Methyl Research Articles

Dissolved gas analysis comparison of electrically stressed methyl ester and mineral oil

Methyl ester is considered one of the alternative substitutes to mineral oil as an insulating liquid. This study investigates the dissolved gas analysis (DGA) of the methyl ester derived from palm oil, under low energy discharge faults. The aims are to understand the gas composition and evaluate the applicability of the well-established fault interpretation methods for mineral oil to the methyl ester. Experimental procedures were conducted based on the International Electrotechnical Commission (IEC) standards. It involved simulating electrical breakdowns in laboratory conditions as per IEC-156 standard and analyzing gas samples using gas chromatography based on IEC-567. Results show that methyl ester oils produce similar types of gases as mineral oils but at higher concentrations. The interpretation of DGA results using fault identification methods such as Duval Triangle, Duval Pentagon, and IEC ratio indicates an overestimation of fault severity in methyl ester oils, and categorizing the faults as high energy discharge. However, the key gas method correctly identifies the discharge in both methyl ester and mineral oils. These findings suggest the need for adjustments in existing DGA methods to account for the higher gas concentrations in methyl ester oils, for effective condition monitoring and maintenance of transformers if it was filled with methyl ester oil.

Biochemical and nutritional analysis of seaweed (Iyengaria stellata) and its therapeutic significance, using antioxidant, antimicrobial, and hypoglycemic activities

Seaweeds have gained significant attention for their bioactive compounds and extensive use in pharmaceuticals, nutraceuticals and cosmeceuticals. Therefore, comprehensive analysis was conducted to investigate the nutritional composition, identify and quantify the Phyco-chemicals and to evaluate the pharmacological potential using hypoglycemic, antimicrobial and antioxidant activities of Iyengaria stellata extract. The results of nutritional analysis revealed 39.72±2.60 % total ash, 14.54±0.44 % crude fat, 9.61±0.60 % proteins, 5.29±0.52 % crude fibers, 10.49±1.00 % moisture content, and total energy was 108.26±2.01 Kcal 100 g−1 of dry powder. Approximately, 15 compounds were tentatively detected in ethyl acetate extract with major compounds being Pentadecanoic acid, 14-methyl-, easter (31.62 %), (Z) -9- stearic acid, methyl easter (13.36 %), Elaidic acid, methyl easter (11.46 %), Phytol (6.31 %), n-Hexadecanoic acid (7.47 %), Linolelaidic acid, methyl ester (5.64 %) and 1-octadecyne (5.34 %). Similarly, n-butanol extract contained 16 compounds with primary compounds being Hexadecanoic acid, methyl ester (25.96 %), Elaidic acid methyl ester (21.39 %), Linolelaidic acid methyl ester (11.53 %), Octadecanoic acid, methyl ester (5.89 %), and Hexanedioic acid, dioctyl ester (5.26 %). FT-IR analysis revealed the presence of similar groups of compounds i.e. alcohols, phenols, lipids, carboxylic acids, amines, aromatics, ketones and halogens. Total phenolic contents (TPC) in ethyl acetate and n-butanol extract were measured as 2.982±0.876 mg GAEg−1 and 1.538±0.711 mg GAE g−1, whereas Total Flavonoids contents (TFC) were 2.058 ± 0.121 mg QE g−1 and 1.614 ± 0.643 mg QE g−1, respectively. Ethyl acetate extract exhibited more antioxidant potential with an IC50 (2.59±1.34) compared to n-butanol extract (2.75±1.60). Moreover, n-butanol extract exhibited strong antimicrobial activity. The most susceptible strains were E. coli, S. aureus and P. aeruginosa. In terms of in-vivo hypoglycemic activity, the n-butanol extract proved to be more effective which significantly reduced the blood glucose level up to 226.17±3.43, 201.33±4.63 and 265.17±3.92 at 300, 200 and 100 mg kg−1 doses respectively after 24 h. In conclusion, the seaweed I. stellata exhibited significant potential in terms of its antioxidant, antimicrobial, and hypoglycemic properties.

