Methylated Compounds Research Articles

Comprehensive Analysis of Antioxidant Properties, GC-MS, and FTIR Profiles of Myrica esculenta Fruit Extracts from Western East Khasi Hills of Meghalaya.

This study investigates the phytoconstituents of Myrica esculenta fruit extracts using various solvents, including n-hexane, dichloromethane, ethyl acetate, methanol, and water. Qualitative phytochemical analysis revealed the presence of several phytochemicals, with the highest concentration found in the methanol extract. The total phenolic (94.5±0.96 mg gallic acid equivalent (GAE)/g) and flavonoid (74.27±0.29 mg quercetin equivalent (QE)/g) contents were also highest in the methanol extract. Antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS), and Ferric Reducing Antioxidant Power (FRAP) assays. The methanol extract exhibited superior antioxidant activity with DPPH and ABTS IC50 values of 22.27±0.98 μg/ml and 19.69±0.36 μg/ml, respectively, compared to ascorbic acid. FRAP activity was also highest in the methanol extract (87.125±0.33 mg Trolox equivalents (TE)/g). Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified antioxidant compounds hexanedioic acid, bis(2-ethylhexyl) ester, methyl 11,12-octadecadienoate, and pentadecanoic acid. while Fourier Transform Infrared Spectroscopy (FTIR) analysis detected functional groups such as alkenes, ketones, esters, alcohols and carboxylic acids. These findings suggest that the methanolic extract of M. esculenta fruits is a rich source of natural antioxidants, making it suitable for pharmaceutical, health, and nutritional supplements aimed at enhancing overall health.

Thiopurine S‑methyltransferase- and indolethylamine N‑methyltransferase-mediated formation of methylated tellurium compounds from tellurite.

Tellurium (Te) is a metalloid widely used in various industries. However, its toxicological impact on humans is poorly understood. In this study, we investigated the role of two methyltransferases, thiopurine S‑methyltransferase (TPMT) and indolethylamine N‑methyltransferase (INMT), in the methylation of tellurite, an inorganic Te oxyanion. The products of the reaction of Te compounds catalyzed by recombinant human TPMT and/or INMT were analyzed by liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (LC-ICP-MS) and gas chromatographymass spectrometry (GC-MS). We found that TPMT catalyzes the methylation of non-methylated Te and methanetellurol to generate dimethyltelluride. On the other hand, INMT catalyzes the methylation of methanetellurol and dimethyltelluride to produce trimethyltelluronium ion, a metabolite excreted into animal urine. We conclude that TPMT and INMT are cooperatively responsible for the detoxification of Te oxyanions through methylation to form trimethyltelluronium ions.

New methyl compounds using the predicted data mining approach (PDMA), coupled with the biotransformation of Streptomyces peucetius O-methyltransferase

The structural modification of natural products using biotransformation is an effective way to produce organic compounds in a regioselective and/or stereoselective manner. O-methylation is a major modification in nature. The predicted data mining approach (PDMA) can efficiently screen out biotransformable precursor candidates to produce new (functional) compounds from thousands of derivatives. Herein, an O-methyltransferase (SpOMT2884) from Streptomyces peucetius (ATCC 27952 strain) was selected to biotransform eight precursors, screened from 4364 commercially available natural compounds via PDMA. Seven of the eight precursors (calceolarioside B, isomangiferin, mangiferin, methyl chlorogenate, plantagoside, protosappanin B, and wedelolactone) could be biotransformed from SpOMT2884. Fourteen biotransformed compounds were confirmed to be methyl products with a high-resolution mass analysis. Three methyl products from two precursors (plantagoside and protosappanin B) were selected for further production and identified using nucleic magnetic resonance spectral methods. One methyl product of protosappanin B was identified as 10-O-methyl protosappanin B (1), which gained potent anti-inflammatory activity (IC50 = 76.1 ± 4.7 μM) compared with its precursor, protosappanin B (IC50 = 157.7 ± 5.0 μM). In a case study, two methyl products of plantagoside were indeed identified as novel 4′-O-methyl plantagoside (3) and 5′-O-methyl plantagoside (4). This study demonstrates that PDMA is a good in silico approach for screening biotransformable precursor candidates for the in vitro production of new or bioactive compounds from numerous natural products.

