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https://www.readbyqxmd.com/read/27914336/thermoresponsive-supramolecular-micellar-drug-delivery-system-based-on-star-linear-pseudo-block-polymer-consisting-of-%C3%AE-cyclodextrin-poly-n-isopropylacrylamide-and-adamantyl-poly-ethylene-glycol
#1
Xia Song, Jing-Ling Zhu, Yuting Wen, Feng Zhao, Zhong-Xing Zhang, Jun Li
Chemotherapy is facing several limitations such as low water solubility of anticancer drugs and multidrug resistance (MDR) in cancer cells. To overcome these limitations, a thermoresponsive micellar drug delivery system formed by a non-covalently connected supramolecular block polymer was developed. The system is based on the host-guest interaction between a well-defined β-cyclodextrin (β-CD) based poly(N-isopropylacrylamide) star host polymer and an adamantyl-containing poly(ethylene glycol) (Ad-PEG) guest polymer...
November 16, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27914283/binding-pattern-of-intermediate-udp-4-keto-xylose-to-human-udp-xylose-synthase-synthesis-and-std-nmr-of-model-keto-saccharides
#2
Claudia Puchner, Thomas Eixelsberger, Bernd Nidetzky, Lothar Brecker
Human UDP-xylose synthase (hUXS1) exclusively converts UDP-glucuronic acid to UDP-xylose via intermediate UDP-4-keto-xylose (UDP-Xyl-4O). Synthesis of model compounds like methyl-4-keto-xylose (Me-Xyl-4O) is reported to investigate the binding pattern thereof to hUXS1. Hence, selective oxidation of the desired hydroxyl function required employment of protecting group chemistry. Solution behavior of synthesized keto-saccharides was studied without enzyme via (1)H and (13)C NMR spectroscopy with respect to existent forms in deuterated potassium phosphate buffer...
November 5, 2016: Carbohydrate Research
https://www.readbyqxmd.com/read/27914179/ammonothermal-synthesis-of-novel-nitrides-case-study-on-cagasin3
#3
Jonas Häusler, Lukas Neudert, Mathias Mallmann, Robin Niklaus, Anna-Carina L Kimmel, Nicolas S A Alt, Eberhard Schlücker, Oliver Oeckler, Wolfgang Schnick
The first gallium-containing nitridosilicate CaGaSiN3 was synthesized in newly developed high-pressure autoclaves using supercritical ammonia as solvent and nitriding agent. The reaction was conducted in ammonobasic environment starting from intermetallic CaGaSi with NaN3 as mineralizer. At 770 K, intermediate compounds were obtained, which were subsequently converted to the crystalline nitride at temperatures up to 1070 K (70 - 150 MPa). The impact of other mineralizers (e. g. LiN3, KN3 and CsN3) on the product formation was investigated as well...
December 3, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27914049/modeling-binding-affinity-of-pathological-mutations-for-computational-protein-design
#4
Miguel Romero-Durana, Chiara Pallara, Fabian Glaser, Juan Fernández-Recio
An important aspect of protein functionality is the formation of specific complexes with other proteins, which are involved in the majority of biological processes. The functional characterization of such interactions at molecular level is necessary, not only to understand biological and pathological phenomena but also to design improved, or even new interfaces, or to develop new therapeutic approaches. X-ray crystallography and NMR spectroscopy have increased the number of 3D protein complex structures deposited in the Protein Data Bank (PDB)...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/27913993/antifreeze-glycopeptides-from-structure-and-activity-studies-to-current-approaches-in-chemical-synthesis
#5
REVIEW
Małgorzata Urbańczyk, Jerzy Góra, Rafał Latajka, Norbert Sewald
Antifreeze glycopeptides (AFGPs) are a class of biological antifreeze agents found predominantly in Arctic and Antarctic species of fish. They possess the ability to regulate ice nucleation and ice crystal growth, thus creating viable life conditions at temperatures below the freezing point of body fluids. AFGPs usually consist of 4-55 repetitions of the tripeptide unit Ala-Ala-Thr that is O-glycosylated at the threonine side chains with β-D-galactosyl-(1 → 3)-α-N-acetyl-D-galactosamine. Due to their interesting properties and high antifreeze activity, they have many potential applications, e...
