Significant Molecular Descriptors Research Articles

A multiple linear regression and partial least squares study of flavonoid compounds with anti-HIV activity

The molecular orbital semi-empirical method PM3 was employed to calculate a set of molecular properties (variables or descriptors) of 21 flavonoid compounds with anti-HIV activity. The correlation between biological activity and structural properties was obtained by using the multiple linear regression and partial least squares methods. The model obtained showed not only statistical significance but also predictive ability. The significant molecular descriptors related to the compounds with anti-HIV activity were: electronegativity (χ) and the charges on atoms C3 and C7 (Q3 and Q7, respectively). These variables led to a physical explanation of electronic molecular property contributions to HIV inhibitory potency.

Relationships of Critical Temperatures to Calculated Molecular Properties

Quantitative structure−property relationships (QSPR) of critical temperatures with small numbers of physically significant molecular descriptors are developed using the CODESSA (comprehensive descriptors for structural and statistical analysis) technique. A highly significant one-parameter model correlates to the critical temperatures of 76 hydrocarbons at R2 = 0.953. A successful three-parameter model for 165 diverse compounds (R2 = 0.955) reveals fundamental structural influences on liquid-state properties.