Cognitive and Histopathological Alterations in Rat Models of Early- and Late-Phase Memory Dysfunction: Effects of Sigma-1 Receptor Activation.

Sigma-1 receptors are highly expressed in brain areas related to cognitive function and are a promising target for anti-amnesic treatments. We previously showed that activation of sigma-1 receptors by the selective agonist compound methyl(1 R,2 S/1 S,2 R)-2-[4-hydroxy-4-phenylpiperidin-1-yl)methyl]-1-(4-methylphenyl) cyclopropane carboxylate [(±)-PPCC] promotes a remarkable recovery in rat models of memory loss associated to cholinergic dysfunction. In this study, we sought to assess the role of (±)-PPCC on working memory deficits caused by noradrenergic depletion. Animals with a mild or severe working memory deficits associated to varying degrees of noradrenergic neuronal depletion were treated with the sigma-1 agonist just prior to the beginning of each behavioral testing session. While (±)-PPCC alone at a dose of 1 mg/kg/day failed to affect working memory in lesioned animals, its association with the α2 adrenergic receptor agonist clonidine, completely blocked noradrenaline release, significantly improving rat performance. This effect, distinct from noradrenaline activity, is likely to result from a direct action of the (±)-PPCC compound onto sigma-1 receptors, as pre-treatment with the selective sigma-1 receptor antagonist BD-1047 reversed the improved working memory performance. Despite such clear functional effects, the treatment did not affect noradrenergic neuron survival or terminal fiber proliferation. Future studies are thus necessary to address the effects of long-lasting (±)-PPCC treatment, with or without clonidine, on cognitive abilities and Alzheimer's disease-like histopathology. Considering the already established involvement of sigma-1 receptors in endogenous cell plasticity mechanisms, their activation by selective agonist compounds holds promises as possibly positive contributor to disease-modifying events in neurodegenerative diseases.

Hydrothermal carbon reduction in the absence of minerals

Abiotic synthesis of CH4 in seafloor hydrothermal fluids is generally assumed to occur via heterogeneous reactions on mineral surfaces. Stepwise homogeneous reduction of CO2 has, however, been suggested as an alternative (but sluggish) abiotic pathway to CH4, potentially via metastable species of intermediate oxidation states. In this study, we examine the effect of two temperature-dependent methylated species − methanol (CH3OH) and methanethiol (CH3SH), on homogeneous CH4 formation rates under long-term simulated hydrothermal conditions. Aqueous solutions containing formic acid (H13COOH, generating 13CO2 and H2) were heated with and without H2S at 300–325 °C (35 MPa) in a flexible Au reaction cell over several years without added minerals. Substantial 13C-labeled CH4 and CH3OH production from 13CO2 was observed over 4.3 yr, with aqueous CH4 formation varying with CH3OH abundance – a strong function of dissolved H2 abundance and, inversely, temperature. CH4 production was slower at 325 °C with lower CH3OH concentrations (in equilibrium with CO2 and H2), and faster at 300 °C, accompanying an equilibrium-controlled increase in CH3OH. Fastest CH4 production occurred at 300 °C following injection of H2S and H13COOH, which led to rapid formation (<4 days) of 13C-labeled CH3SH that subsequently decomposed over a further 0.8 yr, partly to 13CH4. Heating aqueous 13CH4 to 345–387 °C (33–35 MPa) in the presence of an oxidizing hematite-magnetite-pyrite assemblage, however, yielded no detectable CH3SH after 112 days indicating the reverse reaction is inhibited under favorable thermodynamics. Neither direct reduction of CO2 to CH3SH nor CO2-CH3SH equilibrium were evident at 300 °C, implying CH3SH and CH3OH play disparate roles in homogeneous carbon reduction to CH4. Longer chain hydrocarbons (C2+ alkanes) remained low throughout the experiments.CH3SH abundances previously reported in vent fluids at the Von Damm hydrothermal field correlate strongly with demonstrably abiotic HCOOH there, suggesting the reduction of HCOOH to CH3SH observed in this study may also occur in vent fluids. A comparison of mineral-free 13CH4 production rates reported here with 13CO2 reduction experiments involving minerals indicates that homogeneous reduction proceeds at similar rates to purported transition metal-catalyzed 13CH4 production, and is generally faster than experiments with either added olivine or ultramafic rock. Previous claims of substantial mineral-catalyzed abiogenic CH4 production are therefore not supported by our study. Homogeneous CO2 reduction may be a significant source of methylated compounds and CH4 in hydrothermal fluids characterized by decadal (or longer) residence times, such as those found in mineral-hosted inclusions or occluded fractures in igneous basement, requiring only moderate temperatures and abundant H2 to proceed.

