Collision-Induced Dissociation Analysis of Brevianamide A and C in Electrospray Ionization Mass Spectrometry

Author(s)

de Oliveira, Ana Ligia L. ^[1] ; Vessecchi, Ricardo ^[2] ; Lopes, Norberto P. ^[1] ; Debonsi, Hosana M. ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Fis & Quim, NPPNS, BR-14040903 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, BR-14040901 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 26, n. 4, p. 822-827, APR 2015.
• Web of Science Citations: 0

Abstract

Brevianamides A and C are isomeric cyclic peptides with several reported biological activities, isolated from diverse microorganisms. Currently, there has been no previous investigation of brevianamide fragmentation utilizing electrospray ionization mass spectrometry (ESI-MS). In this work experiments were carried out in the positive mode using two different spectrometers (low and high resolution) with an ESI source. Computational chemistry studies helped identify the protonation sites based upon atomic charges, proton affinities and molecular orbitals, computed using the B3LYP/6-31++G (d,p) model. The data suggests that the presence of the allylic position of the lactamic N in brevianamides C governs its fragmentation pathways. Distinguishing between brevianamides A and C using positive ion electrospray tandem mass spectrometry (ESI(+)MS/MS) is made possible by the spectral difference of each isomer and offers an alternative to other spectroscopic techniques. (AU)

• FAPESP's process: 09/51812-0 - Development of a platform for the study of in vitro and in vivo metabolism of natural products, a need for pre-clinical testing system
• Grantee: Norberto Peporine Lopes
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants