AppliedChem最新文献_第7页

An Asymmetric Intramolecular Rauhut-Currier Reaction Initiated by Chiral Selenolate-BINOL Complexes 手性硒酸盐-双酚配合物引发的分子内不对称罗赫特-柯里尔反应

AppliedChem Pub Date : 2022-04-19 DOI: 10.3390/appliedchem2020004

Gabriela Całka-Kuc, Szymon Buda

引用次数: 0

The Influence of Soaking and Sprouting on the Physicochemical Characteristics of Tigernut Tubers (Cyperus esculentus L.) 浸泡和发芽对虎皮块茎理化特性的影响

AppliedChem Pub Date : 2022-03-22 DOI: 10.3390/appliedchem2020003

Djomdi Djomdi, Hamadou Bakari, O. Gibert, T. Tran, R. Ejoh, G. Christophe, P. Michaud, R. Ndjouenkeu

引用次数: 2

Application of a Universal Calibration Method for True Molar Mass Determination of Fluoro-Derivatized Technical Lignins by Size-Exclusion Chromatography 通用校准方法在氟衍生技术木质素真摩尔质量测定中的应用

AppliedChem Pub Date : 2022-03-03 DOI: 10.3390/appliedchem2010002

Esakkiammal Sudha Esakkimuthu, N. Marlin, M. Brochier-Salon, G. Mortha

{"title":"Application of a Universal Calibration Method for True Molar Mass Determination of Fluoro-Derivatized Technical Lignins by Size-Exclusion Chromatography","authors":"Esakkiammal Sudha Esakkimuthu, N. Marlin, M. Brochier-Salon, G. Mortha","doi":"10.3390/appliedchem2010002","DOIUrl":"https://doi.org/10.3390/appliedchem2010002","url":null,"abstract":"The determination of the true molar mass distribution (MMD) of lignin is highly important to understand the physicochemical characteristics for lignin-based value-added applications. It is imperative to develop a universal method to quantify accurate MMD of lignin using size exclusion chromatography (SEC), as the conventional method with polymer standards provides irregular MMD results. This work aims to evaluate the MMD of five lignin samples (Protobind 1000, Organosolv, Indulin, Pine Kraft and Eucalyptus Kraft) in THF. Different derivatization methods (acetylation, fluorobenzylation and fluorobenzoylation) were performed. FTIR and 19F NMR analyses were used to follow derivatization. The MMDs of derivatized and underivatized lignins were determined by the conventional method and compared with the universal calibration method developed using intrinsic viscosity. The 19F NMR spectra provided the information to quantify the degree of substitution of lignin hydroxyl groups, to calculate the true molar mass of the derivatives of lignin monomers. The obtained MMDs values for all the derivatized lignin by universal calibration were found to be three to five times higher than that of the conventional calibration. The polydispersity values obtained with the acetylation method were higher than the fluoro-derivatives. The results demonstrated that fluoro-derivatization is an appropriate method to apply to higher molar mass technical lignins and lacks solubility and aggregation issues.","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87066763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comprehensive Review of the Components in Cat’s Claw (Uncaria tomentosa) and Their Antibacterial Activity 猫爪(Uncaria tomentosa)成分及其抗菌活性的综述

