Talaramide A, an unusual alkaloid from the mangrove endophytic fungus Talaromyces sp. (HZ-YX1) as an inhibitor of mycobacterial PknG

Abstract

An unusual alkaloid, talaramide A (1), was obtained from the mangrove endophytic fungus Talaromyces sp. (HZ-YX1). The structure of 1 was established by analysis of NMR spectroscopic data, X-ray diffraction data, and electronic circular dichroism (ECD) spectra. Talaramide A (1) is the second example of an alkaloid that possesses a unique oxidized tricyclic system. A possible biosynthetic pathway for 1 was proposed. Compound 1 showed promising inhibition of mycobacterial PknG activity with an IC₅₀ value of 55 μM.