Inhibition of nuclear factor-κB activation improves non-nitric oxide-mediated cutaneous microvascular function in reproductive-aged healthy women.

The transcriptional regulator nuclear factor-κB (NF-κB) is a mediator of endothelial dysfunction. Inhibiting NF-κB with salsalate is used to investigate inflammatory mechanisms contributing to accelerated cardiovascular disease risk. However, in the absence of disease, inhibition of NF-κB can impact redox mechanisms, resulting in paradoxically decreased endothelial function. This study aimed to measure microvascular endothelial function during inhibition of the transcriptional regulator NF-κB in reproductive-aged healthy women. In a randomized, single-blind, crossover, placebo-controlled design, nine healthy women were randomly assigned oral salsalate (1,500 mg, twice daily) or placebo treatments for 5 days. Subjects underwent graded perfusion with the endothelium-dependent agonist acetylcholine (ACh, 10-10 to 10-1 M, 33°C) alone and in combination with 15 mM NG-nitro-l-arginine methyl ester [l-NAME; nonselective nitric oxide (NO) synthase inhibitor] through intradermal microdialysis. Laser-Doppler flux was measured over each microdialysis site, and cutaneous vascular conductance (CVC) was calculated as flux divided by mean arterial pressure and normalized to site-specific maximum (CVC%max; 28 mM sodium nitroprusside + 43°C). The l-NAME sensitive component was calculated as the difference between the areas under the dose-response curves. During the placebo and salsalate treatments, the l-NAME sites were reduced compared with the control sites (both P < 0.0001). Across treatments, there was a significant difference between the control and l-NAME sites, where both sites shifted upward following salsalate treatment (both P < 0.0001), whereas the l-NAME-sensitive component was not different (P = 0.94). These data demonstrate that inhibition of the transcriptional regulator NF-κB improves cutaneous microvascular function in reproductive-aged healthy women through non-NO-dependent mechanisms.NEW & NOTEWORTHY The transcription factor nuclear factor-κB (NF-κB) regulates multiple aspects of innate and adaptive immunity by encoding for genes that participate in inflammation and impact endothelial function following NF-κB inhibition with salsalate treatment. Our results show that cutaneous microvascular function is increased through non-nitric oxide (NO)-dependent mechanisms following salsalate treatment in reproductive-aged healthy women.

Evolution of collisional condensation of biodiesel combustion particulate matter in engine exhaust pipe

To investigate the evolution of biodiesel combustion particulate matter (PM) within the engine exhaust system, PM samples were analyzed from diesel fuel, soybean oil methyl ester (SME), catering waste oil methyl ester (WME) and palm oil methyl ester (PME) at various locations along the engine exhaust pipe, and a gas-solid two-phase flow model of exhaust gas and PM was developed using the coupled computational fluid dynamics-discrete element method (CFD-DEM). The results indicate that the average primary particle diameter of biodiesel PM is smaller than that of diesel PM at the same position within the exhaust pipe, and it exhibits an increasing trend with respect to the iodine value of biodiesel. The adhesion forces of diesel, SME, WME, and PME PM at 0m downstream from the exhaust pipe were measured as 9.83 nN, 16.74 nN, 26.54 nN, and 34.31 nN, respectively. The biodiesel PM with higher mass density readily formed structurally stable particulate agglomerates at the inlet of the exhaust pipe. With an increase in exhaust flow velocity, there was a corresponding rise in particle collision frequency. The initial agglomeration probability of particles exhibited an increase followed by a subsequent decrease. The normal overlap of particle collisions decreased with an increase in the Young’s modulus of the particles, thereby reducing the likelihood of adsorption and adhesion during particle collision and hindering the formation of a greater number of particle aggregates.

High-throughput liquid chromatography-vacuum differential mobility spectrometry-mass spectrometry for the analysis of isomeric drugs of abuse in human urine.

