Low Molecular Weight Research Articles

PFAS-Free Energy Storage: Investigating Alternatives for Lithium-Ion Batteries.

The class-wide restriction proposal on perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the European Union is expected to affect a wide range of commercial sectors, including the lithium-ion battery (LIB) industry, where both polymeric and low molecular weight PFAS are used. The PFAS restriction dossiers currently state that there is weak evidence for viable alternatives to the use of PFAS in LIBs. In this Perspective, we summarize both the peer-reviewed literature and expert opinions from academia and industry to verify the legitimacy of the claims surrounding the lack of alternatives. Our assessment is limited to the electrodes and electrolyte, which account for the most critical uses of PFAS in LIB cells. Companies that already offer or are developing PFAS-free electrode and electrolyte materials were identified. There are also indications that PFAS-free electrolytes are in development by at least one other company, but there is no information regarding the alternative chemistries being proposed. Our review suggests that it is technically feasible to make PFAS-free batteries for battery applications, but PFAS-free solutions are not currently well-established on the market. Successful substitution of PFAS will require an appropriate balance among battery performance, the environmental effects associated with hazardous materials and chemicals, and economic considerations.

Role of extractive compounds in emulsion stabilisation capacity of wood hemicelluloses

Abstract Hemicellulose-rich extracts obtained by pressurised hot water extraction of wood residues show promise as emulsion stabilisers. However, pressurised hot water extracts (PHWEs) from wood also contain lower molecular weight extractive components that may influence emulsion performance. This study investigated the effect of extractives on emulsion stability using PHWEs obtained from spruce and birch sawdust with or without solvent pre-extraction. The results indicated that extractives negatively affect the physical stability of emulsions in both spruce and birch and influence oxidative stability in spruce after prolonged storage. However, the roles of different extractives in emulsion performance require further investigation.

Polyethylene glycol-phospholipid functionalized single-walled carbon nanotubes for enhanced siRNA systemic delivery

Small interfering RNAs (siRNA) technology has emerged as a promising therapeutic tool for human health conditions like cancer due to its ability to regulate gene silencing. Despite FDA-approved, their delivery remains localized and limiting their systemic use. This study used single-walled carbon nanotubes (SWNTs) functionalized with polyethylene glycolated (PEGylated) phospholipids (PL-PEG) derivatives for systemic siRNA delivery. We developed an siRNA systemic delivery vehicle (SWNT-siRNA) by conjugating SWNT functionalized with PL-PEG containing either amine (PA) or maleimide (MA). The functionalized SWNT with a lower molecular weight of PA produced the SWNT-siRNA conjugate system with the highest stability and high siRNA loading quantity. The system delivered siRNA to a panel of tumour cell lines of different organs (i.e. HeLa, H1299 and MCF-7) and a non-cancerous human embryonic kidney 293 cells (HEK293T) with high biocompatibility and low toxicity. The cellular uptake of SWNT-siRNA conjugates by epithelial cells was found to be energy dependent. Importantly, the presence of P-glycoprotein, a marker for drug resistance, did not inhibit SWNT-mediated siRNA delivery. Mouse xenograft model further confirmed the potential of SWNT-siRNA conjugates with a significant gene knock-down without signs of acute toxicity. These findings pave the way for potential gene therapy applications using SWNTs as delivery vehicles.

Boosting Supramolecular Gelation Efficiency and Properties: Ionic Strength as a Key to Superior Hydrogels.

