- Interface-controlled calcium phosphate mineralization: effect of oligo(aspartic acid)-rich interfaces
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The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air-water and air-buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression-expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH.
- Hentrich, Doreen,Junginger, Mathias,Bruns, Michael,B?rner, Hans G.,Brandt, Jessica,Brezesinski, Gerald,Taubert, Andreas
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- Synthesis of poly(methyl methacrylate)-S/oc/c-poly(l-histidine) and its use as a hybrid silver nanoparticle conjugate
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Poly[(methyl methacrylate)-block-poly(L-histidine)] (PMMA-b-PHIS) was synthesized by combining atom transfer radical polymerization and living ring-opening polymerization of α-amino acid-N- carboxyanhydride. The resulting hybrid block copolymer forms reverse micelles in the mixture solution of water and N,N-dimethylformamide (DMF) and self-assembles into PHIS/PMMA core/shell spheres with controllable size in the range of 80 to 250 nm depending on the micellization temperature. The self-assembly of PMMA-b-PHIS was carried out in H20/DMF (3/7) mixture in the presence of AgN03. Reduction of the resulting Ag ions encapsulated inside of the reverse micelles yielded an attractive Ag nanoparticle core/polymer shell conjugate system. Copyright
- Shin, Nam Ho,Lee, Jin Kyu,Li, Haiqing,Ha, Chang-Sik,Shchipunov, Yury A.,Kim
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- Construction of a smart glutathione peroxidase mimic with temperature responsive activity based on block copolymer
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To construct a smart artificial antioxidative enzyme on a nano-scaffold, a novel method for designing glutathione peroxidase (GPx) active sites on block copolymer vesicles was developed by simple blending predesigned temperature-sensitive block copolymers with the main catalytic units of GPx. A series of functional block copolymers, poly(N-isopropylacrylamide)-b- polyacrylamides loaded with recognition and catalytic sites, were synthesized via ATRP and click chemistry. Through altering the molar ratio of the functional copolymers, the optimum GPx mimic based on copolymer vesicles was obtained by self-assembly of temperature-sensitive block copolymers through a blending process. Significantly, the catalytic activity of the optimum GPx mimic can be well modulated by changing the temperature. It was proved that the change in self-assembly structure of the block copolymer played an important role in the modulation of the catalytic activity. This method not only bodes well for designing smart antioxidative enzyme mimics that could be used in cosmetics as antioxidative additives but also highlights the construction of other regulatory biologically related functional biomaterials.
- Yin, Yanzhen,Wang, Liang,Jin, Haiyan,Lv, Chunyan,Yu, Shuangjiang,Huang, Xin,Luo, Quan,Xu, Jiayun,Liu, Junqiu
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- Regioselective 2-alkylation of indoles with α-bromo esters catalyzed by Pd/P,P=O system
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A palladium-catalyzed 2-alkylation of indoles with α-bromo esters is developed by employing a P,P=O ligand. The method features excellent regioselectivities, mild reaction conditions, and good functional group compatibility. The employment of the P,P=O ligand as well as 4? molecular sieves were crucial for the success of the transformation. Mechanistic studies indicate the reaction proceed through a radical pathway.
- Tian, Wei,Li, Bowen,Tian, Duanshuai,Tang, Wenjun
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supporting information
p. 197 - 200
(2021/08/13)
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- BENZIMIDAZOLE DERIVATIVES
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The invention relates to benzimidazoles of Formula (I) and pharmaceutically acceptable salts thereof, wherein R1 to R6 are as defined in the description; to their use in medicine; to compositions containing them; to processes for their preparation; and to intermediates used in such processes. The benzimidazoles of Formula (I) are ITK inhibitors and are therefore potentially useful in the treatment of a wide range of disorders including, atopic dermatitis.
