VerbenalinosidesA and B, Two Iridoid–PhenylethanoidGlycoside Conjugates from Verbena officinalis and Their Hepatoprotective Activity

Two novel iridoid–phenylethanoid glycoside heterodimers, verbenalinoside A (<b>1</b>) and B (<b>2</b>), along with two known precursors, verbenalin (<b>3</b>) and verbascoside (<b>4</b>) were isolated from the dry aerial parts of Verbena officinalis. Verbenalinoside A (<b>1</b>) possesses a new 5/6/6/6 core fused by the double bond of iridoid and phenolic hydroxyl groups of the phenylethanoid unit. Verbenalinoside B (<b>2</b>) is a conjugate of verbenalin (<b>3</b>) and verbascoside (<b>4</b>) by an ether bond. The structures of these compounds were elucidated through the comprehensive analysis of spectroscopic data, supported by electronic circular dichroism (ECD) calculations and DP4 plus NMR calculations. Biological assay results showed that <b>1</b>–<b>4</b> can concentration-dependent rescue the ethanol-induced hepatotoxicity in LO2 and HepG2 cells, indicating that <b>1</b>–<b>4</b> should be potential hepatoprotective constituents of V. officinalis.