Additional Methyl Research Articles

Recurrent Small Variants in NESP55/NESPAS Associated with Broad GNAS Methylation Defects and Pseudohypoparathyroidism Type 1b.

Pseudohypoparathyroidism type 1B (PHP1B) is associated with epigenetic changes on the maternal allele of the imprinted GNAS gene that inhibit expression of the alpha subunit of Gs (Gsα), thereby leading to parathyroid hormone resistance in renal proximal tubule cells where expression of Gs from the paternal GNAS allele is normally silent. Although all patients with PHP1B show loss of methylation for the exon A/B differentially methylated region (DMR), some patients with autosomal dominant PHP1B (AD-PHP1B) and most patients with sporadic PHP1B have additional methylation defects that affect the DMRs corresponding to exons XL, AS1, and NESP. Because the genetic defect is unknown in most of these patients, we sought to identify the underlying genetic basis for AD-PHP1B in two multigenerational families with broad GNAS methylation defects and negative clinical exomes. Genome sequencing identified small GNAS variants in each family that were also present in unrelated PHP1B subjects in a replication cohort. Maternal transmission of one GNAS microdeletion showed reduced penetrance in some unaffected patients. Expression of AS transcripts was increased, and NESP was decreased, in cells from affected patients. These results suggest that the small deletion activate AS transcription leading to methylation of the NESP DMR with consequent inhibition of NESP transcription, and thereby provide a potential mechanism for PHP1B.

Mathematical model of RNA-directed DNA methylation predicts tuning of negative feedback required for stable maintenance.

RNA-directed DNA methylation (RdDM) is a plant-specific de novo methylation pathway that is responsible for maintenance of asymmetric methylation (CHH, H = A, T or G) in euchromatin. Loci with CHH methylation produce 24 nucleotide (nt) short interfering (si) RNAs. These siRNAs direct additional CHH methylation to the locus, maintaining methylation states through DNA replication. To understand the necessary conditions to produce stable methylation, we developed a stochastic mathematical model of RdDM. The model describes DNA target search by siRNAs derived from CHH methylated loci bound by an Argonaute. Methylation reinforcement occurs either throughout the cell cycle (steady) or immediately following replication (bursty). We compare initial and final methylation distributions to determine simulation conditions that produce stable methylation. We apply this method to the low CHH methylation case. The resulting model predicts that siRNA production must be linearly proportional to methylation levels, that bursty reinforcement is more stable and that slightly higher levels of siRNA production are required for searching DNA, compared to RNA. Unlike CG methylation, which typically exhibits bi-modality with loci having either 100% or 0% methylation, CHH methylation exists across a range. Our model predicts that careful tuning of the negative feedback in the system is required to enable stable maintenance.

Relationship between structure and properties of bio-based aromatic ionic liquids for tribological applications

This study examined six phosphonium-based room-temperature ionic liquids (PRTILs) having trihexyltetradecyl- or tributyltetradecyl-phosphonium cations with saccharinate, salicylate, or benzoate anions, and obtained a feature parameter to correlate their cationic chain length, anionic ring size, and contact angle with tribological properties. PRTILs with trihexyltetradecyl-phosphonium cations had lower coefficient of friction (COF) and wear than PRTILs with tributyltetradecyl- phosphonium cations, a trend attributed to the additional methylene groups providing lower contact angle. For either cation, PRTILs with the saccharinate anion exhibited much lower COF and wear than single-ring anions, due to the formation of a low-shear-strength-tribofilm facilitated by the double-ring structure and sulfur of saccharinate. Overall, this study revealed PRTIL interfacial mechanisms that can be used to identify anion-cation combinations with optimal tribological performance.

Bulking up: the impact of polymer sterics on emulsion stability.

