Trichoderma polysporum (Link) Rifai HZ-31 fermentation broth was separated and purified by extraction, column chromatography, and high-performance liquid chromatography. Four monomer compounds with strong herbicidal activity were obtained: p-hydroxyphenyl-2,3-dihydroxypropyl ether, o-hydroxy-3-carbonyl-1-phenylpropanol, 1,8-propanediol o-xylene, and 2-3-dihydroxypropyl propionate. The biological activity verification test indicated that the four monomer compounds could inhibit the germination of wild oat (Avena fatua L.) and canola (Brassica napus L.) seeds. Of the four, compound 3 (1,8-propanediol o-xylene) had obvious inhibitory effects on the germination of A. fatua and B. napus seeds, with inhibition rates of 83.33% and 86.67%, respectively. Therefore, the identification of this monomer compound lays a foundation for the further development of a novel microbial herbicide by directly utilizing it and developing new derivatives with herbicidal functions as lead compounds.
