螯形主体分子的设计、包结性能及其在细辛挥发油 有效成分选择分离中的应用

设计了两种新的具有螯形骨架的主体分子反式-1,2-二苯基-1,2-苊二醇(1)和顺式-1,2-二(1'-萘基)-1,2-苊二醇(2),主体(1),(2)可与许多有机小分子化合物形成配位包合物。用IR和粉末XRD表征了主体分子(1)和(2)的包结物,用^1NMR测定了包结物的主客体分子摩尔比：(1)·DMF(1:2),(1)·DMSO(1:2),(1)·THF(1:2),(1)·二氧六环(1:1),(1)·吡啶(1:1),(2)·DMF(1:1)和(2)·DMSO(1:1)。单晶X射线衍射分析了包结物的晶体结构,(1)·DMF：空间群Pnaa,a=0.9377(1)nm,b=1.4351(1)nm,c=4.0463(3)nm;(1)·DMSO：空间群Pbcn,a=1.6278(1)nm,b=1.0751(1)nm,c=1.4980(1)nm;(2)·DMF：P2~1/n,a=0.9796(1)nm,b=1.2377(1)nm,c=2.2344(3)nm,β=93.02(1)°;游离主体(1)：空间群P1,a=1.0461(1)nm,b=1.1213(1)nm,c=1.5496(1)nm,α=81.74(1)°,β=75.71(1)°,γ=89.00(1)°;分析了主体分子的刚性和柔韧性对包结性能的影响。并研究了主体分子(1)选择分离细辛挥发油,将顺甲基异丁香酚从挥发油中分离出来。     

Preparation of maleopimar adducts of polyfluoroalkyl esters of tall colophony

Maleopimar adducts of tall colophony esters with alcohols-telomers 1H,1H,5H-perfluoropentane-1-ol, 1H,1H,7H-perfluoroheptane-1-ol, and 1H,1H,9H-perfluorononane-1-ol were synthesized in conditions of Diels-Alder reaction.     

Kinetic investigations of the process of encapsulation of small hydrocarbons into a cavitand-porphyrin

Exchange of guest molecules into capsule shaped host molecules is the most fundamental process in host-guest chemistry. Several examples of quantitative measurements of guest exchange rates have been reported. However, there have been no reports on the activation energies of these processes. A molecule known as cavitand-porphyrin (H2CP) has been reported to have a flexible host structure capable of facilitating moderate guest exchange rates suitable for kinetic measurements of the guest exchange process with 1H NMR. In this article, various kinetic and thermodynamic parameters related to the process of encapsulation of small hydrocarbons into H2CP in CDCl3 solution were determined by 2D exchange spectroscopy (EXSY): association and dissociation rate constants (k(ass) = 320 M-1 s-1, k(diss) = 1.4 s-1 for methane at 25 degrees C), the corresponding activation energies (E(a,ass) = 27 kJ.mol-1, E(a,diss) = 58 kJ.mol-1), and thermodynamic parameters for each process (DeltaG++(ass) = 59 kJ.mol-1, DeltaG++(diss) = 72 kJ.mol-1, DeltaH++(ass) = 25 kJ.mol-1, DeltaH++(diss) = 55 kJ.mol-1, DeltaS++(ass) = -113 J.K-1.mol-1, and DeltaH++(diss) = 58 J.K-1.mol-1 for methane). The thermodynamic parameters (DeltaG degrees = -13 kJ.mol-1, DeltaH degrees = -31 kJ.mol-1, DeltaS degrees = -60 J.K-1.mol-1 for methane) for this encapsulation equilibrium determined by EXSY were comparable to those for methane determined by 1D 1H NMR titration (DeltaG degrees = -11 kJ.mol-1, DeltaH degrees = -33 kJ.mol-1, DeltaS degrees = -75 J.K-1.mol-1 for methane). In addition, the structure of the methane encapsulation process was revealed by ab initio MO calculations. The activation energies for methane association/dissociation were estimated from MP2 calculations (E(a,ass) = 58.3 kJ.mol-1, E(a,diss) = 89.1 kJ.mol-1, and DeltaH degrees = -30.8 kJ.mol-1). These values are in accord with the experimentally determined values. The observed guest exchange rates and energies are compared with the corresponding values of various reported capsule-shaped hosts.     

