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101.
Danica L. Resuello Stephen B. Lirio Analin E. Porto Allan Patrick G. Macabeo Hsi-Ya Huang Mary Jho-Anne T. Corpuz 《Natural product research》2020,34(4):525-529
AbstractThe methanolic extract of Callyspongia samarensis (MCS) significantly inhibited β-secretase 1 (IC50 99.82?µg/mL) in a dose-dependent manner and demonstrated a noncompetitive type of inhibition. Furthermore, it exhibited the highest AMPK activation (EC50 14.47?μg/mL) as compared with the standard, Aspirin (EC50 >100?μg/mL). HPLC/ESI-MS analysis of MCS extract revealed 15 peaks, in which nine peaks demonstrated similar fragmentation pattern with the known compounds in literature and in database library: 5-aminopentanoic acid (1), 4-aminobutanoic acid (3), Luotonin A (4), (E)-3-(1H-imidazol-5-yl) prop-2-enoic acid (8), Galactosphingosine (10), D-sphingosine (11), 5,7,4′-trihydroxy-3′,5′-dimethoxyflavone (12), hydroxydihydrovolide (13), and 3,5-dibromo-4-methoxyphenylpyruvic acid (14); and 6 peaks are not identified (2, 5–7, 9, and 15). Acute oral toxicity test of MCS extract revealed that it is nontoxic, with an LD50 of >2000?mg/kg. Assessment of BBB permeability of MCS extract showed that compound 15 was able to cross the BBB making it a suitable candidate for developing CNS drugs. 相似文献
102.
103.
Yi-Feng Wang Kwok P. Chan Allan S. Hay 《Journal of polymer science. Part A, Polymer chemistry》1996,34(3):375-385
Facile ring-opening polymerization of cyclic aryl ether oligomers containing the 1,2-dibenzoylbenzene moiety to form high molecular weight linear polymers in the presence of a nucleophilic initiator is described. The polymerization can be initiated in the melt in the presence of a nucleophilic initiator such as potassium carbonate, cesium fluoride, and alkali phenoxides. Various alkali phenoxides were investigated as potential nucleophilic initiators. The polymerization reaction rate in the melt increases in the order of K+ > Na+ > Cs+, and in the order of −OPhPhO− > PhO− > PhOPhO− > PhPhO−. However, the polymerization in an aprotic dipolar solvent is faster in the presence of cesium phenoxide than in the presence of potassium phenoxide. Polymerization of the cyclic oligomers in solution demonstrates that the ring-opening polymerization proceeds via a chain-growth mechanism and involves a transetherification reaction between linear and cyclic aryl ether oligomers. The ring-chain equilibrium is much more favorable towards linear polymers. Since little or no ring strain exists in the cyclic system, the transetherification reactions are indiscriminate with regards to cyclic or linear chains and the interchain equilibration is also a facile process during polymerization. This intermolecular transetherification has been demonstrated by using low molecular weight aryl ethers to control the molecular weight of the polymer formed via ring-opening polymerization. © 1996 John Wiley & Sons, Inc. 相似文献
104.
Haixin Yang Allan S. Hay 《Journal of polymer science. Part A, Polymer chemistry》1996,34(13):2621-2632
The synthesis of N-phenyl phthalazinium salts by condensation of a 1,2-diaroylbenzene with phenylhydrazine is described. This reaction was utilized to prepare novel poly(aryl ether phthalazinium) ionomers by the direct condensation of poly(aryl ether ketone)s with phenylhydrazine. The preparation of poly(aryl ether phthalazinium) ionomers by methylation of poly(aryl ether phthalazine)s is also described. Most of the ionomers are amorphous, thermally stable, and soluble in organic solvents. They can be cast into flexible and strong films. The glass transition temperature of the ionomers ranges from 297 to 363°C, an increase of 12 to 100°C over the corresponding neutral polymers. © 1996 John Wiley & Sons, Inc. 相似文献
105.
106.
