Molecular Weight Research Articles

Investigation of the static and low‐velocity impact performance of 3D braided spacer composites

AbstractTo meet the lightweight requirements of advanced composite materials, the ultralightweight three‐dimensional (3D) braided spacer composites were designed and manufactured by ultra‐high molecular weight polyethylene (UHMWPE). The key structural effects of core column distances and core column heights on the static bending, compression, and low‐velocity impact properties of the composites were further investigated. Results indicated that the mechanical properties of 3D braided spacer composites was closely depended on their structural parameters. The flexure and compression of 3D braided spacer composites decreased with increasing core column distance and core column height. W1/H1 specimen showed the optimal bending and compressive performance. The maximum flexural strength and flexural modulus were approximately 54.77 MPa and 4.95 GPa, respectively. The low‐velocity impact properties were further investigated where the stiffness, energy absorption, and impact resistance of the composite decreased with increasing core column distance. The peak load and energy absorption of the W1 specimen were 2.39 kN and 7.99 J, respectively. While the low‐velocity impact properties increased with increasing core column distance. The H3 specimen exhibited the greatest stiffness, impact resistance and energy absorption with peak loads and energy absorption of 2.81 kN and 8.49 J, respectively. In addition, the macro morphology and scanning electron microscopy (SEM)micrographs were examined to investigate the damage morphology and failure mechanism of the composites. The main failure modes were matrix cracking, interface debonding, fiber buckling, and dislocation, as well as tilting, and failure of the core columns. This work provides guidance for structural design and engineering application of 3D lightweight braided spacer composite.

Terephthalate Copolyesters Based on 2,3-Butanediol and Ethylene Glycol and Their Properties

This study explores the synthesis and performance of novel copolyesters containing 2,3-butanediol (2,3-BDO) as a biobased secondary diol. This presents an opportunity for improving their thermal properties and reducing crystallinity, while also being more sustainable. It is, however, a challenge to synthesize copolyesters of sufficient molecular weight that also have high 2,3-BDO content, due to the reduced reactivity of secondary diols compared to primary diols. Terephthalate-based polyesters were synthesized in combination with different ratios of 2,3-BDO and ethylene glycol (EG). With a 2,3-BDO to EG ratio of 28:72, an Mn of 31.5 kDa was reached with a Tg of 88 °C. The Mn dropped with increasing 2,3-BDO content to 18.1 kDa for a 2,3-BDO to EG ratio of 78:22 (Tg = 104 °C) and further to 9.8 kDa (Tg = 104 °C) for the homopolyester of 2,3-BDO and terephthalate. The water and oxygen permeability both increased significantly with increasing 2,3-BDO content and even the lowest content of 2,3-BDO (28% of total diol) performed significantly worse than PET. The incorporation of 2,3-BDO had little effect on the tensile properties of the polyesters, which were similar to PET. The results suggest that 2,3-BDO can be potentially applied for polyesters requiring higher Tg and lower crystallinity than existing materials (mainly PET).

Advanced Synthesis, Structural Characterization, and Functional Applications of Precision Polymers.

In the realm of biological macromolecules, entities such as nucleic acids and proteins are distinguished by their homochirality, consistently defined chain lengths, and integral sequence-dependent functionalities. Historically, these refined attributes have eluded traditional synthetic polymers, which often exhibit wide variabilities in chain lengths, limited batch-to-batch reproducibility, and stochastic monomer arrangements. Bridging this divide represents a pivotal challenge within the domain of polymer science-a challenge that the burgeoning discipline of precision polymer chemistry is poised to address. Recent advancements have yielded precision polymers that boast prescribed monomer sequences and narrow molecular weight distributions, heralding a new era for developing model systems to decipher structure-property correlations within functional polymers, analogous to those within biological matrices. This review discusses the innovative liquid-phase and solid-phase synthesis techniques for creating precision polymers and the advanced characterization tools essential for dissecting their structure and properties. We highlight potential applications in self-assembly, catalysis, data storage, imaging, and therapy, and provide insights into the future challenges and directions of precision polymers.

Golgi pH homeostasis stabilizes the lysosomal membrane through N-glycosylation of membrane proteins.

