New metabolites from Lepista sordida through liquid fermentation and their herbicidal activities

Two new chlorinated sesquiterpenes, lepistatins d-E (1–2) and one new trinoreudesmane sesquiterpenoid (6) were discovered in the culture broth of Lepista sordida, along with six known compounds. The known compounds include two chlorinated sesquiterpenes, lepistatins A-B (3–4), one eudesmane-type sesquiterpenoid pterodontriol B (5), two trinoreudesmane sesquiterpenoids (7–8), and one diketopiperazine diatretol (9). Their structures were identified by analyzing their physicochemical properties, including NMR, HREIMS, UV, IR, circular dichroism, and single-crystal X-ray crystallography. Notably, in the germination inhibition test of Arabidopsis thaliana seeds, compounds 5 and 9 exhibited significant inhibitory activity, with IC₅₀ values of 88.48 μg/mL and 75.03 μg/mL, respectively. The discovery of these novel chlorinated sesquiterpenes and the significant bioactivity of the identified compounds underscore the potential of L. sordida as a source of new herbicidal agents.