Ethyl Acetate Research Articles

The Effect of Psoralea corylifolia (Babchi) on Neuronal Apoptosis Induced by Palmitate in PC12 Cells and its Role in Alzheimer’s Disease: A Review

Background: Psoralea corylifolia (PC) seed extract (PCE) has been extensively utilized as an herbal drug due to its favorable effects on human health. It’s extracts and active components have demonstrated a variety of biological actions including estrogenic, anticancer, antioxidant, anti-bacterial, anti-depressant, anti-inflammatory and anti-ageing properties. Purpose: A study of this medicinal herb has major constituents extracted using different plant parts has been depicted and among them, Bakuchiol has the highest ethyl acetate extract content. Methods: The mechanism behind PCE’s anti-lipotoxic activity against palmitate (PA)-induced lipotoxicity in PC12 cells was examined. Results: CE therapy not only raised the quantities of mRNA for antioxidant genes such as heme-oxygenase and nuclear factor (erythroid-derived 2)-like 2 but also lowered the production of reactive oxygen species caused by PA. Conclusion: Prenylflavonoids play a unique role in the treatment of Alzheimer’s disease (AD) and can be used as a nootropic agent. This article comprehensively enumerated the literature on the anti-apoptotic effects of PC and its potential pathogenesis in AD.

Hydrophobic hypercrosslinked polymers prepared by secondary pore-forming method as excellent toluene adsorbents

In this work, inspired by molecular imprinting technology, we developed a secondary pore-forming method to chemically etch three hypercrosslinked polymers which are constructed from three novel hexapolar monomers containing imine groups, resulting in three novel hydrophobic porous hyper-crosslinked polymers (HCPs) pGly-TPA, pP-TPA and pBP-TPA. The structures were determined by FT-IR and solid-state 13C NMR spectroscopic techniques. The specific surface areas of pGly-TPA, pP-TPA and pBP-TPA are 694.1, 197.9 and 497.7 m2/g, respectively. All three porous polymers exhibit high hydrophobic properties with wetting angles of much greater than 90°. The breakthrough adsorption experiments revealed that the three prepared polymers exhibited significant adsorption capacity for toluene (322.05 mg/g for pGly-TPA, 114.43 mg/g for pP-TPA and 279.14 mg/g for pBP-TPA), but showed almost no adsorption for ethyl acetate, cyclohexane, and n-hexane, exhibiting certain molecular size and polarity selectivity. The adsorption behaviors of toluene on pGly-TPA, pP-TPA and pBP-TPA can be fit by the Boltzmann model and the Yoon-Nelson model, suggesting that the fixed bed has low mass transfer resistance. The adsorption rate is controlled by both external diffusion and intraparticle diffusion, as shown by the intraparticle diffusion model analysis. In addition, the adsorption capacity of toluene on pGly-TPA is almost unchanged under high humidity (70 %) or five adsorption–desorption processes, which demonstrates exceptional water-resistance and stability. This work is a reference for preparing novel hydrophobic HCPs using the secondary pore-forming method for removing VOCs from humid air.

From Extraction to Stabilization: Employing a 22 Experimental Design in Developing Nutraceutical-Grade Bixin from Bixa orellana L.

Bixin is the main carotenoid found in the outer portion of the seeds of Bixa orellana L., commercially known as annatto. This compound is industrially employed in pharmaceutical, cosmetic, and food formulations as a natural dye to replace chemical additives. This study aimed to extract bixin from annatto seeds and obtain encapsulated bixin in a powder form, using freeze-drying encapsulation and maltodextrin as encapsulating agent. Bixin was extracted from annatto seeds employing successive washing with organic solvents, specifically hexane and methanol (1:1 v/v), followed by ethyl acetate and dichloromethane for subsequent washes, to effectively remove impurities and enhance bixin purity, and subsequent purification by crystallization, reaching 1.5 ± 0.2% yield (or approximately 15 mg of bixin per gram of seeds). Bixin was analyzed spectrophotometrically in different organic solvents (ethanol, isopropyl alcohol, dimethylsulfoxide, chloroform, hexane), and the solvents chosen were chloroform (used to solubilize bixin during microencapsulation) and hexane (used for spectrophotometric determination of bixin). Bixin was encapsulated according to a 22 experimental design to investigate the influence of the concentration of maltodextrin (20 to 40%) and bixin-to-matrix ratio (1:20 to 1:40) on the encapsulation efficiency (EE%) and solubility of the encapsulated powder. Higher encapsulation efficiency was obtained at a maltodextrin concentration of 40% w/v and a bixin/maltodextrin ratio of 1:20, while higher solubility was observed at a maltodextrin concentration of 20% w/v for the same bixin/maltodextrin ratio. The encapsulation of this carotenoid by means of freeze-drying is thus recognized as an innovative and promising approach to improve its stability for further processing in pharmaceutical and food applications.

