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971.
Bergenia (Saxifragaceae) genus is native to central Asia and encompasses 32 known species. Among these, nine are of pharmacological relevance. In the Indian system of traditional medicine (Ayurveda), “Pashanabheda” (stone breaker) is an elite drug formulation obtained from the rhizomes of B. ligulata. Bergenia species also possess several other biological activities like diuretic, antidiabetic, antitussive, insecticidal, anti-inflammatory, antipyretic, anti-bradykinin, antiviral, antibacterial, antimalarial, hepatoprotective, antiulcer, anticancer, antioxidant, antiobesity, and adaptogenic. This review provides explicit information on the traditional uses, phytochemistry, and pharmacological significance of the genus Bergenia. The extant literature concerned was systematically collected from various databases, weblinks, blogs, books, and theses to select 174 references for detailed analysis. To date, 152 chemical constituents have been identified and characterized from the genus Bergenia that belong to the chemical classes of polyphenols, phenolic-glycosides, lactones, quinones, sterols, tannins, terpenes, and others. B. crassifolia alone possesses 104 bioactive compounds. Meticulous pharmacological and phytochemical studies on Bergenia species and its conservation could yield more reliable compounds and products of pharmacological significance for better healthcare. 相似文献
972.
Udhaya Kumar S. Srivarshini Sankar Salma Younes Thirumal Kumar D. Muneera Naseer Ahmad Sarah Samer Okashah Balu Kamaraj Abeer Mohammed Al-Subaie George Priya Doss C. Hatem Zayed 《Molecules (Basel, Switzerland)》2020,25(23)
Filamins (FLN) are a family of actin-binding proteins involved in regulating the cytoskeleton and signaling phenomenon by developing a network with F-actin and FLN-binding partners. The FLN family comprises three conserved isoforms in mammals: FLNA, FLNB, and FLNC. FLNB is a multidomain monomer protein with domains containing an actin-binding N-terminal domain (ABD 1–242), encompassing two calponin-homology domains (assigned CH1 and CH2). Primary variants in FLNB mostly occur in the domain (CH2) and surrounding the hinge-1 region. The four autosomal dominant disorders that are associated with FLNB variants are Larsen syndrome, atelosteogenesis type I (AOI), atelosteogenesis type III (AOIII), and boomerang dysplasia (BD). Despite the intense clustering of FLNB variants contributing to the LS-AO-BD disorders, the genotype-phenotype correlation is still enigmatic. In silico prediction tools and molecular dynamics simulation (MDS) approaches have offered the potential for variant classification and pathogenicity predictions. We retrieved 285 FLNB missense variants from the UniProt, ClinVar, and HGMD databases in the current study. Of these, five and 39 variants were located in the CH1 and CH2 domains, respectively. These variants were subjected to various pathogenicity and stability prediction tools, evolutionary and conservation analyses, and biophysical and physicochemical properties analyses. Molecular dynamics simulation (MDS) was performed on the three candidate variants in the CH2 domain (W148R, F161C, and L171R) that were predicted to be the most pathogenic. The MDS analysis results showed that these three variants are highly compact compared to the native protein, suggesting that they could affect the protein on the structural and functional levels. The computational approach demonstrates the differences between the FLNB mutants and the wild type in a structural and functional context. Our findings expand our knowledge on the genotype-phenotype correlation in FLNB-related LS-AO-BD disorders on the molecular level, which may pave the way for optimizing drug therapy by integrating precision medicine. 相似文献
973.
