• Catalysts were synthetized for bio-oil esterification containing red mud and zeolites • Biomass-derived bio-oil has more carboxylic acid and phenolic compounds, than RDF derived • Catalysts significantly reduced the acid numbers of bio-oils as a function of reaction time • Due to esterification reactions, the carboxylic acid and aldehyde content of bio-oils decreased significantly • (SO 4 2- )RM/HZSM-5, (SO 4 2- )RM/Y-zeolite reduce the activation energy of esterification New-type (SO 4 2- )RM/HZSM-5 and (SO 4 2- )RM/Y-zeolite catalysts were developed for real bio-oil upgrading. Biomass derived bio-oil has higher acid number and contains more carboxylic acid or phenolic compounds, than that of refuse derived fuel sourced bio-oil. The esterification process was made at 120°C, 140°C and 160°C with real bio-oil and 1-decanol (ratio of 1:1.25). Catalysts significantly reduced the acid numbers as function of reaction time. The decrement in the acid numbers in case of biomass sources bio-oil was 23.5%, 48.1%, and 44.8%, while that of the RDF derived bio-oil was 37.8%, 53.8%, and 55.0% at 120°C, 140°C and 160°C, respectively. Significantly lower acid numbers were found at higher temperatures; besides, the carboxylic acid and aldehyde content of bio-oils decreased significantly due to esterification. The amounts of phenolic compounds and ketones only changed slightly. The activation energy of esterification reactions was calculated by a pseudo-homogeneous kinetic model. The activation energy decreased from 51.1kJ/mol to 35.0kJ/mol ((SO 4 2- )RM/HZSM-5) and to 34.8kJ/mol ((SO 4 2- )RM/Y-zeolite) in case of biomass derived bio-oil. In case of refuse derived fuel sourced bio-oil, the activation energy decreased from 42.0kJ/mol to 25.7kJ/mol ((SO 4 2- )RM/HZSM-5) and to 23.8kJ/mol ((SO 4 2- )RM/Y-zeolite). It was confirmed, that multi-component catalysts had been produced by mixing the Y-zeolite and experimentally synthetized ZSM-5 zeolite with a waste derived red mud and their modification by sulfuric acid and the subsequent mechano-chemical activation. Catalysts may have potential industrial value in bio-oil upgrading obtained by real waste, and in the reduction of temperature and energy consumption required for chemical reactions.

Sonochemical hydrogen production in a 300kHz sonoreactor: Comparative effects of short‑chain carboxylic acids, pH, and dissolved gas.

This study investigated the effects of maple syrup grades (maple syrup vs. VR5) and fermentation parameters (sugars, nutrients, and yeast concentrations) on maple wine's kinetics, physicochemical characteristics, and volatile compounds. The results showed that defective maple syrup has the potential to produce maple wine, with faster kinetics than high-quality maple syrup. The product exhibits ethanol, glycerol, and acidity levels suitable for wine. Nutrient addition was a key parameter affecting the final alcohol content for both types of fermented maple. The wort's initial sugar concentration affects the wine's residual sugar concentration. 61 different volatile compounds were identified, including higher alcohols, esters, carboxylic acids, acetals, and aldehyde/ketones. Higher sugar levels increased the production of acetals such as 1,1-diethoxyethane, known for its fruity flavour. Implementing the principles of sustainable development, this research aims to add value to a maple syrup by-product that, despite requiring the same production effort as first-quality, has much lower economic value.

Multi-omics and functional validation reveal that fermentation filtratet of Clavispora lusitaniae P8 attenuates UVA-induced photoaging by modulating the IL-17/NF-κB axis.

