Merohyperins A–C, meroterpenes from the leaves of Hypericum chinense

Abstract

Two new C15 meroterpenes with unprecedented carbon skeletons, merohyperins A (1) and B (2), were isolated from the leaves of Hypericum chinense together with a new C13 meroterpene, merohyperin C (3). The structures of 1–3 were elucidated on the basis of spectroscopic analyses, chemical conversion, and calculations of the NMR spectra. Merohyperins A (1) and B (2) have a γ-lactone moiety and a tetrahydrofuran moiety, respectively. Merohyperin C (3) was obtained as a separable epimeric mixture and assigned as a decarbonyl analog of the known meroterpene, hyperolactone A.