Soumen Dutta Nitee Kumari Sateesh Dubbu Sun Woo Jang Amit Kumar Hiroyoshi Ohtsu Junghoon Kim Seung Hwan Cho Masaki Kawano In Su Lee 《Angewandte Chemie (International ed. in English)》2020,59(9):3416-3422
Rational engineering and assimilation of diverse chemo‐ and biocatalytic functionalities in a single nanostructure is highly desired for efficient multistep chemical reactions but has so far remained elusive. Here, we design and synthesize multimodal catalytic nanoreactors (MCNRs) based on a mesoporous metal‐organic framework (MOF). The MCNRs consist of customizable metal nanocrystals and stably anchored enzymes in the mesopores, as well as coordinatively unsaturated cationic metal MOF nodes, all within a single nanoreactor space. The highly intimate and diverse catalytic mesoporous microenvironments and facile accessibility to the active site in the MCNR enables the cooperative and synergistic participation from different chemo‐ and biocatalytic components. This was shown by one‐pot multistep cascade reactions involving a heterogeneous catalytic nitroaldol reaction followed by a [Pd/lipase]‐catalyzed chemoenzymatic dynamic kinetic resolution to yield optically pure (>99 % ee) nitroalcohol derivatives in quantitative yields. 相似文献
974.
Matheus Dorneles de Mello Gaurav Kumar Tarnuma Tabassum Sheetal K. Jain Tso‐Hsuan Chen Stavros Caratzoulas Xinyu Li Dionisios G. Vlachos Songi‐I Han Susannah L. Scott Paul Dauenhauer Michael Tsapatsis 《Angewandte Chemie (International ed. in English)》2020,59(32):13260-13266
Phosphorus‐modified all‐silica zeolites exhibit activity and selectivity in certain Brønsted acid catalyzed reactions for biomass conversion. In an effort to achieve similar performance with catalysts having well‐defined sites, we report the incorporation of Brønsted acidity to metal–organic frameworks with the UiO‐66 topology, achieved by attaching phosphonic acid to the 1,4‐benzenedicarboxylate ligand and using it to form UiO‐66‐PO3H2 by post‐synthesis modification. Characterization reveals that UiO‐66‐PO3H2 retains stability similar to UiO‐66, and exhibits weak Brønsted acidity, as demonstrated by titrations, alcohol dehydration, and dehydra‐decyclization of 2‐methyltetrahydrofuran (2‐MTHF). For the later reaction, the reported catalyst exhibits site‐time yields and selectivity approaching that of phosphoric acid on all‐silica zeolites. Using solid‐state NMR and deprotonation energy calculations, the chemical environments of P and the corresponding acidities are determined. 相似文献
975.
Amit Kumar Nitee Kumari Sateesh Dubbu Sumit Kumar Taewan Kwon Jung Hun Koo Jongwon Lim Inki Kim Yoon‐Kyoung Cho Junsuk Rho In Su Lee 《Angewandte Chemie (International ed. in English)》2020,59(24):9460-9469
Interest and challenges remain in designing and synthesizing catalysts with nature‐like complexity at few‐nm scale to harness unprecedented functionalities by using sustainable solar light. We introduce “nanocatalosomes”—a bio‐inspired bilayer‐vesicular design of nanoreactor with metallic bilayer shell‐in‐shell structure, having numerous controllable confined cavities within few‐nm interlayer space, customizable with different noble metals. The intershell‐confined plasmonically coupled hot‐nanospaces within the few‐nm cavities play a pivotal role in harnessing catalytic effects for various organic transformations, as demonstrated by “acceptorless dehydrogenation”, “Suzuki–Miyaura cross‐coupling” and “alkynyl annulation” affording clean conversions and turnover frequencies (TOFs) at least one order of magnitude higher than state‐of‐the‐art Au‐nanorod‐based plasmonic catalysts. This work paves the way towards next‐generation nanoreactors for chemical transformations with solar energy. 相似文献
976.