Protein glycosylation plays a vital role in various cellular functions, many of which occur within the Golgi apparatus. The Golgi pH regulator (GPHR) is essential for the proper functioning of the Golgi apparatus. The lysosomal membrane contains highly glycosylated membrane proteins in abundance. This study investigated the role of the Golgi luminal pH in N-glycosylation of lysosomal membrane proteins and the effect of this protein modification on membrane stability using Gphr-deficient MEFs. We showed that Gphr deficiency causes an imbalance in the Golgi luminal pH, resulting in abnormal protein N-glycosylation, indicated by a reduction in sialylated glycans and markedly reduced molecular weight of glycoproteins. Further experiments using FRAP and PLA revealed that Gphr deficiency prevented the trafficking dynamics and proximity condition of glycosyltransferases in the Golgi apparatus. In addition, incomplete N-glycosylation of lysosomal membrane proteins affected lysosomal membrane stability, as demonstrated by the increased susceptibility to lysosomal damage. Thus, this study highlights the critical role of Golgi pH regulation in controlling protein glycosylation and the impact of Golgi dysfunction on lysosomal membrane stability.

Tunable Viscoelasticity of Alginate Hydrogels via Serial Autoclaving.

Alginate hydrogels are widely used as biomaterials for cell culture and tissue engineering due to their biocompatibility and tunable mechanical properties. Reducing alginate molecular weight is an effective strategy for modulating hydrogel viscoelasticity and stress relaxation behavior, which can significantly impact cell spreading and fate. However, current methods like gamma irradiation to produce low molecular weight alginates suffer from high cost and limited accessibility. Here, a facile and cost-effective approach to reduce alginate molecular weight in a highly controlled manner using serial autoclaving is presented. Increasing the number of autoclave cycles results in proportional reductions in intrinsic viscosity, hydrodynamic radius, and molecular weight of the polymer while maintaining its chemical composition. Hydrogels fabricated from mixtures of the autoclaved alginates exhibit tunable mechanical properties, with inclusion of lower molecular weight alginate leading to softer gels with faster stress relaxation behaviors. The method is demonstrated by establishing how viscoelastic relaxation affects the spreading of encapsulated fibroblasts and glioblastoma cells. Results establish repetitive autoclaving as an easily accessible technique to generate alginates with a range of molecular weights and to control the viscoelastic properties of alginate hydrogels, and demonstrate utility across applications in mechanobiology, tissue engineering, and regenerative medicine.

Ice recrystallization inhibition activity of pulse protein hydrolysates after immobilized metal affinity separation

Creating molecules capable of inhibiting ice recrystallization is an active research area aiming to improve the freeze-thaw characteristics of foods and biomedical materials. Peptide mixtures have shown promise in preventing freezing-induced damage, but less is known about the relationship between their amino acid compositions and ice recrystallization inhibition (IRI) activities. In this article, we used Ni2+ immobilized metal affinity chromatography (IMAC) to fractionate pulse protein hydrolysates, created by Alcalase and trypsin, into mixtures lacking and enriched in His, and Cys residues. The aim of this study was to fractionate pulse protein hydrolysates based on their amino acid compositions and evaluate their resulting physicochemical and IRI characteristics. Ni2+ IMAC fractionation induced IRI activity in all of the evaluated soy, chickpea, and pea protein hydrolysates regardless of their amino acid composition. Ni2+ IMAC fractionation produced chemically distinct fractions of peptides, differing by their molecular weights, amino acid composition, and IRI activities. The resulting peptide mixtures' molecular weight, amino acid composition, secondary structure, and sodium ion levels were found to have no correlation with their IRI activities. Thus, we demonstrate for the first time the ability of Ni2+ IMAC fractionation to induce IRI activity in hydrolyzed pulse proteins.

