65294-32-8Relevant academic research and scientific papers
Cooperative self-assembly and molecular binding behavior of cyclodextrin-crown ether conjugates mediated by alkali metal ions
Liu, Yu,Duan, Zhong-Yu,Chen, Yong,Han, Jian-Rong,Cui, Lv
, p. 2359 - 2364 (2004)
In order to quantitatively investigate their molecular binding ability, a series of cyclodextrin-crown ether conjugates containing β-cyclodextrin (β-CyD) and crown ether units, i.e. N-(benzoaza-15-crown-5) acylaminomethylene tethered 6-diethylenetriamino-6-deoxy-β-CyD (1), N-(benzoaza-15-crown-5)acylaminomethylene tethered 6-triethylenetetraamino-6- deoxy-β-CyD (2) and 4′,5′-dimethylene-benzo-15-crown-5 tethered 6-diethylenetriamino-6-deoxy-β-CyD (3), have been prepared as ditopic molecular receptors. Their inclusion complexation behavior with four representative fluorescent dyes, i.e. ammonium 8-anilino-l-naphthalenesulfonate (ANS), sodium 6-toluidino-2-naphthalenesulfonate (TNS), acridine red (AR) and rhodamine B (RhB), has been comprehensively investigated in aqueous NaH 2PO4/Na2HPO4 or KH 2PO4/K2HPO4 buffer solution (pH 7.20) by means of circular dichroism, fluorescence, and 2D NMR spectra. The results indicate that the self-assembly of crown ether modified β-CyD mediated by potassium ion exhibits a dimeric structure, which significantly enhances the original binding ability and molecular selectivity of parent β-CyD and its derivatives towards guest molecules through the cooperative binding of two hydrophobic CyD cavities with one guest. This cooperative binding mode of K+/CyD-crown ether systems are further confirmed by Job's experiments and 2D NMR investigations. Attributed to the positive contributions from the metal-ligated crown ether cap and K+-mediated dimerization of CyDs, the binding constant (Ks) values of CyD-crown ether conjugates 1-3 toward ANS are 10-83 times higher than that of β-CyD. The increased binding ability and molecular selectivity of CyD-crown ether conjugates are discussed from the viewpoints of size/shape-Fit and multiple recognition mechanism.
Fluorescent behaviour in host-guest interactions. Part 2: Thermal and pH-dependent sensing properties of two geometric isomers of fluorescent amino-β-cyclodextrin derivatives
Nakashima, Hironori,Takenaka, Yasushi,Higashi, Miwako,Yoshida, Noboru
, p. 2096 - 2103 (2001)
The fluorescent behaviour in aqueous solution of two types of amino-β-cyclodextrin (amino-β-CDx) isomers 1 and 2 bearing the naphthoamide group at the 1- and 2-position as a fluorescent-sensing unit was investigated using mainly fluorescence spectroscopy. The isomers 1 and 2 show both strong temperature- and pH-responsive photophysical properties in aqueous solution. The protonation of the amino groups of 1 and 2 in acidic media affects efficiently their fluorescence intensities. The equilibrium and thermodynamic quantities of the two-state equilibrium model for 1 and 2 have been determined spectrophotometrically. Solution NMR behaviour in a DMSO-D2O mixed solvent confirms the stereospecific relationship between the appended naphthalene fluorophore and the hydrophobic cavity of CDx. Restricted and/or flexible motion of the naphthalene moiety of 1 and 2 about the bond between the amide group and the amino group at the C-6 carbon atom in the CDx ring is evident from the NMR studies. The potential application of 1 to anion sensing is also discussed.
Functionalized β-cyclodextrins: Thermodynamic studies and NMR titration of 6-diethylenetriamine derivative
Cucinotta, Vincenzo,D'Alessandro, Franca,Impellizzeri, Giuseppe,Maccarrone, Giuseppe,Rizzarelli, Enrico,Vecchio, Graziella
, p. 1785 - 1788 (1996)
A thermodynamic and spectroscopic investigation has been carried out on the protonation and copper(II) complexation of the 6-diethylenetriamine derivative of β-cyclodextrins. By 13C NMR titration, the order of protonation of the three nitrogen atoms has been ascertained. The unusual entropy changes accompanying the different steps of protonation, as well as the copper(II) complexation, are discussed.