Encapsulation of hydrophobic active ingredients is critical for targeted drug delivery as water-insoluble drugs dominate the pharmaceutical marketplace. We previously demonstrated hexadecane-in-water emulsions stabilized with a pH-tunable polymer, poly(acrylic acid) (PAA), via a steric layer preventing particle aggregation. Using vibrational sum frequency scattering spectroscopy (VSFSS), here we probe the influence of steric hindrance on emulsion colloidal stability by tailoring the molecular weight of PAA and by adding an additional methyl group to the polymer backbone via poly(methacrylic acid) (PMAA) at pH 2, 4, and 6. At low polymer molecular weight (2 and 10 kDa), PAA adsorption is entropy driven and akin to surfactant-mediated stabilization. With 450 kDa PAA, the longer polymer chain emphasizes enthalpically favored polymer-oil interactions to initially coat the surface, and forms layers at increasing molecular weight (1000 and 4000 kDa). PMAA exhibits better oil-solubility than PAA at low concentrations but cannot accommodate the steric hindrance at higher concentrations leading to disorder. Finally, we connect our molecular-level understanding of PAA ordering with temperature-dependent dynamic light scattering experiments and observe that emulsions coated with PAA at pH 2 and 4 maintain colloidal stability from 0-90 °C, making PAA a promising polymer for hydrophobic drug delivery.

Low-Energy Electron Interactions with Methyl-p-benzoquinone: A Study of Negative Ion Formation.

Methyl-p-benzoquinone (MpBQ, CH3C6H3(=O)2) is a prototypical molecule in the study of quinones, which are compounds of relevance in biology and several redox reactions. Understanding the electron attachment properties of MpBQ and its ability to form anions is crucial in elucidating its role in these reactions. In this study, we investigate electron attachment to MpBQ employing a crossed electron-molecular beam experiment in the electron energy range of approximately 0 to 12 eV, as well as theoretical approaches using quantum chemical and electron scattering calculations. Six anionic species were identified: C7H6O2 -, C7H5O2 -, C6H5O-, C4HO-, C2H2 -, and O-. The parent anion is formed most efficiently, with large cross sections, through two resonances at electron energies between 1 and 2 eV. Potential reaction pathways for all negative ions observed are explored, and the experimental appearance energies are compared with calculated thermochemical thresholds. Although exhibiting similar electron attachment properties to pBQ, MpBQ's additional methyl group introduces entirely new dissociative reactions, while quenching others, underscoring its distinctive chemical behavior.

Exploring the Potential of Al(III) Photosensitizers for Energy Transfer Reactions.

Three homoleptic Al(III) complexes (Al1-Al3) with different degrees of methylation at the 2-pyridylpyrrolide ligand were systematically tested for their function as photosensitizers (PS) in two types of energy transfer reactions. First, in the generation of reactive singlet oxygen (1O2), and second, in the isomerization of (E)- to (Z)-stilbene. 1O2 was directly evidenced by its characteristic NIR emission at around 1276 nm and indirectly by the reaction with an organic substrate [e.g. 2,5-diphenylfuran (DPF)] using in situ UV/vis spectroscopy. In a previous study, the presence of additional methyl groups was found to be beneficial for the photocatalytic reduction of CO2 to CO, but here Al1 without any methyl groups exhibits superior performance. To rationalize this behavior, a combination of photophysical experiments (absorption, emission and excited state lifetimes) together with photostability measurements and scalar-relativistic time-dependent density functional theory calculations was applied. As a result, Al1 exhibited the highest emission quantum yield (64%), the longest emission lifetime (8.7 ns) and the best photostability under the reaction conditions required for the energy transfer reactions (e.g. in aerated chloroform). Moreover, Al1 provided the highest rate constant (0.043 min-1) for the photocatalytic oxygenation of DPF, outperforming even noble metal-based competitors such as [Ru(bpy)3]2+. Finally, its superior photostability enabled a long-term test (7 h), in which Al1 was successfully recycled seven times, underlining the high potential of this new class of earth-abundant PSs.

