Methanol Water Research Articles

GCMS-based phytochemical profiling and in vitro pharmacological activities of plant Alangium salviifolium (L.f) Wang

BackgroundThere is an urge for traditional herbal remedies as an alternative to modern medicine in treating several diseases. A significant number of modern pharmaceutical drugs are based on or derived from medicinal plants or their extracts. These drugs derived from the plant origin have various antimicrobial, antioxidant, anticancer, anti-inflammatory activities. Alangium salviifolium belongs to Cornaceae family and is well known for its medicinal properties. The present study was carried out to evaluate the antibacterial, antioxidant effect and possible bioactive components present in the chloroform, acetone, ethanol, methanol and aqueous extract of Alangium salviifolium leaves.MethodologyDried leaves of Alangium salviifolium were subjected to serial solvent extraction using increasing polarity of solvents, i.e., chloroform, acetone, methanol, ethanol, and distilled water. Crude extracts were further tested for qualitative analysis of phytochemicals using standard procedure, while GCMS analysis was performed to identify the probable phytocompounds. Antibacterial activity was performed against bacterial pathogens using agar well method, whereas antioxidant activity was performed using in vitro PM, DPPH and FRAP assays.ResultsPhytochemical analysis of the extracts revealed the presence of key phytochemical classes. Using gas chromatography-mass spectrometry, several high and low molecular weight chemical compound kinds were discovered. These chemical substances are regarded as having significant biological and pharmacological effects. All crude extracts had considerable and comparable in vitro antioxidant and antibacterial properties.ConclusionsAccording to the findings of this study, Alangium salviifolium leaves are a rich source of phytoconstituents that are crucial in stopping the advancement of numerous disorders.

The potential of Sonneratia caseolaris mangrove leaves extract as a bioactive food ingredient using various water extract

Background Sonneratia caseolaris, known as the red pidada, has been widely utilized by the Indonesian. S. caseolaris leaves contain various active compounds, contributing to their popularity in the treatment of various diseases. Mangrove leaves are also known to exhibit very high antioxidant activity. This study aims to assess the antioxidant activity of S . caseolaris leaves extracted using different solvents. The resulting extract was evaluated for antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques. Methods Analysis of total flavonoids, total phenols, identification of active compounds with Liquid Chromatography High Resolution Mass Spectrometry (LC-HRMS), and bioinformatics were also carried out to obtain temporary conclusions about the antioxidant activity of S. caseolaris leaf extract. Results The results indicated that S. caseolaris leaves extracted with methanol and distilled water exhibited the highest antioxidant activity compared to other extracts. The analysis of total flavonoids and total phenols yielded results consistent with the antioxidant activity tests. LC-HRMS results identified three compounds in all S. caseolaris leaf extracts with antioxidant activity, namely Tempo, Choline, and Betaine. Tempo demonstrated a higher antioxidant activity than Choline and Betaine, as indicated by the binding affinity values in the bioinformatics analysis. Conclusions It is evident that S. caseolaris leaf extract has the potential to serve as an effective an antioxidant agent. Further research is needed to elucidate confirm the effectiveness of S. caseolaris leaves as an antioxidant substance, in order to utilize them as active components in food and enhance antioxidant consumption among consumers.

Deciphering the Microdroplet Acceleration Factors of Aza-Michael Addition Reactions.

Microdroplet chemistry is emerging as a great tool for accelerating reactions by several orders of magnitude. Several unique properties such as extreme pHs, interfacial electric fields (IEFs), and partial solvation have been reported to be responsible for the acceleration; however, which factor plays the key role remains elusive. Here, we performed quantum chemical calculations to explore the underlying mechanisms of an aza-Michael addition reaction between methylamine and acrylamide. We showed that the acceleration in methanol microdroplets results from the cumulative effects of several factors. The acidic surface of the microdroplet plays a dominating role, leading to a decrease of ∼9 kcal/mol in the activation barrier. We speculated that the dissociation of both methanol and trace water contributes to the surface acidity. An IEF of 0.1 V/Å can further decrease the barrier by ∼2 kcal/mol. Partial solvation has a negligible effect on lowering the activation barrier in microdroplets but can increase the collision frequency between reactants. With acidity revealed to be the major accelerating factor for methanol droplets, reactions on water microdroplets should have even higher rates because water is more acidic. Both theoretically and experimentally, we confirmed that water microdroplets significantly accelerate the aza-Michael reaction, achieving an acceleration factor that exceeds 107. This work elucidates the multifactorial influences on the microdroplet acceleration mechanism, and with such detailed mechanistic investigations, we anticipate that microdroplet chemistry will be an avenue rich in opportunities in the realm of green synthesis.