Methanomethylovorans are the dominant dimethylsulfide-degrading methanogens in gravel and sandy river sediment microcosms

BackgroundRivers and streams are important components of the global carbon cycle and methane budget. However, our understanding of the microbial diversity and the metabolic pathways underpinning methylotrophic methane production in river sediments is limited. Dimethylsulfide is an important methylated compound, found in freshwater sediments. Yet, the magnitude of DMS-dependent methanogenesis nor the methanogens carrying out this process in river sediments have been explored before. This study addressed this knowledge gap in DMS-dependent methanogenesis in gravel and sandy river sediments.ResultsSignificant methane production via DMS degradation was found in all sediment microcosms. Sandy, less permeable river sediments had higher methane yields (83 and 92%) than gravel, permeable sediments (40 and 48%). There was no significant difference between the methanogen diversity in DMS-amended gravel and sandy sediment microcosms, which Methanomethylovorans dominated. Metagenomics data analysis also showed the dominance of Methanomethylovorans and Methanosarcina. DMS-specific methyltransferase genes (mts) were found in very low relative abundances whilst the methanol-, trimethylamine- and dimethylamine-specific methyltransferase genes (mtaA, mttB and mtbB) had the highest relative abundances, suggesting their involvement in DMS-dependent methanogenesis.ConclusionsThis is the first study demonstrating a significant potential for DMS-dependent methanogenesis in river sediments with contrasting geologies. Methanomethylovorans were the dominant methylotrophic methanogen in all river sediment microcosms. Methyltransferases specific to methylotrophic substrates other than DMS are likely key enzymes in DMS-dependent methanogenesis, highlighting their versatility and importance in the methane cycle in freshwater sediments, which would warrant further study.

Methyl Syringate: A Primary Driving Factor in Manuka Honeys Ability to Ameliorate Neutrophil Intracellular ROS Activity and NETosis.

Neutrophils use both the production of reactive oxygen species (ROS) and a specialized process called NETosis to defend the body from material deemed foreign. While these neutrophil behaviors are critical in preventing infection, a dysregulated response can lead to tissue damage and fibrosis at host-biomaterial interfaces. It was hypothesized that applying the flavonoids found in Manuka honey: chrysin, pinocembrin, and pinobanksin, and the phenolic compound methyl syringate to neutrophils exhibiting pro-inflammatory behavior will reduce ROS activity and prevent NETosis in primary human neutrophils. Using primary human neutrophils isolated from donor (n = 5) peripheral blood, concentrations between 1 nM and 10 µM of each flavonoid, 10 µM and 2 mM of methyl syringate, 0.1% v/v and 10% v/v Manuka honey, and combinations of both 1 nM-10 µM of each flavonoid and 10 µM-2 mM of methyl syringate were assayed for reductions in NETosis using Sytox orange extracellular DNA staining and reduction in intracellular ROS activity via standard dichloro-dihydro-fluorescein diacetate (DCFH-DA) oxidation assay. Compared to positive control levels, individual flavonoids showed moderate effect sizes. Higher concentrations of flavonoids, especially in combination, stimulated ROS activity by up to 105%. Whole Manuka honey reduced neutrophil extracellular trap (NET) levels by up to 91% but only reduced ROS activity by 36%. However, methyl syringate reduced NET levels by up to 68% and ROS activity by 66%. Methyl syringate and whole Manuka honey are potent inhibitors of neutrophil intracellular ROS activity and NET formation. Methyl syringate potentially drives the anti-inflammatory capabilities of Manuka honey demonstrated by previous studies.

