bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Signal Substance for Multiplexed Immunosensing Interface Construction: A Mini Review
Authors: Feng Jiejie , Chu Changshun , Ma Zhanfang
Published: January 2022

Appropriate labeling method of signal substance is necessary for the construction of multiplexed electrochemical immunosensing interface to enhance the specificity for the diagnosis of cancer. So far, various electrochemical substances, including organic molecules, metal ions, metal nanoparticles, Prussian blue, and other methods for an electrochemical signal generation have been successfully applied in multiplexed biosensor designing. However, few works have been reported on the summary of electrochemical signal substance applied in constructing multiplexed immunosensing interface. Herein, according to the classification of labeled electrochemical signal substance, this review has summarized the recent state-of-art development for the designing of electrochemical immunosensing interface for simultaneous detection of multiple tumor markers. After that, the conclusion and prospects for future applications of electrochemical signal substances in multiplexed immunosensors are also discussed. The current review can provide a comprehensive summary of signal substance selection for workers researched in electrochemical sensors, and further, make contributions for the designing of multiplexed electrochemical immunosensing interface with well signal.
Single-Step Hydrothermal Synthesis of Biochar from H3PO4-Activated Lettuce Waste for Efficient Adsorption of Cd(II) in Aqueous Solution
Authors: Chen Quyun , Zhang Tian C. , Ouyang Like , Yuan Shaojun
Published: January 2022

Developing an ideal and cheap adsorbent for adsorbing heavy metals from aqueous solution has been urgently need. In this study, a novel, effective and low-cost method was developed to prepare the biochar from lettuce waste with H3PO4 as an acidic activation agent at a low-temperature (circa 200 °C) hydrothermal carbonization process. A batch adsorption experiment demonstrated that the biochar reaches the adsorption equilibrium within 30 min, and the optimal adsorption capacity of Cd(II) is 195.8 mg∙g−1 at solution pH 6.0, which is significantly improved from circa 20.5 mg∙g−1 of the original biochar without activator. The fitting results of the prepared biochar adsorption data conform to the pseudo-second-order kinetic model (PSO) and the Sips isotherm model, and the Cd(II) adsorption is a spontaneous and exothermic process. The hypothetical adsorption mechanism is mainly composed of ion exchange, electrostatic attraction, and surface complexation. This work offers a novel and low-temperature strategy to produce cheap and promising carbon-based adsorbents from organic vegetation wastes for removing heavy metals in aquatic environment efficiently.
Dual-Responsive Alginate Hydrogel Constructed by Sulfhdryl Dendrimer as an Intelligent System for Drug Delivery
Authors: Li Li , Lei Dongyu , Zhang Jiaojiao , Xu Lu , Li Jiashan , Jin Lu , Pan Le
Published: January 2022

Intelligent stimulus-triggered release and high drug-loading capacity are crucial requirements for drug delivery systems in cancer treatment. Based on the excessive intracellular GSH expression and pH conditions in tumor cells, a novel glutathione (GSH) and pH dual-responsive hydrogel was designed and synthesized by conjugates of glutamic acid-cysteine dendrimer with alginate (Glu-Cys-SA) through click reaction, and then cross-linked with polyethylene glycol (PEG) through hydrogen bonds to form a 3D-net structure. The hydrogel, self-assembled by the inner disulfide bonds of the dendrimer, is designed to respond to the GSH heterogeneity in tumors, with a remarkably high drug loading capacity. The Dox-loaded Glu-Cys-SA hydrogel showed controlled drug release behavior, significantly with a release rate of over 76% in response to GSH. The cytotoxicity investigation indicated that the prepared DOX-loaded hydrogel exhibited comparable anti-tumor activity against HepG-2 cells with positive control. These biocompatible hydrogels are expected to be well-designed GSH and pH dual-sensitive conjugates or polymers for efficient anticancer drug delivery.
A Fast and Selective Approach for Profiling Vicinal Diols Using Liquid Chromatography-Post Column Derivatization-Double Precursor Ion Scanning Mass Spectrometry
Authors: Wan Debin , Morisseau Christophe , Hammock Bruce D. , Yang Jun
Published: January 2022

Vicinal diols are important signaling metabolites of various inflammatory diseases, and some of them are potential biomarkers for some diseases. Utilizing the rapid reaction between diol and 6-bromo-3-pyridinylboronic acid (BPBA), a selective and sensitive approach was established to profile these vicinal diols using liquid chromatography-post column derivatization coupled with double precursor ion scan-mass spectrometry (LC-PCD-DPIS-MS). After derivatization, all BPBA-vicinal-diol esters gave a pair of characteristic isotope ions resulting from 79Br and 81Br. The unique isotope pattern generated two characteristic fragment ions of m/z 200 and 202. Compared to a traditional offline derivatization technique, the new LC-PCD-DPIS-MS method retained the capacity of LC separation. In addition, it is more sensitive and selective than a full scan MS method. As an application, an in vitro study of the metabolism of epoxy fatty acids by human soluble epoxide hydrolase was tested. These vicinal-diol metabolites of individual regioisomers from different types of polyunsaturated fatty acids were easily identified. The limit of detection (LOD) reached as low as 25 nM. The newly developed LC-PCD-DPIS-MS method shows significant advantages in improving the selectivity and therefore can be employed as a powerful tool for profiling vicinal-diol compounds from biological matrices.
Biophysical Characterization of Novel DNA Aptamers against K103N/Y181C Double Mutant HIV-1 Reverse Transcriptase
Authors: Ratanabunyong Siriluk , Seetaha Supaphorn , Hannongbua Supa , Yanaka Saeko , Yagi-Utsumi Maho , Kato Koichi , Paemanee Atchara , Choowongkomon Kiattawee
Published: January 2022

The human immunodeficiency virus type-1 Reverse Transcriptase (HIV-1 RT) plays a pivotal role in essential viral replication and is the main target for antiviral therapy. The anti-HIV-1 RT drugs address resistance-associated mutations. This research focused on isolating the potential specific DNA aptamers against K103N/Y181C double mutant HIV-1 RT. Five DNA aptamers showed low IC50 values against both the KY-mutant HIV-1 RT and wildtype (WT) HIV-1 RT. The kinetic binding affinity forms surface plasmon resonance of both KY-mutant and WT HIV-1 RTs in the range of 0.06–2 μM and 0.15–2 μM, respectively. Among these aptamers, the KY44 aptamer was chosen to study the interaction of HIV-1 RTs-DNA aptamer complex by NMR experiments. The NMR results indicate that the aptamer could interact with both WT and KY-mutant HIV-1 RT at the NNRTI drug binding pocket by inducing a chemical shift at methionine residues. Furthermore, KY44 could inhibit pseudo-HIV particle infection in HEK293 cells with nearly 80% inhibition and showed low cytotoxicity on HEK293 cells. These together indicated that the KY44 aptamer could be a potential inhibitor of both WT and KY-mutant HIV-RT.
Biochemical and Structural Analysis of a Glucose-Tolerant β-Glucosidase from the Hemicellulose-Degrading Thermoanaerobacterium saccharolyticum
Authors: Kim In Jung , Bornscheuer Uwe T. , Nam Ki Hyun
Published: January 2022

β-Glucosidases (Bgls) convert cellobiose and other soluble cello-oligomers into glucose and play important roles in fundamental biological processes, providing energy sources in living organisms. Bgls are essential terminal enzymes of cellulose degradation systems and attractive targets for lignocellulose-based biotechnological applications. Characterization of novel Bgls is important for broadening our knowledge of this enzyme class and can provide insights into its further applications. In this study, we report the biochemical and structural analysis of a Bgl from the hemicellulose-degrading thermophilic anaerobe Thermoanaerobacterium saccharolyticum (TsaBgl). TsaBgl exhibited its maximum hydrolase activity on p-nitrophenyl-β-d-glucopyranoside at pH 6.0 and 55 °C. The crystal structure of TsaBgl showed a single (β/α)8 TIM-barrel fold, and a β8-α14 loop, which is located around the substrate-binding pocket entrance, showing a unique conformation compared with other structurally known Bgls. A Tris molecule inhibited enzyme activity and was bound to the active site of TsaBgl coordinated by the catalytic residues Glu163 (proton donor) and Glu351 (nucleophile). Titration experiments showed that TsaBgl belongs to the glucose-tolerant Bgl family. The gatekeeper site of TsaBgl is similar to those of other glucose-tolerant Bgls, whereas Trp323 and Leu170, which are involved in glucose tolerance, show a unique configuration. Our results therefore improve our knowledge about the Tris-mediated inhibition and glucose tolerance of Bgl family members, which is essential for their industrial application.
Two Possible Strategies for Drug Modification of Gemcitabine and Future Contributions to Personalized Medicine
Authors: Pereira Mariana , Vale Nuno
Published: January 2022

Drug repurposing is an emerging strategy, which uses already approved drugs for new medical indications. One such drug is gemcitabine, an anticancer drug that only works at high doses since a portion is deactivated in the serum, which causes toxicity. In this review, two methods were discussed that could improve the anticancer effect of gemcitabine. The first is a chemical modification by conjugation with cell-penetrating peptides, namely penetratin, pVEC, and different kinds of CPP6, which mostly all showed an increased anticancer effect. The other method is combining gemcitabine with repurposed drugs, namely itraconazole, which also showed great cancer cell inhibition growth. Besides these two strategies, physiologically based pharmacokinetic models (PBPK models) are also the key for predicting drug distribution based on physiological data, which is very important for personalized medicine, so that the correct drug and dosage regimen can be administered according to each patient’s physiology. Taking all of this into consideration, it is believed that gemcitabine can be repurposed to have better anticancer effects.
Eco-Friendly, Simple, Fast, and Sensitive UPLC-MS/MS Method for Determination of Pexidartinib in Plasma and Its Application to Metabolic Stability
Authors: Ezzeldin Essam , Iqbal Muzaffar , Asiri Yousif A. , Mostafa Gamal A. E. , Sayed Ahmed Y. A.
Published: January 2022

Pexidartinib is the first drug approved by the U.S. Food and Drug Administration specifically to treat the rare joint tumor tenosynovial giant cell tumor. In the current study, a validated, selective, and sensitive UPLC-MS/MS assay was developed for the quantitative determination of pexidartinib in plasma samples using gifitinib as an internal standard (IS). Pexidartinib and IS were extracted by liquid-liquid extraction using methyl tert-butyl ether and separated on an acquity BEH C18 column kept at 40 °C using a mobile phase of 0.1% formic acid in acetonitrile: 0.1% formic acid in de-ionized water (70:30). The flow rate was 0.25 mL/min. Multiple reaction monitoring (MRM) was operated in electrospray (ESI)-positive mode at the ion transition of 418.06 > 165.0 for the analyte and 447.09 > 128.0 for the IS. FDA guidance for bioanalytical method validation was followed in method validation. The linearity of the established UPLC-MS/MS assay ranged from 0.5 to 1000 ng/mL with r > 0.999 with a limit of quantitation of 0.5 ng/mL. Moreover, the metabolic stability of pexidartinib in liver microsomes was estimated.
Theoretical Studies on the Mechanism of deNOx Process in Cu–Zn Bimetallic System—Comparison of FAU and MFI Zeolites
Authors: Kurzydym Izabela , Czekaj Izabela
Published: January 2022

