Biotransformation refers to a biochemical modification process of xenobiotics inside the living system involving the utilization of special enzymes. In pharmaceutical industry, this term is equivalent to ‘drug metabolism’. Drug metabolism influences drug-like properties of prospective drug molecules which may contribute to the production of metabolites with drastically altered pharmacological and toxicological parameters. The recognition of SOMs containing specific atom(s) in the molecule which are oxidized by CYP isozymes, provides knowledge for the design and optimization of potent candidates in early stage. Cytochrome P450s are accountable for more than 90% of the pharmaceutical drugs to undergo phase I metabolism. Therefore, having prior knowledge about the metabolic liabilities of prospective drug candidates could have important ramifications in drug discovery process. The primary, secondary and tertiary predicted SOMs for selected WS phytoconstituents versus FDA-approved standard reference drugs have been shown in Figure 4. The figure is a graphical output for a combination of all nine isozymes of cytochrome P450. The results indicated that WS phytoconstituents and standard reference drugs were predicted to possess SOMs likely to undergo phase I metabolism.