Effects of twelve organic solvents on process hazards and reaction selectivity of m-xylene nitration: Combined calorimetric technique and DFT calculations

Selection of appropriate solvents is of great significance for achieving efficient and safe m-xylene nitration. In this study, the exothermic behavior of m-xylene nitration under twelve organic solvents were studied by reaction calorimetry. The process hazards were assessed by calculation of thermal safety parameters. The reaction selectivity was quantified. The anhydrides exhibited the prominent promotion as water absorbent and active reagent in nitration, followed by selected aliphatic hydrocarbons, chlorinated hydrocarbons. While acetic acid, propionic acid and ethyl acetate had negative effects. The maximum yield of 95.6 % was achieved in nitric acid-acetic anhydride (HNO3-Ac2O) system. The thermal weight loss of the products appeared at around 150−230 °C by thermogravimetry experiments. The activation energy was determined to be 192.9 kJ/mol through adiabatic kinetic calculations. Furthermore, the solvent effects were analyzed by calculating the solvent polarity and its interaction energy with HNO3. The different action mechanisms of Ac2O and Pc2O on NO2+ generation were revealed. The density functional theory calculations were in agreement with the experimental results. These findings can provide guidance for understanding of the solvent effect on the reaction hazards and selectivity of m-xylene nitration, and provide experimental and theoretical basis for solvent screening for the nitration of similar aromatic compounds.

Toxicity of Bioactive Compounds of Strychnos pseudoquina (Loganiaceae) in Spodoptera frugiperda (Noctuidae)

The objective of this study was to assess the toxicity of leaf and bark extracts of Strycns pseudoquina and their fractions, as well as flavonoids isolated from its bark, in a population of Spodoptera frugiperda. Crude bark and leaf extracts, as well as fractions of these extracts, were obtained using a rotary evaporator and different solvents; the ethyl acetate fraction was obtained, and flavonoid compounds were isolated, consisting mostly of 3-O-methylquercetin and minimally of strychnobiflavone. The crude extracts, extract fractions, and isolated flavonoids were applied separately to maize leaves, which were offered to S. frugiperda larvae; then, biological parameters of this insect population were evaluated. Toxic effects of topical applications of the isolated flavonoids on the larvae were also evaluated. The results highlighted the larvicidal effects of the crude bark extract and its fractions and the significant toxicity of this crude extract (LC50 = 0.048%), which was six times more toxic to larvae than its ethyl acetate fraction (LC50 = 0.288%). The investigated flavonoids showed no significant larvicidal effect. The pronounced larvicidal effect of S. pseudoquina bark crude extract and its fractions on S. frugiperda indicates that this plant presents an insecticidal potential to be explored in integrated pest management programs.

Analyzing The Chemical Constituents and In Vitro Biological Effects of Extracts Artemisia absinthium L. Extracts Obtained Using Different Methodologies and Solvents.

The present study aimed to investigate the chemical constituents of different extracts from aerial parts of A. absinthium and to evaluate their antioxidant and enzyme inhibition activity. Extracts were prepared by maceration, infusion or Soxhlet techniques. Results showed that the highest total phenolic and flavonoids contents was recorded respectively from the hexane extract prepared by maceration and ethyl acetate extract obtained by Soxhlet method. The characteristic compounds of Artemisia species artemetin, casticin, sesartemin and yangambin in addition to coumarins were identified in all extracts. Aqueous extract obtained by infusion exerted the highest radical scavenging and ions reducing properties while that prepared by maceration displayed the highest chelating power. Methanol extracts obtained by the two methods of extraction exerted the highest anti-Tyr activity while that obtained by maceration showed the best α-glucosidase inhibition activity. These findings indicated that A. absinthium is a rich source of bioactive molecules with possible therapeutic applications.

