Computer simulation of collision induced dissociation and isolobal analogy: The case of biotin and its analogs

Abstract

We have studied how collision induced dissociation (CID) products and associated mechanisms change when a chemical group is modified by isolobal substitution, and in particular the sequence S, O, NH and CH2. At this end, we have considered protonated biotin (vitamin B7) and corresponding oxybiotin, N-biotin and C-biotin, which have the same structures except for one chemical group (the S in biotin which is substituted with the aforementioned isolobal ones). Collisional simulations with Ar were performed to model CID fragmentations and to have direct access to related mechanisms. Simulations show that the CID fragmentation of the four compounds are similar and the resulting fragments involve in a similar way the isolobal groups. Details on the mechanisms obtained from simulations are reported and discussed. This result shows that it is possible to predict, in principle and with a reasonable confidence, mass spectra of unknown molecules based on mass spectrum of a known one when isolobal modifications are done.