Sub-Doppler rotationally resolved spectroscopy of lower vibronic bands of benzene with Zeeman effects

Sub-Doppler high-resolution excitation spectra and the Zeeman effects of the 6(0)(1), 1(0)(1)6(0)(1), and 1(0)(2)6(0)(1) bands of the S1(1)B2u<--S(0)(1)A1g transition of benzene were measured by crossing laser beam perpendicular to a collimated molecular beam. 1593 rotational lines of the 1(0) (1)6(0) (1) band and 928 lines of the 1(0)(2)6(0)(1) band were assigned, and the molecular constants of the excited states were determined. Energy shifts were observed for the S1(1)B2u(v1=1,v6=1,J,Kl=-11) levels, and those were identified as originating from a perpendicular Coriolis interaction. Many energy shifts were observed for the S1(1)B2u(v1=2,v6=1,J,Kl) levels. The Zeeman splitting of a given J level was observed to increase with K and reach the maximum at K=J, which demonstrates that the magnetic moment lies perpendicular to the molecular plane. The Zeeman splittings of the K=J levels were observed to increase linearly with J. From the analysis, the magnetic moment is shown to be originating mostly from mixing of the S1(1)B2u and S2(1)B1u states by the J-L coupling (electronic Coriolis interaction). The number of perturbations was observed to increase as the excess energy increases, and all the perturbing levels were found to be a singlet state from the Zeeman spectra.     

Facile Synthesis of Novel Pentofuranose Analogs of Phospha Sugar Derivatives

Novel pentofuranose analogs of phospha sugar derivatives were synthesized starting from 1-phenyl-2-phospholene 1-oxide ( 1 ). First, the allylic oxidation of 1-phenyl-2-phospholene 1-oxide ( 1 ) with CrO 3 in Ac 2 O-AcOH or 3-hydroxy-1-phenyl-2-phospholene ( 2 ) with MnO 2 afforded 1-phenyl-4-oxo-2-phospholene 1-oxide ( 3 ). The C-5 alkylation of 3 in the presence of NaH by using benzyl bromide or methyl iodide as electrophiles afforded the target title compounds.     

Laser spectroscopic studies of several Rydberg states of MgO

We report extensive spectroscopic measurements of rovibronic transitions from the MgO X 1Sigma+ ground state to the high-energy E 1Sigma+, F 1Pi1, and G 1Pi1 Rydberg states. Perturbations in the E 1Sigma+ and G 1Pi1 states were observed. The Rydberg molecular orbital character of the three states is examined, given ab initio calculations by Thummel et al. [Chem. Phys. 129, 417 (1989)]. It is concluded that the E 1Sigma+ and G 1Pi1 states consist primarily of the MgO+ X 2Pi ionic core, surrounded by 3ppi and 3psigma Rydberg electron clouds, respectively, and that the F 1Pi1 state consists primarily of the MgO+ A 2Sigma+ ionic core surrounded by a 3ppi Rydberg electron cloud. Spectroscopic characterizations of some unassigned vibrational levels of analogous MgO 3Pi2 states in this energy region are also reported.     

Synthesis and characterization of an anomeric sulfur analogue of CMP-sialic acid

alpha-2,3-Sialyltransferase catalyzes the transfer of sialic acid from CMP-sialic acid (1) to a lactose acceptor. An analogue of 1 was synthesized in which the anomeric oxygen atom was replaced with a sulfur atom (1S). The key step in the synthesis of 1S was a tetrazole-promoted coupling of a cytidine-5'-phosphoramidite with a glycosyl thiol of a protected sialic acid. Compounds 1 and 1S were characterized for their activity in a sialyl transfer assay. The rate of solvolysis in aqueous buffer of analogue 1S was 50-fold slower than that of 1. Analogue 1S was found to be substrate for alpha-2,3-sialyltransferase. The K(m) of 1S was just 3-fold higher than that of 1, while the k(cat) of 1S was 2 orders of magnitude lower compared to 1.     

