Skeleton‐Rearranged Prenylated Acetophenone Dimers With Anti‐Renal Fibrosis Activity From Maclurodendron oligophlebium

ABSTRACT

Five novel pairs of dimeric prenylated acetophenone (PAP) enantiomers, (+)‐ and (−)‐macluphlebones A–E, were isolated from an ethanolic extract of the bark of Maclurodendron oligophlebium , a plant of ethnopharmacological importance. Their structures were elucidated by comprehensive spectroscopic analyses, single‐crystal x‐ray diffraction, and quantum chemical nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD) calculations. Among them, macluphlebones A–C feature three unprecedented carbon skeletons, each possessing a highly oxygenated cyclopenta[ b ]chromene core, while macluphlebones C–E represent the first examples of PAPs containing a primary enamine group. Putative biosynthetic pathways involving skeletal rearrangement and degradation processes are proposed to account for the formation of these unique scaffolds. Biologically, some isolates exhibited significant, dose‐dependent anti‐renal fibrosis effects at noncytotoxic concentrations, underscoring their potential value in antifibrotic drug research.