Enhancing simultaneous determination of some angiotensin II receptor antagonists and amlodipine in plasma using HPTLC with fluorescence densitometry: Independent fluorescence detection of the co-administrative drugs in the mixture across various pH conditions

A novel and highly sensitive high-performance thin-layer chromatographic (HPTLC) method was developed and validated to quantify a combination of five pharmaceutical mixtures spiked to human plasma. The compounds comprised Amlodipine (AML) along with five angiotensin II receptor antagonist drugs (AIIRAs), namely Olmesartan (OLM), Telmisartan (TLM), Candesartan (CAN), Losartan (LOS), and Irbesartan (IRB). HPTLC was performed on silica gel 60 F254 plates using a mobile phase of Toluene: ethyl acetate: methanol: acetone: acetic acid (6:1.5:1:0.5:1, v/v/v/v/v). In a pioneering move, a reflectance/fluorescence detection mode was employed to identify two concurrently administered drugs at different pH levels for the first time. This method utilized the same chromatographic system, incorporating a specific measurement for AML at a neutral medium to achieve its maximum fluorescence at a 360 nm excitation wavelength, and measuring emission using a 540 nm optical filter. The process involved obtaining a very low fluorescence response from AIIRA. Subsequently, to enhance AIIRA’s fluorescence, the plate was sprayed with perchloric acid to transition to a strong acidic medium, ultimately attaining the maximum fluorescence of AIIRA using various excitation wavelengths and a 400 nm emission filter. Through this strategic process, we could optimize the fluorescence signals of both drugs, thereby elevating the sensitivity of detection for this drug combination. AML demonstrated a linear range of 18–300 ng/band, while AIIRAs drugs exhibited a linear range of 6–150 ng/band. The method satisfied the International Conference on Harmonization (ICH) criteria for recovery, precision, repeatability, and robustness, showcasing exceptional sensitivity. The approach was successfully applied to quantify AML and AIIRAs drugs in both bulk drug and plasma samples, achieving high recovery percentages and minimal standard deviations.

Effect of hydrolyzed soybean on the volatile flavors and microbial community in the traditional brewing process of chi-flavor Baijiu.

Addition of soybean in raw materials could improve the flavor of chi-flavor Baijiu (CFB) in production. For investigating the mechanism of flavor improvement during fermentation, the changes of volatile flavors and their relationship with microbial community were analyzed. The results showed that the average contents of lactic and acetic acid in EG (added with hydrolyzed soybean) samples were higher those of CK (without hydrolyzed soybean) samples. The contents of main volatile esters, including ethyl acetate, ethyl palmitate, and ethyl benzoate, in EG samples were higher than those in CK samples at the end of fermentation. The content of alcohols in EG sample was 140.55mg/L, higher than that in CK sample at the end of fermentation. Especially, the average content of characteristic flavor β-phenylethanol in EG samples increased 17.6% in comparison with that in CK samples during fermentation. Lactobacillus and Pediococcus were the dominant bacterial genera, whereas Saccharomyces, Mortierella, and Trichosporon were dominant fungal genera in both CK and EG samples. Lactobacillus and Weissella confusa showed strong positive correlation with β-phenylethanol, ethyl acetate, and ethyl benzoate. This study provides an in-depth analysis of the effects of hydrolyzed soybeans on the volatile flavor compounds and microbial communities of CFB and theoretical guidance for improving the quality of CFB.

Bioprospecting Antibacterial Properties of Fungi Isolated from Kakinada Sea Coast and Eucalyptus Foliage

