24345-74-2Relevant articles and documents
Regioselective formation of diazafulleroids bridged by glycol diacetate and glycol chains
Chen, Chuanfeng,Li, Jisheng,Ji, Gaijiao,Zhu, Daoben,Zheng, Qiyu
, p. 3097 - 3103 (1998)
Five diazafulleroids with neighbouring double 5, 6-insertion were regioselectivity synthesized by the reactions of C60 with ethylene, diethylene, triethylene glycol di(2-azideacetates) and diethyline, triethylene glycol diazides in refluxing chlorobenzene.
A novel graphite-like stacking structure in a discrete molecule and its molecular recognition behavior
Akine, Shigehisa,Onuma, Takahiro,Nabeshima, Tatsuya
, p. 9369 - 9372 (2018)
A graphite-like stacking structure was nicely reproduced in a discrete molecule that was prepared by 2+2 macrocyclic Schiff base formation. In the crystal structure, two hexabenzocoronene planes are closely stacked with displacement, yielding the intramolecular stacking structure similar to an AB- or ABC-stacking pattern in natural graphite. This molecule showed a recognition ability toward electron-deficient aromatic molecules in solution.
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Durden et al.
, p. 228,229 (1964)
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Visible light-activatable cyclodextrin-conjugates for the efficient delivery of nitric oxide with fluorescent reporter and their inclusion complexes with betaxolol
Seggio, Mimimorena,Payamifar, Sara,Fraix, Aurore,Kalydi, Eszter,Kasal, Petr,Catanzano, Ovidio,Conte, Claudia,Quaglia, Fabiana,Sortino, Salvatore
, p. 8449 - 8455 (2021)
This contribution reports the design, synthesis, photochemical properties and drug inclusion capability of two novel β-cyclodextrin (βCD) conjugates, βCD-NBFNO1 and βCD-NBFNO2, covalently integrating an N-nitroso amino-nitro-benzofurazan in the primary and secondary hydroxyl rims of the βCD scaffold, respectively through flexible spacers of different length. Both βCD conjugates are water-soluble and release nitric oxide (NO) under the input of either blue or green light, with quantum yields ΦNO (blue) = 0.13, 0.31 and ΦNO (green) = 0.007, 0.013 respectively, the former representing the largest values ever reported for nonmetal-containing NO donors activatable by visible light. The good contrast between the fluorescence green emission of the chromogenic moiety after and before the NO release permits the easy and in real-time quantification of the amount of NO generated, without the addition of external fluorescent agents. Despite the presence of the appendages, these βCD derivatives are also able to complex betaxolol, a β-blocker drug widely used for the reduction of the intraocular pressure, with binding constants Kb = 500 ± 50 and 1100 ± 100 M-1, respectively, without affecting the photochemical performances. In view of the well-known vasodilator properties of NO, the present βCD derivatives represent intriguing candidates for biopharmaceutical research studies addressed to combined therapeutic ocular applications.
Catalytic Synthesis of PEGylated EGCG Conjugates that Disaggregate Alzheimer's Tau
El Khoury, Anton,Seidler, Paul M.,Eisenberg, David S.,Harran, Patrick G.
, p. 4263 - 4271 (2021/06/18)
The naturally occurring flavonoid ( )-epigallocatechin gallate (EGCG) is a potent disaggregant of tau fibrils. Guided by the recent cryo-electron microscopy (cryoEM) structure of EGCG bound to fibrils of tau derived from an Alzheimer s brain donor, methods to site-specifically modify the EGCG D-ring with aminoPEGylated linkers are reported. The resultant molecules inhibit tau fibril seeding by Alzheimer s brain extracts. Formulations of aminoPEGylated EGCG conjugated to the (quasi)-brain-penetrant nanoparticle Ferumoxytol inhibit seeding by AD-tau with linker length affecting activity. The protecting groupfree catalytic cycloaddition of amino azides to mono-propargylated EGCG described here provides a blueprint for access to stable nanoparticulate forms of EGCG potentially useful as therapeutics to eliminate Alzheimer s-related tau tangles.
Electrochemical CO2 Reduction-The Effect of Chalcogenide Exchange in Ni-Isocyclam Complexes
Apfel, Ulf-Peter,Battistella, Beatrice,Gerschel, Philipp,Ray, Kallol,Siegmund, Daniel
, p. 1497 - 1510 (2020/04/30)
Among the numerous homogeneous electrochemical CO2 reduction catalysts, [Ni(cyclam)]2+ is known as one of the most potent catalysts. Likewise, [Ni(isocyclam)]2+ was reported to enable electrochemical CO2 conversion but has received significantly less attention. However, for both catalysts, a purposeful substitution of a single nitrogen donor group by chalcogen atoms was never reported. In this work, we report a series of isocyclam-based Ni complexes with {ON3}, {SN3}, {SeN3}, and {N4} moieties and investigated the influence of nitrogen/chalcogen substitution on electrochemical CO2 reduction. While [Ni(isocyclam)]2+ showed the highest selectivity toward CO2 reduction within this series with a Faradaic efficiency of 86% for the generation of CO at an overpotential of-1.20 V and acts as a homogeneous catalyst, the O-and S-containing Ni complexes revealed comparable catalytic activities at ca. 0.3 V milder overpotential but tend to form deposits on the electrode, acting as precursors for a heterogeneous catalysis. Moreover, the heterogeneous species generated from the O-and S-containing complexes enable a catalytic hydride transfer to acetonitrile, resulting in the generation of acetaldehyde. The incorporation of selenium, however, resulted in loss of CO2 reduction activity, mainly leading to hydrogen generation that is also catalyzed by a heterogeneous electrodeposit.