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Page/Page column 53; 66
(2021/06/26)
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- Pyridine oxygen radical suo ester derivative and its preparation method, herbicidal composition and application (by machine translation)
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The invention belongs to the technical field of agricultural chemicals, in particular to a pyridine oxygen radical suo ester derivative and its preparation method, herbicidal composition and application. The pyridine oxygen radical suo acid ester derivative shown in formula I, Wherein A, B are respectively independently represents halogen, contain or not contain halogen alkyl or cycloalkyl; C represents hydrogen, halogen, alkyl, haloalkyl; Q represents halogen, cyano, cyano alkyl, hydroxy alkyl, amino, nitro, formyl, not containing or halogen-containing alkyl group or the like; the representative of M - alkyl - R, R represents an unsubstituted or substituted heterocyclic radical, aryl, heteroaryl; Y represents O or S; X represents a nitryl or NR1 R2 . The herbicidal activity is excellent, and have higher crop safety, especially for rice, soybean key crops has established a good selectivity. (by machine translation)
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Paragraph 0146-0148
(2019/04/10)
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- Enantioselective Synthesis of N-Benzylic Heterocycles: A Nickel and Photoredox Dual Catalysis Approach
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Reported herein is a dual nickel- and photoredox-catalyzed modular approach for the preparation of enantioenriched N-benzylic heterocycles. α-Heterocyclic carboxylic acids, easily obtainable from common commercial material, are reported as suitable substrates for a decarboxylative strategy in conjunction with a chiral pyridine-oxazoline (PyOx) ligand, providing quick access to enantioenriched drug-like products. The presence of a directing group on the heterocyclic moiety is shown to be beneficial, affording improved stereoselectivity in a number of cases.
- Pezzetta, Cristofer,Bonifazi, Davide,Davidson, Robert W. M.
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supporting information
p. 8957 - 8961
(2019/11/11)
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- PROTECTED ORGANOBORONIC ACIDS WITH TUNABLE REACTIVITY, AND METHODS OF USE THEREOF
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Disclosed are a range of protected organoboronic acid reagents useful in the modular assembly of complex organic compounds. The reactivities of the protected organoboronic acid reagents may be varied predictably by changes to the number and identities of their substituents. Also disclosed are methods of using the protected organoboronic acid reagents in the synthesis of organic compounds.
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Page/Page column 45
(2017/03/08)
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- Enantioselective synthesis of quaternary α-amino acids via l -tert-leucine-derived squaramide-catalyzed conjugate addition of α-nitrocarboxylates to enones
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Enantioselective Michael addition of tertiary α-nitroesters to β-unsubstituted vinyl ketones has been carried out in the presence of an l-tert-leucine-derived squaramide as organocatalyst. The products, quaternary α-nitroesters, were formed in excellent yield and moderate to good ee's in most cases. Scale-up of the reaction and synthetic applications of the products, including transformation to representative quaternary α-amino acids, have also been demonstrated.
- Bera, Kalisankar,Satam, Nishikant S.,Namboothiri, Irishi N. N.
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p. 5670 - 5680
(2016/07/14)
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- INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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Compounds of Formulas I-VI, including pharmaceutically acceptable salts thereof, and compositions and methods for treating human immunodeficiency virus (HIV) infection are set forth. Formula I is exemplified below: Formula (i)
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Page/Page column 91
(2016/11/17)
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- On the synthesis, characterization and reactivity of n-heteroaryl-boryl radicals, a new radical class based on five-membered ring ligands
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The synthesis and physical characterization of a new class of N-heterocycle-boryl radicals is presented, based on five membered ring ligands with a N(sp2) complexation site. These pyrazole-boranes and pyrazaboles exhibit a low bond dissociation energy (BDE; B-H) and accordingly excellent hydrogen transfer properties. Most importantly, a high modulation of the BDE(B-H) by the fine tuning of the N-heterocyclic ligand was obtained in this series and could be correlated with the spin density on the boron atom of the corresponding radical. The reactivity of the latter for small molecule chemistry has been studied through the determination of several reaction rate constants corresponding to addition to alkenes and alkynes, addition to O 2, oxidation by iodonium salts and halogen abstraction from alkyl halides. Two selected applications of N-heterocycle-boryl radicals are also proposed herein, for radical polymerization and for radical dehalogenation reactions.
- Tehfe, Mohamad-Ali,Schweizer, Stephane,Chany, Anne-Caroline,Ysacco, Cedric,Clement, Jean-Louis,Gigmes, Didier,Morlet-Savary, Fabrice,Fouassier, Jean-Pierre,Neuburger, Markus,Tschamber, Theophile,Blanchard, Nicolas,Lalevee, Jacques
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supporting information
p. 5054 - 5063
(2014/05/06)
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- COMPOUNDS
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The invention relates to new derivatives of 5-aminolevulinic acid (5-ALA) and their use as photosensitizing agents. In particular, it relates to compounds of general formula I and their pharmaceutically acceptable salts, to methods for preparing such compounds and their medical and cosmetic use, for example in methods of photodynamic therapy and diagnosis: wherein R1 represents a hydrogen atom or an optionally substituted alkyl or cycloalkyl group; R2, each of which may be the same or different, represents a hydrogen atom or an optionally substituted alkyl group; and X is a linking group.