In the present study we propose a more promising catalyst for the deNOx process to eliminate harmful nitrogen oxides from the environment. The study was performed with a computer calculation using density functional theory (DFT) based on an ab initio method. Two zeolite catalysts, FAU and MFI, were selected with additional Cu–O–Zn bimetallic dimer adsorbed inside the pores of both zeolites. Based on the analysis of preliminary studies, the most probable way of co-adsorption of nitric oxide and ammonia was selected, which became the initial configuration for the reaction mechanism. Two types of mechanisms were proposed: with hydroxyl groups on a bridged position of the dimer or a hydroxyl group on one of the metal atoms of the dimer. Based on the results, it was determined that the FAU zeolite with a bimetallic dimer and an OH group on the zinc atom was the most efficient configuration with a relatively low energy barrier. The real advantage of the Cu–Zn system over FAU and MFI in hydrothermal conditions has been demonstrated in comparison to a conventional Cu–Cu catalyst.
Ab Initio Study of Fine and Hyperfine Interactions in Triplet POH
Authors: Bizzocchi Luca , Alessandrini Silvia , Melosso Mattia , Rivilla Víctor M. , Puzzarini Cristina
Published: January 2022

Phosphorous-containing molecules have a great relevance in prebiotic chemistry in view of the fact that phosphorous is a fundamental constituent of biomolecules, such as RNA, DNA, and ATP. Its biogenic importance has led astrochemists to investigate the possibility that P-bearing species could have formed in the interstellar medium (ISM) and subsequently been delivered to early Earth by rocky bodies. However, only two P-bearing molecules have been detected so far in the ISM, with the chemistry of interstellar phosphorous remaining poorly understood. Here, in order to shed further light on P-carriers in space, we report a theoretical spectroscopic characterisation of the rotational spectrum of POH in its 3A″ ground electronic state. State-of-the-art coupled-cluster schemes have been employed to derive rotational constants, centrifugal distortion terms, and most of the fine and hyperfine interaction parameters, while the electron spin–spin dipolar coupling has been investigated using the multi-configuration self-consistent-field method. The computed spectroscopic parameters have been used to simulate the appearance of triplet POH rotational and ro-vibrational spectra in different conditions, from cold to warm environments, either in gas-phase experiments or in molecular clouds. Finally, we point out that the predicted hyperfine structures represent a key pattern for the recognition of POH in laboratory and interstellar spectra.
Spray Deposition Synthesis of Locally Ordered Mesoporous Polycrystalline Titania Films at Low Temperature
Authors: Símonarson Gunnar , Lotsari Antiope , Palmqvist Anders E. C.
Published: January 2022

A low-temperature spray deposition synthesis was developed to prepare locally hexagonally ordered mesoporous titania films with polycrystalline anatase pore walls in an evaporation-induced self-assembly process. The titania film preparation procedure is conducted completely at temperatures below 50 °C. The effects of spray time, film thickness, synthesis time prior to spray deposition, and aging time at high relative humidity after deposition on the atomic arrangement and the mesoorder of the mesoporous titania were studied. We find the crystallite size to depend on both the synthesis time and aging time of the films, where longer times result in larger crystallites. Using the photocatalytic activity of titania, the structure-directing agent is removed with UV radiation at 43–46 °C. The capability of the prepared films to remove the polymer template increased with longer synthesis and aging times due to the increased crystallinity, which increases the photocatalytic efficiency of the titania films. However, with increasingly longer times, the crystallites grow too large for the mesoorder of the pores to be maintained. This work shows that a scalable spray coating method can be used to prepare locally ordered mesoporous polycrystalline titania films by judiciously tuning the synthesis parameters.
Acid-Catalyzed Liquefaction of Biomasses from Poplar Clones for Short Rotation Coppice Cultivations
Authors: Paulo Ivo , Costa Luis , Rodrigues Abel , Orišková Sofia , Matos Sandro , Gonçalves Diogo , Gonçalves Ana Raquel , Silva Luciana , Vieira Salomé , Bordado João Carlos , Galhano dos Santos Rui
Published: January 2022

