Sarcglabates A/B, Aromatized Pentanor Lindenane Sesquiterpenoid Dimers from <i>Sarcandra glabra</i>

Sarcglabates A-F (<b>1</b>-<b>6</b>), six lindenane sesquiterpenoid dimers possessing two unprecedented skeletons, were isolated from <i>Sarcandra glabra</i>. Their structures were thoroughly determined using HR-MS, NMR, and ECD and verified by single crystal X-ray diffraction. Structurally, compounds <b>1</b>-<b>2</b> represent the first examples of aromatized pentanor lindenane dimers featuring a critical 6/5/6 skeleton with a rare benzene ring, which formed via a plausible intramolecular nucleophilic reaction and aromatization assisted departure of a penta-carbon fragment. Lindenanes <b>3</b>-<b>5</b> were fused through rare tetrahydrofuran by nucleophilic addition. Compounds <b>1</b>-<b>6</b> were assessed through screening the inhibitory effect on the inflammatory factor IL-1β, with <b>6</b> further inhibiting the progression of inflammation by suppressing the activation of P65.