Polycyclic meroterpenoids, talaromyolides E − K for antiviral activity against pseudorabies virus from the endophytic fungus Talaromyces purpureogenus
Xun Cao, Yutong Shi, Shanhu Wu, Xiaodan Wu, Kuiwu Wang, Hongxiang Sun, Shan He, Jeroen S. Dickschat, Bin Wu
Anti-pseudorabies virus (PRV) activity-guided isolation of an endophytic fungus Talaromyces purpureogenus resulted in seven rare polycyclic meroterpenoids talaromyolides E–K, together with two known compounds preaustinoid and austinolide. Their structures and absolute configurations were elucidated by HRESIMS, extensive NMR spectroscopic analyses, time-dependent density functional theory (TDDFT) calculations of ECD spectra, and single crystal X-ray diffraction. Talaromyolides I and K showed a dose-dependent inhibition of PRV, of which talaromyolide K had the most potent inhibition effect rate (60.11%), blocking effect rate (53.24%) and killing effect rate (62.16%) at a concentration of 50 μg/mL. A plausible biosynthetic pathway for talaromyolides E–K was proposed.
Circular dichroism, Absolute configuration, Natural products, Biochemistry