Background: Fungi produce a wide range of secondary metabolites with bactericidal or bacteriostatic properties. In search of novel antibacterial compounds recently, many fungi of marine and plant origin have been studied for their antimicrobial properties. Aims: This work aimed to study bio-prospect marine and endophytic fungi for their antibacterial properties. objective: To determine the antibacterial properties of ethyl acetate extracts of fungal isolates. Methods: Intensive microbiological methods were followed for isolation, differential growth, and qualitative screening of enzyme production. The isolates were characterised and identified based on morpho-taxonomy, 18S rRNA gene sequencing, and phylogenetic analysis of the tar-get genes. The antimicrobial activity of fungal ethyl acetate extracts against S. aureus, B. sub-tilis, and E. coli was evaluated using a well-diffusion method, and MIC was determined by the microdilution method. Cell lysis was observed through Transmission Electron Microscopy. Results: A BLAST search of 18S rRNA gene sequences of the marine isolates GSBT S13 and GSBT S14 showed 99.3 % sequence similarity with A. glaucus for both isolates and that of endophyte GSBT E3 showed 99.7 % sequence similarity with B. pinkertoniae. Cellulase pro-duction was comparatively higher in GSBT E3 and lipase from GSBT S13 and GSBT S14. Ethyl acetate extracts of GSBT S14 and GSBT E3 showed a clear zone of inhibition by the well-diffusion method, further confirmed by electron microscopy. HR-TEM showed that the ethyl acetate extracts of the isolates appeared to damage the cell membrane, leading to cell shrinkage and death in E. coli and S. aureus. Conclusion: GSBT S13 and GSBT S14 exhibited extracellular amylase, cellulase, and lipase activities. Ethyl acetate extracts of both GSBT S14 and B. pinkertoniae GSBT E3 showed better antibacterial properties against S. aureus.

Ganlu formula ethyl acetate extract (GLEE) blocked the development of experimental arthritis by inhibiting NLRP3 activation and reducing M1 type macrophage polarization

Ethnopharmacological relevanceThe Tibetan medicine Ganlu Formula, as a classic prescription, is widely used across the Qinghai-Tibet Plateau area of China, which has a significant effect on relieving the course of rheumatoid arthritis (RA). However, the active compounds and underlying mechanisms of Ganlu Formula in RA treatment remain largely unexplored. Aim of the studyThis study aimed to elucidate the active substances and potential mechanisms of the ethyl acetate extract of Ganlu Formula ethyl acetate extract (GLEE) in the treatment of RA. Materials and methodsUltra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was utilized to analyze and identify the chemical constituents within GLEE. Discovery Studio molecular virtual docking technology was utilized to dock the interaction of GLEE with inflammation-related pathway proteins. The GLEE gene library was obtained by transcriptome sequencing. Collagen-induced arthritic（CIA) rats were utilized to assess the antiarthritic efficacy of GLEE. Micro-CT imaging was employed to visualize the rat paw, and ultrasound imaging revealed knee joint effusion. Evaluation of synovial tissue pathological changes was conducted through hematoxylin-eosin staining and saffranine solid green staining, while immunohistochemical staining was employed to assess NLRP3 expression along with inflammatory markers. Immunofluorescence staining was utilized to identify M1 macrophages. ResultsMetabolomic analysis via UPLC-Q-TOF-MS identified 28 potentially bioactive compounds in GLEE, which interacted with the active sites of key proteins such as NLRP3, NF-κB, and STAT3 through hydrogen bonds, C–H bonds, and electrostatic attractions. In vitro analyses demonstrated that GLEE significantly attenuated NLRP3 inflammasome activation and inhibited the polarization of bone marrow-derived macrophages (BMDMs) towards the M1 phenotype. In vivo, GLEE not only prevented bone mineral density (BMD) loss but also reduced ankle swelling in CIA rats. Furthermore, it decreased the expression of the NLRP3 inflammasome and curtailed the release of inflammatory mediators within the knee joint. ConclusionGLEE effectively mitigated inflammatory responses in both blood and knee synovial membranes of CIA rats, potentially through the down-regulation of the NLRP3/Caspase-1/IL-1β signaling pathway and reduction in M1 macrophage polarization.

New Monoterpenoid as the Sex Pheromone of Spanish Populations of the Longtailed Mealybug Pseudococcus Longispinus (Hemiptera: Pseudococcidae).

Pseudococcus longispinus (Targioni-Tozzetti) (Hemiptera: Coccoidea: Pseudococcidae), a polyphagous and cosmopolitan pest native to Australia, is a highly damaging pest for numerous crops of economic importance. The sex pheromone of this species (2-(1,5,5-trimethylcyclopent-2-en-1-yl)ethyl acetate), currently used for pest monitoring purposes, was not attractive to males in field experiments conducted in Spanish persimmon orchards infested with this mealybug. The virgin and mated female volatile profiles of these P. longispinus populations were studied by the volatile collection of effluvia in Porapak-Q. The resulting extracts were analyzed by gas chromatography coupled to mass spectrometry (GC-MS), revealing a new compound specific to virgin females and different from the previously described sex pheromone. Based on GC-MS data and nuclear magnetic resonance experiments, we envisaged monoterpene 2-(1,5-dimethyl-4-methylenecyclopent-2-en-1-yl)ethyl acetate as the new sex pheromone candidate, which was synthesized and shown to be attractive in the field to P. longispinus males of the Spanish population.

Phytochemical profiling, antioxidant, and tyrosinase inhibitory potential of the Acacia cyclops trunk bark: in vitro combined with in silico approach.

The aim of this study was to analyze the phytochemical profile of Acacia cyclops trunk bark ethyl acetate extract using LC-tandem mass spectrometry for the first time, along with evaluating its antioxidant and anti-tyrosinase properties. Consequently, we determined the total phenolic and flavonoid contents of the extract under investigation and identified and quantified 19 compounds, including phenolic acids and flavonoids. In addition to assessing their antioxidant potential against DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis-[3-ethylbenzothiazoline-6-sulfonic] acid) assays, in vitro and in silico studies were conducted to evaluate the tyrosinase inhibitory properties of the A. cyclops extract. The ethyl acetate trunk bark extract exhibited a substantial total phenolic content and demonstrated significant antioxidant activity in terms of free radical scavenging, as well as notable tyrosinase inhibitory action (half-maximal inhibitory concentration [IC50] = 14.08 ± 1.10 μg/mL). The substantial anti-tyrosinase activity of the examined extract was revealed through molecular docking analysis and druglikeness prediction of the main selected compounds. The findings suggest that A. cyclops extract holds promise as a potential treatment for skin hyperpigmentation disorders.

Chemical profiling and biological activities of the roots of Allochrusa gypsophiloides

Allochrusa gypsophiloides is one of the best-known endemic saponin bearing food plants of Central Asia. However, the plant’s secondary metabolites remain unmapped. The current study aimed to chemical profile of the metabolite in the plant roots by an untargeted UHPLC-ESI-MS, together with the isolation of the major compounds followed by a 2D NMR and HR-MS for identification and evaluation of the antioxidant and enzyme inhibitory activity of the extracts. The results revealed the presence of 48 putatively annotated metabolites comprising triterpene glycosides, phenolic compounds and their derivatives, organic acid glycosides, and lignan glycosides. The chromatographic separation and purification of the extract resulted in the isolation of four compounds where two new compounds and along with two known triterpenes were reported. The ethanol/water extracts showed a maximum effect in antioxidant assays, while the ethyl acetate extract achieved the best effect in the enzyme inhibitory assays.

Discovery of Antibacterial Compounds against Xanthomonas citri subsp. citri from a Marine Fungus Aspergillus terreus SCSIO 41202 and the Mode of Action.

Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a severe citrus disease. Currently, copper-containing pesticides are widely used to manage this disease, posing high risks to the environment and human health. This study reports the discovery of naturally occurring anti-Xcc compounds from a deep-sea fungus, Aspergillus terreus SCSIO 41202, and the possible mode of action. The ethyl acetate extract of A. terreus was subjected to bioassay-guided isolation, resulting in the discovery of eight anti-Xcc compounds (1-8) with minimum inhibitory concentrations (MICs) ranging from 0.078 to 0.625 mg/mL. The chemical structures of these eight metabolites were determined by integrative analysis of various spectroscopic data. Among these compounds, Asperporonin A (1) and Asperporonin B (2) were identified as novel compounds with a very unusual structural skeleton. The electronic circular dichroism was used to determine the absolute configurations of 1 and 2 through quantum chemical calculation. A bioconversion pathway involving pinacol rearrangement was proposed to produce the unusual compounds (1-2). Compound 6 exhibited an excellent anti-Xcc effect with a MIC value of 0.078 mg/mL, which was significantly more potent than the positive control CuSO4 (MIC = 0.3125 mg/mL). Compound 6 inhibited cell growth by disrupting biofilm formation, destroying the cell membrane, and inducing the accumulation of reactive oxygen species. In vivo tests indicated that compound 6 is highly effective in controlling citrus canker disease. These results indicate that compounds 1-8, especially 6, have the potential as lead compounds for the development of new, environmentally friendly, and efficient anti-Xcc pesticides.