The use of differential mobility spectrometry at low pressure coupled to liquid chromatography-mass spectrometry (LC-vDMS-MS) was investigated for the analysis of 13 drugs of abuse (DoA) including the following: cocaine, ecgonine methyl ester, cocaethylene, benzoylecgonine, norcocaine, tramadol, isomeric pairs of metabolites; O-desmethyl-cis-tramadol and N-desmethyl-cis-tramadol, and cannabinoids: Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabidiol, 11-hydroxy-Δ9-tetrahydrocannabinol, 11-nor-9carboxy-Δ9-tetrahydrocannabinol, and 11-nor-9carboxy-Δ9-tetrahydrocannabinol glucuronide. Different parameters were optimized for isomeric separation, such as LC mobile phase composition (20%-100% methanol acetonitrile and isopropanol, flow rate: 8-100 μL/min) and DMS separation voltage. Methanol and acetonitrile significantly affected the compensation voltage of the analytes and improved DMS separation. A short trap/elute LC-vDMS-SIM/MS screening method of 1min was developed to quantify 11 drugs of abuse (except THC/CBD), in addition to a 4-min LC-vDMS-SIM/MS method to identify and quantify five cannabinoids including the isomers THC/CBD and three THC metabolites. THC is the principal psychoactive constituent of cannabis and is a controlled substance in comparison to its isomeric counterpart CBD; this highlights the importance and challenges to resolve these isomeric pairs by analytical techniques. The signal responses were linear over a concentration range of 0.005-10μg/mL for the DoA and 1-1000 ng/mL for cannabinoids. The intraday and interday precision were better than 12.2% and accuracy better than 115%. Urine samples from subjects who tested positive for THC and/or cocaine during roadside drug testing were evaluated to assess the performance of the methods LC-vDMS-SIM/MS and LC-MRM/MS. Results show that the developed LC-vDMS-SIM/MS method presents similar performance to LC-MRM/MS with improved sample throughput.

Caudiquinol: A Meroterpenoid with an Intact C20 Geranylgeranyl Chain Isolated from Garcinia caudiculata

The tropical Garcinia genus of flowering plants is a prolific producer of aromatic natural products including polyphenols, flavonoids, and xanthones. In this study, we report the first phytochemical investigation of Garcinia caudiculata Ridl. from the island of Borneo. Fractionation, purification, and structure elucidation by MS and NMR resulted in the discovery of two meroterpenoids. One was a benzofuranone lactone previously isolated from Iryanthera grandis and Rhus chinensis, and the second was a new hydroquinone methyl ester that we named caudiquinol. Both natural products are rare examples of plant meroterpenoids with an intact geranylgeranyl chain.

Extrusion pretreatment of green Arabica coffee beans for lipid enhance extraction

Brazil is the world's largest producer and exporter of green coffee. Coffee beans have intrinsic and extrinsic defects that affect their chemical composition and the consumer perception of the beverage. The aim of this work is to evaluate the impact of extrusion process in green Arabica healthy and defective coffee beans in order to increase oil yield. The chromatographic analyses of the non-processed beans showed that caffeine, diterpenes and serotonin amides did not vary between the samples (p<0.05), while moisture and ash content varied significantly. The extrusion process followed by Soxhlet was optimized using central composite rotation design (CCRD) 22. Extrusion at the point selected as optimal (68ºC and 60 rpm) proved to be efficient when applied in combination with Soxhlet extraction, causing an increase of 61–81 % of oil yield (15.29 ± 0.42 % from defective beans and 16.42 ± 0.63 % from healthy beans), while its use combined with pressing (6.99 ± 0.08 %) was not significant compared to Soxhlet extraction alone (9.05 ± 0.24 %). Caffeine, diterpenes, serotonin amides and fatty acids methyl esters (FAMES) were analyzed in the oils where most of the fatty acids showed similar percentage values (p ≤ 0.05). The total diterpene content was higher in the extruded beans, while serotonin amides varied according to healthy and defective beans and pre-treatment (for defective grains), with defective grains showing consistently higher content compared to healthy grains (p ≥ 0.05). Caffeine content was similar between the healthy extruded, defective and defective extruded grains, with the lowest content in the healthy grain. It can be concluded that extrusion is a pre-treatment with a high impact in coffee oil yield. Green coffee oil is commercially explored by cosmetics and pharmaceutical industries due to its emollient and moisturizer properties. Besides, this oil protects skin against UV radiation. These properties are related to bioactive compounds present in the lipid fraction of coffee bean as diterpene esters, fatty acids and serotonin amides, which together justify this study.

