Experimental and QSPR Studies on n-Octanol/water Partition Coefficient (lgK_(ow)) of Substituted Aniline

The n-octanol/water partition coefficients （lgKow） of 18 substituted anilines were determined at 25 ℃ by shake-flask method. The geometrical optimization of substituted anilines has been performed at B3LYP/6-311G^＊＊ level with Gaussian98 program, and the molecular surface areas of substituted anilines were calculated using ChemOffice 2004 program. The calculated structural parameters of substituted anilines were used as theoretical descriptors and the two-parameter （molecular surface area （MA） and the energy of the highest occupied molecular orbital （EaoMo）） quantitative structure-property relationship （QSPR） model of lgKow for substituted aniline with molecular structural parameters was developed by multi-linear regression method. The regression coefficient square （r^2） is 0.990 and the standard deviation SE 0.109. The model was validated by variance inflation factors （VIF） and t-test, and the results show that there exists small self-correlation between variables of the model with perfect stability. The model gives results in good qualitative agreement with experimental data. At last, the model was applied to predict lgKow values of five substituted anilines whose lgKow values have not been determined experimentally.

Studies of n-Octanol/water Partition Coefficients (lgK_(ow)) for Organophosphate Compounds by Density Functional Theory

Optimized calculation of 35 dialkyl phenyl phosphate compounds （OPs） was carded out at the B3LYP/6-31G^＊ level in Gaussian 98 program. Based on the theoretical linear solvation energy relationship （TLSER） model, the obtained parameters were taken as theoretical descriptors to establish the novel QSPR model for predicting n-octanol/water partition coefficients （lgKow） of OPs. The new model achieved in this work contains three variables, i.e., molecular volume （Vm）, dipole moment of the molecules （μ） and enthalpy （H^0）. For this model, R^2 = 0.9167 and SD = 0.31 at large t values. In addition, the variation inflation factors （VIF） of variables are all close to 1.0, suggesting high accuracy of the predicting model. And the results of cross-validation test （q^2 = 0.8993） and method validation also showed the model of this study exhibited optimum stability and better predictive power than that from semi-empirical method. The model achieved can be used to predict IgKow of congeneric compounds.

DFT and Position of Cl Substitution (PCS) Methods Studies on n-Octanol/water Partition Coefficients (lgK_(ow)) and Aqueous Solubility (–lgS_w) of All PCDD Congeners

Optimized calculations of 75 PCDDs and their parent DD were carded out at the B3LYP/6-31G＊ level by density functional theory （DFT） method. The structural parameters were obtained and significant correlation between the C1 substitution position and some structural parameters was found. Consequently, the number of C1 substitution positions was taken as theoretical descriptors to establish two novel QSPR models for predicting lgKow and -lgSw of all PCDD congeners. The two models achieved in this work contain two variables （Na and Nβ）, of which r = 0.9312, 0.9965 and SD = 0.27, 0.12 respectively, and t values are all large. The variation inflation factors （VIF） of variables in the two models herein are both less than 5.0, suggesting high accuracy of the lgKow and -lgSw predicting models, and the results of cross-validation test also show that the two models exhibit optimum stability and good predictive power. By comparison, the correlation and predictive ability of the present work are more advantageous than those obtained using semi-empirical AM1 and GC-RI methods.

QSPR of n-Octanol/water Partition Coefficient (lgK_(ow)) for Alkyl(1-phenylsulfonyl) Cycloalkane-carboxylates

Quantum chemistry parameters of 28 alkyl（1-phenylsulfonyl） cycloalkane-carboxy-lates were computed at the 6-31G＊ level in fully optimal manner using B3LYP method of density functional theory （DFT）. With GQSARF2.0 program, the correlation equations that can predict n-octanol/water partition coefficient （lgKow） were developed using the structural and thermodynamic parameters of 28 alkyl（1-phenylsulfonyl） cycloalkane-carboxylates with experimental data of lgKow as theoretical descriptors; the correlation coefficient （R^2） was 0.9452 and the cross-validation squared correlation coefficient （Rcv^2） 0.9312. Furthermore, a four-variable model from MEDV was obtained, of which R2 = 0.9497 and Rov^2 =0.9388. The models were validated by variance inflation factor （VIF） and t-test. Cross-validation indicates that the correlation and predicting ability of the model based on both DFT method and MEDV are more advantageous than those obtained from semi-empirical AM1 method.

