Studies on the Effects of Epimedium Extract on Erythrocytes

Epimedium, one of representatives of traditional Chinese herb, is mainly composed of flavones and polysaccharide. It is famous for its antioxidant, antineoplastic and antiaging activities and has been widely used in the field of invigorating kidney and st…     

Studies on Composites of Nanoparti

Studies　on　Composites　of　Nanoparti...     

Chemical Studies on Decahydroacenaphthylene Compounds-Studies on the Synthesis of Hainanolide-Construction of Tricyclic Intermediate

Underthenamesofharrigtonolideandhainanolide,(I)wasobtainedindependentlybyButalandSunZfromdifferentspieces.Itwasdemonstratedsignificalltamivirusandantitumoractivityinvitroandvivotest3.ThecomplicateandnoveltypeofstructurewouldbeagreatchallengetostUdyitstotalsynthesis.Itcanbeobtainedfromhainanolidol(II),theanalogueof(I)isolatedfromCHainannesisL.,byPh(OAc).'.Aretro-syntheticschemethroughatricycliccompound(ill)hasbeendesigned.Inordertoobtaintheintermediate(lll),asyntheticrouteseemedtobereason…     

Studies on Kinetics of Chlorination Reaction of Polyethylene

Through kinetic method, the reaction mechanism and the rate equations of chlorination of polyethylene are suggested in this paper. The rate of chlorination is second order with respect to the concentration of methylene remained and chlorine, respectively. Apparent changes in crystallinity during chlorination processes were determinated by differential scanning calorimetry(DSC). The mathematical model relating crystallinety with kinetic parameters and function of sequence length distribution are derived.     

Study on the Formation Mechanism of Oxygen-containing Groups on the Surfaces of Hypercrosslinked Polystyrenes

Davankov and Tsyurupa described a new series of hypercrosslinked polymeric networks in 19691. Owing to their high internal surface area, unique porosity, and excellent swelling feature, hypercrosslinked polymers have exhibited a good adsorption affinity t…     

Studies on Enantioselective Effect of Chiral Titanate Reagents on the Synthesis of Substituted Benzhydrols

Chiral titanate reagents were prepared for inducing asymmetric syntheses of substituted benzhydrols from Grignard reagents and aldehydes. The solvents, reaction temperature and exchange of reactants by crossing experiments were investigated. Favorable attack of the nucleophile upon the aromatic aldehydes' prochiral face was proposed, the absolute configurations of the synthesized benzhydrols were suggested, and a preliminary reaction mechanism was described.     

Effect of self-aggregation of γ-cyclodextrin on drug solubilization

The purpose of this study was to investigate the physicochemical properties of drug-saturated aqueous cyclodextrin (CD) solutions. Phase solubility profiles of different drugs were determined in aqueous solutions containing γ-cyclodextrin (γCD) and/or hydroxypropyl-γ-cyclodextrin (HPγCD) in absence or presence of water-soluble polymers. ¹H-NMR and turbidity analysis were performed as well as permeation studies. Phase solubility diagrams showed that the observed γCD content (1–20% w/v) was only slightly different from the theoretical values for aqueous solutions that had been saturated with indomethacin, diclofenac sodium or amphotericin B, all displayed A-type profiles, while it was less than the theoretical value in solutions that had been saturated with corticosteroids (hydrocortisone and dexamethasone) that displayed B_S-type profiles. In the latter case self-assemble of drug/CD complexes decreased the overall CD solubility. Water-soluble polymers enhanced aqueous solubility of the drugs tested by stabilizing the drug/CD complexes, i.e. enhancing their stability constants, without affecting the observed aqueous γCD solubility. When the drug solubility leveled off (the B_S-type profiles) the amount of dissolved γCD increased and approached the theoretical values. Hydrocortisone formed partial inclusion complex with γCD and HPγCD and no non-inclusion or aggregates could be detected in diluted solutions by ¹H-NMR. Both permeation and turbidity studies showed that formation of dexamethasone/γCD complex promoted CD aggregation. All these observations indicate that CD aggregate formations play a role in CD solubilization of lipophilic and poorly water-soluble drugs and that the water-soluble polymers enhance the complexation efficiency of γCD and HPγCD by stabilizing the self-assembled drug/CD nanoparticles and promote non-inclusion complex formation.     

