Cytotoxic hexadepsipeptides and anti-coronaviral 4-hydroxy-2-pyridones from an endophytic sp.

Three new hexadepsipeptides (-), along with beauvericin (), beauvericin D (), and four 4-hydroxy-2-pyridone derivatives (-) were isolated from the endophytic fungus sp. CPCC 400857 that derived from the stem of tea plant. Their structures were determined by extensive 1D and 2D NMR, and HRESIMS analyses. The absolute configuration of hexadepsipeptides were elucidated by the advanced Marfey's method and chiral HPLC analysis. Compounds , and - displayed the cytotoxicity against human pancreatic cancer cell line, AsPC-1 with IC values ranging from 3.45 to 29.69 μM, and and also showed the antiviral activity against the coronavirus (HCoV-OC43) with IC values of 13.33 and 6.65 μM, respectively.