Analysis of Quantitative Phytochemical Content and Antioxidant Activity of Leaf, Stem, and Bark of Gymnosporia senegalensis (Lam.) Loes.

To the best of our knowledge, there was no prior report providing valuable preliminary data through a demonstration of the quantitative phytochemical and antioxidant activity of Gymnosporia senegalensis. The total contents of phenols, flavonoid, flavanol, tannin, and saponin were evaluated from different fractions extracted from the leaf, stem, and bark of G. senegalensis by using standards such as gallic acid, quercetin, rutin, tannic acid, and saponin quillaja. The antioxidant potential was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide scavenging (H2O2), superoxide anion radical scavenging, metal chelating ferrous ion, ferric reducing antioxidant power (FRAP), and total antioxidant capacity (TAC). Data were subjected to half-inhibitory concentration (IC50) and one-way analysis of variance (ANOVA) at p < 0.05 as a significant value. The total phenol content was found to be highest in the chloroform extract of stem at 97.7 ± 0.02 mg GAE/g. The total flavonoid and flavonol contents in the aqueous extract were 97.1 ± 0.03 mg QE/g and 96.7 ± 0.07 mg RE/g, respectively. The total tannin content in the ethyl acetate extract of leaf was 97.5 ± 0.01 mg TAE/g, and the total saponin content in the methanol extract of stem was 79.1 ± 0.06 mg SQE/g. The antioxidant analysis indicated that IC50 and percentage (%) inhibition were dose-dependent and showed the highest antioxidant activity (40.9 ± 0.9 µg/mL) in methanol extract of leaf for DPPH, (88.8 ± 1.12 µg/mL) in the chloroform extract of stem for H2O2, (43.9 ± 0.15 µg/mL) in the aqueous extract of bark for superoxide anion radical scavenging activity, (26.9 ± 0.11 µg/mL) in the chloroform extract of leaf for the metal chelating ferrous ion activity, (7.55 ± 0.10 mg/mL) in the benzene extract of leaf for FRAP, and (2.97 ± 0.01 mg/mL) in the methanol extract of bark for TAC. These results show that G. senegalensis has great potential in antioxidant activities. The isolation and characterization of specific bioactive compounds and the in vivo applicability of such activity await further extensive studies for drug discovery and development.

New piperazine derivatives helvamides B–C from the marine-derived fungus Penicillium velutinum ZK-14 uncovered by OSMAC (One Strain Many Compounds) strategy

Four extracts of the marine-derived fungus Penicillium velutinum J.F.H. Beyma were obtained via metal ions stress conditions based on the OSMAC (One Strain Many Compounds) strategy. Using a combination of modern approaches such as LC/UV, LC/MS and bioactivity data analysis, as well as in silico calculations, influence metal stress factors to change metabolite profiles Penicillium velutinum were analyzed. From the ethyl acetate extract of the P. velutinum were isolated two new piperazine derivatives helvamides B (1) and C (2) together with known saroclazin A (3) (4S,5R,7S)-4,11-dihydroxy-guaia-1(2),9(10)-dien (4). Their structures were established based on spectroscopic methods. The absolute configuration of helvamide B (1) as 2R,5R was determined by a combination of the X-ray analysis and by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. The cytotoxic activity of the isolated compounds against human prostate cancer PC-3 and human embryonic kidney HEK-293 cells and growth inhibition activity against yeast-like fungi Candida albicans were assayed.Graphical

The potential correlation between the succession of microflora and volatile flavor compounds during the production of Zhenba bacon

Microbial composition plays an important role in the quality and flavor of bacon. The aims of this study were to detect bacterial community succession using high-throughput sequencing (HTS) and volatile flavor compound changes using gas chromatography-ion mobility spectrometry (GC-IMS) during the production of Zhenba bacon. The results showed that a total of 70 volatile compounds were detected. Among them, ketones, hydrocarbons, aldehydes, esters and alcohols were the main substances in the curing and smoking stages. In addition, the fungal abundance was greater than the bacterial abundance, and there was obvious succession of the microbial community with changes in fermentation time and processing technology. The main functional bacterial genera in the curing and smoking stages were Staphylococcus, Psychrobacter and Latilactobacillus, and the main fungal genera were Fusarium and Debaryomyces. Through correlation analysis, we found that pyrrole, 2-pentanol, methyl isobutyl ketone (MIBK) and ethyl acetate (EA) were significantly correlated with Staphylococcus, Psychrobacter, Pseudomonas and Myroides (p < 0.01), and it is speculated that they contribute significantly to flavor formation. The results of this study are helpful for understanding the microbial dynamics and characteristic volatile flavor compounds in Zhenba bacon, and provide new insights into the relationship between microorganisms and flavor through potential correlations.

