Combined use of tandem mass spectrometry and computational chemistry to study 2H-chromenes from Piper aduncum

Author(s)

Souza, Amauri Alves ^[1] ; Vessecchi, Ricardo ^[2] ; Castro-Gamboa, Ian ^[1] ; Furlan, Maysa ^[1]

Affiliation

^[1] Univ Estadual Paulista UNESP, Inst Quim, Rua Prof Francisco Degni 55, BR-14800900 Araraquara, SP - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Journal of Mass Spectrometry; v. 54, n. 7, p. 634-642, JUL 2019.
• Web of Science Citations: 1

Abstract

Natural 2H-chromenes were isolated from the crude extract of Piper aduncum (Piperaceae) and analyzed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) applying collision-induced dissociation. Density functional theory (DFT) calculations were used to explain the preferred protonation sites of the 2H-chromenes based on thermochemical parameters, including atomic charges, proton affinity, and gas-phase basicity. After identifying the nucleophilic sites, the pathways were proposed to justify the formation of the diagnostic ions under ESI-MS/MS conditions. The calculated relative energy for each pathway was in good agreement with the energy-resolved plot obtained from ESI-MS/MS data. Moreover, the 2H-chromene underwent proton attachment on the prenyl moiety via a six-membered transition state. This behavior resulted in the formation of a diagnostic ion due to 2-methylpropene loss. These studies provide novel insights into gas-phase dissociation for natural benzopyran compounds, indicating how reactivity is correlated to the intrinsic acid-base equilibrium and structural aspects, including the substitution pattern on the aromatic moiety. Therefore, these results can be applied in the identification of benzopyran derivatives in a variety of biological samples. (AU)

• FAPESP's process: 13/07600-3 - CIBFar - Center for Innovation in Biodiversity and Drug Discovery
• Grantee: Glaucius Oliva
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/50265-3 - Distribution and metabolism of natural and synthetic xenobiotics: from the comprehension of reactional process to tissue imaging generation
• Grantee: Norberto Peporine Lopes
• Support type: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 17/15014-8 - MS and NMR predict datasets of benzopyrans from Piperaceae species for new insights into metabolomic studies
• Grantee: Amauri Alves de Souza Júnior
• Support type: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 14/22239-8 - Metabolomic studies of Piperaceae species by MS and NMR: development of analytical methods and dereplication strategies for exploitation of substances of therapeutic interest
• Grantee: Amauri Alves de Souza Júnior
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/23604-1 - Computational chemistry: a tool to studies of mass spectrometry, reactivity and fragmentation/reaction mechanisms of organic compounds
• Grantee: Ricardo Vessecchi Lourenço
• Support type: Regular Research Grants