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Page/Page column 35
(2014/02/16)
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- Cobalt-bisoxazoline-catalyzed asymmetric kumada cross-coupling of racemic α-bromo esters with aryl grignard reagents
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The first cobalt-catalyzed asymmetric Kumada cross-coupling with high enantioselectivity has been developed. The reaction affords a unique strategy for the enantioselective arylation of α-bromo esters catalyzed by a cobalt-bisoxazoline complex. A variety of chiral α-arylalkanoic esters were prepared in excellent enantioselectivity and yield (up to 97% ee and 96% yield). The arylated products were transformed into α-arylcarboxylic acids and primary alcohols without erosion of ee. The new enantioenriched α-arylpropionic esters synthesized herein are potentially useful in the development of nonsteroidal anti-inflammatory drugs. This method was conducted on gram-scale and applied to the synthesis of highly enantioenriched (S)-fenoprofen and (S)-ar-turmerone.
- Mao, Jianyou,Liu, Feipeng,Wang, Min,Wu, Lin,Zheng, Bing,Liu, Shangzhong,Zhong, Jiangchun,Bian, Qinghua,Walsh, Patrick J.
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supporting information
p. 17662 - 17668
(2015/02/02)
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- Preparation of a novel silica gel-adsorbed Br?nsted acid catalyst for the solvent-free esterification of bromoacetic acid with benzyl alcohol
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A new bifunctional Br?nsted acid catalyst that contains two sulfo groups was prepared. The adsorption of this new bifunctional Br?nsted acid catalyst on silica gel made it possible to be reused 10 times without a loss of catalytic activity in the solvent-free esterification of bromoacetic acid with an equiv. of benzyl alcohol without the formation of dibenzyl ether.
- Funabiki, Kazumasa,Komeda, Takuya,Sakaida, Yuta,Kubota, Yasuhiro,Matsui, Masaki
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p. 116 - 120
(2013/02/23)
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- Synthesis of fused 4,5-disubstituted indole ring systems by intramolecular friedel-crafts acylation of 4-substituted indoles
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(Chemical Equation Presented) 4-Substituted indoles containing a variety of electrophiles and N-substituents undergo Friedel-Crafts acylation to give exclusively the products of cyclization at the 5-position of indole. These indanones and tetralones have been scarcely prepared and are subunits in natural products and analogues of potential biological significance.
- Fillion, Eric,Dumas, Aaron M.
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p. 2920 - 2923
(2008/09/19)
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- PIPERIDINE DERIVATIVE AND USE THEREOF
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The present invention provides a novel piperidine derivative and a tachykinin receptor antagonist containing same, as well as a compound represented by the formula:wherein R1 is carbamoylmethyl, methylsulfonylethylcarbonyl and the like; R2 is methyl or cyclopropyl; R3 is a hydrogen atom or methyl; R4 is a chlorine atom or trifluoromethyl; R5 is a chlorine atom or trifluoromethyl; and a group represented by the formula:is a group represented by the formula:wherein R6 is a hydrogen atom, methyl, ethyl or isopropyl; R7 is a hydrogen atom, methyl or a chlorine atom; and R8 is a hydrogen atom, a fluorine atom, a chlorine atom or methyl; or 3-methylthiophen-2-yl, and a salt thereof.
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Page/Page column 83
(2008/12/08)
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- Inclusion complexes of EMPO derivatives with 2,6-di-O-methyl-β- cyclodextrin: Synthesis, NMR and EPR investigations for enhanced superoxide detection
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The free radical trapping properties of eight 5-alkoxycarbonyl-5-methyl-1- pyrroline N-oxide (EMPO) type nitrones and those of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) were evaluated for trapping of superoxide anion radicals in the presence of 2,6-di-O-methyl-β-cyclodextrin (DM-β-CD). 1H-NMR titrations were performed to determine both stoichiometries and binding constants for the diamagnetic nitrone-DM-β-CD equilibria. EPR titrations were then performed and analyzed using a two-dimensional EPR simulation program affording 1: 1 and 1: 2 stoichiometries for the nitroxide spin adducts with DM-β-CD and the associated binding constants after spin trapping. The nitroxide spin adducts associate more strongly with DM-β-CD than the nitrones. The ability of the nitrones to trap superoxide, the enhancement of the EPR signal intensity and the supramolecular protection by DM-β-CD against sodium l-ascorbate reduction were evaluated. The Royal Society of Chemistry 2006.