Synthesis and conjugation of oligosaccharide analogues of fragments of the immunoreactive glycan part of the circulating anodic antigen of the parasite Schistosoma mansoni

The gut-associated circulating anodic antigen (CAA) is one of the major excretory antigens produced by the parasite Schistosoma mansoni. The immunoreactive part of CAA is a threonine-linked polysaccharide composed of long stretches of the unique repeating disaccharide-->6)-[beta-D-GlcpA-(1-->3)]-beta-D-GalpNAc-(1-->. Previously, using surface plasmon resonance and ELISA techniques, it has been shown that some anti-CAA IgM monoclonal antibodies (MAbs) also recognize members of a series of bovine serum albumin (BSA)-coupled synthetic di- to penta-saccharide fragments of the CAA glycan. To generate information on the molecular level about the glycan specificity of the relevant IgM MAbs, two series of oligosaccharides related to the CAA disaccharide epitope were synthesized, and coupled to BSA. The first three analogues, beta-D-GlcpA-(1-->3)-[small beta]-D-GlcpNAc-(1-->O), beta-D-GlcpNAc-(1-->6)-[beta-D-GlcpA-(1-->3)]-beta-D-GlcpNAc-(1-->O), and beta-D-GlcpA-(1-->3)-beta-D-GlcpNAc-(1-->6)-[beta-D-GlcpA-(1-->3)]-beta-D-GlcpNAc-(1-->O), wherein the native beta-D-GalpNAc moiety was replaced by beta-D-GlcpNAc, were synthesized to investigate the specificity of the selected MAbs to the carbohydrate backbone of CAA. The second series of analogues, beta-D-Glcp6S-(1-->3)-beta-D-GalpNAc-(1-->O), beta-D-GalpNAc-(1-->6)-[beta-D-Glcp6S-(1-->3)]-beta-D-GalpNAc-(1-->O), and beta-D-Glcp6S-(1-->3)-beta-D-GalpNAc-(1-->6)-[beta-D-Glcp6S-(1-->3)]-beta-D-GalpNAc-(1-->O), wherein the native beta-D-GlcpA moiety was replaced by beta-D-Glcp6S, was synthesized to evaluate the importance of the type/nature of the charge of CAA for the MAb recognition.     

Synthesis of Functionalized 1-Alkenylboronates via Hydroboration-Dealkylation of Alkynes with Diisopinocampheylborane

Hydroborations of propargyl chloride, ethyl propiolate, 3-trimethylsilyloxy-1-butyne, 1,1-diethoxy-2-propyne, 1-iodo- and 1-bromo-1-hexyne, and 1-bromo-3-chloro-1-propyne with diisopinocampheylborane 1, followed by dealkylation of the isopinocampheyl groups with acetaldehyde provide the corresponding 1-alkenylboronates in high yields with high regioselectivity.     

Characterization of singlet ground and low-lying electronic excited states of phosphaethyne and isophosphaethyne