Functionality of the V-type ATPase during asexual growth and development of Plasmodium falciparum

V-type ATPases are highly conserved hetero-multi-subunit proton pumping machineries found in all eukaryotes. They utilize ATP hydrolysis to pump protons, acidifying intracellular or extracellular compartments, and are thus crucial for various biological processes. Despite their evolutionary conservation in malaria parasites, this proton pump remains understudied. To understand the localization and biological functions of Plasmodium falciparum V-type ATPase, we employed CRISPR/Cas9 to endogenously tag the subunit A of the V1 domain. V1A (PF3D7_1311900) was tagged with a triple hemagglutinin epitope and the TetR-DOZI-aptamer system for conditional expression under the regulation of anhydrotetracycline. Via immunofluorescence assays, we identified that V-type ATPase is expressed throughout the intraerythrocytic developmental cycle and is mainly localized on the digestive vacuole and parasite plasma membrane. Immuno-electron microscopy further revealed that V-type ATPase is also localized on secretory organelles in merozoites. Knockdown of V1A led to cytosolic pH imbalance and blockage of hemoglobin digestion in the digestive vacuole, resulting in an arrest of parasite development in the trophozoite stage and, ultimately, parasite demise. Using Bafilomycin A1, a specific inhibitor of V-type ATPases, we found that the P. falciparum V-type ATPase is likely involved in parasite invasion but is not critical for ring stage development. Further, we detected a large molecular weight complex in BN-PAGE (∼ 1.0 MDa), corresponding to the total molecular weights of V1 and Vo domains. Together, we show that V-type ATPase is localized on multiple subcellular compartments in P. falciparum, and its functionality throughout the asexual cycle varies depending on the parasite developmental stages.

Recyclable Polythioesters and Poly(thioester-co-peptoid)s via Ring-Opening Cascade Polymerization of Amino Acid N-Carboxyanhydrides.

Polythioesters (PTEs) are emerging sustainable polymers for their degradability and recyclability. However, low polymerizability of monomers and extensive side reactions often hampered the polymerization process. Moreover, copolymers containing both thioester and other types of functional groups in the backbone are highly desirable but rarely accomplished owing to several synthetic challenges. Here, we report the ring-opening cascade polymerization (ROCAP) of N-(2-(acetylthio)ethyl)-glycine N-carboxyanhydrides (TE-NCA) to afford recyclable PTEs and unprecedented poly(thioester-co-peptoid)s (P(TE-co-PP)s) in a controlled manner. By developing appropriated carboxylic acid-tertiary amine dual catalysts, intramolecular S-to-N acyl shift is coupled into the ROCAP process of TE-NA to yield products with dispersity below 1.10, molecular weight (Mn) up to 84.5 kDa, and precisely controlled ratio of thioester to peptoids. Random copolymerization of sarcosine NCA (Sar-NCA) and TE-NCA gives thioester-embedded polysarcosine with facile backbone degradation while maintaining the water solubility. This work represents a paradigm shift for the ROP of NCAs, enriches the realm of cascade polymerizations, and provides a powerful synthetic approach to functional PTEs and P(TE-co-PP)s that are otherwise difficult or impossible to make.

Digital Light Processing Resins with Programmable Shape Memory for Biomedical Applications.

The creation of biodegradable and biocompatible shape memory polymers amenable to biofabrication techniques remains a challenge. The ability to create shape-changing biodegradable objects that are triggered at body temperature opens up possibilities in tissue engineering, minimally invasive surgery, and actuating bioimplants. Merging Digital Light Processing (DLP) printing with shape memory polymers brings us closer to new smart biomedical outcomes. Previously, we developed a poly(caprolactone-co-trimethylenecarbonate) urethane acrylate resin for the DLP fabrication of biodegradable 3D objects. In further studies, we observed that some of these resins possessed shape memory properties, triggered by body temperature (37 °C). In this subsequent study, we explored the shape memory properties and tunability of this resin family via changes in copolymer composition, molecular weight, and identity of the acrylate end-capping unit. We found that we could create a library of shape memory resins, amenable to DLP printing, which allowed the creation of shape-actuating structures with some tunability over the speed of shape memory and mechanical properties. We observed that increased mole fraction of caprolactone in the copolymer and increased molecular weight of the polymer led to a decrease in speed of the shape memory switch. Furthermore, we observed a trade-off between the composition and the end-capping moiety on the mechanical properties of the polymers. These polymeric resins were able to be processed into shapes that were able to perform work, including the release of cargo and grabbing/lifting of an object. This platform now provides a way to tune the speed and mechanical properties of a shape memory DLP object created from common and scalable polymerization techniques. This work ultimately provides a new platform to develop customizable and biodegradable devices capable of actuating and delivery devices for numerous biomedical applications.