Estimation of n-Octanol/water Partition Coeffi-cients(lgK_(ow)) and the Aqueous Solubility(-lg_(Sw)) of all PCDF Congeners by Density Functional Theory

Optimized calculation of dibenzofuran （DF） and 135 polychlorinated dibenzofurans （PCDFs） was carried out at the B3LYP/6-31G＊ level in GAUSSIAN 98 program. Based on the theoretical linear solvation energy relationship （TLSER） model, the obtained structural parameters were taken as theoretical descriptors to establish the novel quantitative structureproperty relationship （QSPR） model for predicting n-octanol/water partition coefficients （lgKow） of PCDFs. The new model of lgKow achieved in this work contains three variables： energy of the highest occupied molecular orbital （EHOMO）, the most negative atomic partial charge （q^-） and average molecular polarizability （a）, of which R^2= 0.9011 and SD = 0,17 with larger t values. In addition, the variation inflation factors （VIF） of variables in the present model are all less than 5.5, suggesting high accuracy of the lgKow model. And the results of cross-validation test （q^2 = 0.8688） and method validation also show this model exhibits optimum stability and better predictive power than semi-empirical method. At the same time, it is found that the aqueous solubility （-lgSw） has high relative correlation with constant volume molar heat capacity （Cv^0）, of which R^2 = 0.9777 and SD = 0.22. Moreover, lgKow and -lgSw values of all PCDF congeners were predicted respectively.

Activity of NaOH in Sodium Aluminate Solutions

1.IntroductionSodium aluminate solution is one of themost important intermediate products in al-uminium metallurgy.The structure of so-dium aluminate solutions is rather compli-cated.Various anionic species,includingAl（OH）;,Al（OH）;and[（OH）;-Al-O-Al（OH）;];are co-existent in sodiumaluminate solutions.Using Raman and

Mechanism of aqueous fructus aurantii immaturus extracts in neuroplexus of cathartic colons

AIM: To examine the effect of aqueous fructus aurantii immaturus(FAI) extracts on the intestinal plexus of cathartic colons.METHODS: Cathartic colons were induced in rats with dahuang,a laxative used in traditional Chinese medicine. Once the model was established(after approximately 12 wk),rats were administered mosapride(1.54 mg/kg) or various doses of aqueous FAI extracts(1-4 g/kg) for 14 d. Transit function was assessed using an ink propulsion test. Rats were then sacrificed,and the ultramicrostructure of colonic tissue was examined using transmission electron microscopy. The expression of the 5-hydroxytryptamine receptor 4(5-HTR4) and neurofilament-H was assessed in colon tissues using real-time PCR,Western blot,and immunohistochemistry.RESULTS: Mosapride and high dose(4 g/kg) of aqueous FAI extracts significantly improved the bowel movement in cathartic colons compared to untreated model colons as measured by the intestinal transit rate(70.06 ± 7.25 and 72.02 ± 8.74,respectively,vs 64.12 ± 5.19; P < 0.05 for both). Compared to controls,the ultramicrostructure of cathartic colons showed signsof neural degeneration. Treatment with mosapride and aqueous FAI extracts resulted in recovery of ultrastructural pathology. Treatment with mosapride alone upregulated the gene and protein expression of 5-HTR4 compared to untreated controls(P < 0.05 for both). Treatment with aqueous FAI extracts(≥ 2 g/kg) increased 5-HTR4 m RNA levels(P < 0.05),but no change in protein level was observed by Western blot or immunohistochemistry. The m RNA and protein levels of neurofilament-H were significantly increased with mosapride and ≥ 2 g/kg aqueous FAI extracts compared to controls(P < 0.05 for all).CONCLUSION: Aqueous FAI extracts and mosapride strengthen bowel movement in cathartic colons via increasing the expression of 5-HTR4 and neurofilament-H.