Liquefaction of biomass delivers a liquid bio-oil with relevant chemical and energetic applications. In this study we coupled it with short rotation coppice (SRC) intensively managed poplar cultivations aimed at biomass production while safeguarding environmental principles of soil quality and biodiversity. We carried out acid-catalyzed liquefaction, at 160 °C and atmospheric pressure, with eight poplar clones from SRC cultivations. The bio-oil yields were high, ranging between 70.7 and 81.5%. Average gains of bio-oil, by comparison of raw biomasses, in elementary carbon and hydrogen and high heating, were 25.6, 67, and 74%, respectively. Loss of oxygen and O/C ratios averaged 38 and 51%, respectively. Amounts of elementary carbon, oxygen, and hydrogen in bio-oil were 65, 26, and 8.7%, and HHV averaged 30.5 MJkg−1. Correlation analysis showed the interrelation between elementary carbon with HHV in bio-oil or with oxygen loss. Overall, from 55 correlations, 21 significant and high correlations among a set of 11 variables were found. Among the most relevant ones, the percentage of elementary carbon presented five significant correlations with the percentage of O (−0.980), percentage of C gain (0.902), percentage of O loss (0.973), HHV gain (0.917), and O/C loss (0.943). The amount of carbon is directly correlated with the amount of oxygen, conversely, the decrease in oxygen content increases the elementary carbon and hydrogen concentration, which leads to an improvement in HHV. HHV gain showed a strong positive dependence on the percentage of C (0.917) and percentage of C gain (0.943), while the elementary oxygen (−0.885) and its percentage of O loss (0.978) adversely affect the HHV gain. Consequently, the O/C loss (0.970) increases the HHV positively. van Krevelen’s analysis indicated that bio-oils are chemically compatible with liquid fossil fuels. FTIR-ATR evidenced the presence of derivatives of depolymerization of lignin and cellulose in raw biomasses in bio-oil. TGA/DTG confirmed the bio-oil burning aptitude by the high average 53% mass loss of volatiles associated with lowered peaking decomposition temperatures by 100 °C than raw biomasses. Overall, this research shows the potential of bio-oil from liquefaction of SRC biomasses for the contribution of renewable energy and chemical deliverables, and thereby, to a greener global economy.
Co-Ingestion of Natal Plums (Carissa macrocarpa) and Marula Nuts (Sclerocarya birrea) in a Snack Bar and Its Effect on Phenolic Compounds and Bioactivities
Authors: Manhivi Vimbainashe E. , Slabbert Retha M. , Sivakumar Dharini
Published: January 2022

This study investigated the effect of co-ingesting Natal plums (Carissa macrocarpa) and Marula nuts (Sclerocarya birrea) on the bioaccessibility and uptake of anthocyanins, antioxidant capacity, and the ability to inhibit α-glucosidase. A Natal plum–Marula nut bar was made by mixing the raw nuts and the fruit pulp in a ratio 1:1 (v/v). The cyanidin-3-O-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside content (Cy-3-G) were quantified using the ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). Inclusion of Natal plum in the Marula nut bar increased the Cy-3-Sa, Cy-3-G content, antioxidants capacity and α-glucosidase inhibition compared to ingesting Marula nut separately at the internal phase. Adding Natal plum to the Marula nut bar increased bioaccessibility of Cy-3-Sa, Cy-3-G, quercetin, coumaric acid, syringic acid and ferulic acid to 80.2% and 71.9%, 98.7%, 95.2%, 51.9% and 89.3%, respectively, compared to ingesting the Natal plum fruit or nut separately.
The Role of Neuropeptide-Stimulated cAMP-EPACs Signalling in Cancer Cells
Authors: Gao Zhengyin , Lei Weng I , Lee Leo Tsz On
Published: January 2022

Neuropeptides are autocrine and paracrine signalling factors and mainly bind to G protein-coupled receptors (GPCRs) to trigger intracellular secondary messenger release including adenosine 3′, 5′-cyclic monophosphate (cAMP), thus modulating cancer progress in different kind of tumours. As one of the downstream effectors of cAMP, exchange proteins directly activated by cAMP (EPACs) play dual roles in cancer proliferation and metastasis. More evidence about the relationship between neuropeptides and EPAC pathways have been proposed for their potential role in cancer development; hence, this review focuses on the role of neuropeptide/GPCR system modulation of cAMP/EPACs pathways in cancers. The correlated downstream pathways between neuropeptides and EPACs in cancer cell proliferation, migration, and metastasis is discussed to glimmer the direction of future research.
The Caenorhabditis elegans DEG-3/DES-2 Channel Is a Betaine-Gated Receptor Insensitive to Monepantel
Authors: Hansen Tina V. A. , Sager Heinz , Toutain Céline E. , Courtot Elise , Neveu Cédric , Charvet Claude L.
Published: January 2022

Natural plant compounds, such as betaine, are described to have nematocidal properties. Betaine also acts as a neurotransmitter in the free-living model nematode Caenorhabditis elegans, where it is required for normal motility. Worm motility is mediated by nicotinic acetylcholine receptors (nAChRs), including subunits from the nematode-specific DEG-3 group. Not all types of nAChRs in this group are associated with motility, and one of these is the DEG-3/DES-2 channel from C. elegans, which is involved in nociception and possibly chemotaxis. Interestingly, the activity of DEG-3/DES-2 channel from the parasitic nematode of ruminants, Haemonchus contortus, is modulated by monepantel and its sulfone metabolite, which belong to the amino-acetonitrile derivative anthelmintic drug class. Here, our aim was to advance the pharmacological knowledge of the DEG-3/DES-2 channel from C. elegans by functionally expressing the DEG-3/DES-2 channel in Xenopus laevis oocytes and using two-electrode voltage-clamp electrophysiology. We found that the DEG-3/DES-2 channel was more sensitive to betaine than ACh and choline, but insensitive to monepantel and monepantel sulfone when used as direct agonists and as allosteric modulators in co-application with betaine. These findings provide important insight into the pharmacology of DEG-3/DES-2 from C. elegans and highlight the pharmacological differences between non-parasitic and parasitic nematode species.
Simultaneous Detoxification of Aflatoxin B1, Zearalenone and Deoxynivalenol by Modified Montmorillonites
Authors: Mao Jiaqi , Zhou Ying , Lv Guanglie , Zhou Renxian
Published: January 2022