The characteristic VOCs of different parts of Artocarpus heterophyllus fruit based on HS-SPME-GC-MS and PTR-TOF-MS

Insight investigation on both edible pulps and inedible parts involving inflorescence axis and shreds of Artocarpus heterophyllus Lam were carried out, a total of 98 VOCs and 201 masses were identified by the combination of HS-SPME-GC-MS and PTR-TOF-MS. Among them, according to the consistency of OAV and results of VIP > 1, p < 0.05, compounds methyl isovalerate (A2), 3-methylbutyl acetate (A5) and octanoic acid, ethyl ester (A21) were recognized as aroma markers to distinguish the pulps, shreds and inflorescence axis. Meanwhile, the inflorescence axis (IC50: 1.82 mg/mL) and shreds (IC50: 16.74 mg/mL) exhibited more excellent antioxidant potency than pulps (IC50: 17.43 mg/mL) in vitro. These findings validated the feasibility of coupling HS-SPME-GC-MS and PTR-TOF-MS for rapid detection of characteristic VOCs of this plant, and offered new prospect of fragrance utilization and waste management of the edible and inedible parts of A. heterophyllus fruit.

Algal methylated compounds shorten the lag phase of Phaeobacter inhibens bacteria

The lag phase is key in resuming bacterial growth, but it remains underexplored particularly in environmental bacteria. Here we use transcriptomics and 13C-labelled metabolomics to show that the lag phase of the model marine bacterium Phaeobacter inhibens is shortened by methylated compounds produced by the microalgal partner, Emiliania huxleyi. Methylated compounds are abundantly produced and released by microalgae, and we show that their methyl groups can be collected by bacteria and assimilated through the methionine cycle. Our findings underscore the significance of methyl groups as a limiting factor during the lag phase and highlight the adjustability of this growth phase. In addition, we show that methylated compounds, typical of photosynthetic organisms, prompt diverse reductions in lag times in bacteria associated with algae and plants, potentially favouring early growth in some bacteria. These findings suggest ways to accelerate bacterial growth and underscore the significance of studying bacteria within an environmental context.

Influence of Some Heterocyclic, Cyclic, and Nitrogen-Containing Compounds on Oxidative Deamination of Polyamines in a Cell-Free Test System.

We studied the effects of some nitrogen-containing, heterocyclic, and cyclic compounds on the rate of oxidative deamination of polyamines and putrescine in tissues with a high proliferation rate. For this purpose, the specific activities of the main enzymes of polyamine oxidative degradation - spermine oxidase (SMO), polyamine oxidase (PAO), and diamine oxidase (DAO) were determined using a cell-free test system from regenerating rat liver. The compounds methyl 2-(5-formylfuran-2-yl)benzoate and 2,7-bis-[2-(diethylamino)ethoxy]-9H-fluoren-9-one (and in the form of dihydrochloride) showed mainly activating effect on oxidative degradation of putrescine, spermidine, and spermine, which indirectly indicates their antiproliferative effect. Nitrogen-free compounds inhibited this process, thus exhibiting potentially carcinogenic properties. Correlations were calculated for activity of DAO, PAO, and SMO with 5 topological indices: Wiener (W), Rouvray (R), Balaban (J) in the Trinaistich modification, detour (Ip), and electropy (Ie). The highest dependence was noted for DAO and the Balaban index (R=-0.55), for PAO and the detour index (R=0.78), and for SMO and the electropy index (R=0.53). The remaining dependencies showed insignificant correlation strength.

