Expanding manganese(IV) aqueous chemistry: unusually stable water-soluble hexahydrazide clathrochelate complexes

2021 ◽  
Author(s):  
Sergii I Shylin ◽  
James L. Pogrebetsky ◽  
Alina O. Husak ◽  
Dmytro Bykov ◽  
Andriy Mokhir ◽  
...  

Mn cage complexes are rare, and the ones successfully isolated in the solid state are not stable in water and organic solvents. Herein, we present the first report of mononuclear...

2019 ◽  
Author(s):  
Meifeng Wang ◽  
Liyin Zhang ◽  
Yiqun Li ◽  
Liuqun Gu

<p></p>Anomerization of glycosides were rarely performed under basic condition due to lack of efficiency. Here an imidazole promoted anomerization of β-D-glucose pentaacetate was developed; and reaction could proceed in both organic solvents and solid state at room temperature. Although mechanism is not yet clear, this unprecedent mild anomerization in solid state may open a new promising way for stereoseletive anomerization of broad glucosides and materials design in the future..


1993 ◽  
Vol 58 (10) ◽  
pp. 2321-2336 ◽  
Author(s):  
Zhong-wei Gu ◽  
John D. Spikes ◽  
Pavla Kopečková ◽  
Jindřich Kopeček

In cancer photodynamic therapy (PDT), improved efficiency of photosensitizer delivery to tumors may be obtained by binding them to targetable water soluble polymeric carriers. However, attachment of photosensitizers to Macromolecular carriers may alter their spectral and photosensitizing properties. In this study, a new monosubstituted phthalocyanine derivative, N-glycyl zinc(II) 4,9,16,23-tetraaminophthalocyanine (G-TAPC-Zn) was synthesized by the reaction of zinc(II) 4,9,16,23-tetraaminophthalocyanine (TAPC-Zn) with N-tert-butoxycarbonyl-glycine N'-hydroxybenzotriazole ester followed by deprotection of the tert-butoxycarbonyl (BOC) group. G-TAPC-Zn contains an aliphatic amino group suitable for attachment to water soluble polymeric carriers. By aminolysis of a polymeric precursor, an N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing oligopeptide (GFLG) side-chains terminated in p-nitrophenyl ester groups, with G-TAPC-Zn a polymeric derivative of the latter (P-GFLGG-TAPC-Zn) was synthesized. Spectral data indicated that in aqueous solutions P-GFLGG-TAPC-Zn formed aggregates. The degree of aggregation decreased with increasing concentration of detergents or organic solvents in buffer solutions. Consequently, the release of the drug from carrier catalyzed by thiol proteinases, papain or cathepsin B, took place only in the presence of detergents or organic solvents, i.e., under conditions with a lower probability of aggregate formation. Binding of G-TAPC-Zn to HPMA copolymers decreased the quantum yield of singlet oxygen generation from 0.24 to 0.063 and significantly increased its resistance to photobleaching.


2016 ◽  
Vol 4 (6) ◽  
pp. 490-494 ◽  
Author(s):  
Shihab Adnan ◽  
Kwang-Man Lee ◽  
Mohammad Tayeb Ghasr ◽  
Matthew J. O'Keefe ◽  
Delbert E. Day ◽  
...  

2014 ◽  
Vol 66 (10) ◽  
pp. 1439-1450 ◽  
Author(s):  
Hamdy Abdelkader ◽  
Ossama Y Abdallah ◽  
Hesham Salem ◽  
Adam WG Alani ◽  
Raid G Alany

1976 ◽  
Vol 59 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Bozidar Stavrić ◽  
Raymond Klassen ◽  
W Arnold

Abstract Thirteen saccharin samples used for carcinogenicity tests in animals in various laboratories were analyzed for their chemical purity. Although most of the impurities were water-soluble, some were mainly soluble in organic solvents. These impurities were extracted with chloroform-methanol from a water solution of sodium saccharin. Samples obtained as acid-saccharin were converted to the sodium form before extraction. The major impurity in commercial saccharin, o-toluenesulfonamide, was also soluble in this system. Impurities were separated by gas-liquid chromatography of the underivatized, concentrated extract. Eleven major, well separated peaks were collected from the gas chromatographic column and identified by mass spectroscopy. Some of the peaks were compared with known standards. Qualitative and quantitative differences in impurities were observed among different saccharin samples. The identified impurities (in order of appearance from the gas-liquid chromatographic column) were as follows: o-toluenesulfonamide; p-toluenesufonamide; 1,2-benzisothiazole 1,1-dioxide; 1,2-benzisothiazoline 1,1-dioxide; diphenylsulfone; o,o′-ditolylsulfone; o,m′-ditolylsulfone, o,p′-ditolylsulfone; m,p′-ditolylsulfone; p,p′-ditolylsulfone, and tetracosane.


Nano Research ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3261-3267
Author(s):  
Shenghui Han ◽  
Gang Lian ◽  
Xiaoliang Zeng ◽  
Zhaozhen Cao ◽  
Qilong Wang ◽  
...  

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 548 ◽  
Author(s):  
Serena Bertoni ◽  
Beatrice Albertini ◽  
Nadia Passerini

Delivery of poorly water soluble active pharmaceutical ingredients (APIs) by semi-crystalline solid dispersions prepared by spray congealing in form of microparticles (MPs) is an emerging method to increase their oral bioavailability. In this study, solid dispersions based on hydrophilic Gelucires® (Gelucire® 50/13 and Gelucire® 48/16 in different ratio) of three BCS class II model compounds (carbamazepine, CBZ, tolbutamide, TBM, and cinnarizine, CIN) having different physicochemical properties (logP, pKa, Tm) were produced by spray congealing process. The obtained MPs were investigated in terms of morphology, particles size, drug content, solid state properties, drug-carrier interactions, solubility, and dissolution performances. The solid-state characterization showed that the properties of the incorporated drug had a profound influence on the structure of the obtained solid dispersion: CBZ recrystallized in a different polymorphic form, TBM crystallinity was significantly reduced as a result of specific interactions with the carrier, while smaller crystals were observed in case of CIN. The in vitro tests suggested that the drug solubility was mainly influenced by carrier composition, while the drug dissolution behavior was affected by the API solid state in the MPs after the spray congealing process. Among the tested APIs, TBM-Gelucire dispersions showed the highest enhancement in drug dissolution as a result of the reduced drug crystallinity.


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