Controlling the minimum gelation concentration (MGC) of low molecular weight (LMW) hydrogelators is a key for modulating gel properties, such as mechanical strength, viscoelasticity, and stability, which are crucial for applications ranging from drug delivery to tissue engineering. However, tweaking the MGC under specific conditions, such as pH and/or temperature, poses a considerable challenge. Herein, we varied the ionic strength of buffer solutions using NaCl for several LMW hydrogelators, including Fmoc-Phe, Fmoc-Tyr, Fmoc-Trp, Fmoc-Met, and Fmoc-Cha, and assessed their gelation efficiency at pH 7.4 and ambient temperature. Interestingly, Fmoc-Phe demonstrated a ∼67% (3-fold) MGC reduction, from 0.24 to 0.08 wt %, at 500 mM NaCl, transforming it a "super hydrogelator" (MGC < 0.1 wt %), while Fmoc-Trp showed 60% MGC reduction. Higher ionic strength effectively shields the electrostatic repulsion between negatively charged (-COO-) groups on the Fmoc-Phe, promoting closer aggregation and more efficient self-assembly and allowing for gelation at lower concentrations. In contrast, Fmoc-Met, Fmoc-Cha, and Fmoc-Tyr precipitated in the presence of NaCl, suggesting that NaCl specifically modulates the MGC of Fmoc-amino acid gelators containing unsubstituted aromatic side chains. Furthermore, these results indicate that cation-π interactions likely play a role, alongside carboxylic acid neutralization. While Fmoc-Phe forms gels in the presence of other monovalent cations, it does not form a hydrogel in the presence of divalent (CaCl2) and trivalent (AlCl3), indicating that enhancement of hydrogelation is specific to monovalent cations. Although the fibrillar structure of Fmoc-Phe hydrogels remained consistent, addition of NaCl increased fibril stickiness, creating densely packed networks that modulate the mechanical strength. Unlike typical cases where increased ionic strength leads to precipitation, Fmoc-Phe gelation at high NaCl concentrations (150-500 mM) is significant, yielding a robust supramolecular hydrogel that remains stable in high ionic-strength environments. This outcome suggests that ionic strength could be a valuable factor to enhance the efficient gelation of LMW hydrogelators.

Closed-Loop Chemical Recycling of a Biobased Poly(oxanorbornene-fused γ-butyrolactone).

New polymers, properly designed for end-of-life and efficiently formed from renewable carbon, are key to the transition to a more sustainable circular plastics economy. Ring-opening polymerization (ROP) of bicyclic lactones is a promising method for the production of intrinsically recyclable polyesters, but most lactone monomers lack an efficient synthesis route from biobased starting materials, even though this is essential to sustainably account for material loss during the life cycle. Herein, we present the exceptionally rapid and controlled polymerization of a fully biobased tricyclic oxanorbornene-fused γ-butyrolactone monomer (M1). Polyester P(M1) was formed in low dispersity (D̵ = 1.2-1.3) and controllable molecular weight up to Mn = 76.8 kg mol-1 and exhibits a high glass transition temperature (Tg = 120 °C). The orthogonal olefin and lactone functionalities offer access to a wide range of promising materials, as showcased by postpolymerization modification by hydrogenation of the olefin, which increased polymer thermal stability by over 100 °C. Next to rapid hydrolytic degradation and solvolysis, the poly(oxanorbornene-fused γ-butyrolactone) could be cleanly chemically recycled back to the monomer (CRM), in line with its favorable ceiling temperature (Tc) of 73 °C. The density functional theory (DFT)-computed ΔH° of ring-opening with methanol of γ-butyrolactone-based monomers provided a model to predict Tc, and the DFT-computed and X-ray crystal structure-derived structural parameters of M1, hydrogenated analogue M1-H2, and regioisomer M2 offered insights into the structural descriptors that cause the high polymerizability of M1, which is key to establishing structure-property relations.