- Bardelang, David,Rockenbauer, Antal,Karoui, Hakim,Finet, Jean-Pierre,Biskupska, Inga,Banaszak, Karol,Tordo, Paul
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p. 2874 - 2882
(2008/02/08)
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- Cosmetic skin conditioning compositions containing a salicyloxy α-carboxy acid
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Cosmetic skin conditioning compositions containing a salicyloxo α-carboxy acid. The inventive compositions provide control of sebum secretion from sebocytes, improved oil control and improved skin feel, prevent shine and stickiness, while also providing anti-aging benefits which results in reduced appearance of wrinkles and aged skin, improved skin color, treatment of photoaged skin, improvement in skin's radiance and clarity and finish, and an overall healthy and youthful appearance of the skin.
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- Synthesis and antifolate properties of 9-alkyl-10-deazaminopterins
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Reformatski condensation of benzyl 2-bromopropionate with 4-carbomethoxybenzaldehyde, followed by dehydration afforded benzyl 2-methyl-p-carbomethoxycinnamate (4a). Hydrogenation over a Pd catalyst gave the hydrocinnamic acid 5a. Conversion to the chloromethyl (6a) and azidomethyl ketone (7a) was followed by hydrogenation to the aminomethyl ketone (8a). Direct N-alkylation by 2,4-diamino-5-nitro-6-chloropyrimidine followed by reductive ring closure in Zn-HOAc and subsequent saponification of the benzoate ester yielded 4-amino-4-deoxy-9-methyl-10-deazapteroic acid (11a). Coupling with diethyl L-glutamate and saponification afforded 9-methyl-10-deazaminopterin (13a). The 9-ethyl analogue (13b) was similarly prepared from benzyl 2-bromobutyrate. The 9-methyl analogue (13a) was 21 times more potent than MTX as an inhibitor of cell growth in L1210 cells. The reason for this enhanced cytotoxicity in L1210 is unclear, since enzyme inhibition and transport parameters were similar to those of MTX. In human Manca leukemia cells growth inhibition was not dramatic and paralleled MTX.
- DeGraw,Christie,Kisliuk,Gaumont,Sirotnak
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p. 212 - 215
(2007/10/02)
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- N-SUBSTITUTED-AMIDO-AMINO ACIDS
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Compounds of the formula STR1 wherein R and R 9 are independently hydroxy and lower alkoxy,R 1 and R. sub.2 are independently hydrogen, lower alkyl, aryl-lower alkyl having from 7 to 12 carbon atoms, or heterocyclic-lower alkyl having from 6 to 12 carbon atoms,R 3, R 4, R 5, R 7 and R 8 are hydrogen or lower alkyl,R 6 is heterocyclic and their pharmaceutically acceptable, nontoxic acid addition salts and where R or R 9 or both are hydroxy, their pharmaceutically acceptable, nontoxic basic salts, possess antihypertensive activity.
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- A Simple and Mild Esterification Method for Carboxylic Acids Using Mixed Carboxylic-Carbonic Anhydrides
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A simple and mild esterification method using mixed carboxylic-carbonic anhydrides has been developed.Simple aliphatic carboxylic esters are prepared in high yields by the reaction of acids with equimolar amounts of chloroformates (2,2,2-trichloroethyl chloroformate is an exception) and triethylamine in the presence of a catalytic amount of 4-(dimethylamino)pyridine.Although aromatic acids give a mixture of the ester, the acid anhydride, and the carbonate under normal conditions utilized in this study, it is found that increasing the amount of 4-(dimethylamino)pyridine drastically decreases the formation of the acid anhydride and the carbonate, affording a satisfactory yield of the ester.This method reaches a limit with sterically hindered acids and the formation of the acid anhydride and the carbonate is favored.
- Kim, Sunggak,Lee, Jae In,Kim, Youn Chul
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p. 560 - 565
(2007/10/02)
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- Dihalophenoxypropionic acids and their derivatives, and their use as cotton desiccants
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This invention relates to dihalophenoxypropionic acids and their derivatives useful for desiccating cotton plants, to a process for preparing these compounds, to cotton desiccating compositions containing them and to a method of desiccating cotton using t
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