Herbicidal Sorbicillinoid\nAnalogs Cause Lignin Accumulation\nin Aspergillus aculeatus TE-65L

Five new sorbicillinoid derivatives,\nincluding (±)-aspersorbicillin\nA [(±)-<b>1</b>], a pair of enantiomers at C-9, and aspersorbicillins\nB–D (<b>2</b>–<b>4</b>), together with two\nknown analogs (<b>5</b> and <b>6</b>) were isolated from\nthe endophytic fungus Aspergillus aculeatus TE-65L. Their structures including absolute configurations were\ndetermined by detailed spectroscopic analyses and electronic circular\ndichroism calculations. The herbicidal activity of sorbicillinoids\non the germ and radicle elongation of various weed types was reported\nfor the first time. Compound <b>1</b> displayed significant\nherbicidal activity against <i>Eleusine indica</i> germ\nelongation (IC<sub>50</sub> = 28.8 μg/mL), while compound <b>6</b> inhibited radicle elongation (IC<sub>50</sub> = 25.6 μg/mL).\nBoth were stronger than those of glyphosate (66.2 and 30.9 μg/mL,\nrespectively). Further transcriptomic and LC-MS/MS metabolomic analysis\nindicated that <b>6</b> induced the transcriptional expressions\nof genes related to the lignin biosynthetic pathway, resulting in\nlignin accumulation. Transmission electron microscopy confirmed the\ncell wall thickening of seeds treated with <b>6</b>, suggesting\nweed growth inhibition. This study reveals new lead compounds for\nfabricating natural herbicides and expands the agricultural use of\nsorbicillinoid analogs.