Combined production of biofuel precursors, platform chemicals, and catalyst material from the integral processing of rice bran

This research reports first-time results regarding the complete processing of rice bran through the combination of extraction, processing hydrothermal, sulfonation, and trans-esterification procedures, generating biofuel precursors – fermentable sugars, bio-oil, hydro-char, and methyl esters – platform chemicals, and a catalyst material. Analyzes of XRD, FTIR, BET, SEM, EDS, calorific power, GC, and HPLC were employed for the product characterizations. Concerning the hydrothermal processing, the “temperature” and “biomass/water mass ratio” demonstrated an interesting influence on the results, where the thermal parameter had a greater impact on directing the process to obtain products resulting from the biomass polysaccharides thermal decomposition. At 260 °C, 11.98 and 11.40 g (100 g biomass)−1 of fermentable sugars and platform chemicals were obtained, respectively. At 300 °C, the production of bio-oil and hydro-char were benefited, yielding 10.48 and 30.19 g (100 g biomass)−1 of each component, respectively. The hydro-char-sulfonated catalyst demonstrated an attractive catalytic capacity in esterifying the free fatty acids of the rice bran oil, while simultaneously presenting some difficulty in transesterifying its triglycerides, indicating limitations in the mass transfer of the heterogeneous reaction. Using 4 wt% of catalyst, 90.1 % of the free fatty acids and 60.3 % of the triglycerides contained in the oil were trans-esterified into methyl esters after 6 h, respectively, with no decrease in its catalytic activity being observed after four reuses. This process combination presents an alternative arrangement for the full processing of lignocellulosic and oily biomasses, in addition to representing an approach matchless for the rice bran.

Synthesis of (E)‐Enaminoesters by a 1,6‐Addition/Fragmentation Cascade Involving Coumalic Acid Esters and Secondary Amines

AbstractCoumalic acid methyl ester (methyl coumalate), a biomass‐derived building block, was converted into (E)‐enaminoesters by an original uncatalyzed stereoselective 1,6‐addition/fragmentation cascade involving secondary amines. The transformation occurred under useful experimental conditions as a simple heating of a stoichiometric mixture of the starting compounds led to the desired products. The reaction could be extended to a range of alkyl coumalates and a variety of secondary amines. Given the original character of the transformation, the reaction mechanism was discussed. Therefore, the cascade is supposed to involve a 1,6‐conjugate addition followed by a fragmentation sequence leading ultimately to the decarboxylative elimination of (E)‐enaminoesters. Using this procedure, renewable coumalic acid proved to be a valuable alternative to fossil fuel‐based propiolates for the preparation of enaminoesters.

Construction and Performance Study of a Dual-Network Hydrogel Dressing Mimicking Skin Pore Drainage for Photothermal Exudate Removal and On-Demand Dissolution.

In recent years, negative pressure wound dressings have garnered widespread attentions. However, it is challenging to drain the accumulated fluid under negative pressures for hydrogel dressings. To address this issue, this study prepared a chemical/physical duel-network PEG-CMCS/AG/MXene hydrogel composed by chemical disulfide crosslinked network of four-arm polyethylene glycol/carboxymethyl chitosan (4-Arm-PEG-SH/CMCS), and the physical network of hydrogen bond of agar (AG). Under near-infrared light (NIR) irradiation, the PEG-CMCS/AG/MXene hydrogel undergoes photothermal heating due to integrate of MXene, which destructs the hydrogen bond network and allows the removal of exudate through a mechanism mimicking the sweat gland-like effect of skin pores. The photothermal heating effect also enables the antimicrobial activity to prevent wound infections. The excellent electrical conductivity of PEG-CMCS/AG/MXene can promote cell proliferation under the external electrical stimulation (ES) in vitro. The animal experiments of full-thickness skin defect model further demonstrate its ability to accelerate wound healing. The conversion between thioester and thiol achieved with L-cysteine methyl ester hydrochloride (L-CME) can provides the on-demand dissolution of the dressing in situ. This study holds promises to provide a novel solution to the issue of fluid accumulations under hydrogel dressings and offers new approaches to alleviating or avoiding the significant secondary injuries caused by frequent dressing changes.