Leal Allan M. M. Kyas Svetlana Kulik Dmitrii A. Saar Martin O. 《Transport in Porous Media》2020,133(2):205-206
Transport in Porous Media - In the original publication of the article, Table 2 was published incorrectly. 相似文献
107.
Alexandr Kh. Plyamovatyi Raviya M. Mukhamadeeva Vasily A. Milyukov Oleg G. Sinyashin Alexandr E. Vandyukov Roald R. Shagidullin Allan G. Ginzburg Vyacheslav I. Sokolov 《Heteroatom Chemistry》1995,6(2):177-181
FT-IR spectroscopy and a special mathematical program were used for the real-time monitoring of the mechanistic path of the reaction of S-ethyl-N,N-tetraethyldiamidothiophosphite with [CpMn(CO)-2NO]+BFequation/tex2gif-stack-3.gif. The formation of a few intermediates is described. 相似文献
108.
Allan S. Hoffman 《Macromolecular Symposia》1995,98(1):645-664
One can define “intelligent” polymers as those polymers which respond with large property changes to small physical or chemical stimuli. These polymers may be in various forms, such as in solution, on surfaces, or as solids. One may also combine “intelligent” aqueous polymer systems with biomolecules, to yield a large family of polymers which respond “intelligently” to physical, chemical or biological stimuli. This article overviews such interesting and versatile polymer systems. 相似文献
109.
Hassan Keypour Musa AhmadiMajid Rezaeivala Abdolkarim ChehreganiReza Golbedaghi Allan G. Blackman 《Polyhedron》2011,30(11):1865-1870
Two new branched pentadentate amines (N5), 3,7-bis(2-pyridylmethyl)-5,5-dimethyl-3,7-diazaheptane-1-amine (1) and 4,8-bis(2-pyridylmethyl)-6,6-dimethyl-4,8-diaza octane-1-amine (2) have been prepared. These have been used to synthesis two new Schiff base complexes containing a pyridine and 2-pyridylmethyl pendant arm, by template [1+1] condensation of pyridine-2-carbaldehyde with the amines in the presence of Mn(II) in methanol. Elemental and spectral results are used to characterize the complexes and their structures are confirmed by single crystal X-ray diffraction studies. The structure of MnL1(ClO4)2 indicates that in the solid state the Mn(II) ion adopts a slightly distorted octahedral geometry. The crystal structure of [Ni(1)(MeCN)](ClO4)2 is also reported and exhibits a slightly distorted octahedral geometry. Also the synthesized complexes were screened for their antibacterial activity against Escherichia coli (Lio), Serratia marcescens (PTCC 1330), Staphylococcous aureus (ATCC 6633), and Proteus vulgaris (Lio) and results showed that the all complexes have antibacterial effects and [NiL1](ClO4)2, [MnL2](ClO4) and [MnL1](ClO4)2 have more effective ones against E. coli. 相似文献
110.
Roderick C. Jones Brian W. Skelton Vicki-Anne Tolhurst Allan H. White Adele J. Wilson Allan J. Canty 《Polyhedron》2007
A convenient synthetic method for the preparation of organothiomethylpyridine ligands 2-(RSCH2)C5H4N (R = Ph (L1), Me (L2)), 2-MeS–6-Me-C5H3N (L3), and 2-MeS–4-Me-C5H3N (L4) via the initial lithiation of substituted 2-picolines followed by the nucleophilic reaction with a diorganyldisulfide is described. The complexes [PtBr2L] (L = L1–L4) have been prepared in good to high yields as yellow solids with low solubility in organic solvents. The solid state structures of the complexes have been determined, showing the spatial arrangement of the complexes to depend significantly upon varying substituents within the ligand. The complexes undergo oxidation by bromine to form the tetravalent complexes [PtBr4(L)] (L = L1–L4). The solid state structures of [PtBr4(L2)] and [PtBr4(L4)] have been determined, and shown to be monomeric with the ligand chelating the platinum centre. 相似文献