Effect of Fluorination on Aggregate Structure of Perylene Diimide

The effect of fluorination on the aggregate structure of a novel fluorinated perylene diimide, N, N‘-diperfluorophenyl-3, 4, 9, 10-perylenetetracarboxylic diimide 1, was investigated by UV-Vis absorptions and the conformation simulations from AM1 semi-empirical quantum mechanics modeling. The results showed that in the solid film 1 molecules stacked with the perfluorinated phenyl groups straightly over or below the perylene cores of the adjacent 1 molecules.     

Studies on Effect of Conformation on Spin Multiplicity of m－Phenylene Type of Biradicals by Different Approaches

The effect of the conformation on the spin multiplicity of the ground state and the stability of the ground state were investigated for m-phenylene type of biradicals by means of comparative study with DFT, CASSCF and AM1-CI approaches. It was found that AM1-CI approach is reliable in dealing with the stability of the high-spin ground state with the change of conformation; DFT method can give the reasonable results of the spin density of the high-spin state. Furthermore, when one or two radical centers are twisted sufficiently out of the coniugation with the benzene ring, m-phenylene turns into weak ferromagnetic and weak antiferro-magnetic coupling units, respectively.     

Studies on Synthesis of a Cycloheptapeptide and Effects of Different Metal Ions on the Cyclization

ＩｎｔｒｏｄｕｃｔｉｏｎＣｙｃｌｉｃｐｅｐｔｉｄｅｓ ,ｗｈｉｃｈａｒｅｃｏｎｓｔｒａｉｎｅｄｃｏｎｆｏｒｍａ ｔｉｏｎａｌｌｙａｎｄｍｏｒｅｒｅｓｉｓｔａｎｔｔｏｐｒｏｔｅａｓｅｄｉｇｅｓｔｉｏｎｓｔｈａｎｔｈｅｉｒｌｉｎｅａｒｐｒｅｃｕｒｓｏｒｓ ,ｈａｖｅｂｅｅｎｏｆｇｒｅａｔｉｎｔｅｒｅｓｔａｓｓｙｎｔｈｅｔｉｃｔａｒｇｅｔｓｂｏｔｈａｓｐｏｔｅｎｔｉａｌｄｒｕｇｌｅａｄｓａｎｄａｓｍｏｄｅｌｓｆｏｒｃｏｎ ｆｏｒｍａｔｉｏｎａｌａｎａｌｙｓｉｓ .1 4 Ｃｕｒｒｅｎｔｍｅｔｈｏｄｓｆｏｒｓｙｎｔ…     

Studies on the Interaction of Poly

Studies　on　the　Interaction　of　Poly...     

Studies on the Synthesis of Villosol

TheindoidsxillosoIandt4llosolsidewereisolatalinl985frOmPatriDiavi11osa,atradihonalChineseherbmedicineusedfortreatofconunoncoldandparohhsmUInPS.PhannacologicalstUdieshaveestablishedthattheyshowanti-inflannnatOryachvihes.BasedonspeCtraldata,chenucaltransformationsandanalysisOfCDbehaviorofthelactonering,x-illosolsideandvillosolhavebeengivensmictUresland2respeCtively.[']Itisinterestingthatthesenot-eltridoidshat,ereversedstereocheAnsto'atC5andC9junCtUreSwith5Q,9Qinsteadoftheusuall}'found5…     

Study on Stability of Nateglinide Polymorphism

The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure of nateglinide. Three forms of nateglinide were treated in different conditions, such as in various temperatures, humidity, light and so on.Analysis of their crystal structures was performed by X-ray powder diffraction ( XRD ) and their particle shapes were observed with scanning electron microscope ( SEM ). The results indicated that the stability of S-form of nateglinide is the best among the three forms and their particle shapes are quite difference. S-form is the sheet structure of layer upon layer, H-form looks like a hank of silk lines and B-form is the clubbed shape.     