Triterpenoid and trichothecenes from a rhizospheric soil-derived Paramyrothecium sp. KMU22107

A new phthalide derivative named paramlyktone (1) and a new arborinane-type triterpenoid named paramyrpenoid (2), together with ten previously described trichothecenes derivatives (3–12) were isolated and identified from a rhizospheric soil-derived Paramyrothecium sp. KMU22107 associated with Delphinium yunnanense. Their structural elucidation was achieved by the comprehensive analysis of spectroscopic data and comparison with literature values. Notably, paramyrpenoid (2) was the first example of an arborinane-type triterpenoid with a double bond at Δ12(13) and an additional methyl motif at C-8. This was the first report of arborinane-type triterpenoids from a fungus belonging to Paramyrothecium genus. In pharmacological studies, paramyrpenoid (2) demonstrated significant cytotoxic activity against the HL-60, SW480, A-549, MDA-MB-231 and SMMC-7721 cell lines, with IC50 values from 2.0 to 16.1 μM. Compounds 1 and 2 were also evaluated for anti-inflammatory, anti-acetylcholinesterase (AChE), and protein tyrosine phosphatase 1B (PTP1B) inhibitory activities in vitro.

Comparative performance analysis of mussel-inspired polydopamine, polynorepinephrine, and poly-α-methyl norepinephrine in electrochemical biosensors.

Polydopamine (PDA) has garnered significant interest for applications in biosensors, drug delivery, and tissue engineering. However, similar polycatecholamines like polynorepinephrine (PNE) with additional hydroxyl groups and poly-α-methylnorepinephrine (PAMN) with additional hydroxyl and methyl groups remain unexplored in the biosensing domain. This research introduces three innovative biosensing platforms composed of ternary nanocomposite based on reduced graphene oxide (RGO), gold nanoparticles(Au NPs), and three sister polycatecholamine compounds (PDA, PNE, and PAMN). The study compares and evaluates the performance of the three biosensing systems for the ultrasensitive detection of Mycobacterium tuberculosis (MTB). The formation of the nanocomposites was meticulously examined through UV-Visible, Raman, XRD, and FT-IR studies with FE-SEM and HR-TEM analysis. Cyclic voltammetry and differential pulse voltammetry measurements were also performed to determine the electrochemical characteristics of the modified electrodes. Electrochemical biosensing experiments reveal that the RGO-PDA-Au, RGO-PNE-Au, and RGO-PAMN-Au-based biosensors detected target DNA up to a broad detection range of 0.1 × 10-8 to 0.1 × 10-18M, with a low detection limit (LOD) of 0.1 × 10-18, 0.1 × 10-16, and 0.1 × 10-17M, respectively. The bioelectrodes were proved to be highly selective with excellent sensitivities of 3.62 × 10-4mAM-1 (PDA), 7.08 × 10-4mAM-1 (PNE), and 6.03 × 10-4mAM-1 (PAMN). This study pioneers the exploration of two novel mussel-inspired polycatecholamines in biosensors, opening avenues for functional nanocoatings that could drive further advancements in this field.

Innovative application of CRISPR for eliminating Ustiloxin in Cordyceps militaris: Enhancing food safety and quality

Cordyceps militaris (L.) Fr. Has long been recognized as a valuable functional food consumed in numerous countries. However, biosynthetic gene clusters of this species and safety regarding mycotoxin production remain largely unexplored. In this study, a ribosomally synthesized and post-translationally modified peptide (RiPP) cluster responsible for the production of cyclopeptide mycotoxins in Cordyceps was unveiled via genome mining. Ustiloxin B and a novel, predominant and Cordyceps specific ustiloxin I were confirmed by extraction and structural analysis. The difference between Ustiloxins I and B lied in the side chain at C19, where an additional methyl substituent in Ustiloxin I resulted in an alanine moiety substitution for glycine of Ustiloxin B. The simultaneous deletion of the two adjacent core genes, CmustYb and CmustYa, using a single guide RNA designed in the intergenic region, and subsequent in-situ complementation via AMA-mediated CRISPR/Cas9 system confirmed the RiPP cluster's responsibility for ustiloxin production. The cultivation of the edited strain yielded ustiloxin-free fruiting bodies without affecting agronomic characters. PCR and genome resequencing confirmed the absence of any off-target events or foreign sequence remnants. This study marks a significant advancement in utilizing CRISPR technology to control ustiloxins in food, underscoring its broader implications for food safety and quality improvement.

REGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS BY PHYTOSTEROL: ACTIONS AND MECHANISM OF ACTION

Phytosterols (PS), commonly referred to as plant sterols, are naturally occurring chemicals found in plants that resemble cholesterol in structure but have an additional methyl (campesterol) or ethyl (β-sitosterol) group in the side chain. The present review was based on the regulation of the hypothalamic-pituitary-adrenal axis by phytosterol: actions and mechanism of action. PS have been shown to have endocrine-disrupting properties, and studies on humans, rats, mice, goldfish (Carassius auratus), and Japanese quail have all reported experiencing this effect. Dietary PS has been shown to accumulate in the brain lately. Dietary β-sitosterol has the ability to cross the blood–brain barrier (BBB) and build up permanently in the membranes of brain cells. The stress response, which consists of a complex interplay between elements of the central nervous system (CNS) and peripheral systems such the endocrine, immunological, and cardiovascular systems, is triggered by exposure to environmental, physical, or physiological stressors. Under stressful circumstances, the HPA axis mediates the physiological maintenance of homeostasis. In conclusion, adult male quails fed PS alone had lower testosterone concentrations in their plasma and pituitary without appreciably changing their levels of LH. Furthermore, LH release from the pituitary gland and testosterone release from the testes were both markedly increased by cGnRH-1 stimulation. In contrast to control animals, quails fed PS had lower amounts of testosterone and LH.

HGG-06. MOLECULAR PATTERNS OF PEDIATRIC HIGH-GRADE GLIOMAS IN SOUTHEAST ASIA

Abstract BACKGROUND Molecular characteristics of pediatric high-grade gliomas are largely based on cohorts derived from North America and Europe. In this study, we compare the molecular findings of a Southeast Asian cohort of pediatric high-grade gliomas with published data. METHODS We collated clinical, histopathological, and molecular data from pediatric high-grade gliomas diagnosed in our laboratory over the past 5 years. Molecular testing methods used included Illumina’s Childhood Cancer Panel (26 cases), FoundationOne’s CDx panel (2 cases), and Archer FUSIONPlex Pan Solid Tumour v2 panel (2 cases). 7 cases had no molecular data. 11 cases underwent additional DNA methylation analysis using Illumina’s Infinium MethylationEPIC v1.0 kit. RESULTS 37 cases of pediatric high-grade gliomas from 34 patients were identified. Patient age ranged from 2 to 26 years (median 14 years). The male-female ratio was 1.1:1. Diffuse midline gliomas, H3K27-altered (DMG, H3K27-altered) constituted 51% of the cases (19/37), followed by diffuse pediatric-type high-grade gliomas, H3-wildtype and IDH-wildtype (32%; 12/37) and diffuse hemispheric gliomas H3G34-mutant (16%; 6/37). The commonest genes with pathogenic single nucleotide variants were TP53 (79%;22/28), followed by H3F3A (54%;15/28). The commonest amplified genes were MYCN and EGFR (both 4/28; 14%). Three gene fusions were detected, none of which arose from infants – 2 were found in diffuse pediatric-type high-grade gliomas, H3-wildtype and IDH-wildtype (CSTF3::ALK and PRCC::NTRK1 fusions), and one occurred in a DMG, H3K27-altered (ERC1::RET fusion). The most common methylation groups identified were DMG, H3K27-altered and diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype, MYCN subtype (both 3/11; 27%). CONCLUSIONS Although small, our Southeast Asian cohort comprised a higher percentage of TP53-mutant high-grade gliomas amongst all pediatric high-grade gliomas as a group. The commonest amplified genes were MYCN and EGFR. We detected gene fusions in non-infant gliomas. These findings suggest geographical differences in the biology of pediatric high-grade gliomas.

