Do they identify the compounds by comparison of the fragmentation patterns with a database?

Any nucleophilic substitution catalyst should fit, e.g. proteases which are important for digestion of proteins in the digestive system or for meat tenderisation.

The confusion arises from 'catalyst' being used in two different ways:

1) Basic textbook definitions: enabling elementary step of specific substrate X --> specific product Y (e.g. a specific stereoisomer)

2) Favouring one of multiple products (Y, Y', Y''...) that can be formed from X

'Stereoselective catalysis' is making a statement about 4 reaction rates, that the rate of formation of a R-stereocenter, k_cat(R) is larger than any of k_cat(S), k_uncat(R), k_uncat(S)

Catalysis refers to a specific elementary step that produces a specific product (e.g. an enantiomer). E.g. reduction to form a (+)-alcohol can be catalyzed by an enzyme, but that doesn't necessarily imply anything about the k_cat/k_uncat for formation of the (-)-alcohol or any racemization process.

Hi, my Google Scholar profile is at scholar.google.com/citations?us....

Thanks!