Talarolactones A-G, ?-Pyrone Dimers with Anti-inflammatory Activities from Talaromyces adpressus, and Their Biosynthetic

Talarolactones A-G (1-7), seven novel alpha-pyrone adducts with unprecedented scaffolds, together with two pairs of alpha-pyrone monomers [(+/-)-8 and (+/-)-9)] were isolated from Talaromyces adpressus. Compounds 1-7 are highly modified alpha-pyrone dimers with a 4,7,7,8-tetrasubstitued 5,6,7,8-tetrahydro-2H-chromen-2-one. Compounds 5 and 6 possessed a significant NO production inhibitory effect, with IC50 values of 2.3 +/- 0.1 and 3.7 +/- 0.3 mu M, respectively. Plausible biosynthetic pathways were proposed and supported by the results of heterologous expression experiments.

Automated summary

Seven novel alpha-pyrone adducts, Talarolactones A-G, were isolated from Talaromyces adpressus, along with two pairs of alpha-pyrone monomers (+/-)-8 and (+/-)-9. Compounds 5 and 6 exhibited significant inhibition of NO production. Plausible biosynthetic pathways were proposed and supported by heterologous expression experiments.