Pivalic anhydride mediated synthesis of Weinreb amides from carboxylic acids

Selective enhancement of bio-oil from pyrolysis of corn stalk: A tandem dual-catalyst system of reduced red mud and Fe/Ca catalyst

Peptide-based self-assembled gels are promising soft materials and have applications in biomedicine and material science. While the effect of the substituents on the N-terminal protecting group on the gelation behavior of peptides is often discussed, the role of the C-terminal substitution is seldom addressed. We report a tetrapeptide, P1 (Boc-Ala-Ala-Val-Phe-OMe) with a methyl ester at the C-terminus that forms organogels in various organic solvents. However, hydrolysis of the ester group in P1 to get a carboxylic acid (P2), or preparing a methyl (P3) or an isopropyl (P4) amide converted the peptide into hydrogelators, whereas the dimethyl amide (P5) derivative resulted in the loss of gelation. FE-SEM and AFM studies showed entangled fibrillar networks, driven by the formation of β-sheets, which was confirmed by spectroscopic studies. Rheological measurements demonstrated predominantly elastic behavior for the hydrogels, with P4 exhibiting the highest mechanical strength. To establish the observed effect and to understand the role of aromatic and hydrophobic sidechains, four other peptides were prepared and their gelation behavior was analyzed. These results show how modifications of the C-terminal carboxyl group of a given peptide sequence can affect its gelation and may provide an easier solution in tuning the properties of peptide-based gels.

Nutrients Abatement from digestate filtrate using Flow-Electrode capacitive Deionization: Role of carboxylate and amino acids.

Revealing brain network hierarchy and molecular correlates in temporal lobe epilepsy: A multimodal neuroimaging study.

Sustainable co-upcycling of waste PET plastic and ethylene glycol to high-value carboxylic acids on a carbon-encapsulated RuNi bimetallic catalyst

Per- and polyfluoroalkyl substances and pesticides in black bears (Ursus americanus) and grizzly bears (Ursus arctos horribilis) from Montana's Cabinet-Yaak ecosystem: A baseline assessment of emerging and legacy contaminants.

Kinetics and mechanism of ultrasound-enhanced citric acid leaching of chromium from steel slag.

New insights into the interplay between chain elongation and homoacetogenesis in microbial electrosynthesis: Chloroform-enhanced medium-chain carboxylate production.

Organic fraction of municipal solid waste (OFMSW) is a valuable feedstock within a circular economy. At well-defined process conditions, enzymatic hydrolysis followed by microbial conversion of hydrolysis products can lead to valuable carboxylic acids. The present study assesses enzymatic hydrolysis of OFMSW at 15% dry matter and thermophilic conditions (55°C). Torque measurements from a four-vessel parallel bioreactor system were made to monitor changes in viscosity of the OFMSW slurry. Additionally, the influence of minimum pH setpoints at pH 5.0 and pH 6.0 on enzymatic hydrolysis as well as on the formation of organic acids was evaluated. Adding enzymes, which are tailored to the substrate, led to a rapid drop in torque at the beginning of the incubation. This reduction in viscosity by liquefaction of the OFMSW slurry can improve the processability of the slurry as well as reduce the energy consumption during stirring. It was possible to correlate the release of glucose as well as the changes in torque to the enzyme addition. A minimum pH setpoint of 6.0 appears to favour organic acid formation from indigenous microorganisms. This resulted in an 26.6% increase of lactic acid to 27.9 ± 0.49 g L -1 and a metabolisation into butyric acid of up to 15.4 ± 1.8 g L -1 . The presented results provide valuable information about the processing of OFMSW for future valorisation within biorefinery processes. • Enzyme addition led to rapid reduction in torque and viscosity. • Liquefaction and reduced disturbances during stirring were achieved. • Substantial concentrations of lactic acid and butyric acid were obtained.

Synthesis and antiprotozoal activity of β-carboline-(piperazinyl)-1,3,5-triazine hybrids.

Stereoselective synthesis of 1,2-trans-β-glycosyl esters from glycosyl chlorides via phase-transfer catalysis.

NiAl-LDH nanocomposite: a promising platform for non-enzymatic electrochemical detection of nicotinic acid in food samples.