Hansen parameters and GastroPlus assisted optimized topical elastic liposomes to treat breast cancer using a novel isatin derivative

Breast cancer treatment is a global health challenge using conventional toxic chemotherapeutic agents. A novel isatin could be a promising alternative. An isatin derivative (TM-19) was synthesized and characterized using NMR (nuclear magnetic resonance), mass spectrometry, Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC). HSPiP and GastroPlus predictive software were used to predict suitable solvents for solubility and in vivo oral pharmacokinetics in humans (fasted condition), respectively. Based on predictive findings, topical elastic liposomes (phosphatidylcholine as PC and span 80 by film hydration method) was prepared, characterized, and optimized using QbD (quality by design). QbD identified the impact of composition on response variables (Y1 for size, Y2 for polydispersity index, Y3 for zeta potential, and Y4 for %EE). In vitro cytotoxicity study was carried out against MCF-7 cell lines. Low molecular weight and lipophilic TM-19 was crystalline in nature (255 g/mol). GastroPlus program predicted limited in vivo dissolution and poor oral absorption (10.4 %). Results confirmed the highest TM-19 solubility in DMSO (dimethyl sulfoxide) ˃ chloroform ˃ PEG 400 (polyethylene glycol 400). Considering experimental and predicted data, topical delivery of TM-19 using optimized (desirability parameter value = 0.97) elastic liposomes (TF1) was quite promising due to optimal size (344 nm), high %EE (61.7 %), low PDI (0.45), and optimal zeta potential (− 12.34 mV). TM-19 loaded TF1 elicited concentration dependent cytotoxic effect (˃ 90 % at 10 µM) against MCF-7 as compared to TM-19 suspension.

Emulsifying and ethanol-induced gelling properties of capsicum pectin: The impact of capsicum variety and deproteinization using the Sevag method.

This study investigated the emulsifying and ethanol-induced gelling properties of capsicum pectins from bell pepper and chili pepper, and also examined the effect of deproteinization (using the Sevag method). The research revealed that bell pepper pectin (BPP) formed smaller aggregates (337 nm at pH 2) with a higher hydrophobicity in solution due to its lower molecular weight (2.02 × 105 g/mol) and higher degree of esterification (82.15 %) compared to chili pepper pectin (CPP) (3.29 × 105 g/mol, 78.33 %). Consequently, BPP exhibited superior interfacial tension reduction ability, resulting in emulsion with smaller droplet size (483 nm at pH 2). Conversely, CPP showed superior ethanol-induced gelling property in comparison to BPP, as its lower degree of esterification and higher molecular weight facilitated hydrogen bonding interactions and crosslinking during gelation. Deproteinization with the Sevag method reduced protein content, molecular weight and esterification degree of BPP and CPP, but its impact on their emulsifying properties differed significantly. Interestingly, deproteinization notably improved the ethanol-induced gelling property of both pectins, since the increased carboxyl groups in the deproteinized products promoted hydrogen bonding during gelation. This study could facilitate the comprehensive utilization of capsicum and also advance our understanding of the impact of the Sevag method.

Unveiling the optical and molecular characteristics of aging microplastics derived dissolved organic matter transformed by UV/chlor(am)ine oxidation and its potential for disinfection byproducts formation

The investigations into the existence and behavior of microplastics (MPs) in water environment were widely conducted, while the characteristics of dissolved organic matter derived from MPs (MPs-DOM) during advanced oxidation have garnered comparatively little attention. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was employed along with multiple statistical analyses to gain a deeper understanding of the conversion of MPs-DOM in UV/chlor(am)ine advanced oxidation processes (AOPs). The diverse treatments exhibited varying degrees of augmentation in both aging and fragmentation of MPs with the order of UV/Cl2 > UV > UV/NH2Cl. The fragmentation degree of MPs upon two UV-based AOPs (UV-AOPs) was dependent on their monomer chemical structure. The highest TOC values of three MPs-DOM were observed after UV/Cl2 AOP and the lowest after UV/NH2Cl AOP. Polyvinyl chloride (PVC) displayed a greater release of MPs-DOM under varying leaching conditions. UV/Cl₂ AOP favored the reaction with saturated MPs-DOM, while UV/NH₂Cl AOP reduced unsaturated MPs-DOM, alleviating disinfection byproducts (DBPs) formation after chlorination. The precursors generated by UV/Cl₂ AOP owned lower H/C, higher modified aromatic index (AImod), and lower molecular weight (MW) products after chlorination. PVC-DOM with fewer CH₂ groups was more reactive. -H₂O, +O and -CH₂ reactions dominated in PVC-DOM (CHO compounds), while -2H, +O, -CH₂ did in PVC-DOM (CHON compounds). The dominant chlorine addition/substitution reactions occurred in PVC-DOM treated by UV/Cl₂ AOP, identifying 195 Cl-DBPs with 220 precursor-product pairs. Mass difference analyses showed that +2H and +O reactions were the most frequent of the 24 reaction types. Environmental ImplicationMicroplastics derived dissolved organic matters (MPs-DOM) transformed into disinfection byproducts (DBPs) under advanced oxidation processes (AOPs), heightening environmental risks. In this study, Fourier transform ion cyclotron resonance mass spectrometry was employed to gain a deeper understanding of MPs-DOM conversion in UV/chlor(am)ine AOPs. MPs fragmentation and fluorescent components varied with monomer chemistry and polymers. UV/Cl₂ AOP reacted with saturated MPs-DOM. UV/NH₂Cl AOP reduced unsaturated MPs-DOM, alleviating DBPs formation. DBPs precursors generated by UV/Cl₂ AOP owned higher modified aromatic index, lower H/C and molecular weight. Unveiling the MPs-DOM transformation during AOPs can mitigate the negative environmental impacts of MPs and their derivatives.

Ethylenediamine-modified alginate - A hemocompatible platform for polymer-drug conjugates

The study is dedicated to the synthesis, rheological properties, hemocompatibility, and further modification of water-soluble derivatives of sodium alginate containing fragments of ethylenediamine (Alg-EDA). Alg-EDA with an equal ratio of amide/amine groups and varying degrees of substitution were synthesized by the carbodiimide method. The influence of the molecular weight of Alg-EDA on the attachment of bioactive molecules such as hydroxybenzoic and ferulic acids was determined. Modification of alginate with ethylenediamine fragments leads to a reduction in dynamic viscosity and sensitivity to Ca2+ ions (internal gelation method). Alg-EDA derivatives, with differ in molecular weight and degree of substitution with phenolic acids, are characterized by high hemocompatibility (in vitro tests: erythrocyte hemolysis, blood recalcification time, activated partial thromboplastin time). Antioxidant properties of the synthesized alginate derivatives were characterized using models of varying complexity (including cellular models). It was found that Alg-EDA, at a concentration of 0.5 mg/mL, had a statistically significant membrane-protective activity under conditions of acute oxidative stress induced by both H2O2 and AAPH. Derivatives with lower molecular weight were more effective than high molecular weight ones. Modification of polysaccharides by the fragments of phenolic acids into the structure contributed to the enhancement of antioxidant properties. The hemocompatible macromolecular antioxidants synthesized in this study are promising for further in-depth investigation for the creation of biomedical materials.

Degradation of low-molecular-weight fucoidans by human intestinal microbiota and their regulation effect on intestinal microbiota and metabolites during in vitro fermentation

Fucoidan, a sulfated polysaccharide from brown algae, has been shown to improve gut microbiota balance and function. However, the relationship between molecular weight of fucoidan and colonic fermentation characteristics is still unclear. Here, the interaction between different-molecular-weight fucoidans and intestinal microbiota was analyzed via an in vitro fecal fermentation model. Results showed that fucoidan and its 2 low-molecular-weight derivatives (Dfuc1 and Dfuc2) could be utilized by intestinal microbiota after 48 h of fermentation, and among them, Dfuc2 exhibited the highest utilization efficiency of 30.1%, followed by Dfuc1 (24.5%) and fucoidan (14.4%). Notably, the components glucose, mannose and galactose, but not fucose, in different-molecular-weight fucoidans could be utilized. Moreover, intestinal microbiota could degrade Dfuc1 and Dfuc2 to produce oligosaccharide fragments, such as fucose-hexose disaccharide. In addition, fucoidan, Dfuc1 and Dfuc2 displayed different prebiotic effects on the intestinal microbiota community. Native fucoidan preferred to promote Bacteroides and Lactococcus, and low-molecular-weight fucoidans tended to promote Parabacteroides and Lactobacillus. Furthermore, metabolites analysis showed that fucoidan, Dfuc1 and Dfuc2 had similar promoting effects on acetic acid and propionic acid, and had no effect on butyric acid. But they could regulate carbohydrate metabolic pathways and amino acid pathways to varying degrees and with decreasing molecular weight, more differential metabolites were found. Thus, Dfuc2 with a lower molecular weight has more potential to become a potential prebiotics to improve intestinal health.