Contribution of extractives to the bark color of Caesalpinia sappan

The purpose of this study was to investigate the contribution of Caesalpinia sappan (sappan wood) bark extractives by analyzing color change of the bark after extraction and the color of the extracts with several color measurement methods. Successive extraction was performed with n-hexane, ethyl acetate, methanol, and hot water. Color change of the bark was measured using CIELab color system and the extracts were analyzed with Ultraviolet-Visible Spectrophotometer, total phenolic content (TPC), and Gas Chromatography Mass Spectrometry (GC-MS). The results showed that the highest change on the bark color after methanol extraction with the Δa* and Δb* values of -2,53 ± 0,60 and -3,64 ± 1,20 respectively. Also, methanol extract showed the highest total phenolic content (860,24 ± 30,19 mg GAE/g). In addition, the Ultraviolet-Visible is analysis showed a peak at 478 nm in the hot-water soluble extract and two peaks in the methanol soluble extract at 396 nm and 478 nm. Hydroquinone was detected as one of the major compounds by Gas Chromatography Mass Spectrometry in the methanol soluble extract. It was suggested that the color of Caesalpinia sappan (sappan wood) bark as well as the deep red coloration of its extract might be contributed by multiple phenolic compounds contained in the methanol extract with hydroquinone as its precursor. Therefore, it is also a potential source for coloring matter.

Guardians of Citrus Groves: An In-Depth Analysis of Neem Leaf Extract's Effects on Asian Citrus Psyllid Attractiveness, Diaphorina citri kuwayama, And its Potential for Integrated Pest Management

Background: The pervasive impact of fungal diseases on wheat crops necessitates the exploration of sustainable and safe pest control alternatives. Neem (Azadirachta indica) is renowned for its medicinal properties and is being investigated for its potential as a biopesticide in agriculture. Objective: To evaluate the antifungal efficacy of Azadirachta indica leaf extracts on fungal pathogens in wheat crops, aiming to offer an environmentally benign alternative to chemical fungicides. Methods: Neem leaves were collected, sterilized, dried, and ground to powder. This powder was subjected to solvent extraction using methanol, diethyl ether, chloroform, petroleum ether, and distilled water. The resulting extracts were tested for antifungal activity against Diaphorina citri kuwayama using the agar well diffusion method. Wheat plants treated with the extracts were monitored for fungal disease incidence and yield changes. Results: Methanolic extracts of Azadirachta indica showed a significant zone of inhibition of 34.67 mm against Diaphorina citri kuwayama. Additionally, methanolic extracts displayed a zone of inhibition of 31.6±2.04 mm, while the control showed 31.33±0.58 mm. The MIC values ranged from 35 µg/ml for methanol to 24 µg/ml for distilled water, with the control at 20 µg/ml. Treatment of wheat crops with these extracts resulted in reduced fungal contamination and enhanced yield. Conclusion: The study confirms that Azadirachta indica leaf extracts have substantial antifungal properties, demonstrating potential as a natural and environmentally friendly pest management strategy in wheat production. This approach aligns with sustainable agricultural practices and could have a beneficial impact on human health by reducing harmful chemical residues in food.

Comparative Phytochemical Constituents of Extracts of Bryophyllum pinnatum Grown in Anambra State, Nigeria

Bryophyllum pinnatum is a plant abundant in several phytochemicals, that can be extracted, purified, and packaged for the goal of promoting public health. In this study, the phytochemical composition of the leaf extracts of Bryophyllum pinnatum grown in Anambra State, Nigeria, was compared. B. pinnatum leaves were obtained from a farm in Anambra State, Nigeria. The leaves were processed and extracted using cold water and hot water extraction, methanol extraction, and ethanol extraction. The extraction processes were carried out following standard extraction methods. Preliminary qualitative and quantitative analyses were conducted to determine the presence and concentration of phytochemicals in the plants. Phytochemicals tested include alkaloids, flavonoids, saponins, tannins, anthocyanins, reducing sugars, carbohydrates, proteins, cardiac glycosides, terpenoids, and phlobatannins. All the tested phytochemicals were recovered in the solvent (methanol and ethanol) extracts; carbohydrates, reducing sugar, protein, and anthocyanin were absent in the aqueous (cold and hot water) extracts. Varying concentrations of the phytochemicals in the different extracts were recorded, and they range from 0.00±0.00% to 13.30±0.22%, with the highest concentration of the extracts recovered in the solvent (methanol and ethanol) extracts. This study revealed that the extraction method used can influence the type and concentration of phytochemicals recovered in Bryophyllum pinnatum. Therefore, the specific desired phytochemical should determine the extract method to use in any study. Int. J. Appl. Sci. Biotechnol. Vol 12(1): 1-7.

