Benzophenones from an Endophytic Fungus, Graphiopsis chlorocephala, from Paeonia lactiflora Cultivated in the Presence of an NAD+‑Dependent HDAC Inhibitor

Graphiopsis chlorocephala was separated from the surface-sterilized healthy leaves of Paeonia lactiflora (Paeoniaceae) and cultivated with nicotinamide (an NAD+-dependent HDAC inhibitor). The culture conditions significantly enhanced secondary metabolite production in the fungus and led to the isolation of a structurally diverse set of new benzophenones, cephalanones A–F (1–6), and a known 2-(2,6-dihydroxy-4-methylbenzoyl)-6-hydroxybenzoic acid (7). The structures of 1–6 were determined from NMR data, single crystal X-ray diffraction, and chemical transformations.