Study on hyaluronic acid aquaphotomics-from one dimension to two dimension analysis.

Hyaluronic acid (HA) is widely used in cosmetics because of its unique hygroscopic properties. However, it is difficult to characterize the interactions between HA and water molecules in the skin. In this study, we developed a fast and nondestructive method for visualizing skin water species based on aquaphotomics to elucidate the mechanism by which HA affected water species. The first HA-water system was introduced to investigate the relationship between HA and water species based on near-infrared (NIR) spectroscopy and aquaphotomics. NIR-hyperspectral imaging was then applied to characterize the distribution of different water species in the skin. The HA-water system results indicated that oligo HA had hydration behaviors opposite to those of low molecular weight HA. NIR hyperspectral imaging results showed that the intensity and spatial distribution of each water species within the skin model can be directly characterized by upgrading aquaphotomics from one-dimensional to two-dimensional. Studies showed that HA tetrasaccharides and 600-700kDa HA could maintain the strength of skin water species. In summary, the visual representation of water species distribution enables rapid and nondestructive monitoring of macromolecule hydration with skin which could help cosmetics formulators to optimize their HA formulation to realize their best hygroscopic properties in the future.

Degradation of (1→3)(1→6)-α-D-dextran by ultrasound: Molecular weight, viscosity and kinetics

The (1→3)(1→6)-α-D-dextran (alternating dextran) produced by Leuconostoc citreum SK24.002 is a novel functional exopolysaccharide, and its low molecular weight derivatives have potential applications in the food, pharmaceutical, and chemical industries. In this work, we used sonication, a green polysaccharide disruption method, to study the degradation process of this dextran by changing the intensity and duration of the sonication treatment and the concentration of the dextran solution. The molecular weight and viscosity of the dextran products were measured with a high-performance size exclusion column chromatography–multi-angle laser light scattering–refractive index system and by rheometry, respectively. The degradation efficiency of dextran was directly affected by the duration and intensity of the ultrasonic treatment and the concentration of the dextran solution. The polydispersity index fluctuated as the duration of the sonication treatment increased. The combination of a high intensity (672 W/cm2) and long (120 min) sonication treatment and a low solution concentration (3 g dextran/100 mL) was most effective for reducing the apparent and complex viscosities of dextran. The storage modulus of dextran was always slightly larger than its loss modulus, indicating that it formed a gel-like structure. The second-order kinetic model (1/Mwt - 1/Mw0 = kt) was the best fit to explain the degradation dynamics of dextran by sonication at intensities of 168 W/cm2–834 W/cm2 and with dextran solution concentrations of 1 g/100 mL – 7 g/100 mL. Our findings show that sonication is an effective way to reduce the molecular weight of alternating dextran.

Study on the "Anti-Age" Effectiveness of Low Molecular Weight Chitosan

Study on the "Anti-Age" Effectiveness of Low Molecular Weight Chitosan

Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications.