Study of pre-equilibrium effects on α-induced reactions on copper

A stack of natural copper was bombarded with -particles. Cumulative cross-sections for⁶⁵Ga,⁶⁶Ga and⁶⁵Zn production, and the excitation functions for⁶⁸Ga and⁶⁷Ga production, were measured using high resolution gamma-ray spectroscopy. The data are compared with the theoretical result provided by equilibrium and pre-equilibrium reaction model, for this purpose we used the code ALICE of Blann. The overall agreement with theory is good. Besides, we present the experimental data obtained by other authors.     

Influence of temperature on the structure of liquid water

Molecular dynamics simulations have been carried out for liquid water at 7 different temperatures to understand the nature of hydrogen bonding at molecular level through the investigation of the effects of temperature on the geometry of water molecules. The changes in bond length and bond angle of water molecules from gaseous state to liquid state have been observed, and the change in the bond angle of water molecules in liquid against temperature has been revealed, which has not been seen in literature so far. The analysis of the radial distribution functions and the coordinate numbers shows that, on an average, each water molecule in liquid acts as both receptor and donor, and forms at least two hydrogen bonds with its neigbors. The analysis of the results also indicates that the water molecules form clusters in liquid.     

Studies on the Synthesis of Preverecynarmin

Prev~n1,acembranopditerpenoid,wasfirstisolatedfromsoftcoral(VeretilIumcoporium)inl99(),anditSmCtUrwasehablishedas(+)-(lE,3E,7E,llE)-cembra-l,3,7,ll-tetraen6-olaeetate[l].SofarasweknOW,thetotalSynthsisof1hasnobeenrePOrtedyet.Herein.wewishtodescribethetotalpeisoftheprecursor(9),theSynthhcroutewasouthnedbelowfa)HBr.80%;b).CH3C02Na.CH3CO2H,75%,c).Se02-I-Bu00H,70%,d).CCl',PPh3,83%,e).NaSQPh.DMF.9O%,O.K=CO3.MeOH,95%,g).DHP,Ts0H.8O%,h),TBAB,5O%NaOH,aq.,5%;i).Li-Effez.M,70%;j…     

Synthesis of adamantane on zeolite catalysts

The synthesis of adamantane from tetrahydrodicyclopentadiene on zeolites with different framework structures was studied. The adamantane yield on HY zeolites is higher than on HM and HZSM-5 zeolites. Among various types of dealuminated HY zeolites the HEY and HUSY zeolites give higher adamantane yields than conventional HY zeolite. The changes in activity and selectivity of the main and side reactions are correlated with the acidity and the pore structure of the zeolites. To ion-exchange the HY and HUSY zeolites with Ni2+ and La3+ cations may further improve the activity and selectivity of the zeolite catalysts.     

Studies on Synthesis of Diadenylyl Sulfites

Diadenylyl sulfites were obtained by the condensation of protected adenosines using O,O-bis (1-ben-zotriazolyl) sulfite as a coupling reagent.     

Prediction on amphiphilicity of hypocrellin derivatives

Hypocrellins are most suitable for photodynamic therapy (PDT) of the diseases occurring in the superficial layer, such as microvascular diseases, because of their special absorption spectral properties. However, hypocrellins and most of their derivatives are basically lipophilic, while the hydrophilic derivatives lose the PDT activity in vivo. Therefore, the key problem for practical application of PDT of microvascular diseases focuses on finding the derivatives which possess optimized amphiphilicity. Herein, we developed a theoretical method to estimate the amphi-philicity of a molecule by the calculated average polarity. Compared with the experimentally measured results, the method is proved to be applicable. Based on the computation and available experimental results, it can be concluded that the derivative must have the polarities around C.22 for optimized amphiphilicity.