Unraveling the structural intricacy of synthetic humic substance via, UV-vis, FTIR, 13C NMR and non-targeted silylation-GC-Orbitrap MS

Phenolic precursors combined with Maillard precursors can be converted into humic-acid like polycondensate during oxidation either via catalysis or non-catalysis processes. Current work was conducted on structural elucidation of synthetic humic substances (SHS) by avoiding alkaline extraction, using silylation coupled with high resolution mass spectrometery, while utilizing the mass spectral data of trimethylsilyl (TMS) derivatives. SHS mimicking natural humic substances was prepared by a bottom-up approach via polycondensation of catechol and Maillard precursors (glucose/glycine) at mild temperature (50 °C) and alkaline pH conditions. Reaction was monitored via UV–vis spectroscopy during the time period of 25 days by measuring the UV–vis curves. FTIR and 13C NMR curves were compared with IHSS Leonardite HA, gallic acid-protocatechuic acid-humic acid-like polycondensate (GA-PA-HALP), catechol: vanillic acid oligomer via oxidative coupling (CAVA) and corn straw HA via hydrothermal synthesis. SHS was subjected to silylation (BSTFA+1 %TMCS) in two solvents (pyridine or ethyl acetate) and then characterized via non-targeted analysis of GCOrbitrap MS. Mass spectrometery (MS) data showed that TMS fragments included more acidic and glucose oxidation moieties along with presence of Maillard reaction moieties. While remaining TMS fragments consisted of amines, aldehydes, ketones, amides, phenols etc. as well as conjugated moieties, adducts, quinones and oxidation/reduction moieties of catechol. Current method suggests that the combination of silylation with high-resolution gas chromatography-mass spectrometery (GCOrbitrap MS) offers an alternative approach for characterizing substances formed in biotic or abiotic reactions, as well as in water-extracted dissolved organic matter samples.

In vitro evaluation of anti-ulcer activity of ethyl acetate extract of Strychnos wallichiana roots

In vitro evaluation of anti-ulcer activity of ethyl acetate extract of Strychnos wallichiana roots

Solubility of N-Acetyl-L-glutamine in twelve Mono-solvents: Characterization, Determination, Analysis, and model correlation

In this work, the solid–liquid equilibrium solubility and solvent effects of N-acetyl-L-glutamine in twelve mono-solvent systems (water, methanol, ethanol, n-propanol, n-butanol, isobutanol, sec-butanol, acetonitrile, acetone, ethyl acetate, 2-butanone, methyl acetate) were reported at the pressure of 101.2 kPa (at T = 283.15–––323.15 K). Among the twelve mono-solvents, the solubility increased with the increase of absolute temperature, the order is: water > methanol > ethanol > sec-butanol > n-propanol > 2-butanone > isobutanol > acetone > methyl acetate > ethyl acetate > n-butanol > acetonitrile. The modified Apelblat model, Wilson model, NRTL model and UNIQUAC model were employed to correlate the experimental solubility, and the fitting results of the four models were all satisfactory. In addition, through comparison of the average ARD and RMSD values of the four models, the modified Apelblat model achieved the best correlation result. Hirshfeld surface analysis (HS) and molecular electrostatic potential surface (MEPS) were used to determine the internal interactions within N-acetyl-L-glutamine solutions. The Hansen solubility parameters (HSPs) and the coverage Pearson correlation coefficients (PCC) heatmap were utilized to assess the solvents’ capability and to elucidate its ability to dissolve N-acetyl-L-glutamine. Furthermore, mixing thermodynamic characteristics of N-acetyl-L-glutamine in selected solvents were calculated by the NRTL model, which revealed that the mixing process was spontaneous and entropy-driven. These experimental results could be utilized for the purification, crystallization, and industrial applications of N-acetyl-L-glutamine as well as similar substances.