Antitumor activity and transcriptome sequencing (RNA-seq) analyses of hepatocellular carcinoma cells in response to exposure triterpene-nucleoside conjugates

Fifteen betulonic/betulinic acid conjugated with nucleoside derivatives were synthesized to enhance antitumor potency and water solubility. Among these, the methylated betulonic acid-azidothymidine compound (8c) exhibited a broad-spectrum of antitumor activity against three tested tumor cell lines, including SMMC-7721 (IC50 = 5.02 μM), KYSE-150 (IC50 = 5.68 μM), and SW620 (IC50 = 4.61 μM) and along with lower toxicity (TC50 > 100 μM) estimated by zebrafish embryos assay. Compared to betulinic acid (<0.05 μg/mL), compound 8c showed approximately 40-fold higher water solubility (1.98 μg/mL). In SMMC-7721 cells, compound 8c induced autophagy and apoptosis as its concentration increased. Transcriptomic sequencing analysis was used to understand the potential impacts of the underlying mechanism of 8c on SMMC-7721 cells. Transcriptomic studies indicated that compound 8c could activate autophagy by inhibiting the PI3K/AKT pathway in SMMC-7721 cells. Furthermore, in the xenograft mice study, compound 8c significantly slowed down the tumor growth, as potent as paclitaxel treated group. In conclusion, methylated betulonic acid-azidothymidine compound (8c) not only increases water solubility, but also enhances the potency against hepatocellular carcinoma cells by inducing autophagy and apoptosis, and suppressing the PI3K/Akt/mTOR signaling pathway.

Methylotrophic methanogenesis induced by ammonia nitrogen in an anaerobic digestion system

This lab-scale study aimed to investigate the effect of total ammonia nitrogen (TAN) stress on the methanogenic activity and the taxonomic and functional profiles of the microbial community of anaerobic sludge (AS) from a full-scale bioreactor. The AS was subjected to a stepwise increase in TAN every 14 days at concentrations of 1, 2, 2.5, 3, 3.5, and 4g TAN/L (Acclimated-AS or AAS). This acclimation stage was followed by an ammonia stress stage (4g/L). A blank-AS (BAS) was maintained without TAN during the acclimation stage. In the second stress stage (ST), the BAS was divided into two new treatments: a control (BAS') and one that received a shock load of TAN of 4g/L (SBAS'). Methane production was measured, and a metagenomic analysis was conducted to describe the microbial community. A decrease in the relative abundance of Methanothrix soehngenii of 16% was related to a decrease of 23% in the methanogenic capacity of AAS when comparing with the final stage of BAS. However, recovery was observed at 3.5g TAN/L, and a shift to methylotrophic metabolism occurred, indicated by a 4-fold increase in abundance of Methanosarcina mazei. The functional analysis of sludge metagenomes indicated that no statistical differences (p>0.05, RM ANOVA) were found in the relative abundance of methanogenic genes that initiate acetoclastic and hydrogenotrophic pathways (acetyl-CoA synthetase, ACSS; acetate kinase, ackA; phosphate acetyltransferase, pta; and formylmethanofuran dehydrogenase subunit A, fwdA) into the BAS and AAS during the acclimation phase. The same was observed between groups of genes associated with methanogenesis from methylated compounds. In contrast, statistical differences (p<0.05, one-way ANOVA) in the relative abundance of these genes were recorded during ST. The functional profiles of the genes involved in acetoclastic, hydrogenotrophic, and methylotrophic methanogenic pathways were brought to light for acclimatation and stress experimental stages. TAN inhibited methanogenic activity and acetoclastic metabolism. The gradual acclimatization to TAN leads to metabolic and taxonomic changes that allow for the subsequent recovery of methanogenic functionality. The study highlights the importance of adequate management of anaerobic bioprocesses with high nitrogen loads to maintain the methanogenic functionality of the microbial community.

Halitosis in young patients with chronic kidney disease: findings from a randomized controlled trial

