Phenyl- O -β- d -ribofuranoside Derivatives from the Plant Endophytic Fungus Neofusicoccum sp. LZUC-S1 and Their Herbicidal Activity

Abstract

Seven novel phenyl-O-β-d-ribofuranoside derivatives (1–7), along with four known naphthalenones (8–11), were isolated from the endophytic fungus Neofusicoccum sp. LZUC-S1 using a bioactivity-guided isolation. Their chemical structures were elucidated through an integrated analysis of IR, NMR, and HRESIMS data, and verified by crystallography and degradative experiments. Compounds 1–7 represent the first reported instance of phenyl ribosides. The phytotoxic potency of the purified metabolites was assessed against seedlings of Chloris virgata and Portulaca oleracea. The results demonstrated that phenyl-O-β-d-ribofuranoside derivatives showed higher herbicidal activity than naphthalenones. Notably, compounds 1 and 2 demonstrated potent herbicidal activity against both weed species at 100 mg/L, exhibiting efficacy superior to the commercial herbicide glyphosate at the same concentration. Preliminary mechanism studies indicated that the phenyl-O-β-D-ribofuranoside derivatives probably exert their herbicidal effect by disrupting energy metabolism, specifically through the inhibition α-amylase functionality. These findings expand the structural diversity of phenolic glycosides and offer valuable leads for developing new fungal-derived herbicides.