Anthocyanin Profiles in the Tropical Fruits Eugenia jambolana and Inga edulis: A Comparative Study Using Paper Spray Ionization (PSI-MS), Tissue Spray Ionization (TSI-MS), and Direct Infusion (DI-MS).

Paper spray ionization (PSI-MS) and tissue spray ionization (TSI-MS) mass spectrometry are simple and rapid ambient ionization mass spectrometry techniques that offer numerous advantages over conventional analysis methods. This study aims to analyze the efficiency of detecting anthocyanins from Eugenia jambolana fruit peel and Inga edulis seeds using PSI-MS, TSI-MS, and DI-MS (direct infusion). DI-MS exhibited high efficiency, detecting all compounds in abundance, with anthocyanins malvidin 3,5-O-diglucoside (1) and petunidin 3,5-O-diglucoside (2) being the most prevalent. PSI-MS, however, struggled to detect delphinidin 3-O-glucoside and showed lower abundances for compounds 1, 2, 3 (delphinidin 3,5-O-diglucoside), and 4 (petunidin 3-O-glucoside) compared to DI-MS, attributed to the technique's challenges with molecular weight and polarity. TSI-MS was least effective, detecting only compounds 1, 2, and 3 at low intensities. The overall unique compounds identified across techniques were 134, emphasizing the importance of comprehensively employing multiple methods to analyze anthocyanins in these edible plants.

Spatiotemporal response of the optical characteristics of dissolved organic matter to seasonality and land use in tropical island rivers.

Dissolved organic matter (DOM), a pivotal component in the global carbon cycle, plays a crucial role in maintaining the productivity and functionality of aquatic ecosystems. However, the driving factors of variations in the properties of riverine DOM in tropical islands still remain unclear. In this study, the spatiotemporal response of the optical characteristics of riverine DOM to seasonality and land use on Hainan Island in southern China was investigated. Our results revealed that DOM in the rivers of Hainan Island exhibited a relatively high proportion of fulvic acid and demonstrated strong terrestrial sources. The optical properties of DOM exhibited significant variations both seasonally and spatially. Land use exerted a dominant influence on riverine DOM. Specifically, during the wet season, riverine DOM exhibited larger molecular weight, increased chromophoric DOM (CDOM) abundance, and higher Fmax compared to the dry season. Furthermore, riverine DOM influenced by grassland and farmland showed higher CDOM abundance, Fmax, and humification degree in contrast to those impacted by forest and urban. Random forest and correlation analysis results indicated that grassland and farmland enhanced the Fmax of DOM by increasing levels of TP, NO3--N, Chl a, and NH4+-N in the dry season. However, during the wet season, the increased Fmax of DOM induced by grassland and farmland relied on the increments of Chl a and TP concentrations. This study improves our understanding of the spatiotemporal fluctuations of DOM in the rivers of Hainan Island, highlighting the effects of season and land use on DOM. It offers valuable support for improving water quality and contributes to enhancing human comprehension of the global carbon cycle.

3D-/2D-covalent organic framework (COF) bilayered membranes for efficient pharmaceutical purification

Covalent organic frameworks (COFs), with their regularly organized structures and solvent resistance, offer distinct advantages for constructing liquid-phase separation membranes. In nearly a decade of development, research has mainly focused on two-dimensional (2D) COFs, which yet give insufficient molecular selectivity due to inherent large pores. Here, we present a mixed-dimensional strategy of growing three-dimensional (3D) COFs on 2D COFs to build bilayered membranes for efficient organic solvent nanofiltration (OSN). The pores of 3D COFs interlace with those of 2D counterparts, resulting in a subnanoporous composite. We develop this 3D-/2D-COFs composite as robust membranes with a nanoscale thickness. The optimal bilayered membrane yields ethanol permeance of 12.2 L m−2 h−1 bar−1 with a molecular weight cutoff as low as ∼400 g mol−1, surpassing conventional COF-based OSN membranes. Importantly, the designed 3D-/2D-COFs membrane exhibits stable separation performance and excellent sieving ability to discriminate molecular mixtures. This exceptional molecular selectivity ultimately allows the separation of bioactive pharmaceuticals from impurities through our membrane. Overall, this work provides a design strategy for producing mixed-dimensional COF membranes to advance molecular separation in liquids.