Siderophores are low molecular weight compounds produced by microorganisms to scavenge iron in iron-deficient environments. Rhodotorulic acid, a natural hydroxamate siderophore, plays a vital role in iron acquisition for fungi and bacteria. As the simplest natural hydroxamate siderophore, it exhibits a high affinity for ferric ions, enabling it to form stable complexes that facilitate iron uptake and transport within microorganisms. This article provides a comprehensive analysis of this hydroxamate siderophore, rhodotorulic acid, its synthesis, physicochemical properties, and biological significance. It also explores its applications in antifungal and plant protection strategies. Insights into RA derivatives reveal distinct biological effects and applications with potential in various fields, from antioxidants to antifungals. Rhodotorulic acid and its derivatives show promise for novel therapies, plant protection strategies, and iron supplementation in agriculture. Understanding their properties could advance science and medicine with sustainable practices.

Preventative and curative treatment of venous thromboembolic disease in cancer patients

Cancer-associated venous thromboembolism (CAT) is common in patients with cancer and associated with significant morbidity and mortality. The incidence of CAT continues to rise, complicating patient care and burdening healthcare systems. Patients with cancer experiencing VTE face poorer prognoses, making prevention and effective management imperative. This narrative review synthesizes evidence on thromboprophylaxis in ambulatory patients with cancer receiving systemic therapy and acute treatment strategies for CAT. Risk assessment models (e.g., Khorana score) aid in identifying high-risk patients who may benefit from thromboprophylaxis. Pharmacological thromboprophylaxis with low molecular weight heparins (LMWHs) direct oral anticoagulants (DOACs) has been shown to reduce the risk of CAT without significantly increasing the risk of bleeding complications. However, implementation of risk-based strategies remains limited in clinical practice. For acute CAT management, LMWHs have been the standard of care, but DOACs are increasingly favored due to their convenience and efficacy. However, challenges persist, including bleeding risks and drug interactions. Emerging therapies targeting Factor XI inhibitors present promising alternatives, potentially addressing current limitations in anticoagulation management for CAT.

The sports performance improving effects of konjac glucomannan with varying molecular weights in overtrained mice

Overtraining affects individuals engaged in high-volume training, potentially hindering athletic performance and revealing shortcomings in suggested solutions. This study evaluated the impact of konjac glucomannan (KGM) with varying molecular weights on the gut microbiome, endurance, and strength in mice subjected to excessive training. The native KGM (1.82 × 107 Da) was enzymatically degraded using endo-1,4-β-mannanase to generate moderate molecular weight KGM (KGM-EM, 1.89 × 105 Da) and low molecular weight KGM (KGM-EL, 1.34 × 104 Da). These fractions were characterized and compared with the native KGM regarding their effects on mice undergoing excessive training. The results demonstrated a positive correlation between KGM's molecular weight and its capacity to mitigate the adverse impacts of excessive training on strength or/and endurance (a significant increase of 55.57 % and 55.70 % by the native KGM compared with the excessive training group). In addition, the native KGM exhibited superior preservation of microbial diversity and composition in fecal samples against excessive training-induced shifts, along with increased production of individual and total short-chain fatty acids in plasma compared with the two degraded products. Overall, these results highlight the potential benefits of high molecular weight KGM for preventing overtraining syndrome and enhancing athletic performance in animal models.

Potential blood pressure regulatory effect of low molecular weight α-chymotrypsin extract and its peptides from Stichopus japonicus: Peptide-ACE interaction study via in silico molecular docking

Hypertension is a significant risk factor for cardiovascular disease and heart damage. Stichopus japonicus (S. japonicus) is a red sea cucumber with antioxidant and anti-hypertensive activities. However, its anti-hypertensive mechanism remains unclear. In this study, we evaluated the inhibitory effects of angiotensin-converting enzyme (ACE) of α-chymotrypsin-assisted hydrolysate of S. japonicus (α-chy) and its ultrafiltrate fractions (>10 kDa [α-chy-I], 5–10 kDa [α-chy-II], and <5 kDa [α-chy-III]). Low molecular α-chy-III exerted excellent ACE inhibitory and anti-hypertensive activities in spontaneously hypertensive rats (SHR). Moreover, α-chy-III significantly reduced the systolic and diastolic blood pressure by modulating the serum angiotensin and ACE levels. Histological analysis revealed that α-chy-III markedly protected the aorta, heart, and kidney tissues of SHR from hypertension-induced tissue damage.Taken together, our findings highlight the potential of α-chy-III as a functional food ingredient for the treatment of hypertension and its comorbidities.