The singlet ground ((approximate)X(1)Sigma1+) and excited (1Sigma-,1Delta) states of HCP and HPC have been systematically investigated using ab initio molecular electronic structure theory. For the ground state, geometries of the two linear stationary points have been optimized and physical properties have been predicted utilizing restricted self-consistent field theory, coupled cluster theory with single and double excitations (CCSD), CCSD with perturbative triple corrections [CCSD(T)], and CCSD with partial iterative triple excitations (CCSDT-3 and CC3). Physical properties computed for the global minimum ((approximate)X(1)Sigma+HCP) include harmonic vibrational frequencies with the cc-pV5Z CCSD(T) method of omega1=3344 cm(-1), omega2=689 cm(-1), and omega3=1298 cm(-1). Linear HPC, a stationary point of Hessian index 2, is predicted to lie 75.2 kcal mol(-1) above the global minimum HCP. The dissociation energy D0[HCP((approximate)X(1)Sigma+)-->H(2S)+CP(X2Sigma+)] of HCP is predicted to be 119.0 kcal mol(-1), which is very close to the experimental lower limit of 119.1 kcal mol(-1). Eight singlet excited states were examined and their physical properties were determined employing three equation-of-motion coupled cluster methods (EOM-CCSD, EOM-CCSDT-3, and EOM-CC3). Four stationary points were located on the lowest-lying excited state potential energy surface, 1Sigma- -->1A", with excitation energies Te of 101.4 kcal mol(-1) (1A"HCP), 104.6 kcal mol(-1)(1Sigma-HCP), 122.3 kcal mol(-1)(1A" HPC), and 171.6 kcal mol(-1)(1Sigma-HPC) at the cc-pVQZ EOM-CCSDT-3 level of theory. The physical properties of the 1A" state with a predicted bond angle of 129.5 degrees compare well with the experimentally reported first singlet state ((approximate)A1A"). The excitation energy predicted for this excitation is T0=99.4 kcal mol(-1) (34 800 cm(-1),4.31 eV), in essentially perfect agreement with the experimental value of T0=99.3 kcal mol(-1)(34 746 cm(-1),4.308 eV). For the second lowest-lying excited singlet surface, 1Delta-->1A', four stationary points were found with Te values of 111.2 kcal mol(-1) (2(1)A' HCP), 112.4 kcal mol(-1) (1Delta HPC), 125.6 kcal mol(-1)(2(1)A' HCP), and 177.8 kcal mol(-1)(1Delta HPC). The predicted CP bond length and frequencies of the 2(1)A' state with a bond angle of 89.8 degrees (1.707 A, 666 and 979 cm(-1)) compare reasonably well with those for the experimentally reported (approximate)C(1)A' state (1.69 A, 615 and 969 cm(-1)). However, the excitation energy and bond angle do not agree well: theoretical values of 108.7 kcal mol(-1) and 89.8 degrees versus experimental values of 115.1 kcal mol(-1) and 113 degrees. of 115.1 kcal mol(-1) and 113 degrees.     

Purification of Complex of SAV1 with PP1A

SAV1 is a core component involved in the Hippo pathway which can control the organ size via regulating cell proliferation and apoptosis simultaneously. We explored the regulatory mechanism of SAV1. We established the HEK293T cell pool, the cells in which can stably express SAV1 by retroviruses infection and found that SAV1 stable cells reduced the movement of themselves and resulted in multicellular aggregation. We purified SAV1 interacting protein complex using streptavidin resin and subsequently analyzed the digested peptides by high performance liquid chromatography(HPLC)-MS/MS. Results show that about 150 proteins were identified in the complex of SAV1 with protein. TUBA1A, OTUD4, and ATD were identified as proteins interacting with SAV1. Importantly, PP1A, serine/threonine protein phosphatase PP1-alpha 1 catalytic subunit, was also in the top 10 list. The interaction between PP1A and SAV1 was detected by both co-immunoprecipitation(CO-IP) and immunostaining. Our results indicate that PP1A might be the phosphatase of SAV1 and may take part in the regulation of the Hippo pathway.     

Synthesis of derivatives of 1-phenylhydropyrimidines

The synthesis has been effected, via the corresponding N-phenyl-ß-aminopropionic acids, of 1-(o-methoxyphenyl)-, 1-(o-ethoxyphenyl)-, and 1-(o-tolyl)dihydrouracils and also of 1-(o-methoxyphenyl)-, 1-(o-ethoxyphenyl)-, and 1-(o-tolyl)-2-thiodihydrouracils. The dihydrouracits and thiodihydrouracils obtained have been reduced with LiAlH₄ to the corresponding 2-oxohexahydro-, and 2-thioxohexahydropyrimidines. By the action of bromine and the subsequent splitting out of HBr, the dihydrouracils have been converted into 1-(o-methoxyphenyl)-, 1-(o-ethoxyphenyl)-, and 1-(o-tolyl)uracils.     