BackgroundChronic kidney disease (CKD) directly affects oral health. Yet data about halitosis in young CKD patients and the impact of dental prophylaxis is limited. Therefore, as part of this randomized clinical trial, halitosis in young CKD patients undergoing intensive or standard oral preventive procedures was to be explored.MethodsThree volatile sulfur compounds (hydrogen sulfide, methyl mercaptan and dimethyl sulfide) were measured in 30 young patients with CKD (mean age 14.2 years; 16 males, 14 females). Breath samples were taken after 3 and 6 months and analyzed with selective gas chromatography (OralChroma). Tongue coating (Winkel Index) and clinical indices to determine local inflammation or oral hygiene (Papillary Bleeding Index and Quigley-Hein Index) were assessed. Within an extended anamnesis, patients and their mothers and nurses were questioned about the perceived halitosis. Corresponding quotes were noted verbatim. Patients were randomized to either intensive need-related oral health care measures (oral preventative program, OPP) or a one-stage standard prevention (treatment as usual, TAU).ResultsWhile there were no differences in volatile sulfur compound levels between TAU and OPP at the three time points of measurements (p > 0.05), there was a tendency towards a reduction in dimethyl sulfide and hydrogen sulfide of affected patients within the OPP group over time. Looking at potential differences between both groups with regard to tongue coating, significant differences were observed between baseline and 3 months after study start in the OPP group, and between baseline and 6 months after study start in the TAU group (p < 0.05). The burden of halitosis was frequently reported by patients’ mothers and nurses.ConclusionsYoung CKD patients regularly suffered from halitosis and dimethyl sulfide was its main source. Preventive measures mainly resulted in a reduction of tongue coating. Trial registration: The German Clinical Trial Register (# DRKS00010580).

Small Peptide Conjugates of Benzothiazole‐2‐Carboxylic Acids Targeting DprE1 Against Tuberculosis

AbstractInhibitors of Decaprenylphosphoryl‐β‐D‐ribose 2′‐epimerase (DprE1) are being thoroughly explored as potential pharmacological entities for the development of new anti‐tubercular therapeutics. In this context, benzothiazole‐bearingcompounds have emerged as potential non‐covalent DprE1 inhibitors active against mycobacterium tuberculosis. In view of the promising anti‐tubercular activity of benzothiazole based non‐covalent DprE1 inhibitor TCA1; a series of thirty small peptide conjugates of benzothiazole‐2‐carboxylic acid has been synthesized and evaluated for their anti‐tubercular activity against the M.tb H37Ra strain by broth microdilution assay. Among the compounds tested, compounds methyl (6‐methoxybenzo[d]thiazole‐2 carbonyl)tryptophylalaninate and methyl (6‐methylbenzo[d]thiazole‐2‐carbonyl)tryptophylalaninate demonstrated potential anti‐tubercular activity with minimum inhibitory concentration (MIC) values of 4 and 8 μg/mL, respectively. These compounds were further identified to be mycobactericidal and are completely killing the microbes at 8‐16 μg/mL concentrations. Furthermore, the cytotoxicity study of most potent compound methyl (6‐methoxybenzo[d]thiazole‐2 carbonyl)tryptophylalaninate illustrated no significant toxicity to the human cell line HepG2. Moreover, synthesised compounds were subject to molecular docking, ADME studies and MM‐GBSA calculations. In silico studies suggest that these compounds show strong interactions with key amino acids in the binding pocket of DprE1 (PDBID: 4KW5) with the most active conjugates residing well (with docking scores of −08.49 and −7.902 kcal/mol).

Structural, spectral analysis, reactivity, topological and pharmacological investigations on an antihistamine agent

In this work, quantum computational techniques have been applied to the title compound (Methyl [2-(pyridin-3-yl) ethyl] amine) for insights into structural, vibrational, and electronic spectral features and chemical reactivity. The observed vibrational spectra in solid-phase have been compared with the theoretical one (DFT together with B3LYP /6–311++G (d, p). For the understanding of intra-molecular hyper conjugative interactions, a natural bond orbital (NBO) study was carried out. Nonlinear optical (polarizabilities) calculations have been performed. The molecule's bioactivity is confirmed by the frontier molecular orbital energy gap, and information regarding intra- and inter-non-covalent interactions is provided by non-covalent bond interaction (NCI) analysis. Molecular electrostatic potential (MEP) can identify a molecule's electrophilic and nucleophilic areas, and it can explain a molecule's chemical implications using electron localization function (ELF). The compound's reactive sites were examined using the Fukui function computations, and the molecule's reactivity is defined by its chemical descriptors. The bioactivity of a molecule is supported by molecular docking using the Histamine 1 receptors 3RZE and 7DFL protein, and drug likeness factors were computed to understand the biological properties of MP3EA.