Synthesis of novel bis(β-cyclodextrin)s and metallobridged bis(β-cyclodextrin)s with 2,2′-diselenobis(benzoyl) tethers and their molecular multiple recognition with model substrates
Liu, Yu,Li, Li,Zhang, Heng-Yi,Song, Yun
, p. 527 - 536 (2003)
To investigate quantitatively the cooperative binding ability of β-cyclodextrin dimers, a series of bridged bis(β-cyclodextrin)s with 2,2′-diselenobis(benzoyl) spacer connected by different lengths of oligo(ethylenediamine)s (2-5) and their platinum(IV) complexes (6-9) have been synthesized and their inclusion complexation behavior with selected substrates, such as Acridine Red, Neutral Red, Brilliant Green, Rhodamine B, ammonium 8-anilino-l-naphthalenesulfonate, and 6-p-toluidino-2-naphthalenesulfonic acid, were investigated by means of ultraviolet, fluorescence, fluorescence lifetime, circular dichroism, and 2D-NMR spectroscopy. The spectral titrations have been performed in aqueous phosphate buffer solution (pH 7.20) at 25 °C to give the complex stability constants (Ks) and Gibbs free energy changes (-ΔG°) for the inclusion complexation of hosts 2-9 with organic dyes and other thermodynamic parameters (ΔH° and TΔS°) for the inclusion complexation of 2-5 with fluorescent dyes ANS and TNS. The results obtained indicate that β-cyclodextrin dimers 2-5 can coordinate with one or two platinum(IV) ions to form 1:1 or 1:2 stoichiometry metallobridged bis(β-cyclodextrin)s. As compared with parent β-cyclodextrin (1) and bis(β-cyclodextrin)s 2-5, metallobridged bis(β-cyclodextrin)s 6-9 can further switch the original molecular binding ability through the coordinating metal to orientate two β-cyclodextrin cavities and an additional binding site upon the inclusion complexation with model substrates, giving the enhanced binding constants Ks for both ANS and TNS. The tether length between two cyclodextrin units plays a crucial role in the molecular recognition with guest dyes. The binding constants for TNS decrease linearly with an increase in the tether length of dimeric β-cyclodextrins. The Gibbs free energy change (-ΔG°) for the unit increment per ethylene is 0.32 kJ.mol-1 for TNS. Thermodynamically, the higher complex stabilities of both ANS and TNS upon the inclusion complexation with 2-5 are mainly contributed to the favorable enthalpic gain (-ΔH°) by the cooperative binding of one guest molecule in the closely located two β-cyclodextrin cavities as compared with parent β-cyclodextrin. The molecular binding ability and selectivity of organic dyes by hosts 1-9 are discussed from the viewpoints of the multiple recognition mechanism and the size/shape-fitting relationship between host and guest.
NITRIC OXIDE-RELEASING CYCLODEXTRINS AS BIODEGRADABLE ANTIBACTERIAL SCAFFOLDS AND METHODS PERTAINING THERETO
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Page/Page column 97-99; 100, (2019/10/01)
Disclosed herein are cyclodextrin molecules covalently modified to store and release nitric oxide, as well as methods of making and uses thereof. The covalently modified cyclodextrin molecules may be tailored, in several embodiments, to release nitric oxide in a controlled manner and are useful for reduction and/or eradication of bacteria and for the treatment of disease.
