Absolv

Absolv is a software tool from ACD/Labs for calculating Abraham solvation parameters and solvation-related properties directly from chemical structure. It is intended for researchers in pharmaceutical, environmental, and biological chemistry who need to characterize solute properties such as hydrogen bonding potential, polarity, and partitioning behavior. The tool was developed in collaboration with Prof. M. H. Abraham, the author of the Abraham general solvation model.

Absolv calculates the quantitative solute descriptors defined by the Abraham model: A (hydrogen bonding acidity, α2H), B and BO (hydrogen bonding basicity parameters, β2H and β2O), S (polarity/polarizability, π2H), L (gas-phase to hexadecane partitioning coefficient, logL16), V (McGowan volume characteristic, Vx), and E (excessive molar refraction, R2). These parameters are used in environmental chemistry to estimate the behavior of new compounds and are key determinants of many biological properties.

Core Calculation Capabilities

• Predict all seven Abraham solvation parameters (A, B, BO, E, S, L, V) from structure
• Calculate solvent-solvent or gas-solvent partition coefficients using more than 100 predefined Abraham-type equations
• Estimate solute partitioning in biological systems, such as water-skin and water-cell systems
• Define custom partition coefficient equations, and edit or delete existing ones
• Access a database of Abraham coefficients for more than 5,000 compounds compiled by Prof. M. H. Abraham et al., including compound name, CAS registry number, literature values, and references

Structure Input Options

• Draw structures directly within the application
• Copy and paste from third-party structure drawing packages
• Enter SMILES strings or InChI codes
• Import MOL, SK2, SKC, or CDX files
• Search by compound name using the built-in dictionary

Visualization and Result Assessment

• Color-mapping of contributing atoms on the structure for each Abraham solvation parameter
• Reliability index to evaluate prediction accuracy
• Display of the five most similar structures in the training library, with experimental values and literature references
• User-defined label colors in spreadsheet view to identify favorable and unfavorable compounds in a library

Library and Batch Analysis

• Calculate solvation parameters for libraries of compounds
• Sort results by ascending or descending values
• Filter results numerically
• Create scatter plots and rank compounds
• View previously calculated values in the history
• Report results to PDF or copy into external applications

Workflow Steps

1. Draw or import a chemical structure
2. Review predicted solvation parameters, partition coefficients, and reliability information
3. Export results to PDF or copy into another application

Absolv is available in three deployment configurations: a desktop thick client with a full graphical user interface; a batch mode for processing tens of thousands of compounds with minimal user intervention, compatible with Windows and Linux and supporting integration with tools such as Pipeline Pilot; and a browser-based thin client via the Percepta Portal, which supports KNIME integration and can be hosted on a corporate intranet or in the cloud on Linux or Windows.