Quantitative retention-biological activity relationship study by micellar liquid chromatography.

Area of Science:

• Analytical Chemistry
• Chromatography
• Medicinal Chemistry

Background:

• Previous work established micellar liquid chromatography (MLC) for predicting octanol-water partition coefficients.
• Quantitative structure-activity relationship (QSAR) models often require multiple molecular descriptors.
• Biological activity prediction is crucial for drug discovery and environmental science.

Purpose of the Study:

• To conduct the first quantitative retention-activity relationship (QRAR) study using MLC for phenolic compounds.
• To correlate MLC retention factors with the biological activity of para-substituted phenols.
• To compare the predictive power of MLC retention parameters with conventional molecular descriptors.

Main Methods:

• Employed micellar liquid chromatography (MLC) to analyze 26 para-substituted phenols.
• Measured the capacity factor (k') in MLC as the primary retention parameter.
• Correlated k' with bioactivity (log 1/C, 50% inhibitory growth concentration).

Main Results:

• Achieved excellent correlation between MLC capacity factor (k') and phenol bioactivity (log 1/C).
• A single MLC retention parameter effectively described bioactivity, unlike traditional QSAR requiring log P(ow), pKa, and R.
• A hybrid micellar system with 10% 2-propanol provided the best bioactivity estimation.
• MLC retention parameters implicitly capture both hydrophobic and electronic interactions.

Conclusions:

• MLC-based QRAR is a powerful and simpler alternative to QSAR for predicting phenolic bioactivity.
• The amphiphilic nature of surfactants in MLC systems integrates multiple interaction types into a single parameter.
• Optimized chromatographic conditions (hybrid system, pH, stationary phase) enhance predictive accuracy.