Raw Ca-based montmorillonite (MMT) was treated by H2SO4, calcination and organic compounds (hexadecyltrimethyl ammonium bromide (HTAB), cetylpyridinium chloride (CPC) and chitosan (CTS)), respectively. The modified montmorillonites were characterized by different methods and their adsorption performances for three mycotoxins (Aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON)) were evaluated at pH = 2.8 and 8.0, respectively. The results indicate that surfactants (CPC and HTAB) intercalation is the most efficient modification, which obviously improves the adsorption performance of montmorillonite for mycotoxins, with adsorption efficiency of above 90% for AFB1 and ZEA whether under acid or alkaline conditions, due to the increase in basal spacing and the improvement of hydrophobicity. Moreover, the adsorption efficiencies of AFB1 and ZEA over CPC-modified montmorillonite (CPC-AMMT-3) coexisting with vitamin B6 or lysine are still at a high level (all above 94%). All modified montmorillonites, however, have low adsorption efficiency for DON, with somewhat spherical molecular geometry.
Cool Temperature Enhances Growth, Ferulic Acid and Flavonoid Biosynthesis While Inhibiting Polysaccharide Biosynthesis in Angelica sinensis
Authors: Dong Han , Li Meiling , Jin Ling , Xie Xiaorong , Li Mengfei , Wei Jianhe
Published: January 2022

Angelica sinensis, a perennial herb that produces ferulic acid and phthalides for the treatment of cardio-cerebrovascular diseases, prefers growing at an altitude of 1800–3000 m. Geographical models have predicted that high altitude, cool temperature and sunshade play determining roles in geo-authentic formation. Although the roles of altitude and light in yield and quality have been investigated, the role of temperature in regulating growth, metabolites biosynthesis and gene expression is still unclear. In this study, growth characteristics, metabolites contents and related genes expression were investigated by exposing A. sinensis to cooler (15 °C) and normal temperatures (22 °C). The results showed that plant biomass, the contents of ferulic acid and flavonoids and the expression levels of genes related to the biosynthesis of ferulic acid (PAL1, 4CLL4, 4CLL9, C3H, HCT, CCOAMT and CCR) and flavonoids (CHS and CHI) were enhanced at 15 °C compared to 22 °C. The contents of ligustilide and volatile oils exhibited slight increases, while polysaccharide contents decreased in response to cooler temperature. Based on gene expression levels, ferulic acid biosynthesis probably depends on the CCOAMT pathway and not the COMT pathway. It can be concluded that cool temperature enhances plant growth, ferulic acid and flavonoid accumulation but inhibits polysaccharide biosynthesis in A. sinensis. These findings authenticate that cool temperature plays a determining role in the formation of geo-authentic and also provide a strong foundation for regulating metabolites production of A. sinensis.
Synthesis of High Performance Thiophene–Aromatic Polyesters from Bio-Sourced Organic Acids and Polysaccharide-Derived Diol: Characterization and Degradability Studies
Authors: Djouonkep Lesly Dasilva Wandji , Tamo Arnaud Kamdem , Doench Ingo , Selabi Naomie Beolle Songwe , Ilunga Emmanuel Monga , Lenwoue Arnaud Regis Kamgue , Gauthier Mario , Cheng Zhengzai , Osorio-Madrazo Anayancy
Published: January 2022

In this work, the feasibility of replacing petroleum-based poly(ethylene terephthalate) (PET) with fully bio-based copolyesters derived from dimethyl 2,5-thiophenedicarboxylate (DMTD), dimethyl 2,5-dimethoxyterephthalate (DMDMT), and polysaccharide-derived 1,6-hexanediol (HDO) was investigated. A systematic study of structure-property relationship revealed that the properties of these poly(thiophene–aromatic) copolyesters (PHS(20–90)) can be tailored by varying the ratio of diester monomers in the reaction, whereby an increase in DMTD content noticeably shortened the reaction time in the transesterification step due to its higher reactivity as compared with DMDMT. The copolyesters had weight-average molar masses (Mw) between 27,500 and 38,800 g/mol, and dispersity Đ of 2.0–2.5. The different polarity and stability of heterocyclic DMTD provided an efficient mean to tailor the crystallization ability of the copolyesters, which in turn affected the thermal and mechanical performance. The glass transition temperature (Tg) could be tuned from 70–100 °C, while the tensile strength was in a range of 23–80 MPa. The obtained results confirmed that the co-monomers were successfully inserted into the copolyester chains. As compared with commercial poly(ethylene terephthalate), the copolyesters displayed not only enhanced susceptibility to hydrolysis, but also appreciable biodegradability by lipases, with weight losses of up to 16% by weight after 28 weeks of incubation.
Comparison of a Rapid Light-Induced and Forced Test to Study the Oxidative Stability of White Wines
Authors: Celotti Emilio , Lazaridis Georgios , Figelj Jakob , Scutaru Yuri , Natolino Andrea
Published: January 2022

The oxidation processes of white wines can occur during storage and commercialization due to several factors, and these can negatively affect the color, aroma, and quality of the wine. Wineries should have faster and simpler methods that provide valuable information on oxidation stability of wines and allow fast decision-making procedures, able to trigger suitable technological interventions. Using a portable prototype instrument for light irradiations at different wavelengths and times was considered and evaluated on sensorial, spectrophotometric, and colorimetric parameters of white wines. The sensorial analysis revealed that white and light blue were the most significant, after only 1 h of irradiation. The experimental results showed that hydrogen peroxide could enhance the effect of light treatment, allowing a contemporary evaluation of the oxidation stability of wine against light and chemical stresses. As expected, a good correlation (R2 > 0.89) between optical density at 420 nm and b* parameter was highlighted. The synergic effect of light and H2O2 was also studied on the hydrolyzable and condensed tannins’ additions to white wine. The proposed methodology could be used to evaluate the oxidative stability of white wines, but also to evaluate the effect of some oenological adjuvants on wine stability.
Nanosheets with High-Performance Electrochemical Oxygen Reduction Reaction Revived from Green Walnut Peel
Authors: Zhou Yifei , Yan Lei , Hou Junhua
Published: January 2022

