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

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.