Enzymatic synthesis of biobased aliphatic-hetero-aromatic furanic copolyesters: Influence of furan dimethyl ester isomerism

Due to environmental concerns, there is a growing demand for more sustainable materials. As a result, the renewability of the raw materials and catalysts involved in production is important for rendering sustainable and circular polymers. Due to its environmentally friendly nature and high selectivity, enzymatic polymerization is a viable approach for producing such polymers. Recent developments in the field of biobased furan building blocks have led to renewed interest in 2,4-furandicarboxylic acid (2,4-FDCA) and 3,4-FDCA. Furthermore, far too little attention has been given to 2,5-bis(hydroxymethyl)furan (2,5-BHMF), another class of hetero-aromatic diol that can be derived from carbohydrates. These furan monomers are attractive due to their potential for producing novel biobased polyesters with interesting properties. To date, however, there has been little discussion about the use of these materials for polymerization via enzymatic approaches. Hence, a comparative study of CALB-catalyzed copolymerization involving two FDCA dimethyl ester isomers, either 2,4- or 3,4-DMFDCA, with 2,5-BHMF and various aliphatic diols has been carried out. This provides further insight into the regioselectivity promoted by CALB for asymmetrical 2,4-DMFDCA over symmetrical 3,4-DMFDCA. This is evidenced by the high degree of polymerization achieved with a weight-average molecular weight of up to 14 kg mol−1. In agreement with previous findings, a preference for the formation of cyclic species from symmetrical monomers catalyzed by CALB was observed. Structural characterization and thermal and crystallinity analyses were used to assess the correlation between structure and material properties.

Radioactive ADME Demonstrates ARV-110's High Druggability Despite Low Oral Bioavailability.

Proteolysis-targeting chimeras (PROTACs) have emerged as potentially effective therapeutic medicines, but their high molecular weight and poor solubility directly impact their oral bioavailability. This work synthesized 14C-labeled bavdegalutamide (ARV-110) as a model compound of PROTACs to evaluate its ADME features. Compared with targeted antitumor drugs, the use of food increased oral bioavailability of ARV-110 in rats from 10.75% to 20.97%, which is still undesirable. However, the therapeutic effect of ARV-110 at a low dose was much better than that of enzalutamide, demonstrating the specific catalytic medicinal properties of PROTACs. Moreover, the specific distribution of ARV-110 in subcutaneous prostate tumors was determined by quantitative whole-body autoradiography (QWBA). Notably, the specificity and activity of PROTACs take precedence over their oral absorption, and high oral bioavailability is not necessary to produce excellent therapeutic effects. This work presents a roadmap for developing future PROTAC medications from a radioactive drug metabolism and pharmacokinetics (DMPK) perspective.

Hyaluronic Acid-Coated Nanoliposomes as Delivery Systems for Fisetin: Stability, Membrane Fluidity, and Bioavailability

Fisetin has shown numerous health benefits, whereas its food application is constrained by water insolubility, poor stability, and low bioaccessibility. This work investigated the potential of hyaluronic acid (HA)-coated nanoliposomes for the encapsulation and delivery of fisetin. It was observed that HA can adsorb onto the liposomal membrane through hydrogen bonding and maintain the spherical shape of nanoliposomes. Fluorescence analysis suggested that the HA coating restricted the motion and freedom of phospholipid molecules in the headgroup region and reduced the interior micropolarity of the nanoliposomes but did not affect the fluidity of the hydrophobic core. These effects were more pronounced for the HA with a low molecular weight (35 kDa) and moderate concentration (0.4%). The HA coating improved the storage and thermal stability of the nanoliposomes, as well as the digestive stability and bioaccessibility of the encapsulated fisetin. These findings could guide the development of HA-coated nanoliposomes for the controlled delivery of hydrophobic bioactives such as fisetin in functional foods.