In-silico study unveils potential phytocompounds in Andrographis paniculata against E6 protein of the high-risk HPV-16 subtype for cervical cancer therapy

Despite therapeutic advancements, cervical cancer caused by high-risk subtypes of the human papillomavirus (HPV) remains a leading cause of cancer-related deaths among women worldwide. This study aimed to discover potential drug candidates from the Asian medicinal plant Andrographis paniculata, demonstrating efficacy against the E6 protein of high-risk HPV-16 subtype through an in-silico computational approach. The 3D structures of 32 compounds (selected from 42) derived from A. paniculata, exhibiting higher binding affinity, were obtained from the PubChem database. These structures underwent subsequent analysis and screening based on criteria including binding energy, molecular docking, drug likeness and toxicity prediction using computational techniques. Considering the spectrometry, pharmacokinetic properties, docking results, drug likeliness, and toxicological effects, five compounds—stigmasterol, 1H-Indole-3-carboxylic acid, 5-methoxy-, methyl ester (AP7), andrographolide, apigenin and wogonin—were selected as the potential inhibitors against the E6 protein of HPV-16. We also performed 200 ns molecular dynamics simulations of the compounds to analyze their stability and interactions as protein–ligand complexes using imiquimod (CID-57469) as a control. Screened compounds showed favorable characteristics, including stable root mean square deviation values, minimal root mean square fluctuations and consistent radius of gyration values. Intermolecular interactions, such as hydrogen bonds and hydrophobic contacts, were sustained throughout the simulations. The compounds displayed potential affinity, as indicated by negative binding free energy values. Overall, findings of this study suggest that the selected compounds have the potential to act as inhibitors against the E6 protein of HPV-16, offering promising prospects for the treatment and management of CC.

Isolation of aflatoxin biosynthetic inhibitor from Chondrostereum purpureum mushroom culture filtrate

Aflatoxins (AFs) are highly toxic mycotoxins produced by the fungi, Aspergillus flavus and Aspergillus parasiticus. AFs pose severe health risks owing to their acute toxicity and carcinogenic properties. The control of AF contamination remains significantly challenging despite the extensive efforts toward controlling it. Here, we investigated the potential of mushroom extracts as a source of AF biosynthetic inhibitors. The A.parasiticus mutant strain, NFRI-95, that accumulates an AF biosynthesis intermediate, norsolorinic acid, was used in the bioassay to detect the inhibitory activity against AF biosynthesis. The screening of 195 mushroom extracts revealed that the culture filtrate extract of Chondrostereum purpureum exhibited strong inhibitory activity against AF biosynthesis. Next, large-scale culturing of C.purpureum was performed to isolate the compounds accounting for the inhibitory activity. The culture filtrate was extracted with ethyl acetate, after which the active compound was isolated by silica gel column chromatography and preparative high performance liquid chromatography (HPLC). The active compound was identified as cyclo(Val-Pro) by spectroscopic analyses. Further, four stereoisomers of cyclo(Val-Pro) were synthesized by the condensation of the N-Boc derivatives of d- and l-valine with the methyl esters of d- and l-proline. The naturally isolated compound was identified as cyclo(l-Val-l-Pro) by comparing its retention time with those of synthetic compounds by chiral HPLC analysis and CD spectra. The IC50 value of cyclo(L-Val-L-Pro) was 2.4mM, whereas the LD, DL, and DD isomers exhibited weaker activities, with IC50 values of >5mM.