The synthesis of metal-free carbon-based electrocatalysts for oxygen reduction reactions (ORR) to replace conventional Pt-based catalysts has become a hot spot in current research. This work proposes an activation-assisted carbonization strategy, to manufacture N-doped ultra-thin carbon nanosheets (GWS180M800) with high catalytic activity, namely, melamine is used as an accelerator/nitrogen source, and walnut green peels biological waste as a carbon source. The melamine acts as a nitrogen donor in the hydrothermal process, effectively enhancing the nitrogen doping rate. The content of pyridine nitrogen groups accounts for up to 48.5% of the total nitrogen content. Electrochemical tests show that the GWS180M800 has excellent ORR electrocatalytic activity and stability, and makes a quasi-four-electron ORR pathway clear in the alkaline electrolyte. The initial potential and half slope potential are as high as 1.01 and 0.82 V vs. RHE, respectively. The GWS180M800 catalyst has a better ability to avoid methanol cross poisoning than Pt/C has. Compared with 20 wt% Pt/C, GWS180M800 has improved methanol tolerance and stability. It is a metal-free biochar ORR catalyst with great development potential and application prospects. This result provides a new space for the preparation of valuable porous nano-carbon materials based on carbonaceous solid waste and provides new ideas for catalyzing a wide range of electrochemical reactions in the future.
Evaluation of Substituted Pyrazole-Based Kinase Inhibitors in One Decade (2011–2020): Current Status and Future Prospects
Authors: El-Gamal Mohammed I. , Zaraei Seyed-Omar , Madkour Moustafa M. , Anbar Hanan S.
Published: January 2022

Pyrazole has been recognized as a pharmacologically important privileged scaffold whose derivatives produce almost all types of pharmacological activities and have attracted much attention in the last decades. Of the various pyrazole derivatives reported as potential therapeutic agents, this article focuses on pyrazole-based kinase inhibitors. Pyrazole-possessing kinase inhibitors play a crucial role in various disease areas, especially in many cancer types such as lymphoma, breast cancer, melanoma, cervical cancer, and others in addition to inflammation and neurodegenerative disorders. In this article, we reviewed the structural and biological characteristics of the pyrazole derivatives recently reported as kinase inhibitors and classified them according to their target kinases in a chronological order. We reviewed the reports including pyrazole derivatives as kinase inhibitors published during the past decade (2011–2020).
Effect of Kaempferol and Its Glycoside Derivatives on Antioxidant Status of HL-60 Cells Treated with Etoposide
Authors: Kluska Magdalena , Juszczak Michał , Żuchowski Jerzy , Stochmal Anna , Woźniak Katarzyna
Published: January 2022

Kaempferol is a well-known antioxidant found in many plants and plant-based foods. In plants, kaempferol is present mainly in the form of glycoside derivatives. In this work, we focused on determining the effect of kaempferol and its glycoside derivatives on the expression level of genes related to the reduction of oxidative stress—NFE2L2, NQO1, SOD1, SOD2, and HO-1; the enzymatic activity of superoxide dismutases; and the level of glutathione. We used HL-60 acute promyelocytic leukemia cells, which were incubated with the anticancer drug etoposide and kaempferol or one of its three glycoside derivatives isolated from the aerial parts of Lens culinaris Medik.—kaempferol 3-O-[(6-O-E-caffeoyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside (P2), kaempferol 3-O-[(6-O-E-p-coumaroyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside (P5), and kaempferol 3-O-[(6-O-E-feruloyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside (P7). We showed that none of the tested compounds affected NFE2L2 gene expression. Co-incubation with etoposide (1 µM) and kaempferol (10 and 50 µg/mL) leads to an increase in the expression of the HO-1 (9.49 and 9.33-fold at 10 µg/mL and 50 µg/mL, respectively), SOD1 (1.68-fold at 10 µg/mL), SOD2 (1.72-fold at 10–50 µg/mL), and NQO1 (1.84-fold at 50 µg/mL) genes in comparison to cells treated only with etoposide. The effect of kaempferol derivatives on gene expression differs depending on the derivative. All tested polyphenols increased the SOD activity in cells co-incubated with etoposide. We observed that the co-incubation of HL-60 cells with etoposide and kaempferol or derivative P7 increases the level of total glutathione in these cells. Taken together, our observations suggest that the antioxidant activity of kaempferol is related to the activation of antioxidant genes and proteins. Moreover, we observed that glycoside derivatives can have a different effect on the antioxidant cellular systems than kaempferol.
The Roles and Associated Mechanisms of Adipokines in Development of Metabolic Syndrome
Authors: Kim Ji-Eun , Kim Jin-Sun , Jo Min-Jee , Cho Eunjung , Ahn Shin-Young , Kwon Young-Joo , Ko Gang-Jee
Published: January 2022

Metabolic syndrome is a cluster of metabolic indicators that increase the risk of diabetes and cardiovascular diseases. Visceral obesity and factors derived from altered adipose tissue, adipokines, play critical roles in the development of metabolic syndrome. Although the adipokines leptin and adiponectin improve insulin sensitivity, others contribute to the development of glucose intolerance, including visfatin, fetuin-A, resistin, and plasminogen activator inhibitor-1 (PAI-1). Leptin and adiponectin increase fatty acid oxidation, prevent foam cell formation, and improve lipid metabolism, while visfatin, fetuin-A, PAI-1, and resistin have pro-atherogenic properties. In this review, we briefly summarize the role of various adipokines in the development of metabolic syndrome, focusing on glucose homeostasis and lipid metabolism.
Rapid Measurement of Cellulose, Hemicellulose, and Lignin Content in Sargassum horneri by Near-Infrared Spectroscopy and Characteristic Variables Selection Methods
Authors: Ai Ning , Jiang Yibo , Omar Sainab , Wang Jiawei , Xia Luyue , Ren Jie
Published: January 2022