AppliedChem Pub Date : 2022-02-22 DOI: 10.3390/appliedchem2010001

Jason J. Blanck, T. Huebner, Alyssa M. Rolls, Josh S. Cornell, Candy S. Hwang

{"title":"Comprehensive Review of the Components in Cat’s Claw (Uncaria tomentosa) and Their Antibacterial Activity","authors":"Jason J. Blanck, T. Huebner, Alyssa M. Rolls, Josh S. Cornell, Candy S. Hwang","doi":"10.3390/appliedchem2010001","DOIUrl":"https://doi.org/10.3390/appliedchem2010001","url":null,"abstract":"Cat’s claw (Uncaria tomentosa (Willd. ex Schults) DC.), a plant that is exceptionally rich in phytochemicals, has been used for centuries by the indigenous people of South and Central America as a therapeutic and is currently widely exported for medicinal purposes. Extracts and individual components have shown considerable potential as antibacterials in the literature. The purpose of this review is twofold: first, to provide a substantiated, comprehensive collection of the known chemical constituents of U. tomentosa, including their detailed structures; second, to identify those components that offer some promise as antibacterials based on the research to date. Bacterial resistance to currently available antibiotics continues to increase and is widely recognized as an impending, potentially catastrophic, problem. There is research to suggest that U. tomentosa components may have antibacterial potential individually or synergistically with established antibiotics against microbes, including Borrelia burgdorferi, the causative agent of Lyme disease. It is our intention that this review will provide a valuable resource to investigators in search of new antimicrobials to meet the daunting challenge of antibiotic resistance.","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82908906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Hydrogels Made of Poly-γ-Glutamic Acid and Sugar Alcohols for Enhanced Survival of Probiotic Strains Subjected to Low pH and Freeze Drying 聚γ-谷氨酸和糖醇制备水凝胶提高低pH和冷冻干燥条件下益生菌的存活率

AppliedChem Pub Date : 2021-12-13 DOI: 10.3390/appliedchem1020013

I. Kwiecień, A. Ekere, Monika Śmiga-Matuszowicz

{"title":"Hydrogels Made of Poly-γ-Glutamic Acid and Sugar Alcohols for Enhanced Survival of Probiotic Strains Subjected to Low pH and Freeze Drying","authors":"I. Kwiecień, A. Ekere, Monika Śmiga-Matuszowicz","doi":"10.3390/appliedchem1020013","DOIUrl":"https://doi.org/10.3390/appliedchem1020013","url":null,"abstract":"Probiotics are microorganisms that have a beneficial influence on the human gastrointestinal tract. Unfortunately, their viability can be negatively affected by manufacturing, storage conditions and gastrointestinal tract conditions. Therefore, there is a need to develop delivery systems, which can protect probiotics against adverse conditions. Previously, we reported on hydrogels made of poly-γ-glutamic acid (γ-PGA) and selected PEGs with the potential application as probiotic delivery vehicles. In the next step of research, we decided to develop fully biobased hydrogels with the potential application as probiotic oral-delivery systems. Selected sugar alcohols, erythritol, xylitol and sorbitol, have been used as cross-linkers in the synthesis of γ-PGA-based hydrogels. It was examined if obtained hydrogels enhanced the survival rate of entrapped probiotic strains subjected to acidic conditions. Results have been discussed in relation to the previously reported γ-PGA-PEG hydrogels. Moreover, the possibility of using developed hydrogels as a cryoprotectant was investigated during freeze drying of entrapped probiotic cells.","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81284684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterization of Potential Pollutants from Poly(lactic acid) after the Degradation Process in Soil under Simulated Environmental Conditions 模拟环境条件下聚乳酸在土壤中降解过程中潜在污染物的表征