Polyethylene Glycol‐Based Refolding Kinetic Modulation of CRABP I Protein

ABSTRACTCrowding environment has a significant impact on the folding and stability of protein in biological systems. In this work, we have used four different sizes of a molecular crowder, polyethylene glycol (PEG), to analyze the unfolding and refolding kinetics of an iLBP protein, CRABP I, using urea as chemical denaturant. In general, the stability of the native state of the protein is boosted by the presence of crowding agents in the solution. However, our findings show that not only the type of crowder but also the crowder size played a key role in the effects of excluded volume. In case of lower molecular weight of PEG (M.W. 400), even at 200 g/L concentration, only the viscosity effect is observed, whereas for higher molecular weight of PEG (M.W. 1000), both the viscosity effect and excluded volume effect are noticed, and even at a higher concentration (200 g/L) of PEG 1000, the excluded volume predominates over the viscosity effect. Using the transition state theory, we were also able to determine the free energies of activation for the unfolding and refolding studies from their respective rate constants. Additionally, MD simulation studies provide strong support for our experimental observation. Analysis of secondary structure propensity (SSP) reveals a marked decline in the presence of structural elements (β‐sheet, β‐bridge, turn, and α‐helix) from 81% to 43% over the 1 μs time scale unfolding MD simulation under 8 M urea conditions. Conversely, in a 200 ns refolding simulation, the rate of refolding notably increases at a concentration of 200 g/L PEG 1000.

Insights into the photosensitivity and photobleaching of dissolved organic matter from microplastics: Structure-activity relationship and transformation mechanism

Revealing the structure-activity relationship between physicochemical properties and photoactivities of microplastic dissolved organic matter (MPDOM) is significant for understanding the environmental fate of MPs. Here, we systematically analyzed the physicochemical properties and molecular composition of DOM derived from MPs including polystyrene (PS), polyethylene glycol terephthalate (PET), polyadipate/butylene terephthalate (PBAT), polylactic acid (PLA), polypropylene (PP), and compared their photosensitivity and photobleaching behaviors. Results indicated that PSDOM and PETDOM had more similar properties and compositions, and showed stronger photosensitivity and photobleaching effects than PBATDOM, PLADOM and PPDOM. The [3DOM∗]SS and [1O2]SS varied in the range of 0.31-13.03 × 10-14 and 1.71-5.49 × 10-13M, respectively, which were within the reported range of DOM from other sources. The SUVA254, HIX, AImodwa, Xcwa and lignin/CRAM-like component showed positive correlation with the [3DOM∗]SS, [1O2]SS and Φ3DOM*. The negative correlation between E2/E3 and [3DOM∗]SS was due to the higher proportion of low-molecular weight components in MPDOM. The lignin/CRAM-like component was identified to be the crucial photobleaching-component. The lignin/CRAM-like in PSDOM showed a deepened oxidation degree, while its change trend in PETDOM was from unsaturated to saturated. These findings provide new insights into the relevant photochemical fate of MPDOM.

Degradation of gluten using plant proteases

The paper describes the fact of the presence of a proteolytic enzyme in the leaves of the natural hybrid variety of grape - Isabella (Vitis Labrusca L.) and the perspective of its practical application for breaking down wheat gluten. As our research has shown, this enzyme effectively degradates the constituent components of the protein fraction of wheat flour-the gluten fraction. It is known that the wheat gluten is a strong allergen for many people, which can initiate a disease such as celiac disease. Protease from Isabella leaves carries out deep hydrolysis of gluten to low molecular weight soluble peptides and amino acids. This effect can be successfully used in the production of gluten-free bread products.