Near-infrared (NIR) spectroscopy and characteristic variables selection methods were used to develop a quick method for the determination of cellulose, hemicellulose, and lignin contents in Sargassum horneri. Calibration models for cellulose, hemicellulose, and lignin in Sargassum horneri were established using partial least square regression methods with full variables (full-PLSR). The PLSR calibration models were established by four characteristic variables selection methods, including interval partial least square (iPLS), competitive adaptive reweighted sampling (CARS), correlation coefficient (CC), and genetic algorithm (GA). The results showed that the performance of the four calibration models, namely iPLS-PLSR, CARS-PLSR, CC-PLSR, and GA-PLSR, was better than the full-PLSR calibration model. The iPLS method was best in the performance of the models. For iPLS-PLSR, the determination coefficient (R2), root mean square error (RMSE), and residual predictive deviation (RPD) of the prediction set were as follows: 0.8955, 0.8232%, and 3.0934 for cellulose, 0.8669, 0.4697%, and 2.7406 for hemicellulose, and 0.7307, 0.7533%, and 1.9272 for lignin, respectively. These findings indicate that the NIR calibration models can be used to predict cellulose, hemicellulose, and lignin contents in Sargassum horneri quickly and accurately.
Evaluation of the Pharmacokinetics of the Pancreastatin Inhibitor PSTi8 Peptide in Rats: Integration of In Vitro and In Vivo Findings
Authors: Valicherla Guru R. , Katekar Roshan A. , Dadge Shailesh , Riyazuddin Mohammed , Syed Anees A. , Singh Sandeep K. , Husain Athar , Wahajuddin Muhammad , Gayen Jiaur R.
Published: January 2022

PSTi8 is a pancreastatin inhibitory peptide that is effective in the treatment of diabetic models. This study investigates the pharmacokinetic (PK) properties of PSTi8 in Sprague Dawley rats, for the first time. In vitro and in vivo PK studies were performed to evaluate the solubility, stability in plasma and liver microsomes, plasma protein binding, blood–plasma partitioning, bioavailability, dose proportionality, and gender difference in PK. Samples were analyzed using the validated LC-MS/MS method. The solubility of PSTi8 was found to be 9.30 and 25.75 mg/mL in simulated gastric and intestinal fluids, respectively. The protein binding of PSTi8 was estimated as >69% in rat plasma. PSTi8 showed high stability in rat plasma and liver microsomes and the blood–plasma partitioning was >2. The bioavailability of PSTi8 after intraperitoneal and subcutaneous administration was found to be 95.00 ± 12.15 and 78.47 ± 17.72%, respectively, in rats. PSTi8 showed non-linear PK in dose proportionality studies, and has no gender difference in the PK behavior in rats. The high bioavailability of PSTi8 can be due to high water solubility and plasma protein binding, low clearance and volume of distribution. Our in vitro and in vivo findings support the development of PSTi8 as an antidiabetic agent.
Role of Functional Groups in the Monomer Molecule on the Radical Polymerization in the Presence of Graphene Oxide. Polymerization of Hydroxyethyl Acrylate under Isothermal and Non-Isothermal Conditions
Authors: Tsagkalias Ioannis S. , Achilias Dimitrios S.
Published: January 2022

Functional groups in a monomer molecule usually play an important role during polymerization by enhancing or decreasing the reaction rate due to the possible formation of side bonds. The situation becomes more complicated when polymerization takes place in the presence of graphene oxide since it also includes functional groups in its surface. Aiming to explore the role of functional groups on polymerization rate, the in situ bulk radical polymerization of hydroxyethyl acrylate (HEA) in the presence or not of graphene oxide was investigated. Differential scanning calorimetry was used to continuously record the reaction rate under both isothermal and non-isothermal conditions. Simple kinetic models and isoconversional analysis were used to estimate the variation of the overall activation energy with the monomer conversion. It was found that during isothermal experiments, the formation of both inter- and intra-chain hydrogen bonds between the monomer and polymer molecules results in slower polymerization of neat HEA with higher overall activation energy compared to that estimated in the presence of GO. The presence of GO results in a dissociation of hydrogen bonds between monomer and polymer molecules and, thus, to higher reaction rates. Isoconversional methods employed during non-isothermal experiments revealed that the presence of GO results in higher overall activation energy due to the reaction of more functional groups on the surface of GO with the hydroxyl and carbonyl groups of the monomer and polymer molecules, together with the reaction of primary initiator radicals with the surface hydroxyl groups in GO.
Narrowband Deep-Blue Multi-Resonance Induced Thermally Activated Delayed Fluorescence: Insights from the Theoretical Molecular Design
Authors: Wu Yuting , Zhu Yanan , Zhang Zewei , Zhao Chongguang , He Junpeng , Yan Chaoyi , Meng Hong
Published: January 2022

