Two new dimeric benzofuran diastereomers from the roots of Eupatorium heterophyllum

A pair of novel epimers of benzofuran dimers (1 and 2), together with two known compounds that were considered to be their monomeric precursor, was isolated from the methanol extract of the roots of Eupatorium heterophyllum. The structures of 1 and 2 were elucidated by 1D and 2D NMR, HRFABMS, and DFT calculations of their NMR data, including DP4+ and CP3 analysis, which assisted in determining of their relative configurations. The absolute configurations of the dimers were determined by TDDFT cal-culations of their ECD spectra. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Two novel epimers of benzofuran dimers (1 and 2), along with their monomeric precursor, were isolated from the roots of Eupatorium heterophyllum. The structures and configurations of the dimers were determined using NMR, HRFABMS, and DFT calculations. The absolute configurations were confirmed using TDDFT calculations of the ECD spectra.