Investigation of the Structural and Electronic Properties of the Novel Synthesized Methyl 2-(2-oxo-2H-chromen-4-ylamino) benzoate Compound by DFT Method and Evaluation of its Anti-Leishmania Agent Potential by Molecular Docking Study

Leishmaniasis is a disease caused by different species of the leishmania parasite, transmitted through the sandfly, within the group of protozoa. According to the World Health Organization, leishmaniasis is one of the most encountered seven tropical diseases. Trypanothione reductase is a vital enzyme for the parasite. This has made Trypanothione reductase a potential target in the treatment of leishmaniasis. The limitations of current therapeutic options and the high cost have increased the motivation for research on the inhibition of Trypanothione reductase. In this study, the structural and electronic properties of the newly synthesized compound methyl 2-(2-oxo-2H-chromen-4-ylamino) benzoate were calculated using DFT/B3LYP and 6-311++G(d,p) basis set. The calculated structural parameters were found to be highly compatible when compared with experimental studies. The crystal packing of the compound was examined through the Hirshfeld surface analysis method. When the potential of the compound to be used as a drug was evaluated using Lipinski criteria, no hindrance to its use in living organisms was found. As the crystal structure of the enzyme was unknown, homology modeling was performed. Finally, in the molecular docking study, the interaction mechanisms of the compound mentioned in the title and the compound clomipramine used as a control in the receptor's active site were examined. The results revealed that the compound mentioned in the title demonstrated a better potential compared to the control compound.

Diversity of flavour characteristics of table grapes and their contributing volatile compounds analysed by the solvent-assisted flavour evaporation method.

To identify the compounds that contribute to the diverse flavours of table grapes, the flavours and volatile compounds of 38 grape cultivars harvested over 3 years are evaluated through sensory analysis and solvent-assisted flavour evaporation (SAFE). The cultivars are characterized and grouped into seven clusters by hierarchical cluster analysis (HCA) using sensory evaluation data with a flavour wheel specific to table grapes. These clusters were similar to conventional flavour classifications, except that the foxy and neutral cultivars form multiple clusters, highlighting the flavour diversity of table grapes. The SAFE method provides a comprehensive profile of the volatile compounds, including slightly volatile compounds whose profiles are lacking in hybrid grapes and Vitis rotundifolia. The sensory evaluation is supported by the volatile compound profiles, and relationships between the datasets are clarified by multivariate analysis. Specific accumulations and combinations of compounds (α-pinene, β-pinene, phenylethyl alcohol, furaneol, mesifurane, methyl N-formylanthranilate, and mixed ethyl ester and monoterpenoid) were also identified that contribute to the diversity of flavours (fresh green, floral, fruity, fatty green, sweet, fermented/sour) in table grapes, including linalool and linalool analogues (muscat flavour) along with ethyl ester and hydroxyethyl esters (foxy flavour). The accumulation of these compounds was positively related to a higher flavour intensity. Their specific accumulation and combination supported the flavour diversity of table grapes. This study identified novel flavour-associated compound profiles in table grapes through in-depth volatile compound analysis and non-conventional multivariate analysis.

Methyl benzoate-related compounds as potential repellents and fumigants for the control of cigarette beetle, Lasioderma serricorne (F.)

The cigarette beetle, Lasioderma serricorne (F.), presents a significant management challenge as a stored product pest. The beetle's increasing resistance to conventional fumigants necessitates the search for alternative solutions to mitigate losses in agro-based industries. Here, we constructed a small molecule compounds library containing twenty-eight methyl benzoate-related compounds (MBCs) and evaluated their repellent and toxic effects against cigarette beetles by Y-tube olfactometer behavioral assays, free-choice box assays and fumigation assays. We found that six MBCs (methyl 3-methoxybenzoate, methyl benzoate, methyl 3-formylbenzoate, methyl 2-aminopyridine-3-carboxylate, methyl 2-aminobenzoate and methyl 4-amino-2-methoxybenzoate) act as repellents for cigarette beetles. Notably, methyl benzoate (MeBA) was effective across a broader range of concentrations (200–4000 ppm) compared to other MBCs. Four compounds (methyl 3-formylbenzoate, methyl 2-aminopyridine-3-carboxylate, methyl 2-aminobenzoate and methyl 4-amino-2-methoxybenzoate) required higher minimum concentrations (500–4000 ppm) than MeBA for repellence, while methyl 3-methoxybenzoate was effective at a concentration (10 ppm) lower than that for MeBA. Mixtures of MeBA with methyl 3-methoxybenzoate and methyl 3-formylbenzoate enhanced the repellent effect against cigarette beetles when compared to MeBA alone. Additionally, exposure to varying concentrations of MeBA, methyl 3-methoxybenzoate, methyl 3-formylbenzoate, and methyl 2-aminobenzoate resulted in 100% mortality of cigarette beetles. Our findings indicate that specific MBCs offer the potential for their use as repellents and fumigants for this problematic stored product pest.