Investigation of biodiesel blends and hydrogen addition effects on CI engine characteristics through statistical analysis

This study investigates the performance, combustion, and emission characteristics of a single-cylinder compression ignition engine fueled with blends of Soy methyl ester (BS100) and macauba methyl ester (BM100) biodiesels, with hydrogen addition. Biodiesel blends (BSM10 - BSM50), and hydrogen addition (2–5%) were tested at various engine loads and speeds. The optimal blend, BSM20 (80% BS100 + 20% BM100), showed up to 7.8% higher brake thermal efficiency and 6.2% lower brake-specific fuel consumption than diesel. Emissions were significantly reduced: NOx by 12.9%, HC by 22.4%, CO by 27.5%, and smoke opacity by 18.7%. Adding 5% hydrogen to BSM20 further improved performance, reducing fuel consumption by up to 3.1% and increasing thermal efficiency by 2.5%, with substantial reductions in hydrocarbon and carbon monoxide emissions. This investigation highlights the potential of sustainable biodiesel blends and hydrogen as viable alternatives to conventional diesel fuels, offering significant environmental benefits and enhanced engine performance.

Evaluating the potential impact of sodium-glucose cotransporter-2 inhibitor "canagliflozin" on the hepatic damage triggered by hypertension in rats.

Hypertension (HTN) is a prevalent chronic disease. HTN and liver disease association is extensively noted. Thus, finding a medication that can alleviate HTN and its accompanying liver insult would be promising. This study investigated the potential impacts of canagliflozin "sodium-glucose cotransporter-2 inhibitor" on the liver of the Nω-nitro-L-arginine methyl ester (L-NAME)-induced HTN rat model. Twenty-four adult male rats were divided into four groups; negative control group, canagliflozin group, L-NAME group: 50 mg/kg of L-NAME was injected daily for 5 weeks and L-NAME + canagliflozin group: 1 week after L-NAME injection both L-NAME + canagliflozin (40 mg/kg) were given concomitantly daily for further 4 weeks. Liver functions, serum lipid profile, hepatic oxidative/nitrative stress biomarkers, gene expression of lipogenic enzymes, B-cell lymphoma 2 (Bcl2), and DNA fragmentation, were measured. Besides, hepatic histology and immunohistochemistry of nuclear factor kappa B (NF-κB) and endothelial nitric oxide synthase (eNOS) were assessed. Canagliflozin improved hepatic lipogenesis via the downregulation of fatty acid synthase (FAS) and transcriptional regulatory element binding protein 1c (SREBP1c) genes leading to an improved serum lipid profile. Further, canagliflozin modified the eNOS/inducible nitric oxide synthase (iNOS) pathway and decreased the NF-κB immunoreactivity besides restoring the oxidants-antioxidants balance; increased reduced glutathione concomitant with declined malondialdehyde. This improvement of the liver was mirrored by the significant restoration of liver architecture and confirmed by the preserved liver DNA content and upregulation of the antiapoptotic Bcl2 mRNA level and attenuation of the alanine transaminase, aspartate aminotransferase. In conclusion, canagliflozin is a promising anti-hypertensive and hepatic-supportive medication. RESEARCH HIGHLIGHTS: Canagliflozin's antioxidant, anti-inflammatory, anti-lipogenic, and antiapoptotic characteristics mitigate remote liver compromise caused by hypertension. Canagliflozin can be exploited as a hepatoprotective and antihypertensive medication.

Gestationally administered RAS modulators reprogram endotoxic cardiovascular and inflammatory profiles in adult male offspring of preeclamptic rats.