Multi-resonance thermal activated delayed fluorescence (MR-TADF) has been promising with large oscillator strength and narrow full width at half maxima of luminescence, overcoming the compromise of emission intensity and energy criteria of traditional charge transfer TADF frameworks. However, there are still limited theoretical investigations on the excitation mechanism and systematic molecular manipulation of MR-TADF structures. We systematically study the highly localized excitation (LE) characteristics based on typical blue boron-nitrogen (BN) MR-TADF emitters and prove the potential triangular core with theoretical approaches. A design strategy by extending the planar π-conjugate core structure is proposed to enhance the multiple resonance effects. Moreover, several substituted groups are introduced to the designed core, achieving color-tunable functions with relatively small energy split and strong oscillator strength simultaneously. This work provides a theoretical direction for molecular design strategy and a series of potential candidates for highly efficient BN MR-TADF emitters.
Modern Approaches in the Discovery and Development of Plant-Based Natural Products and Their Analogues as Potential Therapeutic Agents
Authors: Najmi Asim , Javed Sadique A. , Al Bratty Mohammed , Alhazmi Hassan A.
Published: January 2022

Natural products represents an important source of new lead compounds in drug discovery research. Several drugs currently used as therapeutic agents have been developed from natural sources; plant sources are specifically important. In the past few decades, pharmaceutical companies demonstrated insignificant attention towards natural product drug discovery, mainly due to its intrinsic complexity. Recently, technological advancements greatly helped to address the challenges and resulted in the revived scientific interest in drug discovery from natural sources. This review provides a comprehensive overview of various approaches used in the selection, authentication, extraction/isolation, biological screening, and analogue development through the application of modern drug-development principles of plant-based natural products. Main focus is given to the bioactivity-guided fractionation approach along with associated challenges and major advancements. A brief outline of historical development in natural product drug discovery and a snapshot of the prominent natural drugs developed in the last few decades are also presented. The researcher’s opinions indicated that an integrated interdisciplinary approach utilizing technological advances is necessary for the successful development of natural products. These involve the application of efficient selection method, well-designed extraction/isolation procedure, advanced structure elucidation techniques, and bioassays with a high-throughput capacity to establish druggability and patentability of phyto-compounds. A number of modern approaches including molecular modeling, virtual screening, natural product library, and database mining are being used for improving natural product drug discovery research. Renewed scientific interest and recent research trends in natural product drug discovery clearly indicated that natural products will play important role in the future development of new therapeutic drugs and it is also anticipated that efficient application of new approaches will further improve the drug discovery campaign.
Fucoidan and Alginate from the Brown Algae Colpomenia sinuosa and Their Combination with Vitamin C Trigger Apoptosis in Colon Cancer
Authors: Al Monla Reem , Dassouki Zeina , Sari-Chmayssem Nouha , Mawlawi Hiba , Gali-Muhtasib Hala
Published: January 2022

Brown seaweeds are producers of bioactive molecules which are known to inhibit oncogenic growth. Here, we investigated the antioxidant, cytotoxic, and apoptotic effects of two polysaccharides from the brown algae Colpomenia sinuosa, namely fucoidan and alginate, in a panel of cancer cell lines and evaluated their effects when combined with vitamin C. Fucoidan and alginate were isolated from brown algae and characterized by HPLC, FTIR, and NMR spectroscopy. The results indicated that highly sulfated fucoidans had higher antioxidant and cytotoxic effects than alginate. Human colon cancer cells were the most sensitive to the algal treatments, with fucoidan having an IC50 value (618.9 µg/mL−1) lower than that of alginate (690 µg/mL−1). The production of reactive oxygen species was increased upon treatment of HCT-116 cells with fucoidan and alginate, which suggest that these compounds may trigger cell death via oxidative damage. The combination of fucoidan with vitamin C showed enhanced effects compared to treatment with fucoidan alone, as evidenced by the significant inhibitory effects on HCT-116 colon cancer cell viability. The combination of the algal polysaccharides with vitamin C caused enhanced degeneration in the nuclei of cells, as evidenced by DAPI staining and increased the subG1 population, suggesting the induction of cell death. Together, these results suggest that fucoidan and alginate from the brown algae C. sinuosa are promising anticancer compounds, particularly when used in combination with vitamin C.
The Evaluation of Phenolic Acids and Flavonoids Content and Antiprotozoal Activity of Eryngium Species Biomass Produced by Biotechnological Methods
Authors: Kikowska Małgorzata , Chanaj-Kaczmarek Justyna , Derda Monika , Budzianowska Anna , Thiem Barbara , Ekiert Halina , Szopa Agnieszka
Published: January 2022

Three species from the Eryngium L. genus—E. campestre, E. maritimum, and E. planum, plants with a rich chemical composition, were selected for phytochemical and biological studies. The applied biotechnological methods allowed to obtain the biomass of these rare or protected species in the form of multiplied shoots (stationary system) and roots cultured in a liquid medium (agitated system). In the extracts from the raw material obtained under in vitro conditions, the content of selected phenolic acids and flavonoids (HPLC-DAD method) as well as the total of polyphenols (Folin–Ciocalteu assay) were quantified. The highest amount of all phenolic compounds was found in extracts from E. planum roots (950.90 ± 33.52 mg/100 g d.w.), and the lowest from E. campestre roots (285.00 ± 10.07 mg/100 g d.w.). The quantitatively dominant compound proved to be rosmarinic acid. The highest amounts were confirmed for E. planum root extract (694.58 mg/100 g d.w.), followed by E. planum (388.95 mg/100 g d.w.) and E. campestre (325.85 mg/100 g d.w.) shoot extracts. The total content of polyphenols was always increased in the biomass from in vitro cultures in comparison to the analogous organs of intact plants of each species. The obtained extracts were assessed for antiprotozoal activity against Acanthamoeba sp. The strength of biological activity of the extracts correlated with the content of phenolic compounds. To our knowledge, this is the first report on the amoebicidal activity of E. campestre, E. maritimum, and E. planum extracts from biomass produced by biotechnological methods.