Synthesis of Urinary Metabolites of Retinoic Acid

Urinary metabolites 5-methyl-5-[2-(2,6,6-trimethyl -3-oxo-1-cyclohexen-1-yl)-vinyl]-2-tetrahydrofuranone (1) and 5-[2-(6-hydroxymethyl-2, 6-dimethyl-3-oxo-1- cyclohexen-1-yl)vinyl]-5-methyl-2-tetrahydrofuranone (2) of retinoic acid have been synthesized from 4-[2,2,6-trimethyl-3-(tetrahydro-2 H -pyran-2-yl)oxy-1-cyclohexen-1-yl]-3-buten-2-one (4) and methyl 2-(3,3-ethylenedioxy-1-butenyl)-1, 3-dimethyl-4-oxo-2-cyclohexene-1-carboxylate (5) .     

Synthesis of new analogues of diphenylpyraline

1-Unsubstituted 4-dimethylamino-5,6-dihydropyridine-2(1H)-thiones were converted to isomeric piperidin-4-ols which were separated and N-methylated to 2-substituted 1-methylpiperidin-4-ols. Their 1-phenyl analogues were prepared from 4-dimethylamino-5,6-dihydro-1-phenylpyridine-2(1H)-thiones. After their conversion to dihydro-1-phenylpyridin-4(1H)-ones the hydrogenation gave isomeric 1-phenylpiperidin-4-ols which were separated. O-Alkylation of the 1-substituted piperidin-4-ols by various methods yielded 2-substituted analogues of diphenylpyraline. Their antimycobacterial activity was examined. The configurations and conformations of the piperidine derivatives were investigated by NMR spectroscopy.     

Kinetics and Mechanism of Monomolecular Heterolysis of Commercial Organohalogen Compounds: XXXVII.1 Effect of Nucleofuge and Solvent of the Relative Rates of Heterolysis of 1-Halo-1-methylcyclopentanes and 1-Halo-1-methylcyclohexanes. Correlation Analysis of Solvation Effects

The effect of solvent ionizing ability on heterolysis rate enhances in the series 1-chloro-1-methylcyclohexane < 1-bromo-1-methylcyclohexane 1-chloro-1-methylcyclopentane < 1-bromo-1-methyl- cyclopentane. The lower sensitivity of cyclohexyl substrates compared with cyclopentyl is determined by conformational effects. Bromides are more sensitive to solvent effects than chlorides because of the stronger polarizability of the C-Br bond.     

Cycloaddition of benzoheteroazepine III Reaction of 2,3-dihydro-1H-15benzodiazepines with dichlorocarbene and stereo-structures of products

Reaction of 2, 3-dihydro-1H-1. 5-benzodiazepines with dichlorocarbene generated in situ using benzyltriethylammonium chloride (TEBA) as a phase transfer catalyst in chloroform-aqueous sodium hydroxide mixture gave mainly 1,2-cycloadducts, cis and trans-1a, 3-disubstituted-1, 1-dichloro-1a, 2,3,4-tetrahydro-1H-azirino[1,2-a][1,5]benzodiazepines (2.3), and formylated 1,2-cycloadducts, trans-1a,3-disubstituted-1, 1-dichloro-4-formyl-1a, 2, 3, 4–1 H-azirino[1, 2-a][1, 5]benzodiacepines (4). The stereo-structures of cycloadducts and the mechanism are also discussed.     