Previous studies showed that preeclampsia (PE) amplifies cardiovascular dysfunction induced by endotoxemia in adult male, but not female, offspring. Here, we asked if such aggravated endotoxic insult could be nullified by modulators of the renin-angiotensin system (RAS). PE was induced by gestational administration of Nω-nitro-L-arginine methyl ester(L-NAME, a nitric oxide synthase inhibitor). Adult male offspring of PE mothers treated gestationally with angiotensin 1-7 (Ang1-7, angiotensin II-derived vasodilator), losartan (AT1 receptor antagonist), pioglitazone (peroxisome proliferator-activated receptor gamma, PPARγ, agonist), or combined losartan/pioglitazone were instrumented with femoral indwelling catheters and challenged intravenously with a 5-mg/kg dose of lipopolysaccharides (LPS, 5mg/kg). LPS caused significant decreases in blood pressure (BP) and spectral index of overall heart rate variability and increases in heart rate and left ventricular contractility (dP/dtmax). These effects were mostly reduced to similar magnitudes by individual drug therapies. In offspring born to Ang1-7-treated dams, the spectral index of cardiac sympathovagal balance showed elevated sympathetic dominance in response to LPS. Immunohistochemistry revealed that Ang1-7, but not losartan/pioglitazone, abolished the exaggerated increases in toll-like receptor 4 (TLR-4) expression caused by PE/LPS in heart tissues and neuronal circuits of brainstem rostral ventrolateral medulla (RVLM). By contrast, the losartan/pioglitazone regimen, but not Ang1-7, decreased and increased angiotensin converting enzyme (ACE) and ACE2 expression, respectively. Together, gestational fetal reprogramming of Ang II (depression) and Ang1-7 (activation) arms of RAS effectively counterbalance worsened endotoxic cardiovascular and inflammatory profiles in adult male offspring of PE rats.

Biodiesel Production from Waste Cooking Oil Using Recombinant Escherichia coli Cells Immobilized into Fe3O4–Chitosan Magnetic Microspheres

Developing reusable and easy-to-operate biocatalysts is of significant interest in biodiesel production. Here, magnetic whole-cell catalysts constructed through immobilizing recombinant Escherichia coli cells (containing MAS1 lipase) into Fe3O4–chitosan magnetic microspheres (termed MWCC@MAS1) were used for fatty acid methyl ester (FAME) production from waste cooking oil (WCO). During the preparation process of immobilized cells, the effects of chitosan concentration and cell concentration on their activity and activity recovery were investigated. Optimal immobilization was achieved with 3% (w/v) chitosan solution and 10 mg wet cell/mL cell suspension. Magnetic immobilization endowed the whole-cell catalysts with superparamagnetism and improved their methanol tolerance, enhancing the recyclability of the biocatalysts. Additionally, we studied the effects of catalyst loading, water content, methanol content, and reaction temperature on FAME yield, optimizing these parameters using response surface methodology and Box–Behnken design. An experimental FAME yield of 89.19% was gained under the optimized conditions (3.9 wt% catalyst loading, 22.3% (v/w) water content, 23.0% (v/w) methanol content, and 32 °C) for 48 h. MWCC@MAS1 demonstrated superior recyclability compared to its whole-cell form, maintaining about 86% of its initial productivity after 10 cycles, whereas the whole-cell form lost nearly half after just five cycles. These results suggest that MWCC@MAS1 has great potential for the industrial production of biodiesel.

Application of mixed phosphorus/sulfur ligands based on terpenoids in Pd-catalyzed asymmetric allylic substitution and Rh-catalyzed hydrogenation.

A small library of easily prepared diamidophosphite-sulfides based on 1,3-thioether alcohols, primarily of terpenoid nature, was developed. Upon complexation with Pd(II) ions, these hemilabile ligands showed the ability to form both P,S-chelates and complexes with two ligands P-monodentately bonded to the metal. The structures of the ligands and their complexes were determined by 2D NMR spectroscopy and X-ray diffraction. The use of these stereoselectors provided up to 95% ee in the classic Pd-catalyzed asymmetric allylic substitution reactions of (E)-1,3-diphenylallyl acetate with C- and N-nucleophiles and up to 80% ee in the Pd-mediated allylic alkylation of cinnamyl acetate with β-ketoesters. In addition, ee values of up to 90% with quantitative conversion were achieved in the Rh-catalyzed asymmetric hydrogenation of methyl esters of unsaturated acids. The effects of the structural parameters, reaction conditions and ligand-to-metal ratio on the catalytic results are discussed.