Methyl‐ and Methoxy‐substituted 2‐(Pyridin‐2‐yl)‐4‐(4‐aminophenyl)quinazolines: Synthesis and Photophysical Properties

AbstractA series of novel 2‐(2‐pyridyl)quinazoline luminophores containing a donor aryl fragment at position 4 and methyl or methoxy groups at benzene ring has been synthesized by efficient three‐step route. The linear optical properties have been studied by UV/Vis absorption and photoluminescence spectra in two solvents. We revealed that introduction of additional methyl group or the replacement of methyl substituents with methoxy ones lead to sequentially shift of absorption and emission maximum to blue region. 9H‐Carbazol‐9‐yl‐containing derivative is characterized by hypsochromically shifted absorption band compared to its NEt2 and NPh2 counterparts. Unlike 9H‐carbazol‐9‐yl‐derivative, Et2N‐ and Ph2N‐bearing quinazolines demonstrate considerable decrease in quantum yield values when going from toluene to MeCN. Solvatochromic properties have been explored, the pronounced bathochromic shift was observed in fluorescence spectra with the increase of solvents polarity. Moreover, the compounds show significant shift of emission band with the increase of water fraction in DMSO/H2O mixture. Two‐photon optical properties have been also studied, the two‐photon absorption cross‐sections in MeCN and toluene reached 120 GM and 210 GM, respectively. The presence of additional methyl group has little impact on δTPA value, while introduction of methoxy substituents dramatically decreases TPA cross sections. Additionally, a quantum‐chemical calculations of synthesized compounds were performed to support the experimental data.

In Vitro and In Silico Studies on Cytotoxic Properties of Oxythiamine and 2'-Methylthiamine.

It is important to search for cytostatic compounds in order to fight cancer. One of them could be 2'-methylthiamine, which is a thiamine antimetabolite with an additional methyl group at the C-2 carbon of thiazole. So far, the cytostatic potential of 2'-methylthiamine has not been studied. We have come forward with a simplified method of synthesis using commercially available substrates and presented a comparison of its effects, as boosted by oxythiamine, on normal skin fibroblasts and HeLa cancer cells, having adopted in vitro culture techniques. Oxythiamine has been found to inhibit the growth and metabolism of cancer cells significantly better than 2'-methylthiamine (GI50 36 and 107 µM, respectively), while 2'-methylthiamine is more selective for cancer cells than oxythiamine (SI = 180 and 153, respectively). Docking analyses have revealed that 2'-methylthiamine (ΔG -8.2 kcal/mol) demonstrates a better affinity with thiamine pyrophosphokinase than thiamine (ΔG -7.5 kcal/mol ) and oxythiamine (ΔG -7.0 kcal/mol), which includes 2'-methylthiamine as a potential cytostatic. Our results suggest that the limited effect of 2'-methylthiamine on HeLa arises from the related arduous transport as compared to oxythiamine. Given that 2'-methylthiamine may possibly inhibit thiamine pyrophosphokinase, it could once again be considered a potential cytostatic. Thus, research should be carried out in order to find the best way to improve the transport of 2'-methylthiamine into cells, which may trigger its cytostatic properties.

Syntheses and reactivities of polymethylated ferrocenes: The effect of methylation upon electrophilic addition

A series of ferrocene derivatives with three, four, five, six and seven methyl group substituents has been prepared and characterized by multinuclear NMR, high resolution mass spectrometry and elemental analyses. Chemical oxidation of heptamethylferrocene with silver tetrafluoroborate produced paramagnetic heptamethylferricenium tetrafluorborate and the structure of one isomer of [C5Me4HFeC5Me3H2][BF4] was determined by single crystal X-ray diffraction. Electrochemical studies of the entire series of iron sandwich compounds from ferrocene to decamethylferrocene reveal a highly linear shift of the reversible half-wave potential (E1/2) for the FeIII/FeII couple such that each additional methyl group lowers E1/2 by an average of 54 mV. A new triple-decker complex has been synthesized by the addition of a ruthenium electrophile, [Cp*Ru(NCMe)3][PF6], (Cp* = C5Me5) to heptamethylferrocene, Me7FcH. While previous work established that reactions between [Cp*Ru(NCMe)3][PF6] and ferrocene derivatives with eight or more methyl group substituents readily form bimetallic complexes, reactions with ferrocene derivatives with six or fewer methyl groups brought about ring abstraction and afforded only monometallic products. Thus it may be concluded that there is a “tipping point” in the series of polymethylated ferrocenes such that the electron donating ability and/or steric influence of seven methyl groups is just sufficient to stabilize a ruthenium-iron tripledecker complex.