Imprinting-based smart syringe: A fast, efficient, and selective approach for extraction of methyl gallate from Caesalpinia pulcherrima extract

A simple, facile, quick, highly selective, and efficient extraction protocol for a medicinal compound methyl gallate (MG) is developed for the first time using molecularly imprinted-based solid phase extraction (MISPE). Density functional theory (DFT) was employed to calculate the binding energies of the complex of MG with the functional monomer in the gas and in the implicit solvent to evaluate the best combination of the functional monomer, crosslinker, and porogen for MG. Decisively, the synthesis of a molecularly imprinted polymer (MIP) and its respective non-imprinted polymer (NIP) was conducted using methacrylamide (MAAm) as a functional monomer, trimethylolpropane trimethacrylate (TRIM) as a crosslinker, and methanol as a porogen. The polymers were characterized by SEM, FT-IR, BET, and TGA, while the adsorption properties of MG-MIP/NIP were evaluated by batch rebinding experiments. Theoretical modeling was done by Langmuir, Freundlich, Scatchard analysis, LF-isotherm, and kinetic models. The MG-MIP appeared to have a higher binding capacity towards MG compared to the corresponding NIP: 57.6 mg/g compared to only 17.6 mg/g rendering an imprinting factor 3.3. Moreover, in competitive recognition studies, the synthesized MG-MIP showed good selectivity towards MG compared to its structural analogs, confirming the presence of MG-specific imprinting sites. In competitive recognition tests and real-sample analysis, HPLC was used to determine the concentration of MG and the analogous compounds. Furthermore, the volume and elution times of the washing solvent (DI water) and elution solvent (acetonitrile) were optimized. Finally, MG-MISPE frits were successfully designed for selective enrichment of MG from Caesalpinia pulcherrima methanolic extract using a syringe, PTFE membrane, and MG-MIPs. Hence, MG-MISPE is a promising alternative of traditional extraction methods for selective extraction and enrichment of MG from complex plant matrices. The approach has potential to be applied to any compound of interest.

Electroantennographic and Behavioral Responses of the Melon fly, Zeugodacus cucurbitae (Coquillett), to Volatile Compounds of Ridge Gourd, Luffa acutangular L.

The melon fly, Zeugodacus cucurbitae (Coquillett), is a major invasive pest, widely distributed in the Asia-Pacific region and some parts of Africa. Melon fly attractants could improve the effectiveness of current pest management measures. Previous studies have shown that some host fruits are attractive to melon flies but few have investigated the chemical compounds responsible for their attraction. In this study, we aimed to identify the volatile compounds from Luffa acutangula L that attract Z. cucurbitae. In headspace trapping, chemical profiling identified 19 compounds from ridge gourds, with 1-pentadecene being the major component. EAG results revealed that seven compounds elicited antennal responses in Z. cucurbitae, and significant differences in antennal responses between male and female Z. cucurbitae adults were recorded to p-xylene, alpha-pinene, and 1-octadecene. Behavioral experiments demonstrated that the EAG-active compounds methyl isovalerate and methyl myristate had either attractive or repellent effects on Z. cucurbitae at different concentrations, and 1-octadecene attracted Z. cucurbitae. Our findings provide a theoretical basis producing repellents or attractants for effective Integrated Pest Management of Z. cucurbitae.