Application of Fast Grey RA to the spectrophotometric determination of copper in soft tissues of Egyptian camels

Copper in different organs of Egyptian camels was successfully determined spectrophotometrically using Fast Grey RA. Its values amounted to: 200.8 ± 11.4, 155.8 ± 16.1, 142 ± 6.8, 128.3 ± 6.9, 117.6 ± 5.1, 113.0 ± 5.3, 86.3 ± 3.2, 79.0 ± 5.2, 76.3 ± 3.7, 66.3 ± 4.3, 59.8 ± 1.7, 57.6 ± 3.0, 53.0 ± 2.2, 36.3 ± 2.3 and 3.03 ± 0.32 μg/g dry matter of hair, liver, spleen, lung, heart, integument, muscle, brain, lymph gland, small intestine, large intestine, kidney, adrenal, fourth stomach, and hump, respectively, while 1 ml citrated blood contained 6.97 ± 0.64 μg. Of 16 elements mentioned, only vanadium interferes with the determination of copper in hair by the present method.     

Synthesis of fragments of the glycocalyx glycan of the parasite Schistosoma mansoni

The chemical synthesis of alpha-L-Fucp-(1 --> 3)-beta-D-GalpNAc-(1 --> 4)-beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2, beta-D-GalpNAc-(1 --> 4)-[alpha-L-Fucp-(1 --> 3)-]beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2, and alpha-L-Fucp-(1 --> 3)-beta-D-GalpNAc-(1 --> 4)-[alpha-L-Fucp-(1 --> 3)-]beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2 is described. These structures represent fucosylated oligosaccharide fragments of the glycocalyx glycan of the cercarial stage of the parasite Schistosoma mansoni, and in protein-conjugated form they are potential diagnostics in the search for antibodies raised against the glycan in the serum of infected humans.     

Ab initio study of the electronic spectrum of dichlorocarbene CCl2

The equilibrium geometries, excitation energies, force constants and vibrational frequencies for seven low-lying electronic states X ¹A₁, ¹B₁, ³B₁, ¹A₂, ³A₂, ¹B₂ and ³B₂ of dichlorocarbene CCl₂ have been calculated at the MRSDCI level with a double-zeta plus polarization basis set. Our calculated equilibrium geometry for the X ¹A₁ state, excitation energy for X ¹A₁ → ¹B₁ and vibrational frequencies for the X ¹A₁ and ¹B₁ states are in good agreement with experimental data. The electronic transition dipole moments, oscillator strengths for the ¹B₁ → X ¹A₁ and ¹B₂ → X ¹A₁ transitions, radiative lifetimes for the ¹B₁ and ¹B₁ states are calculated using MRSDCI wavefunctions, predicting results in reasonable agreement with experiment.     

Kinetics and thermodynamics of the reaction of deoxyhemerythrin with nitric oxide

Deoxyhemerythrin reacts with NO to form a 1:1 adduct shown spectrophotometrically. The kinetics of the formation have been studied directly by stopped-flow measurements at four different temperatures (0.0-23.6 degrees C). The kinetics of the dissociation have been studied, also by stopped-flow techniques, at five different temperatures (4.0-35.1 degrees C) using three different scavengers [Fe(II)(edta)2-, O2 and sperm whale deoxymyoglobin], which gave similar values. For the formation kf = (4.2 +/- 0.2) x 10(6) M-1 s-1, delta Hf not equal = 44.3 +/- 2.3 kJ mol-1, delta Sf not equal to = 30 +/- 8 J mol-1 K-1 and for the dissociation kd = 0.84 +/- 0.02 s-1, delta Hd not equal to 95.6 +/- 2.1 kJ mol-1 delta Sd not equal to = 74 +/- 7 J mol-1 K-1 (25 degrees C, I = 0.2 M and pH 7-8.1). From the kinetic data the thermodynamic data for the formation of HrNO were calculated: Kf = (5.0 +/- 0.3) x 10(6) M-1, delta H = -51.3 +/- 3.1 kJ mol-1 and delta S = -44 +/- 11 J mol-1 K-1 (25 degrees C). The kinetic data suggest that NO occupies the same iron(II) site in deoxyhemerythrin as oxygen does. The equilibrium constant for the formation of Fe(II)(edta)(NO)2- has been redetermined: K1 = (1.45 +/- 0.07) x 10(7) M-1, delta H = -77.5 +/- 1.5 kJ and mol-1 and delta S = -123.5 J mol-1 K-1 (25 degrees C).