Stabilized 5' Cap Analogue for Optochemical Activation of mRNA Translation.

The 5' cap is a distinguishing feature of transcripts made by polymerase II and characterized by an N7-methylated guanosine (m7G) linked to the first transcribed nucleotide by a 5'-5' triphosphate bridge. It stabilizes eukaryotic mRNAs and plays a crucial role in translation initiation. Its importance in mRNA processing, translation, and turnover makes the 5' cap a privileged structure for engineering by non-natural modifications. A photocleavable group at the 5' cap of guanosine was recently used to mute translation of exogenous mRNAs. Its removal by light enabled direct control of protein production at the posttranscriptional level. Modifications in the triphosphate bridge impede degradation by specific decapping enzymes and maintain translation. Here, we combined 5' cap modifications at different positions and investigated how they impact 5' cap-dependent processes in distinct manners. We synthesized 5' cap analogues with a photocleavable group at the N2-position of m7G in addition to a medronate in the triphosphate bridge to obtain a photoactivatable 5' cap analogue featuring a methylene group between the β and γ phosphates. The resulting Medronate-FlashCap transiently or permanently impeded distinct crucial interactions of the 5' cap required for translation and degradation. We show that the Medronate-FlashCap is compatible with in vitro transcription to generate muted mRNA and that light can be used to activate translation in cells. After light-induced removal of the photocleavable group, the Medronate-FlashCap remained stable against degradation by the decapping enzyme DcpS. The additional methylene group renders the 5' cap resistant to DcpS, while maintaining the interaction with cap-binding proteins.

Trinucleotide mRNA Cap Analogue N6-Benzylated at the Site of Posttranscriptional m6Am Mark Facilitates mRNA Purification and Confers Superior Translational Properties In Vitro and In Vivo.

Eukaryotic mRNAs undergo cotranscriptional 5'-end modification with a 7-methylguanosine cap. In higher eukaryotes, the cap carries additional methylations, such as m6Am─a common epitranscriptomic mark unique to the mRNA 5'-end. This modification is regulated by the Pcif1 methyltransferase and the FTO demethylase, but its biological function is still unknown. Here, we designed and synthesized a trinucleotide FTO-resistant N6-benzyl analogue of the m6Am-cap-m7GpppBn6AmpG (termed AvantCap) and incorporated it into mRNA using T7 polymerase. mRNAs carrying Bn6Am showed several advantages over typical capped transcripts. The Bn6Am moiety was shown to act as a reversed-phase high-performance liquid chromatography (RP-HPLC) purification handle, allowing the separation of capped and uncapped RNA species, and to produce transcripts with lower dsRNA content than reference caps. In some cultured cells, Bn6Am mRNAs provided higher protein yields than mRNAs carrying Am or m6Am, although the effect was cell-line-dependent. m7GpppBn6AmpG-capped mRNAs encoding reporter proteins administered intravenously to mice provided up to 6-fold higher protein outputs than reference mRNAs, while mRNAs encoding tumor antigens showed superior activity in therapeutic settings as anticancer vaccines. The biochemical characterization suggests several phenomena potentially underlying the biological properties of AvantCap: (i) reduced propensity for unspecific interactions, (ii) involvement in alternative translation initiation, and (iii) subtle differences in mRNA impurity profiles or a combination of these effects. AvantCapped-mRNAs bearing the Bn6Am may pave the way for more potent mRNA-based vaccines and therapeutics and serve as molecular tools to unravel the role of m6Am in mRNA.

Total Synthesis of Icumazole A Using a Modified Cadiot-Chodkiewicz Coupling.

The first total synthesis of myxobacteria metabolite icumazole A (1) is reported. Key steps in the route include an organocatalyzed asymmetric self-aldol reaction followed by an acetate aldol reaction to form the stereotriad present in the oxazole moiety, an intramolecular Diels-Alder reaction to form the isochromanone, and an acetylide addition and selective methylation. The final steps involved a high-yielding modified Cadiot-Chodkiewicz coupling and stereoselective reduction to secure the Z,Z-diene and afford 1.