Antispasmodic Activity of Light-Roasted Coffee Extract and Its Potential Use in Gastrointestinal Motility Disorders

Antispasmodic agents are crucial in managing gastrointestinal motility disorders by modulating muscle contractions and reducing symptoms like cramping and diarrhea. This study investigated the antispasmodic potential of different coffee bean extracts, including light coffee (LC), medium coffee (MC), and dark coffee (DC), on ileum contractions induced by potassium chloride (KCl), and elucidated their mechanisms of action using in vitro isolated tissue techniques. The results demonstrated that all coffee extracts reduced spontaneous contractions of rat ileum tissue in a dose-dependent manner. Among these, LC showed the most significant reduction in ileum contractions, particularly at higher concentrations. The key findings reveal that LC at 5 mg/mL significantly reduced CaCl2-induced contractions in isolated rat ileum tissue, indicating that LC may inhibit calcium influx or interfere with calcium signaling pathways. The presence of nifedipine, propranolol, and N-nitro-L-arginine methyl ester (L-NAME) have been confirmed in their involvement; they block calcium influx and calcium channels and activate β-adrenergic pathways as part of LC’s mechanism of action. The presence of their active compounds, particularly chlorogenic acid and caffeine, likely contributes to the observed antispasmodic effects. These findings suggest that LC exerts its antispasmodic effects by targeting key mechanisms involved in muscle spasms and intestinal motility, providing a potential for managing such conditions.

Reactivity of a Morita-Baylis-Hillman adduct derivative bearing a triphenylamine moiety with lysine models.

The reactivity of Morita-Baylis-Hillman Adduct (MBHA) derivative 7 was studied with different primary amine derivatives such as n-butylamine, Na-acetyl-L-lysine methyl ester, and a poly-(L-lysine) derivative as lysine models to obtain information about the possible reactions in complex protein environments. MBHA derivative 7 reacted with n-butylamine or Na-acetyl-L-lysine methyl ester producing monoadducts 9a or 9c, which showed bright emission features in the green region at 526-535 nm with photoluminescence quantum yield values in solutions of 73% and 51%, respectively. Based on these results, MBHA derivative 7 can be considered an interesting new fluorogenic probe potentially useful in the labelling of basic amino acid residues. Furthermore, similar to other MBHA derivatives, compound 7 showed the tendency to produce diadducts especially in polar solvents system where specific interactions between the extended aromatic moieties may play a major role.

Advancing biorefinery technologies through transesterification and hydrothermal liquefaction for biodiesel and bioproducts production

BackgroundThe multicriteria assessment of advancing biorefinery to produce biodiesel (fatty acid methyl ester), glycerol, and torrefied pellets is a strategic approach towards sustainable development. MethodsA successive transesterification process was applied to separate lipids with alcohol, with a 1:7 mass-to-mass ratio in the presence of a heterogeneous catalyst of chitosan/polyvinyl alcohol-sodium hydroxide (CS/PVA-NaOH), to produce biodiesel and glycerol. Moreover, the remaining biomass is extracted to produce torrefied pellets by applying torrefaction through hydrothermal liquefication at 200–300 ℃ temperature. The biorefinery system using 613 kg organic fraction of municipal solid waste (OFMSW) produced 127.3 L of biodiesel, 14.5 kg of glycerol, and 387.5 kg of torrefied pellets. The whole systematic approach revealed two distinct areas with required characterized equipment such as dryer (A = 721.28m2), suspended in tank (V = 751.56m3), reactor (V = 721.56m3), cyclone (A = 743.48 m2), grinder (Q = 1352.31 m3/h), compactor (Q = 1367.31 m3/h), correspondingly. A gate-to-gate life cycle assessment (LCA) was performed for life cycle impact assessment (LCIA) through GaBi by using the ReCiPe 2016 Mid-point (H) and Endpoint (H) approach with a functional unit of 1000 kg municipal solid waste (MSW). Significant findingsThe economic assessment reveals the economic feasibility of the biorefinery project. The annual revenue determined the profitability index, which is $ 1.59 million annually, with a payback period of 1.8 years. The environmental analysis determined an eco-friendly production unit which can save 13.6% of carbon emissions by alternate use of photovoltaic energy. Conclusively, the calculated values and findings prove that biorefinery development using OFMSW is scientifically a win-win situation and notably assists in achieving circular bioeconomy and sustainable development goals (SDGs).