Studies on the inclusion complex reaction and fluorescent analytical application of β-cyclodextrin with hymecromone

The inclusion complex reaction condition and the mechanism of β-cyclodextrin with hymecromone have been studied by fluorescent spectrum. The fluorescent intensity and the stability of the system can be qreatly increased in qiven condition, and the formation constant of the inclusion complex reaction has been determined too. The system can be applied to the determination of trace amounts of hymecromone, the maximum fluorescent intensity is obtained with excitation and emission wavelength at 362 nm and 452 nm, respectively. The linear range for hymecromone is 8.0×10⁻⁹ mol·L⁻¹ to 1.0×10⁻⁵ mol·L⁻¹. The detection limit is 1.8×10⁻⁹ mol·L⁻¹. A simple, rapid and highly sensitive fluorimetric method is proposed for the determination of hymecromone. The results obtained are in agreement with those given by an official method. Foundation item: Supported by the National Natural Science Foundation of China (G1999046703) Biography: Luo Zhao-fu(1947-), female, Associate professor.     

Synthesis and Characterization of a Novel β-cyclodextrin Fluorescent Probe

1 Introduction In recent years, new development for the fluorescent chemical sensor has made the method and application of fluorescent probes been greatly enhanced and extended fully. Fluorescent probes has important value not only in research of pharmacology and physiology, but also has made great contribution in environmental science, information science etc.Cyclodextrin modified by fluorescence group as a spectral probe in supramolecular chemistry has important applications, and Japan‘s Ueno researc...     

Preparation,Characterization and Antioxidant Activity of Inclusion Complex of Bakuchiol with Hydroxypropyl-β-cyclodextrin

Bakuchiol isolated from Psoralea corylifolia is a naturally occurring prenylated phenolic monoterpene with a variety of bioactivities. The aim of this study was to improve the water solubility and thermal stability of bakuchiol through complexing it with hydroxypropyl-β-cyclodextrin(HP-β-CD). The bakuchiol/HP-β-CD inclusion complex's behavior and characterization were investigated by ultraviolet-visible(UV-vis) spectroscopy, Fourier transform infrared spectroscopy(FT-IR), thermogravimetric analysis(TGA),X-ray diffraction(XRD),~1H nuclear magnetic resonance(NMR), and two-dimensional(2 D) NMR. The obtained results indicated the formation of 1∶1 inclusion complex for bakuchiol with HP-β-CD. Water solubility of bakuchiol was significantly improved by complexation with HP-β-CD as demonstrated by phase solubility studies. The encapsulation of bakuchiol was confirmed by UV-vis, FT-IR, and XRD. The thermal stability was effectively enhanced by TGA and derivative thermogravimetry(DTG) analysis. In vitro antioxidant activity showed that bakuchiol/HP-β-CD inclusion complex had a little higher antioxidant ability than free bakuchiol. Moreover, we got the possible inclusion mode for the bakuchiol/HP-β-CD inclusion complex through NMR analysis. These results suggest that the inclusion complex can be a potentially useful approach in the design of novel formulations of bakuchiol for medical applications.     

Non-viral gene delivery carrier of probe type host molecule ——Interactions between DNA and β-cyclodextrin derivative complexes (I)

GENE THERAPY IS A COMMON PROCESS TO DELIVER EXTRIN- SIC GENES INTO TARGET CELLS FOR FURTHER GENE EXPRESSION, FOR THE PURPOSE OF TREATING DISEASES. A WELL DESIGNED GENE DELIVERY CARRIER CAN EFFICIENTLY PACKAGE AND PRO- TECT NUCLEIC ACID FROM BEING DIGESTED BY A VARIETY OF ENZYMES IN VIVO AND SHOULD BE ABLE TO SPECIFICALLY LO- CATE EXTRINSIC GENES INTO THE TARGET ORGANISMS. S…     

Sulfoalkyl ether β-cyclodextrin derivatives synthesized by a single step method as pharmaceutical biomaterials

We report a simple ＂one pot＂ single step method to synthesize sulfoalkyl ether β-cyclodextrin （β-CD） derivatives in aqueous solution, which avoids the limitations associated with commonly used organic synthesis of such derivatives including multi-step reactions, use of expensive, toxic, and often environmentally hazardous organic solvents and/or reagents. Using this method, we obtained sulfopropyl and sulfobutyl ethyl β-CDs. We characterized these two derivatives and evaluated their ability to enhance solubility of fluconazole, a commonly used antifungal drug with poor water solubility. Experimental results indicate that these derivatives are structurally analogous to some of the commercially available β-CD derivatives. More importantly, when they formed supramolecular inclusion complexes with fluconazole, they demonstrated similar, if not better, capacity to enhance fluconazole solubility compared with commercially available β-CD derivatives, suggesting that the simple ＂one pot＂ single step synthesis may provide an effective alternative approach to produce large quantity of β-CD derivatives as pharmaceutical biomaterials for medicinal applications.     