Eco-friendly removal of methyl tert-butyl ether from contaminated water using steam and CO2-activated carbons

AbstractPetrol frequently contains the additive methyl tertiary butyl ether (MTBE). Because of its significant health risks, MTBE pollution of surface and ground water is a severe concern for the environment. Highly porous physically activated carbons, particularly CO2-activated carbon (CO2-AC) and steam-activated carbon (Steam-AC), were obtained from date stones as potential eco-friendly adsorbents for MTBE from contaminated water. The chemical composition, microstructure, textural, and structural characteristics of adsorbents were characterised by elemental analysis, SEM, N2 sorption, XRD, and FTIR. The adsorption process evaluation based on the initial MTBE concentration, liquid-to-solid ratio, and equilibrium contact time. CO2-AC and steam-AC adsorbents have high surface areas of 819.5 m2/g, and 567.7 m2/g, respectively. At 40 °C, CO2-AC has an adsorption capability of 181.36 mg/g. The adsorption result was best fitted by the Freundlich model. The two-step intraparticle diffusion process prevailed the adsorption process, and the pseudo-second-order model presented an optimal fit for the adsorption kinetics models. Spontaneous physical adsorption was endothermic when CO2-AC adsorbs at 40 °C because ∆G was − 6.34 kJ/mol. Finally, the water quality improved and the salt content, the alkalinity, and the hardness decreased with the use of CO2-AC as an environmentally friendly adsorbent for removing MTBE from the polluted water.

4,4-Dimethylsterols Reduces Fat Accumulation via Inhibiting Fatty Acid Amide Hydrolase InVitro and InVivo.

4,4-Dimethylsterols constitute a unique class of phytosterols responsible for regulating endogenous cannabinoid system (ECS) functions. However, precise mechanism through which 4,4-dimethylsterols affect fat metabolism and the linkage to the ECS remain unresolved. In this study, we identified that 4,4-dimethylsterols, distinct from 4-demethseterols, act as inhibitors of fatty acid amide hydrolases (FAAHs) both invivo and invitro. Genetic ablation of FAAHs (faah-1) abolishes the effects of 4,4-dimethylsterols on fat accumulation and locomotion behavior in a Caenorhabditis elegans model. We confirmed that dietary intervention with 4,4-dimethylsterols in a high-fat diet (HFD) mouse model leads to a significant reduction in body weight (>11.28%) with improved lipid profiles in the liver and adipose tissues and increased fecal triacylglycerol excretion. Untargeted and targeted metabolomics further verified that 4,4-dimethylsterols influence unsaturated fatty acid biosynthesis and elevate oleoyl ethanolamine levels in the intestine. We propose a potential molecular mechanism in which 4,4-dimethylsterols engage in binding interactions with the catalytic pocket (Ser241) of FAAH-1 protein due to the shielded polarity, arising from the presence of 2 additional methyl groups (CH3). Consequently, 4,4-dimethylsterols represent an unexplored class of beneficial phytosterols that coordinate with FAAH-1 activity to reduce fat accumulation, which offers new insight into intervention strategies for treating diet-induced obesity.

Plasma-chemical pyrolysis of a mixture of fuel oil and methyl tert-butyl ether

NTP-pyrolysis of heavy petroleum products is a difficult task due to high viscosity, low hydrogen-to-carbon ratio and tendency to polycondensation with formation of high-molecular products. The use of oxygen-containing compounds for NTP-pyrolysis can reduce the yield of polycondensation products due to internal oxygen. In the present work, NTP pyrolysis of fuel oil in the presence of oxygen-containing additive (methyl tert-butyl ether) was carried out at a current source voltage of 700V. The influence of the content of the doping component in the range of 5-15 wt% on conversion, energy consumption and product composition was investigated. At increase in the content of methyl-tert-butyl ether up to 15 wt% in fuel oil the energy consumption decreases and the yield of gaseous products increases from 21.7 to 47.9 wt%. Carrying out NTP-pyrolysis process in the presence of oxygen-containing additive leads to an increase in the depth of processing of heavy fractions.