Magnetic Solid-Phase Extraction of Phthalate Esters from Environmental Water Samples using Fibrous Phenyl-functionalized Fe3O4@SiO2@KCC-1

A new kind of phenyl-functionalized magnetic fibrous mesoporous silica(Fe3 O4@Si O2@KCC-1-phenyl) was prepared by copolymerization as an efficient adsorbent for the magnetic extraction of phthalate esters from environmental water samples. The obtained Fe3 O4@Si O2@KCC-1-phenyl showed monodisperse fibrous spherical morphology, fairly strong magnetic response(29 emu/g), and an abundant π-electron system, which allowed rapid isolation of the Fe3 O4@Si O2@KCC-1-phenyl from solutions upon applying an appropriate magnetic field. Several variables that affect the extraction efficiency of the analytes,including the type of the elution solvent, amount of adsorbent, extraction time and reusability, were investigated and optimized. Under optimum conditions, the Fe3 O4@Si O2@KCC-1-phenyl was used for the extraction of four phthalate esters from environmental water samples followed by high-performance liquid chromatographic analysis. Validation experiments indicated that the developed method presented good linearity(0.1-20 ng/m L), low limit of detection(7.5-29 μg/L, S/N =3). The proposed method was applied to the determination of phthalate esters in different real water samples, with relative recoveries of 93%-103.4%and relative standard deviation of 0.8%-8.3%.

QSPR Studies on lgK_(ow) and lgK_(oc) of Fluorobenzenes and Property Parameters Based on HF and DFT Calculations

Quantum chemistry parameters of 22 fluorobenzenes were computed at six levels using Hartree-Fock and DFT methods. Based on the experimental data of n-octanol/water partition coefficient （lgKow）, a three-parameter （dipole moments （μ）, zero point energy （ZPE） and free energy （G°）） quantitative correlation equation that can predict IgKow was developed using structural and thermodynamic parameters as theoretical descriptors. Similarly, based on experimental data of soil organic carbon sorption coefficient （lgKoc）, the other three-parameter （the most negative atomic net charge of molecule （q^-）, dipole moments （μ） and molecular volume （Vi）） quantitative correlation equation that can predict lgKoc was given. Quantitative correlation equations based on B3LYP/6- 311 G^＊＊ calculation were validated by VIF （variance inflation factors） and t-test and used to predict IgKow and lgKoc of a series of compounds. The result showed that the correlation and prediction ability of lgKoc equations based on three levels of HF/STO-3G, B3LYP/6-31 G^＊ and B3LYP/6- 311G^＊＊ are all more advantageous than those based on AMI.

Determination of lgK_(ow) and QSPR Study on Some Fluorobenzene Derivatives

In this paper, n-octanol/water partition coefficients （1gKow） of 15 fluorobenzene derivatives at 25 ℃ were determined with shake-flask method. Molecular structures of 19 fluorobenzene derivatives were fully optimized with B3LYP method of density functional theory （DFT） on the 6-311G^＊＊ basis set. The obtained structural parameters and thermodynamic parameters were taken as theoretical descriptors with SPSS 12.0 for windows program so as to obtain the predicted correlation model of 1gKow. Its correlation coefficient R^2 is 0.966, and the model was verified with variance inflation factor （VIF） and t vaine so that the cross-validation coefficient （q^2） was obtained as 0.931. In addition, the four homogeneous compounds were predicted.