Ashutosh Kumar Buddhadev Purohit Kuldeep Mahato Sharmili Roy Ananya Srivastava Pranjal Chandra 《Electroanalysis》2020,32(1):59-69
We report for the first time sinapic acid (SA) sensing based on nanocomposite comprising electrochemically tuned gold nanoparticles (EAuNPs) and solvothermally reduced graphene oxide (rGO). The synthesized EAuNPs, rGO, and EAuNPs‐rGO nanocomposite were characterized using X‐ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), particle size analysis, and Raman spectroscopy. A proof‐of‐concept electrochemical sensor for SA was developed based on synthesized EAuNPs‐rGO nanocomposite, which was characterized by electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The developed sensor detected SA with a linear dynamic range (LDR) between 20 μM and 200 μM and detection limit (DL) of 33.43 (±0.21) nM (RSD<3.32 %). To show the useful purpose of the sensor probe in clinical applications, SA was detected in human urine samples, which showed the percentage recovery between 82.6 % and 92.8 %. Interferences due to various molecules such as L‐cystine, glycine, alanine, serum albumin, uric acid, citric acid, ascorbic acid, and urea were tested. Long‐term stability of the sensor probe was examined, which was found to be stable up to 6 weeks. The sensor fabricated using EAuNPs‐rGO nanocomposite has many attractive features such as; simplicity, rapidity, and label‐free detection; hence, it could be a method of choice for SA detection in various matrices. 相似文献
977.
Our work is focused on facile synthesis and modification of amylopectin‐grafted block copolymers by using reversible addition?fragmentation chain transfer (RAFT) polymerization technique. This technique yields polymers with controlled molecular weight and low polydispersity indexes and is feasible with a wide range of monomers. Five different grades of amylopectin‐grafted polymethacrylic acid and polyacrylamide block copolymers have been synthesized via RAFT, by varying the amount of acrylamide employing amylopectin‐based macro chain transfer agent. Graft copolymers have been upgraded as smart responsive graft copolymers, through the incorporation of iron oxide nanoparticles (IONPs) via condensation reaction. The polymeric materials have been extensively characterized by energy‐dispersive X‐ray analysis, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy, scanning electron microscopy, ultraviolet‐visible spectroscopy, gel permeation chromatography, transmission electron microscopy, thermogravimetric analysis, and X‐ray diffraction analysis. Normal and responsive graft copolymers have been studied for removal of model contaminant (kaolin), and responsive graft copolymers have been used to remove methylene blue dye (without using any adsorbent) from water by applying external magnetic field. The upgraded block copolymers have shown best performance in wastewater treatment. 相似文献
978.
Kumar K. Santhosh Siddaiah V. Lilakar J. D. Sunanda K. Ganesh A. 《Russian Journal of Organic Chemistry》2020,56(11):2014-2021
Russian Journal of Organic Chemistry - An efficient and simple continuous-flow synthetic protocol for novel quinoline-tethered pyrazoline derivatives, which involves condensation of... 相似文献
979.
Jyoti Kannoujia Pavan Kumar Bangalore Srinivas Kantevari Prabhakar Sripadi 《Journal of mass spectrometry : JMS》2020,55(10)
The HPLC‐DAD and GC/MS methods were successfully used for the identification and characterization of the impurities in an agrochemical insecticide, bifenthrin technical. Three impurities ranging from 0.175%–0.541% were detected by the HPLC‐DAD method. The LC/MS technique with ESI or APCI source failed to detect the impurities detected by HPLC‐DAD, due to lack of ionization in ESI or APCI. The three impurities were enriched by prep‐HPLC, and then their structures were elucidated based on the GC/EIMS and CIMS data. The EI mass spectra of bifenthrin and its impurities displayed molecular ion and provided structure indicative fragment ions; the CIMS data further confirmed their molecular weight. The identity of the impurity 1 was further confirmed by the synthesis of the authentic sample followed by NMR and GC/MS data. 相似文献
980.
Gautam Rajesh Kumar Seth Debabrata 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2633-2640
Journal of Thermal Analysis and Calorimetry - We have reported the thermal conductivities of three deep eutectic solvents (DESs). We have used choline chloride, N,N-diethyl ethanol ammonium... 相似文献