- Glutathione Responsive β-Cyclodextrin Conjugated S-Nitrothiols as a Carrier for Intracellular Delivery of Nitric Oxide
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Nitric oxide (NO) exerts multiple functions in many life processes and was of great significance in a variety of biomedical scenarios. However, the mismatches between releasing locations and NO active sites seriously limited the available NO at areas of i
- Jia, Fan,Deng, Yongyan,Fang, Yu,Jin, Qiao,Ji, Jian
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- Biofilm microenvironment activated supramolecular nanoparticles for enhanced photodynamic therapy of bacterial keratitis
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Infectious keratitis caused by bacterial biofilms is one of the main causes of corneal blindness, presenting a serious threat to public health. In this study, matrix metalloproteinase (MMP)-sensitive supramolecular nanoparticles (denoted as MMP-S NPs) were constructed for enhancing photodynamic antibacterial effect against biofilm-associated bacterial keratitis. MMP-S NPs were prepared by host-guest self-assembly of chlorin e6 (Ce6) conjugated β-cyclodextrin (β-CD) prodrug (β-CD-Ce6) and MMP-9-sensitive peptides (YGRKKKRRQRRR-GPLGVRG-EEEEEE) terminated with adamantane (Ad) (Ad-MMP-S PEPs). MMP-S NPs with EEEEEE peptide shell had a negatively charged surface, preventing adhesion to the normal ocular surface or healthy corneal cells, thus enhancing tear retention time. After arriving at the infected lesions, the protective EEEEEE peptide shell of MMP-S NPs was removed, triggered by overexpressed MMP-9 in the keratitis microenvironment. The subsequently exposed cationic peptides helped the nanoparticles penetrate and accumulate in biofilms as well as bind to Gram-negative bacteria Pseudomonas aeruginosa (P. aeruginosa), which eventually improved the photodynamic antibacterial effect. Furthermore, the P. aeruginosa keratitis model verified the high effectiveness of a topical eye drop formulation of MMP-S NPs in killing bacteria by destroying the bacterial membrane as a result of in situ photodynamic activation of reactive oxygen species (ROS) formation under light irradiation. Moreover, the inflammatory response in the cornea was inhibited to a great extent. As a result, further damage to the corneal tissue was completely suppressed. This research provides a viable antibacterial alternative to fight against bacterial keratitis through effective elimination of infectious bacteria and eradication of bacterial biofilms in the cornea.
- Han, Haijie,Gao, Yifan,Chai, Mengyin,Zhang, Xiaobo,Liu, Shaorui,Huang, Yue,Jin, Qiao,Grzybowski, Andrzej,Ji, Jian,Yao, Ke
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- A oleanolic acid with amine cyclodextrin clathrate
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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.
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Paragraph 0051-0052
(2017/12/02)
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- Host-guest inclusion system of glycyrrhetic acid with polyamine-β-cyclodextrin: Preparation, characterization, and anticancer activity
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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.
- Shen, Zhi,Qin, Qi,Liao, Xiali,Yang, Bo
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p. 155 - 161
(2017/08/04)
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- Merging supramolecular catalysis and aminocatalysis: Amino-appended β-cyclodextrins (ACDs) as efficient and recyclable supramolecular catalysts for the synthesis of tetraketones
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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.
- Ren, Yufeng,Yang, Bo,Liao, Xiali
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p. 22034 - 22042
(2016/03/08)
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- Synthesis, characterization, and in vitro evaluation of artesunate-β-cyclodextrin conjugates as novel anti-cancer prodrugs
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A novel series of artesunate-β-cyclodextrin (ATS-β-CD) conjugates, in which artesunate (ATS) was coupled covalently to one of the primary hydroxyl groups of β-cyclodextrin (β-CD) through amino bond formation, were synthesized and characterized by 1H NMR, HRMS, 2D NMR (ROESY), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the aqueous solubility of ATS-β-CD conjugates was 26-45 times better than that of free ATS. The cytotoxicity of the ATS-β-CD conjugates was evaluated on human colon cancer cell lines HCT116, LOVO, SW480, and HT-29, and the results indicated that ATS-2NβCD exhibited a very high cytotoxicity against HCT116, LOVO, and HT-29 with IC50 values of 0.58, 1.62, and 5.18 μmol/L, respectively. In addition, the supposition of better cytotoxicity was further supported by the control experiment of fluorescent cyclodextrin.
- Jiang, Rui-Jian,Zhao, Yu-Lin,Chen, Yun-Jian,Xiao, Dan,Wang, Fen,Han, Bin,Yang, Jian,Liao, Xia-Li,Yang, Li-Juan,Gao, Chuan-Zhu,Yang, Bo
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- Cooperative self-assembly and molecular binding behavior of cyclodextrin-crown ether conjugates mediated by alkali metal ions
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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.
- Liu, Yu,Duan, Zhong-Yu,Chen, Yong,Han, Jian-Rong,Cui, Lv
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p. 2359 - 2364
(2007/10/03)
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- 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
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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.
- Liu, Yu,Li, Li,Zhang, Heng-Yi,Song, Yun
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p. 527 - 536
(2007/10/03)
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- Preparation and characterization of 6A-polyamine-mono-substituted β-cyclodextrins
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General syntheses for eleven β-cyclodextrins (cyclomaltoheptaoses) mono-substituted at the C6 position by a polyamine are described. The basis of the synthesis is the reaction of 6A-O-(4-methylphenylsulfonyl)-β-cyclodextrin in the presence of KI in 1-methylpyrrolidin-2-one solution. This produces a clean product and obviates the substantial purification procedures which other preparative methods often entail. Systematic studies of the variations of the P-KaS of the protonated amine groups and the 13C NMR spectra of the modified β-cyclodextrins with pH are reported.
- May, Bruce L.,Kean, Suzanna D.,Easton, Christopher J.,Lincoln, Stephen F.
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p. 3157 - 3160
(2007/10/03)
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