The activity of leaf extracts, fractions, and isolated compounds from Ptaeroxylon obliquum against nine phytopathogenic fungi and the nematode Meloidogyne incognita

Phytopathogenic fungi and nematodes cause great losses in economically important crops and food production especially in developing countries. To minimize the use of fungicides and nematicides, researchers have concentrated on the use of natural products for crop disease prevention or control. The aim of the study was to investigate the antifungal activity of Ptaeroxylon obliquum leaf extracts, fractions, and isolated compounds (obliquumol and a mixture of lupeol and β-amyrin) and nematocidal activity of fractions (hexane, chloroform and 30% water in methanol and the isolated compounds) on Meloidogyne incognita. Nine phytopathogenic fungi (Aspergillus niger, A. parasiticus, Colletotrichum gloeosporioides, Fusarium oxysporum, Penicillium digitatum, P. expansum, P. italicum, P. janthinellum, and Rhizoctonia solani) were used for testing and nematocidal activity was determined on motility of plant parasitic nematode Meloidogyne incognita race 2 juveniles. Serial microdilution test was utilized to determine the minimum inhibitory concentration (MIC) of each sample against the fungus. Motility tests was done on the second-stage juveniles (J2s) of M. incognita. The most susceptible phytopathogenic fungal species to the acetone crude leaf extracts were A. niger, C. gloeosporioides and P. digitatum with MIC of 80 μg/ml which is considered pharmacological significant. Rhizoctonia solani was the most susceptible fungus against obliquumol and, lupeol and β-amyrin mixture with MIC values of 8 μg/ml and 16 μg/ml respectively. Lupeol & β-amyrin mixture had good activity on juvenile motility at high concentrations used which was significantly high (p ≤ 0.05) after 24 h, further incubation resulted in temporary paralysis at lower concentrations. Fractions and obliquumol showed good activity after 48 h, stable paralysis was observed up to 72 h. The extracts and isolated compounds may be useful as fungicides if the in vitro results can be confirmed under field conditions at levels not toxic to beneficial soil organisms.

Antibacterial Activity of the Leaf Extract of Acalypha wilkesiana against some Human Bacterial Pathogens

Humanity has long been creating traditional treatments based on the knowledge of medicinal plants found worldwide. The medicinal potential of Acalypha wilkesiana in treating skin and gastrointestinal problems is highly appreciated. This study aimed to examine the Acalypha wilkesiana leaf extract's antibacterial effectiveness against a variety of human bacterial infections. Standard techniques were used to determine whether secondary metabolites were present in methanolic, ethanolic, and hot water extracts. The plant extracts were evaluated for their ability to inhibit the growth of bacteria obtained from Bells University of Technology, including Staphylococcus aureus, Staphylococcus saprophyticus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Agar diffusion was used for antibacterial activities, and Mueller Hinton Agar (MHA) minimum inhibitory concentration (MIC) was determined using the agar dilution method. According to the study's findings, the plant sample included flavonoids, tannin, alkaloids, and saponins. With a MIC of 2.5 mg/mL against Pseudomonas aeruginosa and Enterococcus faecalis and 5.0 mg/mL against Staphylococcus aureus, hot water extract exhibited the highest activity level against all tested isolates. As a result, Acalypha wilkesiana leaf extract exhibited broad-spectrum antibacterial activity.