Studies on the interactions of 2,5-diphenyl 1,3,4-oxadiazole and 2,5-diphenyl 1,3-oxazole with β-cyclodextrin

Interactions of 2,5-diphenyl 1,3,4-oxadiazole (PPD) and 2,5-diphenyl 1,3-oxazole (PPO) with β-cyclodextrin (β-CD) are studied by 1H-NMR and steady-state fluorescence measurements, and the stoichiometries and the association constants are estimated. It is found that the hydrophobic interaction is the main driving force for the formation of inclusion complexes of PPD and PPO with β-CD. In the presence of aliphatic alcohols (from 1-propanol to 1-pentanol), PPD and PPO transfer from the CD cavity to the aqueous phase. Quenching experiments of PPD and PPO by iodide further prove the above conclusions. The results suggest that stereo effect is the crucial factor to the inexistence of nanotube in PPD (or PPO)-β-CD systems.     

Label-free selective sensing of Pb2＋ lead（II） sensors based on the aggregation of a pyrene fluorescent probe

In the present work, we report a label-free fluo- rescence turn-on approach for the sensitive and selective sensing of Pb2＋. Pyrene with one positive charge was used as the fluorescent probe, and thrombin aptamer （TBA）, which was a G-rich oligonucleotide, was employed to form G-quadruplex with lead（II）. When TBA and Pb2＋ were mixed with lead（II） in an aqueous solution, it was folded into a stable G-quadruplex. Subsequently, a single-stranded nucleic acid-specific nuclease S1 was added. The G-quad- ruplex stabilized by Pb2＋ lead（II） had markedly a significant resistant ability to nuclease S1 digestion. However, in the absence of Pb2＋ lead（II）, no quadruplex or less stable quadruplex was formed and TBA was digested by nuclease S1 in 3 min under the optimized experimental conditions. Finally, pyrene probe was Pb2＋ lead（II）. Electrostatic mixed with oligonucleotide in interactions between oligonu- cleotide （a polyanion） and the probe induced the aggregation of the probe, which in turn produced strong emission of the strong pyrene excimer emission. The intensity of the induced excimer emission was directly proportional to the amount of Pb2＋ added. Our approach shows good selectivity and sen- sitivity for the detection of Pb2＋ with a limit of detection limit as low as 800 nmol/L.     

Theory of restriction degree of Triple I method with total inference rules of fuzzy reasoning

Based on the theory of sustentation degree of Triple I method together with the formulas of a-Triple I modus ponens (MP) and a-Triple I modus tollens( MT), the theory of restriction degree of Triple I method is proposed. Its properties are analyzed, and the general formulas of supremum of a-Triple IMP and infimum of a-Triple I MT are obtained.     

Investigation of adsorption of surfactant at the air-water interface with quantum chemistry method

Density functional theory （DFT） of quantum chemistry was used to optimize the configuration of the anionic surfactant complexes CH3（CH2）7OSO3^- （H2O）n （n=0-6） and calculate their molecular frequencies at the B3LYP/6-311＋G^＊ level. The interaction of CH3（CH2）7OSO3^- with 1 to 6 water molecules was investigated at the air-water interface with DFT. The results revealed that the hydration shell was formed in the form of H-bond between the hydrophilic group of CH3（CH2）7OSO3^- and 6 waters. The strength of H-bonds belongs to medium. Binding free energy revealed that the hydration shell was stable. The increase of the number of water molecules will cause increases of the total charge of hydrophilic group and S10-O9-C8 bond angle, but decreases of the alkyl chain length and the bond lengths of S10-O11, S10-O12 as well as S10-O13, respectively.     

