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Prediction of the Aerobic Biodegradability of Chlorinated Aromatic Compounds Using QSBR

LIU Chang-ning, FENG Chang-jun

Abstract （541）

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The molecular electronegativity distance vector(MD) of chlorinated aromatic molecules were calculated based on the molecular topological theory. The optimal two-parameter(M25, M21) QSAR model of aerobic biodegradability(Km, dm ^-3•(μmol•h) ^-1)for 12 above compounds was set up by leaps-and-bounds regression(LBR). The traditional correlation coefficient (R2) and the cross-validation correlation coefficient (R2cv) of leave-one-out (LOO) are 0.950 and 0.902, respectively. The result demonstrates that the model is better reliable and has good predictive ability from the point of view of statistics. Form the two parameters(M25, M21) of the model, it can be seen that the molecular structure characteristics of two-dimensional (such as the structural fragment —OH, —C—, —Cl)are the decisive factors to affect the aerobic biodegradability. 

2012, 25 (5): 6-9. DOI: 10.3969/j.issn.1006-396X.2012.05.002

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Prediction of Bioconcentration Factors of Nonionic

FENG Chang-jun，TANG Zi-qiang，YANG Wei-hua，MU Lai-long

Abstract （886）

PDF （243KB）（521）

The Hall＇s electrotopological state indices （EIk ） for atom type have been calculated for165 nonionic organic compounds based on the characteristics of atom types．A satisfactory relationship between bioconcentration factor （lgBCF） and EIk of 122 nonionic organic compounds by Leaps－and－Bounds regression and Leave－One－Out cross validation （LOO） can be expressed．The model has an overall robustness，which could provide logical prediction for the lgBCF of 43 nonionic organic chemicals by means of Jackknife testing． The result shows that the model can be used to estimate and predict the BCF of nonionic organic compounds．

2009, 22 (1): 31-35.

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The QSPR Research of Photolysis Half-Lives of PCDD/Fs Adsorbed on Spruce Needles Foliage

DU Xi-hua, FENG Chang-jun

Abstract （272）

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The quantitative relationships between photolysis half-lives（t _1/2） and molecular structures of dioxins (PCDD/Fs) was described. Atomic characteristic value δi of PCDD/Fs were defined. The topological descriptor Km and orientating group bedeck index mXJ were acquired by the technique of molecule graphics and AM1. The QSPR model，which could predict photolysis half-lives of PCDD/Fs adsorbed to spruce needle surfaces，were established using the index，the regression equations was proposed with mean deviation was 0.056. A modified leave-one-out procedure test was performed to validate model robustness，predicted the t _1/2 of other some PCDD/Fs molecules by the regression equation，and the error analysis were discussed. The results show that the model developed can make a better agreement between predicted and observed values of t _1/2.

2008, 21 (2): 29-32.

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Correlativity Research Between Topological Dyeing Index and Gas Chromatography Retention Index of Fatty Esters

DU Xi-hua, FENG Chang-jun

Abstract （280）

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In order to study on the QSRR of fatty esters, 100 fatty esters were optimized by semiempirical calculations AM1，then calculated them by quantum chemistry algorithnl and the technique of molecule graphics and AM1 to acquire the Kier index and Kappa shape index. Based on the molecular topological thoery， introduced a modified topological dyeing index ^mL and use these index to study on the correlational relationship of gas chromatography retention index of 100 esters，the correlation coefficient was 0.999 and the mean relative error was 1.02%. These models can better indicate the change rule of retention indices for the fatty esters，and the QSRR models have high relative coefficients，good stability and good predictability.

2008, 21 (1): 16-20.