Biodegradation Prediction Worksheet: Saccharine

	Saccharine Non-nutritive sweetener

Please draw proposed bacterial pathway(s) for the microbial biodegradation of Saccharine, then answer the questions below.

Compound names in bold feed into known biodegradation pathways.

1. What was the first thing you focused on to guide your development of a pathway(s)?

Initial thoughts: One of the rings must be cleaved first. The five membered ring contains bonds susceptable to hydrolytic cleavage. Hydrolytic bond cleavage reactions can generate an intermediate; a disubstituted benzene that is further metabolized by known reactions.

2. How did you proceed after your initial focus point?

Following the hydrolytic cleavages, I predict that a dioxygenation followed by a dehydrogenation or elimination will set up the six-membered ring for cleavage. It is reasonable that this dioxygenation will also remove one of the side groups. Both possible removals are shown

3. How might this expert reasoning be captured for use in a computerized predictive system?