Tea (Camellia sinensis) cultivated in three agro-ecological regions of Bangladesh: Unveiling the variability of methylxanthine, bioactive phenolic compound, and antioxidant activity

Tea (Camellia sinensis) is a widely consumed beverage known for its numerous health benefits, largely attributed to its rich content of quality determining secondary metabolites such as methylxanthine compounds and bioactive phenolic compounds. The goal of this study was to find out variations of the levels of methylxanthines, bioactive phenolic compounds, and antioxidant activity in methanolic and hot water extracts of 129 tea samples grown in three different ecological regions of Bangladesh named Panchagar, Sylhet, and Chattogram. Methylxanthine and bioactive phenolic compounds were determined by using HPLC-DAD, and the antioxidant profile was analysed by UV–vis spectrophotometric methods for methanol and hot water extracts of tea leaves. The IC50 values showed the trend as Panchagar > Sylhet > Chattogram and Sylhet > Chattogram > Panchagar for water and methanol extract, respectively. The results revealed significant (p < 0.05) variations in the levels of methylxanthines content: Panchagar > Chattogram > Sylhet. Caffeine was significantly higher (103.02 ± 5.55 mg/g of dry extract) in the methanolic extract of tea leaves of Panchagar district and lower (53.33 ± 4.30 mg/g of dry extract) in the hot water extract of Sylhet district. Panchagar and Chattogram possessed significantly (p < 0.05) higher catechin content for methanol (57.01 ± 5.50 mg/g dry extract) and hot water (55.23 ± 4.11 mg/g dry extract) extracts, respectively. The utilization of canonical discriminant functions yielded highly favorable outcomes in the classification of tea from three distinct cultivation origins in Bangladesh, relying on their inherent features. This study demonstrated the potential effects of geographical variations on the bioactive compounds and antioxidant properties of tea, emphasizing the importance of regional differences in tea cultivation for optimizing its health benefits as well as dispersing tea cultivation across the country.

Comparative description of the extraordinary phenomenon "thermally activated isobaric partial structure compaction" of water as a solute in some alkanols and alkylamines

This review summarises the data available in the literature. It also includes the authors' published results of precision densimetric measurements. The research concerns with the physically unusual phenomenon of "thermally activated isobaric partial densification of the structure" (TIPCS) of dissolved water, or its so-called "negative partial molar expandability" (NPEA) in several organic solvents. They contain amphiproton hydroxyl-containing media of three alcohols: methyl alcohol (MA), tertiary butyl alcohol (TBAlcohol), and amyl or pentyl alcohol (TPA), so asprotophilic media of two amines: tert butylamine (TBAmine) and ethylenediamine (EDA). The discussed TIPCS phenomenon, associated with a decrease in the standard (partial at infinite dilution) volume of solvated water with increasing temperature, was discovered about half a century ago in alkanol solutions of H2O and recently - in water-containing media of alkylamines. However, nowadays this extraordinary effect has not yet found its physically based interpretation. It allows ones to predict the possibility of TIPCS occurrence in the binary liquid-phase system specifically selected for the study. Our comprehensive data analysis allowed us to make several inferences regarding the main characteristics of a standard solution of H2O in an organic solvent. They cause extraordinary changes in the volume of the formed solvatocomplex of water under the influence of increasing temperature. Firstly, the energy parameters of the intermolecular interaction (relative affinity) water solvent noticeably dominate over those of the solvent-solvent interaction. Those differences become more evident with increasing temperature. Secondly, a higher rate of thermal expansion of the organic solvent structure in volume (inbulk) is found than influence of temperature on structural packing of the resulting mixed molecular aggregate or water solvates complex. Thirdly, the difference in the parameters of water-solvent and solvent-solvent interactions depends not only on the proton-donor/acceptor properties of the molecules contacting in solution, but also on the configuration of the structural packing of the solvating medium. It determines the nature of steric hindrances to the formation of H-bonds. Therefore, the absolute values of the mentioned parameters of relative affinity at 298.15 K increase in the series: MA &lt;&lt; EDA ≈ TBAmine &lt; TPAlcohol &lt; TBAmine. It can indicate a relative strengthening of the specific interaction (mainly through the formation of hydrogen bonds) between the molecules of water and amphiprotonic or protophilic solvent in the above sequence. Indeed, difference in the solvent-solvent and water-solvent hydrogen bonding energies in the discussed liquid media of alkylamines (TBAmine and EDA) and tertiary isomeric alkanols (TBAlcohol and TPA) - with the most evident basicity - turned out to be noticeably larger than in the structural packing of water methanol solution. The ability of the components to specific interactions is quite comparable in those compounds.