December 2, 2016: Amino Acids
https://www.readbyqxmd.com/read/27913418/a-novel-rhamnose-rich-hetero-exopolysaccharide-isolated-from-lactobacillus-paracasei-dg-activates-thp-1-human-monocytic-cells
#6
Silvia Balzaretti, Valentina Taverniti, Simone Guglielmetti, Walter Fiore, Mario Minuzzo, Hansel N Ngo, Judith B Ngere, Sohaib Sadiq, Paul N Humphreys, Andrew P Laws
: Lactobacillus paracasei DG is a bacterial strain with recognized probiotic properties and is used in commercial probiotic products. However, the mechanisms underlying its probiotic properties are mainly unknown. In this study, we tested the hypothesis that the capability of strain DG to interact with the host is, at least partly, associated with its ability to synthesize a surface-associated exopolysaccharide (EPS). Comparative genomics revealed the presence of putative EPS gene clusters in DG genome; accordingly, EPS was isolated from the surface of the bacterium...
December 2, 2016: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/27913183/nmr-strategies-to-support-medicinal-chemistry-workflows-for-primary-structure-determination
#7
Paul Oguadinma, Francois Bilodeau, Steven R LaPlante
Central to drug discovery is the correct characterization of the primary structures of compounds. In general, medicinal chemists make great synthetic and characterization efforts to deliver the intended compounds. However, there are occasions which incorrect compounds are presented, such as those reported for Bosutinib and TIC10. This may be due to a variety of reasons such as uncontrolled reaction schemes, reliance on limited characterization techniques (LC-MS and/or 1D 1H NMR spectra), or even the lack of availability or knowledge of characterization strategies...
November 24, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27913182/virtual-screening-and-biophysical-studies-lead-to-hsp90-inhibitors
#8
Renjie Huang, Daniel M Ayine-Tora, M Nasri Muhammad Rosdi, Yu Li, Jóhannes Reynisson, Ivanhoe K H Leung
Heat shock protein 90 (HSP90) is a molecular chaperone that plays important functional roles in cells. The chaperone activity of HSP90 is regulated by the hydrolysis of ATP at the protein's N-terminal domain. HSP90, in particular the N-terminal domain, is a current inhibition target for therapeutic treatments of cancers. This paper describes an application of virtual screening, thermal shift assaying and protein NMR spectroscopy leading to the discovery of HSP90 inhibitors that contain the resorcinol structure...
November 23, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27913179/phytochemical-and-cytotoxic-studies-on-the-roots-of-euphorbia-fischeriana
#9
Qun Shi, Yi-Wei Sun, Dali Meng
With the aim of supporting the folk applications of Euphorbia fischeriana, a phytochemical study was performed, which led to the discovery of 9 compounds, including three new ones (1-3) and six known ones (4-9). Their structures were determined by 1D, 2D NMR, and HRESIMS analysis. In the cytotoxic assays on Hep-3B cell line, 2 showed stronger inhibitory effects (IC50 8.1μmol/L) than that of positive control, and 1, 8 and 9 also gave inhibitory effects in a certain degree with IC50 values of 12.5, 12.0 and 18...
November 23, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27912969/triterpenoid-saponins-with-anti-inflammatory-activities-from-ilex-pubescens-roots
#10
Peng Wu, Hui Gao, Jian-Xin Liu, Liang Liu, Hua Zhou, Zhong-Qiu Liu
Seven triterpenoid saponins, named ilexsaponin I-O, along with twelve known ones, were isolated from the roots of Ilex pubescens. The structures of all compounds were elucidated by use of extensive spectroscopic methods (IR, HR-ESI-MS, and 1D and 2D NMR). Sugar residues obtained after acid hydrolysis were identified by TLC and HPLC. The in vitro anti-inflammatory effects of the triterpenoid saponins were also evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Among the isolated saponins, seven compounds were shown to inhibit LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production by suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively, in LPS-stimulated RAW 264...
November 29, 2016: Phytochemistry
https://www.readbyqxmd.com/read/27912907/bioactivity-guided-isolation-of-anti-inflammatory-triterpenoids-from-the-sclerotia-of-poria-cocos-using-lps-stimulated-raw264-7-cells
#11
Seoung Rak Lee, Seulah Lee, Eunjung Moon, Hye-Jin Park, Hyun Bong Park, Ki Hyun Kim
Poria cocos Wolf (Polyporaceae) has been used as a medicinal fungus to treat various diseases since ancient times. This study aimed to investigate the anti-inflammatory chemical constituents of the sclerotia of P. cocos. Based on bioassay-guided fractionation using lipopolysaccharide (LPS)-stimulated Raw264.7 cells, chemical investigation of the EtOH extract of the sclerotia of P. cocos resulted in the isolation and identification of eight compounds including six triterpenoids, namely poricoic acid A (1), 3-O-acetyl-16α-hydroxydehydrotrametenolic acid (2), polyporenic acid C (3), 3β-hydroxylanosta-7,9(11),24-trien-21-oic acid (4), trametenolic acid (5), and dehydroeburicoic acid (6), as well as (-)-pinoresinol (7) and protocatechualdehyde (8)...