Recombinant GH3 β-glucosidase stimulated by xylose and tolerant to furfural and 5-hydroxymethylfurfural obtained from Aspergillus nidulans

The β-glucosidase gene from Aspergillus nidulans FGSC A4 was cloned and overexpressed in the A. nidulans A773. The resulting purified β-glucosidase, named AnGH3, is a monomeric enzyme with a molecular weight of approximately 80 kDa, as confirmed by SDS-PAGE. Circular dichroism further validated its unique canonical barrel fold (β/α), a feature also observed in the 3D homology model of AnGH3. The most striking aspect of this recombinant enzyme is its robustness, as it retained 100% activity after 24 h of incubation at 45 and 50 ºC and pH 6.0. Even at 55 °C, it maintained 72% of its enzymatic activity after 6 h of incubation at the same pH. The kinetic parameters Vmax, KM, and Kcat/KM for ρ-nitrophenyl-β-D-glucopyranoside (ρNPG) and cellobiose were also determined. Using ρNPG, the enzyme demonstrated a Vmax of 212 U mg − 1, KM of 0.0607 mmol L − 1, and Kcat/KM of 4521 mmol L − 1 s − 1 when incubated at pH 6.0 and 65 °C. The KM, Vmax, and Kcat/KM using cellobiose were 2.7 mmol L − 1, 57 U mg − 1, and 27 mmol –1 s − 1, respectively. AnGH3 activity was significantly enhanced by xylose and ethanol at concentrations up to 1.5 mol L − 1 and 25%, respectively. Even in challenging conditions, at 65 °C and pH 6.0, the enzyme maintained its activity, retaining 100% and 70% of its initial activity in the presence of 200 mmol L − 1 furfural and 5-hydroxymethylfurfural (HMF), respectively. The potential of this enzyme was further demonstrated by its application in the saccharification of the forage grass Panicum maximum, where it led to a 48% increase in glucose release after 24 h. These unique characteristics, including high catalytic performance, good thermal stability in hydrolysis temperature, and tolerance to elevated concentrations of ethanol, D-xylose, furfural, and HMF, position this recombinant enzyme as a promising tool in the hydrolysis of lignocellulosic biomass as part of an efficient multi-enzyme cocktail, thereby opening new avenues in the field of biotechnology and enzymology.

Mechanochemical cleavage of wheat lignin into a more homogeneous fraction

Lignin, the second most abundant biopolymer in earth, represents nature’s largest carbon sources, has high polydispersity and uncertain reactivity, that limit efficient modification/degradation and use of products obtained. In order to decrease by mechanochemical means the average molecular mass and polydispersity of lignin fragments of the CIMV organosolv lignin named Biolignin™, we applied a sodium hydroxide-assisted planetary ball milling process. Experimental conditions were first optimized on purified Biolignin™ then to Biolignin™ without prior purification in 20 mL jars before applying it successfully to a 500 mL planetary ball milling apparatus. Extensive, quantitative HSQC NMR, IR and GPC studies, overtaken supported our three most important findings: reduction of the needed quantity of sodium hydroxide of 75 % compared to the literature, obtention of halve (-51 %) the occurrence of β-O-4’ linkages in lignin fragment, an optimum of 14 wt% of moisture is useful in the degradation process.

Antioxidant and Emulsifying Activity of the Exopolymer Produced by Bacillus licheniformis

The exopolymer (ESPp) was obtained from Bacillus licheniformis IDN-EC, composed of a polyglutamic acid and polyglycerol phosphate chain O-substituted with αGal moieties (αGal/αGlcNH2 3:1 molar ratio) and with a 5000 Da molecular weight. The cytotoxicity activity of EPSp was determined by reducing the MTT (3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide) to formazan on HeLa cells. This EPS did not show cytotoxicity against the tested cell line. The ESPp presented great advantages as an antioxidant with free radical scavenging activities (1,1-diphenyl-2-picryl-hydrazyl radical (DPPH),hydroxyl radical (OH), and superoxide anion (O2−)) (65 ± 1.2%, 98.7 ± 1.9%, and 97 ± 1.7%), respectively. Moreover, EPSp increased the enzyme activity for catalase (CAT) and glutathione peroxidase (GSH-Px) in HeLa cells (CAT, 2.6 ± 0.24 U/mL; and GSH-Px, 0.75 ± 0.3 U/L). The presence of ESPp showed a significant protective effect against H2O2 in the cell line studied, showing great viability (91.8 ± 2.8, 89.9 ± 2.9, and 93.5 ± 3.6%). The EPSp presented good emulsifying activity, only for vegetable oils, olive oil (50 ± 2.1%) and sesame (72 ± 3%). Sesame was effective compared to commercials products, Triton X-100 (52.38 ± 1.6%), Tween 20 (14.29 ± 1.1%), and sodium dodecyl sulphate (SDS) (52.63 ± 1.6%). Furthermore, the EPS produced at 0.6 M has potential for environmental applications, such as the removal of hazardous materials by emulsification whilst resulting in positive health effects such as antioxidant activity and non-toxicity. EPSp is presented as a good exopolysaccharide for various applications.