DFT Study on Dissolvability-structure Relationship of Halogeno-benzene

Structural parameters of 36 fluorobenzene, chlorobenzene and bromobenzene compounds were computed at the B3LYP/6-31G^＊ level with DFT method. Based on the experimental data of aqueous solubility （–lgSw） and n-octanol/water partition coefficient （lgKow）, using the modified theoretical linear solvation energy relation （MTLSER） model, correlation equations that can predict –lgSw and lgKow were developed using structural parameters as theoretical descriptors. The correlation coefficients （r） of these equations are 0.9728 and 0.9967, respectively. These equations were further validated by variance inflation factors （VIF） and t-test methods and then used to predict –lgSw and lgKow values. By comparison, the correlation and predictive ability of our work are more advantageous than those calculated from valence molecular connectivity indices method and molecular topology index method.

Structure-Activity Relationships in the Chelation Activity by Derivatives of 1,2-Dithiole-3-Thiones

The structure and electronic properties of a series of biologically active dithiolethiones （1） have been calculated using semi-empirical. Multi-linear regression analysis suggests that there is a reasonable correlation between the experimental activity of the derivatives against chelation activity and calculated properties such as the HOMO energies, molar refractivity, dipole moments and experimental partition coefficient. From the derived QSAR equations the 3-Methylthio-4p-Tolyle-1,2-Dithiolylium accompanying ion （CH3SO4） and 4-para-tolyl-1,2-dithiole-3-thione （2b and 2） are predicted to show the highest activity against chelation activity, while 3-Methylthio-5p-methoxy phenyl-1,2-Dithiolylium accompanying ion （I-） （3a） is predicted to be the least active in line with the experimental results.

QSRR Study on the Relationship between the Chromatographic Capacity Factor and Lipophilicity and Structure Parameters of Halogenated Thiophenols

The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relationships between the logarithm of capacity factor lgK＇ and methanol ratio ψ were analyzed. A fair linear relationship is found between lgK＇ and ψ, and the correlation coefficients R2 of the constructed linear equations are all greater than 0.990. Relationship between the chromatographic data lgKw＇ when extrapolated to pure water and n-octanol/water partition coefficient lgKow obtained by the group contribution method has shown a good linear correlation with R2= 0.956. The structure parameters of fourteen halogenated thiophenols were calculated by using DFT, and the correlation equation of lgKw＇ and structure parameters was obtained by using SPSS, lgKw＇ = -0.409 ＋ 0.039a and R2 = 0.981, meaning that lgKw＇ is mainly determined by the polarizability α.

Energetic Study on Jordanian Olive Cake and Woody Biomass Materials

In this work, the potential for energy production in Jordan was explored using four distinct types of biomass samples (olive cakes, woods). The proximate analysis, oil content, and higher heating value were all determined experimentally and compared to other biomass previously published in the literature. The findings appear to be similar to other biomass materials utilized as solid biofuel feed-stock materials. Olive cake and wood samples have lower calorific values than anthracite coal, ranging from 25% to 40% lower. According to the results of this study, olive cake samples had the highest oil extractive content (14.5 wt%), followed by pine and beech woody samples with 8.9 wt% and 3.1 wt%, respectively. The calorific values of the biomass samples tested ranged from 18 to 22 MJ/kg, making them suitable for use as fuel. Moreover, the high volatile matter content (78% to 93%) was appropriate for chemical energy conversion by gasification or combustion process. Jordan can create roughly 8000 tons of pomace oil per year from the waste solid olive cake, based on existing results. Furthermore, the olive cake’s energy potential in Jordan is estimated to be 38 MW based on the higher heating value of the tested samples and the annual quantity of this resource. In the meantime, due to limited annual production, Jordanian firewood has the modest energy potential (2.4 MW).

Experimental investigation into the oxidation reactivity,morphology and graphitization of soot particles from diesel/n-octanol mixtures

Aiming to investigate the impacts of n-octanol addition on the oxidation reactivity,morphology and graphitization of diesel exhaust particles,soot samples were collected from a four-cylinder turbocharged diesel engine fueled with D100(neat diesel fuel),DO15(85%diesel and 15%n-octanol,V/V)and DO30(70%diesel and 30%n-octanol,V/V).All tests were conducted at two engine speeds of 1370 and 2150 r/min under a fixed torque of 125 N·m.The soot properties were characterized by thermogravimetric analyzer(TGA),transmission electron microscopy(TEM)and Raman spectroscopy(RS).The higher volatile organic fraction content,lower soot oxidation temperatures and lower activation energy from TGA results indicated that both the increasing n-octanol concentration and engine speed enhanced the soot oxidation reactivity.Additionally,quantitative analysis of TEM images showed that the soot derived from DO30 had the smallest primary particle diameters and fractal dimension,followed by those of soot produced by DO15 and D100.The RS results demonstrated that the n-octanol addition and higher engine speed led to a larger D1-FWHM(D1-full width at half maximum),A_(D1)/A_(T)(area ratio of D1 band and the total spectral)and A_(D3)/A_(T)(area ratio of D3 band and the total spectral)as well as a smaller L_(a)(crystallite width),revealing a lower degree of graphitization.Furthermore,the correlations between characterization parameters of soot properties and reactivity were nonlinear.

Inhibition mechanism of compound ethanol extracts from Wuweizi(Fructus Schisandrae Chinensis) on renal interstitial fibrosis in diabetic nephropathy model mice

OBJECTIVE：To evaluate inhibition effect and mech- anism of compound ethanol extracts from Wuweizi （Fructus Schisandrae Chinensis）, Chuanxiong （Rhi- zoma Chuanxiong） and Muli （Cocha Ostreae） （FRC） on glomerular and tubular interstitial fibrosis in streptozocin （STZ）-induced diabetic nephropathy （ND） model mice. METHODS： Twenty-seven male C57BL/6 mice were divided randomly into 3 groups： nondibetic （ND）, STZ-induced diabetic （D）, and STZ-induced diabetic that were treated with .5 g. kg1. daylof FRC by oral gavage （DFRc）, with 9 in each group. The protein ex- pressions of E-cadherin, a-smooth muscle actin （a-SMA）, Plasminogen Activator Inhibitor-1 （PAl-l） in renal tissues were investigated by Western blot- ting. The expressions of fibronectin （FN） and o-SMA were detected by immunohistochemical method. The morphological changes of renal tissues were observed under a microscope. RESULTS： Renal tissues in the DFRC group showed a lessened degree of fibrosis. Meanwhile, the expres- sions of FN, o-SMA and PAl-lwere significantly lower in the DrRc group than those in the D group （all P〈0.05）.CONCLUSION： FRC can ameliorate the DN in the C57BL/6 mice, and its mechanism may relate to in- hibition on the epithelial to mesenchymal transdif- ferentiation, endothelial-myofibroblast transition and PAl-1 expression.

Quantitative Structure-property Relationship Studies on Amino Acid Conjugates of Jasmonic Acid as Defense Signaling Molecules

Jasmonates and related compounds, including amino acid conjugates of jasmonic acid, have regulatory functions in the signaling pathway for plant developmental processes and responses to the complex equilibrium of biotic and abiotic stress. But the molecular details of the signaling mechanism are still poorly understood. Statistically significant quantitative structure-property relationship models （r^2 〉 0.990） constructed by genetic function approximation and molecular field analysis were generated for the purpose of deriving structural requirements for lipophilicity of amino acid conjugates of jasmonic acid. The best models derived in the present study provide some valuable academic information in terms of the 2/3D-descriptors influencing the lipophilicity, which may contribute to further understanding the mechanism of exogenous application ofjasmonates in their signaling pathway and designing novel analogs of jasmonic acid as ecological pesticides.

Quantitative Structure-Activity Relationship for Some Substituted Aromatic Compounds

In recent years, since thousands of new chemicals have been produced and put into the environment, it is important for us to screen the chemicals which have potential toxicity. So QSAR (quantitative structure-activity relationship) has been widely used.