AppliedChem Pub Date : 2021-12-10 DOI: 10.3390/appliedchem1020012

Marta Krawczyk-Walach, K. Gzyra-Jagieła, A. Milczarek, Jagoda Jóźwik-Pruska

{"title":"Characterization of Potential Pollutants from Poly(lactic acid) after the Degradation Process in Soil under Simulated Environmental Conditions","authors":"Marta Krawczyk-Walach, K. Gzyra-Jagieła, A. Milczarek, Jagoda Jóźwik-Pruska","doi":"10.3390/appliedchem1020012","DOIUrl":"https://doi.org/10.3390/appliedchem1020012","url":null,"abstract":"In recent years, the amount of produced petrochemical plastic waste has been growing at an alarming rate. According to the Plastics Europe Market Research Group (PEMRG)/Conversio Market & Strategy GmbH, in 2018 the global production of plastics amounts to 359 million tons, and in Europe—61.8 million tons. More than 80% of all marine litter is plastic, which accumulates in the environment due to its durability. Due to the growing problem, biodegradable polymer products are introduced to the market. Therefore, it is necessary to conduct research on degradation products in order to estimate the risk arising from their presence in the environment. This paper discusses research on compounds that may potentially remain in the soil after the degradation of the double green PLA polymer. The aim of the research was to prove whether products made of PLA, e.g., packaging, films and other waste can release substances harmful to the environment. Therefore, soil was selected as a medium to characterize the substances potentially released from the polymer under conditions simulating the degradation process in the environment. The soil was always used from the same producer. Before the polymer biodegradation process, it was additionally checked for pH, C and N content, number of microorganisms, etc. PLA degradation in soil was carried out in a laboratory accredited by the Polish Accreditation Center (PCA). During the research, soil samples at various stages of the degradation process under laboratory conditions were subjected to both extraction in an aqueous environment and organic solvent extraction The studies used the gas chromatography coupled with mass spectrometry (GC/MS), as well as pyrolysis gas chromatography (Py-GC/MS). In addition, the study used the gel permeation chromatography (GPC/SEC) allowing to determine the distribution of molar masses, average molar masses and polydispersity, and the infrared spectroscopy (FTIR).","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88440602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Nonenzymatic Deamidation Mechanism on a Glutamine Residue with a C-Terminal Adjacent Glycine Residue: A Computational Mechanistic Study 谷氨酰胺残基与c端相邻甘氨酸残基的非酶脱酰胺机制:计算机制研究

AppliedChem Pub Date : 2021-12-08 DOI: 10.3390/appliedchem1020011

Haruka Asai, K. Kato, T. Nakayoshi, Y. Ishikawa, E. Kurimoto, A. Oda, N. Fukuishi

{"title":"Nonenzymatic Deamidation Mechanism on a Glutamine Residue with a C-Terminal Adjacent Glycine Residue: A Computational Mechanistic Study","authors":"Haruka Asai, K. Kato, T. Nakayoshi, Y. Ishikawa, E. Kurimoto, A. Oda, N. Fukuishi","doi":"10.3390/appliedchem1020011","DOIUrl":"https://doi.org/10.3390/appliedchem1020011","url":null,"abstract":"The deamidation of glutamine (Gln) residues, which occurs non-enzymatically under physiological conditions, triggers protein denaturation and aggregation. Gln residues are deamidated via the cyclic glutarimide intermediates to l-α-, d-α-, l-β-, and d-β-glutamate residues. The production of these biologically uncommon amino acid residues is implicated in the pathogenesis of autoimmune diseases. The reaction rate of Gln deamidation is influenced by the C-terminal adjacent (N +1) residue and is highest in the Gln-glycine (Gly) sequence. Here, we investigated the effect of the (N + 1) Gly on the mechanism of Gln deamidation and the activation barrier using quantum chemical calculations. Energy-minima and transition-state geometries were optimized by the B3LYP density functional theory, and MP2 calculations were used to obtain the single-point energy. The calculated activation barrier (85.4 kJ mol−1) was sufficiently low for the reactions occurring under physiological conditions. Furthermore, the hydrogen bond formation between the catalytic ion and the main chain of Gly on the C-terminal side was suggested to accelerate Gln deamidation by stabilizing the transition state.","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76981878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Organic Ion-Associate Phase Microextraction/Back-Microextraction for Preconcentration: Determination of Nickel in Environmental Water Using 2-Thenoyltrifluoroacetone via GF-AAS 有机离子相微萃取/反微萃取预富集:2-烯酰三氟丙酮- GF-AAS法测定环境水中镍

AppliedChem Pub Date : 2021-12-01 DOI: 10.3390/appliedchem1020010

Mitsuhito Kosugi, Kenta Mizuna, Kazuto Sazawa, Takuya Okazaki, H. Kuramitz, S. Taguchi, N. Hata