Сравнительная характеристика неординарного явления «термоактивируемого изобарического парциального уплотнения структуры» воды как растворенного вещества в некоторых алканолах и алкиламинах

This review summarises the data available in the literature. It also includes the authors' published results of precision densimetric measurements. The research concerns with the physically unusual phenomenon of "thermally activated isobaric partial densification of the structure" (TIPCS) of dissolved water, or its so-called "negative partial molar expandability" (NPEA) in several organic solvents. They contain amphiproton hydroxyl-containing media of three alcohols: methyl alcohol (MA), tertiary butyl alcohol (TBAlcohol), and amyl or pentyl alcohol (TPA), so asprotophilic media of two amines: tert butylamine (TBAmine) and ethylenediamine (EDA). The discussed TIPCS phenomenon, associated with a decrease in the standard (partial at infinite dilution) volume of solvated water with increasing temperature, was discovered about half a century ago in alkanol solutions of H2O and recently - in water-containing media of alkylamines. However, nowadays this extraordinary effect has not yet found its physically based interpretation. It allows ones to predict the possibility of TIPCS occurrence in the binary liquid-phase system specifically selected for the study. Our comprehensive data analysis allowed us to make several inferences regarding the main characteristics of a standard solution of H2O in an organic solvent. They cause extraordinary changes in the volume of the formed solvatocomplex of water under the influence of increasing temperature. Firstly, the energy parameters of the intermolecular interaction (relative affinity) water solvent noticeably dominate over those of the solvent-solvent interaction. Those differences become more evident with increasing temperature. Secondly, a higher rate of thermal expansion of the organic solvent structure in volume (inbulk) is found than influence of temperature on structural packing of the resulting mixed molecular aggregate or water solvates complex. Thirdly, the difference in the parameters of water-solvent and solvent-solvent interactions depends not only on the proton-donor/acceptor properties of the molecules contacting in solution, but also on the configuration of the structural packing of the solvating medium. It determines the nature of steric hindrances to the formation of H-bonds. Therefore, the absolute values of the mentioned parameters of relative affinity at 298.15 K increase in the series: MA &lt;&lt; EDA ≈ TBAmine &lt; TPAlcohol &lt; TBAmine. It can indicate a relative strengthening of the specific interaction (mainly through the formation of hydrogen bonds) between the molecules of water and amphiprotonic or protophilic solvent in the above sequence. Indeed, difference in the solvent-solvent and water-solvent hydrogen bonding energies in the discussed liquid media of alkylamines (TBAmine and EDA) and tertiary isomeric alkanols (TBAlcohol and TPA) - with the most evident basicity - turned out to be noticeably larger than in the structural packing of water methanol solution. The ability of the components to specific interactions is quite comparable in those compounds.

Evaluation of Antiplatelet Aggregation and Anticoagulant Effects of Oxalis Debilis Kunth Rhizome Extracts

Cardiovascular disease is one of the leading causes of death globally. The discovery and use of natural products in the prevention and treatment of cardiovascular diseases have achieved great interest. Oxalis debilis is traditionally used for the treatment of various ailments. This study aimed to investigate the potential antiplatelet and anticoagulant properties of extracts derived from O. debilis rhizome. The rhizome of O. debilis was extracted with methanol and then fractionated to obtain four extracts: the total methanol extract, the n-hexane, ethyl acetate, and water fraction. These four extracts were then tested for their ability to inhibit platelet aggregation and blood coagulation in human blood samples. This report demonstrated for the first time that O. debilis had inhibitory effects on platelet aggregation induced by both adenosine diphosphate and collagen as well as blood coagulation. Moreover, the total methanol extract, the ethyl acetate, and the water fraction had strong antiplatelet aggregation effects. All tested extracts had mild anticoagulant activities. This plant could be a valuable natural source for searching for antithrombotic substances, or for the development of supplementary products for the treatment and prevention of heart diseases and thrombosis.&#x0D;

Control of the Ionomer Contents in the Electrode Catalyst Layer for Enhanced Performance of Methanol–Water Electrolyzers for Hydrogen Production

Control of the Ionomer Contents in the Electrode Catalyst Layer for Enhanced Performance of Methanol–Water Electrolyzers for Hydrogen Production

Determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry

Objective: To establish a method for the determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry. Methods: In November 2022, urine samples were extracted by acidic methanol, purified by WAX solid phase extraction column, and eluted with methanol water, then Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) was used with 1.0 mmol/L ammonium acetate solution and methanol as mobile phase. The gradient elution was carried out, the detection was carried out by electrospray negative ion multiple response monitoring (MRM) mode, and the quantitative method was internal standard method. Results: Perfluorooctanoic acid and perfluorooctane sulfonic acid had a good linear relationship in the concentration range of 0.5-50.0 μg/L, and the correlation coefficient was >0.999. The limit of detection was 0.017 μg/L, and the limit of quantitation was 0.005 μg/L. The average recoveries were 96.3% and 101.8%, respectively. Days of precision were 3.5%-6.2% and 3.1%-7.4%, respectively, daytime precision were 4.3%-6.8% and 4.7%-8.1%, respectively. Conclusion: The established method of liquid chromatography-tandem mass spectrometry is high sensitivity and accuracy, and is suitable for the determination of perfluorooctanoic acid and perfluorooctane sulfonic acid in human urine.

Analysis of drug-impregnated paper samples seized in English prisons between 2018 and 2020

Novel psychoactive substances (NPS) in the form of impregnated papers delivered to prisoners are of particular concern in prison settings, where they are commonly used by vaping. The purpose of this study was to create a qualitative method for identifying the various emerging NPS impregnated onto paper samples sent to prisoners. It helps to demonstrate that these findings can be used to predict drug prevalence and trends in prisons. Between 2018 and 2020, 1250 non-judicial paper samples seized from 12 English prisons were analysed to determine the NPSs being circulated. Approximately 1 cm2 paper were cut and added to 50 % (v/v) methanol in LCMS-grade water. Vortex-mixing was used to prepare extracts (30 min). Q-TOF LC/MS was used to screen the extracts. This study showed that synthetic cannabinoid receptor agonist (SCRA) was the most common drug group detected in impregnated paper seizures in English prisons between 2018 and 2020, followed by cocaine, heroin type drugs (A) and amphetamine, ketamine type drugs (B). Male prisons had a higher prevalence of SCRAs, whereas female prisons had a higher prevalence of A drugs. Furthermore, lower security prisons were found to have a higher prevalence of B drugs, pregabalin, gabapentin type drugs (C), and abused and prescription drugs than higher security prisons which unveiled a higher prevalence of nicotine. The findings of this study have revealed new information about drug use in prisons. This study will also aid in the identification of drug smuggling routes into jails, keeping prison staff up to date with the trends.

Highly Sensitive Microwave Sensors Based on Open Complementary Square Split-Ring Resonator for Sensing Liquid Materials.

This paper presents high-sensitivity sensors based on an open complementary square split-ring resonator and a modified open complementary split-ring resonator operating at 4.5 GHz and 3.4 GHz, respectively. The sensors are designed for the detection of multiple liquid materials, including distilled water, methanol, and ethanol. The liquid under test is filled in a glass container loaded using a pipette. Compared to the conventional OCSSRR, the modified OCSSRR with multiple rings exhibits a higher frequency shift of 1200 MHz, 1270 MHz, and 1520 MHz for ethanol, methanol, and distilled water, respectively. The modified sensor also demonstrates a high sensitivity of 308 MHz/RIU for ethanol concentration which is the highest among the existing microwave sensors. The sensors in this manuscript are suitable for multiple liquid-material-sensing applications.

Variation in Phenolic Content, Antioxidant Activity and Alpha-amylase and Acetylcholinesterase Inhibitory Capacities of Different Extracts from Tunisian Satureja barceloi (Willk) L.

The antioxidant activity and the anti-α-amylase and anti-acetylcholinesterase capacities of secondary metabolites from different organs (roots, stems, leaves and flowers) of Tunisian Satureja barceloi were determined. The variation in the distribution of phenolic metabolites among roots, stems, leaves and flowers extracts of S. barceloi with various solvent systems (methanol, ethyl acetate, hexane and distilled water) has not been characterized before. Significant variation of phenolic compounds was observed according to organs rather than to extracting solvents. The analyzed organs show a high level of phenolic compounds although the stems contains the highest total polyphenols (132.53±0.48 mg AGE/g Ex), flavonoids (48.99±0.65 mg RE/g Ex) and flavonols (34.93±0.29 mg QE/g Ex) contents. The phenolic fraction was dominated by sagerinic acid, caffeic acid glucoside and epigallocatechin, detected using HPLC-PDA/ESI-MS. The antioxidant activity of all extracts, evaluated by four in vitro tests, was high and varied significantly according to the type of solvent used and the plant organ. The aqueous extracts of leaves exhibited the greatest inhibitory effect on alpha-amylase while the methanolic extract of leaves and stems revealed the most important acetylcholinesterase inhibitory effect. Hence, S. barceloi extracts could be used as a source of various bioactive molecules in pharmaceutical industry.