Land cover classification of remotely sensed image with hierarchical iterative method

Land cover classification is one of the most wide ly used applications of remote sensing. The use ofmultitemporal remote sensing data in land cover clas sification is one of the effective methods of obtainingaccurate land cover/land use data. For a particularimage, different land cover types often show a similarspectral response and are difficult to separate. Theadvantage of using multitemporal data is that differentvegetation types show different spectral characteristicsin…     

New method for the preparation of adsorbent with high adsorption capacity

Polyamidoamine （PAMAM） is a type of macromolecule having a definite chemical structure and a large number of terminal functional groups. The synthetic approach of the adsorbent with high adsorption capacity involved arching of PAMAM onto cellulose beads by reaction with epichlorohydrin. The product thus prepared had a large number of amino groups of 2.94 mmol/g derived from 0.23 mmol/g epoxy groups on cellulose beads. This method presents an effective method for the preparation of high-loading adsorbents.     

Land cover classification of remotely sensed image with hierarchical iterative method

Based on the analysis of the single-stage classification results obtained by the multitemporal SPOT 5 and Landsat 7 ETM+ multispectral images separately and the derived variogram texture, the best data combinations for each land cover class are selected, and the hierarchical iterative classification is then applied for land cover mapping. The proposed classification method combines the multitemporal images of different resolutions with the image texture, which can greatly improve the classification accuracy. The method and strategies proposed in the study can be easily transferred to other similar applications.     

Synthesis and Characterization of A Novel Water-soluble Block Copolymer with A Rod-coil Structure

In this paper, a novel water-soluble block copolymer with rod-coil structures was prepared using polyfluorene （PF） as rod segment and polyethylene glycol （PEG） as coil segment in the main chain. A new but simple way of polycondensation （shown in Scheme 1 ） was employed, compared with tedious atom transfer radical polymerization and ionic polymerization approaches.     

Formation of the Inclusion Complex of Orange Ⅱ with β-Cyclodextrin and Its Photostability

0　IntroductionCyclodextrins (CD)arenon reducingcyclicmaltooligosaccharidesproducedfromstarchbycyclodextringlycosyltransferaseandarecom posedofahydrophilicoutersurfaceandahy drophobicinnercavity .β cyclodextrinsarecom posedofsevenD glucopyranoseunits.Theringshapedstructureandhydrophobicinnercavityal lowthemtohousevariousguestmoleculesandtoformhost/ guestinclusioncomplexes.Cyclodex trinswereusedtoforminclusioncomplexwithdrugstoincreasewatersolubilityandbioavailabili tyofpoorlywater solubledru…     

Fluoresence quenching method for the determintion of trace amount of cadmium with iodide-acridine red system

Ａｎｕｍｂｅｒｏｆｆｌｕｏｒｅｓｃｅｎｃｅｍｅｔｈｏｄｓｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄｆｏｒｔｈｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｃａｄｍｉｕｍ，ｂａｓｅｄｏｎｉｔｓｃｏｍｐｌｅｘｗｉｔｈｏｒｇａｎｉｃｄｙｅｓ，ｓｕｃｈａｓ８ｈｙｄｒｏｘｙｑｕｉｎ...     

Formation of the inclusion complex of Orange II with β-Cyclodextrin and its photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange II is 1∶1. The formation constantK = 1.236×10³ L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constantK = 1.266×10³ L/mol was determined by¹H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange II solutions containing β-CD and TiO₂ was smaller by 51.9% than that of the Orange II solutions only containing TiO₂, while in the case of direct photolysis of Orange II solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange II under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis. Foundation item: Supported by the National Natural Science Foundation of China (20177017) Biography: Lu Ping (1958), male. Associate professor, research direction: environmental photochemistry.     

Copolymers of Styrene with Conjugated Dienes by Titanium Catalysts:Synthesis,Characterization and Evaluation of the Mechanical Properties

1 Results Polymerization of butadiene,isoprene and styrene and binary copolymerization of styrene with butadiene and isoprene were investigated using the catalyst Ti(η5-C5H5)(η2-MBMP)Cl (1) (MBMP=2,2′-methylenebis(6-tert-butyl-4-methylphenoxo) activated with methylaluminoxane (MAO).Syndiotactic polystyrene, cis-1,4- polybutadiene and cis-1,4-polyisoprene were obtained in good yields at 50 °C.Binary copolymerization of styrene with butadiene yielded block copolymers containing segments of cis-1,4-polybutadiene and crystalline syndiotactic polystyrene. Novel pseudorandom copolymers of styrene with isoprene were synthesized using the 1/MAO catalyst.The 13C NMR chemical shifts of the carbon atoms diagnostic of the different monomer diads and triads were predicted and assigned using properly calculated additive shift factors.Despite the syndiotactic arrangement of the styrene homosequences,the styrene-co-isoprene polymers are completely soluble in organic solvents and completely amorphous also at high styrene concentration.