{"title":"Organic Ion-Associate Phase Microextraction/Back-Microextraction for Preconcentration: Determination of Nickel in Environmental Water Using 2-Thenoyltrifluoroacetone via GF-AAS","authors":"Mitsuhito Kosugi, Kenta Mizuna, Kazuto Sazawa, Takuya Okazaki, H. Kuramitz, S. Taguchi, N. Hata","doi":"10.3390/appliedchem1020010","DOIUrl":"https://doi.org/10.3390/appliedchem1020010","url":null,"abstract":"An ion-associate phase (IAP) microextraction/ back-microextraction system was applied for the enrichment, separation, and detection of trace amounts of nickel from environmental water samples. Thenoyltrifluoroacetone (HTTA) acted not only as a chelating reagent for nickel, but also as a component of the extraction phase, i.e., IAP. Nickel in a 40 mL sample solution was pH-adjusted with phenolsulfonate (PS−) and tetramethylammonium hydroxide and converted by chelation reaction in the presence of thenoyltrifluoroacetonate (TTA−). When benzyldodecyldimethylammonium ion (C12BzDMA+) was added, a suspension of IAP formed in the solution. The IAP consisted of TTA−, a chelating reagent, the PS−, a component of pH buffer, and C12BzDMA+, which helps extract the chelating complex. When the solution was centrifuged, the IAP separated from the suspension and the nickel-TTA chelate was extracted into the bottom phase of the centrifuge tube. After the aqueous phase was taken away, 100 µL of nitric acid (2 M) solution containing phosphate was used to back-microextract nickel from the IAP. The acid phase was measured via graphite-furnace atomic-absorption spectrometry (GF-AAS). The proposed method facilitated a 400-fold enrichment. The limit of detection was 0.02 µg L−1. The proposed method was applied for the determination of nickel in river water and seawater samples.","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79720489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Opoka—Sediment Rock as New Type of Hybrid Mineral Filler for Polymer Composites 聚合物复合材料中新型杂化矿物填料的研究

AppliedChem Pub Date : 2021-11-03 DOI: 10.3390/appliedchem1020008

R. Przekop, Paulina Jakubowska, B. Sztorch, R. Kozera, K. Dydek, M. Jałbrzykowski, T. Osiecki, P. Marciniak, A. Martyla, Arkadiusz Kloziński, Dariusz Brząkalski

引用次数: 6

Carbon–Heteroatom Bond Formation via Coupling Reactions Performed on a Magnetic Nanoparticle Bed 在磁性纳米颗粒床上通过偶联反应形成碳杂原子键

AppliedChem Pub Date : 2021-10-04 DOI: 10.3390/appliedchem1020007

M. Tajbakhsh, A. Ramezani, M. Qandalee, Mobina Falahati, C. Durán-Valle, S. Izquierdo, I. López-Coca

{"title":"Carbon–Heteroatom Bond Formation via Coupling Reactions Performed on a Magnetic Nanoparticle Bed","authors":"M. Tajbakhsh, A. Ramezani, M. Qandalee, Mobina Falahati, C. Durán-Valle, S. Izquierdo, I. López-Coca","doi":"10.3390/appliedchem1020007","DOIUrl":"https://doi.org/10.3390/appliedchem1020007","url":null,"abstract":"Cross-coupling reactions leading to carbon–heteroatom bonds yield compounds that attract substantial interest due to their role as structural units in many synthetic protocols for bioactive and natural products. Therefore, many research works aim at the improvement of heterogeneous catalytic protocols. We have studied the use of magnetite nanoparticles and solid base compounds in organic synthetic reactions in carbon–heteroatom bond formation because they can be flocculated and dispersed, and reversibly controlled by applying a magnetic field. In this work, we have developed an efficient and simple synthetic approach for the C–O/C–N cross-coupling reaction under ligand-free conditions by using CuI as a catalyst and KF/Fe3O4 as a base. We performed the nucleophilic aromatic substitution of electron-deficient aryl halides and phenols. It was found that both the solvent nature and the base have a profound influence on the reaction process. This approach affords good to excellent yields of arylated products. KF/Fe3O4 displayed convenient magnetic properties and could be easily separated from the reaction using a magnet and recycled several times without significant loss of catalytic activity. This method has been successfully investigated for the Ullmann coupling reaction.","PeriodicalId":8123,"journal":{"name":"AppliedChem","volume":"167 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84828055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2