Nitric Oxide-Releasing Cyclodextrins
Jin, Haibao,Yang, Lei,Ahonen, Mona Jasmine R.,Schoenfisch, Mark H.
supporting information, p. 14178 - 14184 (2018/10/24)
A series of secondary amine-modified cyclodextrin (CD) derivatives was synthesized with diverse exterior terminal groups (i.e., hydroxyl, methyl, methoxyl, and primary amine). Subsequent reaction with nitric oxide (NO) gas under alkaline conditions yieldedN-diazeniumdiolate-modified CD derivatives. Adjustable NO payloads (0.6-2.4 μmol/mg) and release half-lives (0.7-4.2 h) were achieved by regulating both the amount of secondary amine precursors and the functional groups around the NO donors. The bactericidal action of these NO-releasing cyclodextrin derivatives was evaluated againstPseudomonas aeruginosa, a Gram-negative pathogen, with antibacterial activity proving dependent on both the NO payload and exterior modification. Materials containing a high density of NO donors or primary amines exhibited the greatest ability to eradicateP. aeruginosa. Of the materials prepared, only the primary amine-terminated heptasubstituted CD derivatives exhibited toxicity against mammalian L929 mouse fibroblast cells. The NO donor-modified CD was also capable of delivering promethazine, a hydrophobic drug, thus demonstrating potential as a dual-drug-releasing therapeutic.
A oleanolic acid with amine cyclodextrin clathrate
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Paragraph 0037-0038, (2017/12/02)
The invention discloses a clathrate compound of pentacyclic triterpene oleanolic acid and amine cyclodextrin, the amine cyclodextrin is amino-substituted beta-cyclodextrin, The clathrate compound is prepared by employing a solvent method or an ultrasonic method; after oleanolic acid and amine cyclodextrin form the clathrate, the solubility of clathrate in water can be greatly increased, stability is increased, and bioavailability is increased. The antitumor in-vitro experiment shows that the clathrate has good antitumor in-vitro activity; the preparation method has the advantages of simple process, easy operation and mild reaction condition, and can be used for development of new oleanolic acid preparation.
Host-guest inclusion system of glycyrrhetic acid with polyamine-β-cyclodextrin: Preparation, characterization, and anticancer activity
Shen, Zhi,Qin, Qi,Liao, Xiali,Yang, Bo
, p. 155 - 161 (2017/08/04)
The inclusion complexation behaviors of glycyrrhetic acid (CTA) with four polyamine-modified β-cyclodextrins (CDs) have been investigated by 1H and 2D NMR, thermal gravimetric analysis, X-ray power diffraction and scanning electron microscopy. The results showed that Glycyrrhetic acid was encapsulated into the cavity of cyclodextrin to form the complexes with 1:1 stoichiometry. The water solubility of GTA was significantly enhanced by inclusion complexation with polyamine-modified β-cyclodextrins. The calculated IC50 values indicated that the antitumor activities of inclusion complexes were better than that of GTA. Satisfactory aqueous solubility, along with high thermal stability of inclusion complexes will be potentially useful for their application on the formulation design of natural medicine.
Merging supramolecular catalysis and aminocatalysis: Amino-appended β-cyclodextrins (ACDs) as efficient and recyclable supramolecular catalysts for the synthesis of tetraketones
Ren, Yufeng,Yang, Bo,Liao, Xiali
, p. 22034 - 22042 (2016/03/08)
Well-designed amino-appended β-cyclodextrins (ACDs) with an amino side chain of different lengths at the primary face of β-CD were synthesized and employed in the catalytic synthesis of a series of tetraketones as supramolecular catalysts in water for the first time. Yields of 58-97% were obtained with up to 30 examples of substrate. The catalyst could be recycled easily, while a 92% yield and 84% rate of catalyst recovery could be achieved after 8 cycles of catalyst recycling. Moreover, a catalytic mechanism merging supramolecular catalysis and aminocatalysis could be proposed through detailed 1D and 2D NMR, ESI-MS and Job plot analyses. This protocol retained the promising characteristics of ambient temperature, green medium, simple operation, broad substrate scope, excellent yields, superb catalyst recycling performance and unique catalytic mechanism.
NUCLEIC ACID COMPLEXES
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Paragraph 0115; 0116, (2015/07/27)
The invention relates to nucleic acid complexes, methods of preparation thereof, and uses thereof for delivering a nucleic acid into a cell.