November 23, 2016: Bioorganic Chemistry
https://www.readbyqxmd.com/read/27912872/anti-allergic-potential-of-typhonium-blumei-inhibition-of-degranulation-via-suppression-of-pi3k-plc%C3%AE-2-phosphorylation-and-calcium-influx
#12
Michal Korinek, Kuan-Ming Chen, Yu-Han Jiang, Mohamed El-Shazly, Joel Stocker, Chon-Kit Chou, Tsong-Long Hwang, Yang-Chang Wu, Bing-Hung Chen, Fang-Rong Chang
BACKGROUND: Typhonium blumei Nicolson & Sivadasan (Araceae) is a traditional Chinese medicinal herb possessing detumescent, detoxifying, and anti-inflammatory activities. It is used in Taiwan as a folk medicine to treat cancer and inflammatory diseases. Typhonium blumei is usually not distinguished from Typhonium roxburghii Schott and they are commonly used interchangeably. PURPOSE: To evaluate and compare the anti-allergic and anti-inflammatory properties of T...
December 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
https://www.readbyqxmd.com/read/27912082/low-dimensional-compounds-containing-bioactive-ligands-part-viii-dna-interaction-antimicrobial-and-antitumor-activities-of-ionic-5-7-dihalo-8-quinolinolato-palladium-ii-complexes-with-k-and-cs-cations
#13
Veronika Farkasová, Sayed Ali Drweesh, Andrea Lüköová, Danica Sabolová, Ivana D Radojević, Ljiljana R Čomić, Sava M Vasić, Helena Paulíková, Stanislav Fečko, Tatiana Balašková, Mária Vilková, Ján Imrich, Ivan Potočňák
Starting from well-defined NH2(CH3)2[PdCl2(XQ)] complexes, coordination compounds of general formula Cat[PdCl2(XQ)] have been prepared by cationic exchange of NH2(CH3)2(+) and Cat cations, where XQ are biologically active halogen derivatives of quinolin-8-ol (5-chloro-7-iodo-quinolin-8-ol (CQ), 5,7-dibromo-quinolin-8-ol (dBrQ) and 5,7-dichloro-quinolin-8-ol (dClQ)) and Cat is K(+) or Cs(+). The cation exchange of all prepared complexes, K[PdCl2(CQ)] (1), K[PdCl2(dClQ)] (2), K[PdCl2(dBrQ)] (3), Cs[PdCl2(CQ)] (4), Cs[PdCl2(dClQ)] (5) and Cs[PdCl2(dBrQ)] (6) was approved using IR spectroscopy, their structures in DMSO solution were elucidated by one- and two-dimensional NMR experiments, whereas their stability in solution was verified by UV-VIS spectroscopy...
November 16, 2016: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/27911811/the-structure-of-the-catechin-binding-site-of-human-sulfotransferase-1a1
#14
Ian Cook, Ting Wang, Mark Girvin, Thomas S Leyh
We are just beginning to understand the allosteric regulation of the human cytosolic sulfotransferase (SULTs) family-13 disease-relevant enzymes that regulate the activities of hundreds, if not thousands, of signaling small molecules. SULT1A1, the predominant isoform in adult liver, harbors two noninteracting allosteric sites, each of which binds a different molecular family: the catechins (naturally occurring flavonols) and nonsteroidal antiinflammatory drugs (NSAIDs). Here, we present the structure of an SULT allosteric binding site-the catechin-binding site of SULT1A1 bound to epigallocatechin gallate (EGCG)...
November 23, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911361/spin-saturation-transfer-difference-nmr-sstd-nmr-a-new-tool-to-obtain-kinetic-parameters-of-chemical-exchange-processes
#15
María Teresa Quirós, Colin Macdonald, Jesús Angulo, María Paz Muñoz
This detailed protocol describes the new Spin Saturation Transfer Difference Nuclear Magnetic Resonance protocol (SSTD NMR), recently developed in our group to study processes of mutual-site chemical exchange that are difficult to analyze by traditional methods. As the name suggests, this method combines the Spin Saturation Transfer method used for small molecules, with the Saturation Transfer Difference (STD) NMR method employed for the study of protein-ligand interactions, by measuring transient spin saturation transfer along increasing saturation times (build-up curves) in small organic and organometallic molecules undergoing chemical exchange...
