid peroxidative (65.0%) and α-glucosidase inhibitory (52.4%) effects. The α-glucosidase inhibitory potency of the fractions (1-8) from the EtOAc extracts correlated with their flavonoid contents, with fraction 5 outperforming other fractions. The fraction comprised a pool of fractions obtained from the DCM:MeOH:water (7:3:0.281 v/v/v) solvent system. LC-MS revealed the predominant presence of epicatechin in fraction 5, which was later isolated from one of the sub-fractions (sub-fraction 4) of fraction 5. This sub-fraction had stronger anti-lipid peroxidative (65.5%), α-glucosidase inhibitory (65.8%) and glucose uptake modulatory (38.2%) effects than the other sub-fractions from fraction 5, which could have been influenced by the isolated epicatechin. Moreover, the isolated epicatechin inhibited α-glucosidase (IC50 = 35.3 µM), modulated cellular glucose uptake (EC50 = 78.5 µM) and inhibited LPS-induced ROS production in RAW 264.7 macrophages in a dose-dependent fashion [IC50 = 18.9 µM; statistically comparable (p > 0.05) to ascorbic acid, IC50 = 9.57 µM]. Epicatechin from litchi peel EtOAc extract could potentiate glucose uptake modulatory, α-glucosidase inhibitory and ROS suppressive capacities, which could be influential in the use of litchi fruit peel for managing diabetes and associated oxidative damage.