Quantum-Mechanics Calculations Elucidate Skin-Sensitizing Pharmaceutical Compounds.

Skin sensitization is a critical end point in occupational toxicology that necessitates the use of fast, accurate, and affordable models to aid in establishing handling guidance for worker protection. While many in silico models have been developed, the scarcity of reliable data for active pharmaceutical ingredients (APIs) and their intermediates (together regarded as pharmaceutical compounds) brings into question the reliability of these tools, which are largely constructed using publicly available nonspecialty chemicals. Here, we present the quantum-mechanical (QM) Computer-Aided Discovery and REdesign (CADRE) model, which was developed with the bioactive and structurally complex chemical space in mind by relying on the fundamentals of chemical interactions in key events (versus structural attributes of training-set data). Validated in this study on 345 APIs and intermediates, CADRE achieved 95% accuracy, sensitivity, and specificity and a combined 79% accuracy in assigning potency categories compared to the mouse local lymph node assay data. We show how historical outcomes from CADRE testing in the pharmaceutical space, generated over the past 10 years on ca. 2500 chemicals, can be used to probe the relationships between sensitization mechanisms (or the underlying chemical classes) and the probability of eliciting a sensitization response in mice of a given potency. We believe this information to be of value to both practitioners, who can use it to quickly screen and triage their data sets, as well as to model developers to fine-tune their structure-based tools. Lastly, we leverage our experimentally validated subset of APIs and intermediates to show the importance of dermal permeability on the sensitization potential and potency. We demonstrate that common physicochemical properties used to assess permeation, such as the octanol-water partition coefficient and molecular weight, are poor proxies for the more accurate energy-pair distributions that can be computed from mixed QM and classical simulations using model representations of the stratum corneum.

Molecular cloning and characterization of heat-responsive LcOPR1, a gene encoding oxophytodienoic acid reductase in lentil.

Improving crop plants using biotechnological implications is a promising and modern approach compared to traditional methods. High-temperature exposure to the reproductive stage induces flower abortion and declines grain filling performance, leading to smaller grain production and low yield in lentil and other legumes. Thus, cloning effective candidate genes and their implication in temperature stress tolerance in lentil (Lens culinaris Medik.) using biotechnological tools is highly demandable. The 12-oxophytodienoic acid reductases (OPRs) are flavin mononucleotide-dependent oxidoreductases with vital roles in plants. They are members of the old yellow enzyme (OYE) family. These enzymes are involved in the octadecanoid pathway, which contributes to jasmonic acid biosynthesis and is essential in plant stress responses. Lentil is one of the vital legume crops affected by the temperature fluctuations caused by global warming. Therefore, in this study, the LcOPR1 gene was successfully cloned and isolated from lentils using RT-PCR to evaluate its functional responses in lentil under heat stress. The bioinformatics analysis revealed that the full-length cDNA of LcOPR1 was 1303 bp, containing an 1134 bp open reading frames (ORFs), encoding 377 amino acids with a predicted molecular weight of 41.63 and a theoretical isoelectric point of 5.61. Bioinformatics analyses revealed that the deduced LcOPR1 possesses considerable homology with other plant 12-oxophytodienoic acid reductases (OPRs). Phylogenetic tree analysis showed that LcOPR1 has an evolutionary relationship with other OPRs in different plant species of subgroup I, containing enzymes that are not required for jasmonic acid biosynthesis. The expression analysis of LcOPR1 indicated that this gene is upregulated in response to the heat-stress condition and during recovery in lentil. This study finding might be helpful to plant breeders and biotechnologists in LcOPR1 engineering and/or plant breeding programs in revealing the biological functions of LcOPR1 in lentils and the possibility of enhancing heat stress tolerance by overexpressing LcOPR1 in lentil and other legume plants under high temperature.