November 12, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27910948/improved-in-cell-structure-determination-of-proteins-at-near-physiological-concentration
#16
Teppei Ikeya, Tomomi Hanashima, Saori Hosoya, Manato Shimazaki, Shiro Ikeda, Masaki Mishima, Peter Güntert, Yutaka Ito
Investigating three-dimensional (3D) structures of proteins in living cells by in-cell nuclear magnetic resonance (NMR) spectroscopy opens an avenue towards understanding the structural basis of their functions and physical properties under physiological conditions inside cells. In-cell NMR provides data at atomic resolution non-invasively, and has been used to detect protein-protein interactions, thermodynamics of protein stability, the behavior of intrinsically disordered proteins, etc. in cells. However, so far only a single de novo 3D protein structure could be determined based on data derived only from in-cell NMR...
December 2, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27910815/in-vitro-and-in-vivo-evaluations-of-a-novel-post-electrospinning-treatment-to-improve-the-fibrous-structure-of-chitosan-membranes-for-guided-bone-regeneration
#17
Hengjie Su, Kwei-Yu Liu, Anastasios Karydis, Daniel G Abebe, Chaoxi Wu, Kenneth M Anderson, Najib Ghadri, Pradeep Adatrow, Tomoko Fujiwara, Joel D Bumgardner
Electrospun chitosan membranes have been investigated for guided bone regeneration but are susceptible to swelling, dissolution, and loss of biomimetic nanofiber structure due to residual acid salts. A novel process was investigated for acidic salt removal from chitosan electrospun in 70% trifluoroacetic acid (TFA) by treating with triethylamine (TEA)/acetone and di-tert-butyl dicarbonate (tBOC) instead of the common Na2CO3 treatment. TFA salt removal and nanofiber structure stabilization were confirmed by EDS, FTIR, (19)F NMR and electron microscopy before and after soaking in water...
December 2, 2016: Biomedical Materials
https://www.readbyqxmd.com/read/27910702/a-new-isoquinolone-alkaloid-from-an-endophytic-fungus-r22-of-nerium-indicum
#18
Yang-Min Ma, Ke Qiao, Yang Kong, Meng-Yun Li, Lin-Xin Guo, Zhi Miao, Chao Fan
A new isoquinolone alkaloid named 5-hydroxy-8-methoxy-4-phenylisoquinolin-1(2H)-one (3), together with two known quinolinone alkaloids 3-O-methylviridicatin (1) and viridicatol (2) were isolated from the fermentation of an endophytic fungus Penicillium sp. R22 in Nerium indicum. Their structures were elucidated by NMR, IR and MS data, and were also confirmed by comparing with the reported data in the literature. Meanwhile, the antibacterial and antifungal activities of all compounds were tested, and the results showed that three compounds had strong antifungal activity...
December 2, 2016: Natural Product Research
https://www.readbyqxmd.com/read/27910220/inverse-vulcanization-of-sulfur-with-natural-dienes-as-sustainable-materials-for-lithium-sulfur-batteries
#19
David Mecerreyes, Iñaki Gomez, Alberto Blazquez, Olatz Leonet
Lithium sufur batteries are among the most promising next generation battery systems due to the high capacity properties of sulfur as cathodic material. Beyond its interesting intrinsic properties, sulfur possesses a very low conductivity and complex electrochemistry which involves the high solubility of the lithium sulfides in the electrolyte. These two characteristics trigger a series of limitations on its performance as active cathode material which leads to batteries with low cyclability. Recently, inverse vulcanizated sulfur has shown to retain capacity far better than elemental sulfur leading to batteries with excellent cyclability...
December 2, 2016: ChemSusChem
https://www.readbyqxmd.com/read/27910174/combined-application-of-uhplc-qtof-ms-hplc-elsd-and-1-h-nmr-spectroscopy-for-quality-assessment-of-da-9801-a-standardised-dioscorea-extract
#20
Kyo Bin Kang, Jayoung Ryu, Youngwoong Cho, Sang-Zin Choi, Miwon Son, Sang Hyun Sung
INTRODUCTION: DA-9801, a standardised 50% aqueous ethanolic extract of a mixture of Dioscorea japonica and D. nipponica, is a botanical drug candidate for the treatment of diabetic neuropathy, which finished its US phase II clinical trials recently. An advanced quality control method is needed for further development of DA-9801, considering its high contents of both primary and secondary metabolites. OBJECTIVE: Development of a quality assessment strategy for DA-9801, based on the combination of UHPLC-QTOF/MS, HPLC-ELSD, and (1) H-NMR spectroscopy...
December 1, 2016: Phytochemical Analysis: PCA
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