Excerpts from the UM-BBD Guided Pathway Prediction starting from the compound benzyl alcohol, see text. (A) First step, showing six possible biotransformations. The user proceeds by selecting ‘next’ to indicate the next compound to be transformed, or ‘rule’ to see the biotransformation (bt) rule for that transformation, including, where possible, a link to a UM-BBD reaction with bibliographic reference. (B) Last step in one predicted pathway branch. The compounds in the pathway are numbered 1–6, in pathway order. Additional rules are needed to handle the degradation of the last compound.