Digital olfaction potential for quality aroma discrimination in table olive breeding programs

Environmental sustainability is a major priority in modern anaesthesia [1]. Currently, total intravenous anaesthesia (TIVA) is often considered more environmentally friendly than volatile inhalational anaesthesia because it has reduced greenhouse gas emissions. However, this view ignores the potential water pollution caused by intravenous drugs. Propofol, used widely in TIVA, is a phenol derivative that is detected frequently in hospital wastewater due to significant clinical wastage [2]. As a lipophilic compound, propofol may accumulate in aquatic organisms, posing a risk to the ecosystem. The introduction of remimazolam, an ultra-short-acting benzodiazepine, offers a potential alternative for TIVA. Unlike propofol, remimazolam is hydrolysed rapidly by tissue esterases into a carboxylic acid metabolite (CNS 7054) [3]. The environmental impact of this metabolite is not well understood. The aim of this study was to utilise in-silico quantitative structure–activity relationship modelling to compare the predicted aquatic toxicity of propofol and the remimazolam metabolite, providing a more complete ecological assessment. Aquatic toxicity was evaluated using the Ecological Structure Activity Relationships Class Program (Version 2.2; United States Environmental Protection Agency) [4]. This in-silico methodology aligns with ‘replacement, reduction and refinement’ principles, offering an ethical alternative to in-vivo animal testing for risk assessment [5]. We retrieved the chemical structures of propofol and the remimazolam metabolite (CNS 7054) from the PubChem database and converted them into Simplified Molecular Input Line Entry System codes. The model predicts toxicity based on structure-specific regression equations derived from measured data. We analysed the octanol–water partition coefficient (LogKow) to estimate bioaccumulation potential and calculated standard acute toxicity endpoints (LC50 and EC50) for fish, daphnids and green algae. Propofol is characterised by a high octanol–water partition coefficient (LogKow 3.79), classifying it as a lipophilic substance with significant bioaccumulation potential. In contrast, CNS 7054 exhibits a low LogKow of 1.25, indicating high water solubility and minimal risk of bioaccumulation. In terms of acute toxicity, propofol was predicted to be toxic to aquatic organisms, with 96-h LC50 values of 4.6 mg.l-1 for fish and 48-h LC50 values of 0.85 mg.l-1 for daphnids. Conversely, CNS 7054 was predicted to be practically non-toxic across all trophic levels, with estimated lethal concentrations exceeding 100 mg.l-1 (Table 1). While propofol is favoured for its lack of greenhouse gas emissions, our data suggest it poses a persistent threat to aquatic ecosystems due to its lipophilic nature and potential for bioaccumulation. In recent years, remimazolam has emerged as a valuable drug for procedural sedation and general anaesthesia [6, 7]. As its clinical use expands, its environmental profile becomes increasingly relevant. Remimazolam appears to exemplify the principles of ‘benign-by-design’ pharmaceuticals. Its rapid hydrolysis into a highly polar, hydrophilic metabolite ensures that the excreted compound does not accumulate in aquatic organisms and is virtually non-toxic. We acknowledge several limitations in this study. First, the results are based on in-silico predictions rather than in-vivo biological assays. However, the quantitative structure–activity relationship is a validated tool for initial risk screening [5]. Second, we focused solely on the excretion phase. A complete life-cycle assessment is necessary to determine the total carbon footprint. Crucially, such future comparisons must ensure clinical equipotency. Since remimazolam often exhibits higher bispectral index values than propofol at equivalent sedation levels [7], strictly adhering to traditional bispectral index targets may lead to overdosing and an unfair inflation of its environmental impact. We recommend that future comparative studies standardise anaesthetic depth using multiparametric monitoring to ensure a fair ecological comparison. In conclusion, while propofol remains a cornerstone of TIVA, its environmental footprint extends into the water cycle. Remimazolam offers a promising alternative with a significantly more favourable aquatic safety profile. Future ‘green anaesthesia’ strategies should adopt a holistic view, balancing carbon mitigation with the protection of water resources. No external funding or competing interests declared.

Benzylamines represent a promising yet underexplored class of building blocks in C(sp3)─C(sp3) bond formation. The scarcity of deaminative coupling methods of benzylamines with other ubiquitous native functionalities, such as alcohols and carboxylic acids, has constrained their synthetic utility. Herein, we report two metallaphotoredox C(sp3)─C(sp3) cross-coupling reactions that merge structurally diverse benzylamines with carboxylic acids and 3° alcohols. In both transformations, the key bond-forming step proceeds via a Fe-porphyrin-catalyzed SH2 radical sorting pathway. Both reactions exhibit broad substrate scope, with their synthetic utility further highlighted in the synthesis of complex, biologically active compounds, semisaturated aromatic scaffolds, and enantiopure pyrrolidine derivatives.