Study on 2-arylbenzo[b]furans from Itea omeiensis and their fragmentation patterns with Q-Orbitrap mass spectrometry

Abstract

One new 2-arylbenzo[b]furan named iteafuranal F (1) as well as two known analogues (2–3) were isolated from the 95% EtOH extract of aerial parts of Itea omeiensis. Their chemical structures were constructed based on extensive analyses of UV, IR, 1D/2D NMR and HRMS spectra. Antioxidant assays revealed significant superoxide anion radical scavenging capacity of 1 with IC₅₀ value of 0.66 mg/mL, which was comparable to the efficiency of positive control of luteolin. In addition, the preliminary MS fragmentation patterns in negative ion mode were established to distinguish 2-arylbenzo[b]furans with C-10 in different oxidation states: the characteristic loss of CO molecule [M-H-28]^- was observed for 3-formyl-2-arylbenzo[b]furans, and the loss of CH₂O fragment [M-H-30]^- for 3-hydroxymethyl-2-arylbenzo[b]furans, and the loss of CO₂ fragment [M-H-44]^- for 2-arylbenzo[b]furan-3-carboxylic acids.

Graphical Abstract

Keywords:

• Itea
• Itea omeiensis
• 2-arylbenzo[b]furans
• fragmentation patterns
• antioxidant capacity

Disclosure statement

The authors declared no potential conflict of interest.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China (81860764), the Department of Science and Technology of Guizhou Province for Basic Research (QKHJC[2019]1036), the Innovation and Entrepreneurship Program for High Level Talents of Guizhou Province (GCCZYZZ (2021)07), the 1000 Talent Plan (Qian Cengci) of Guizhou Province (ZQ2018002), and the Special Project for Academic Seed Training and Innovation Exploration of Guizhou University of Traditional Chinese Medicine (QKHPTRC-[2017]5735-23).