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Internet Electronic Journal of Molecular Design - IEJMD, ISSN 1538-6414, CODEN IEJMAT
| ABSTRACT - Internet Electron. J. Mol. Des. February 2006, Volume 5, Number 2, 102-115 |
Prediction of Gas Chromatographic Retention Indices of Methylalkanes
Produced by Insects
Fengping Liu, Yizeng Liang, and Chenzhong Cao
Internet Electron. J. Mol. Des. 2006, 5, 102-115
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Abstract:
The methylalkanes studied in this work are produced by insects
and are usually considered to be waterproofing agents present on
the cuticle. A quantitative structure-retention relationships (QSRR)
study has been carried out on a set of 177 methylalkanes by using
molecular descriptors. A small number of molecular descriptors
proposed by our team were used to establish a QSRR model.
Multiple Linear Regression (MLR) analysis has been carried out to
derive the best QSRR model. The model was supported by leave-one-out
cross validation. Additional validation was performed on
an external data set consisting of 30 methylalkanes. The best
QSRR models for 177 methylalkanes are obtained with five
structural descriptors, with R2 = 0.9999 and SEC = 4.6. The QSRR
model contains the molecular tightness index (MTI), the
polarizability effect index (PEI), the number of carbon atom in the
molecule backbone (NC), the number of the 2-methyl group (N2-CH3)
and the number of the methyl group attached to the carbon
backbone (NCH3). Good results are obtained for the external data
set with R2 = 0.9999 and SEP = 3.7. Compared with an earlier
model for the prediction of these compounds, our model exhibits
slightly improved performance, and the generated molecular
descriptors have explicit physical meaning and easy to calculate.
The model equations developed by present paper can be used to
predict the chromatographic retention index of alkanes and support
the identification of substances in cases the retention data for
candidate structures are not available.
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