The Effect of Bacterial AHL on the Cyclic Adenosine Monophosphate Content in Plants According to High-Performance Liquid Chromatography.

Cyclic adenosine monophosphate (cAMP) is an important second messenger in cells, mediating various stimulation signals such as the growth and development of organisms and stress and participating in regulating various biological processes of cells. This article explores the quantitative determination of cAMP in plants using High-Performance Liquid Chromatography (HPLC) and applies this method to analyzing the changes in cAMP content during the process of plant response to the bacterial quorum sensing signal N-acyl homoserine lactone (AHL). Research has shown that the optimal detection conditions for HPLC are as follows: the chromatographic column is Venusil MP C18 (2), the mobile phase is methanol-water (0.1% trifluoroacetic acid) (v:v, 10:90), the detection wavelength is 259 nm, the column temperature is 35 °C, and the flow rate is 0.8 mL/min. The precision of the standard sample of this method is 98.21%, the precision of the sample is 98.87%, and the recovery rate is 101.067%. The optimal extraction conditions for cAMP in Arabidopsis are to use 15% methanol ultrasonic extraction for 10 min, followed by a 40 °C water bath for 4 h. Bacterial AHL signal processing can significantly stimulate an increase in cAMP levels in Arabidopsis leaves and roots. The establishment of HPLC detection methods for the cAMP content in plants is of great significance for in-depth research on the signal transduction mechanisms of plant-bacterial interactions.

Influence of Genotype on Antioxidant Activity and Phenolic Profile of Fennel Bulbs

Currently, fennel bulb is becoming a highly demanded and consumed vegetable due to its licorice flavor and health benefits. Although the chemical composition of fennel essential oil has been extensively studied, the nonvolatile bioactive compounds of fennel bulbs have drawn less attention. Here, the phenolic profile and the antioxidant activity in terms of DPPH radical scavenging activity, reducing power, chelating ability of ferrous ions, and inhibition of lipid peroxidation were analyzed using four different fennel hybrid genotypes and three different extraction solvents (methanol, aqueous-methanol, and hot water). Antioxidant activity results revealed significant variation amongst fennel varieties (&gt;3-fold difference for DPPH and reducing power and &gt;2.7-fold for the inhibition of lipid peroxidation), with methanolic extracts exhibiting the highest antioxidant activity. Total phenol content peaked in the aqueous-methanol extracts, exhibiting a 2-fold difference across fennel genotypes. HPLC–PDA/MS analyses identified high levels of caffeic acid derivatives in hot water extracts, particularly in the commercial genotype. The therapeutic benefits associated with these compounds make it reasonable to use detailed phytochemical screening in fennel breeding programs to obtain varieties with new functionalities and thus higher added value.

Experimental study on the effects of water addition in methanol on the performance of diesel-methanol diffusion combustion on a high-speed engine

Methanol is regarded as a low-carbon renewable fuel which is friendly to the environment. For purpose of investigating the impact of water introduction in methanol on diesel-methanol diffusion combustion, experimental tests were performed on a refitted dual-fuel high-speed diesel engine test bench. This research compared the differences between diesel-methanol diffusion combustion (DMDC) mode and diesel-hydrous methanol diffusion combustion (DHMDC) mode with a water mass content of 20%. The tests were performed by maintaining the engine speed of 3000 rpm and varying engine load as well as methanol injection timing (MIT). The results indicate that the heat release process in DHMDC mode begins later but is more rapid and concentrated compared to DMDC mode. The addition of 20% water in methanol does not significantly decreases the peak average in-cylinder temperature. However, it decreases the NOx emissions by up to approximately 40%. Water introduction leads to higher CO and THC emissions in DHMDC mode, but the retardation of MIT helps mitigate the increase in CO and THC emissions. The exhaust losses in DHMDC mode decrease by about 5%–8%, while the heat transfer losses increase by over 20%, resulting in a lower indicated thermal efficiency (ITE) in comparison with DMDC mode. The effects of the 20% water addition in methanol are sensitive to changes in engine load and MIT. Higher engine load and appropriately retarded MIT facilitate more efficient and cleaner combustion in DHMDC mode.