Constituents from the Polar Extract of Pisolithus arhizus and Their Anti-inflammatory Activity.

The phytochemical study of the Pisolithus arhizus fruiting body methanol extract led to the isolation of six new triterpenoids ( 1 - 6 ) and one new naphthalenoid pulvinic acid derivative ( 7 ), together with five known compounds, including norbadione A ( 8 ). Their structure was established from 1D and 2D NMR spectroscopy and HRESIMS analyses. The absolute configuration of the triterpenoids was determined by circular dichroism. The two pulvinic acid derivatives 7 and 8 , showing the highest activity in modulating IL-6 secretion, were tested for their effect on COX-2, STAT3, and p-STAT3 proteins; both compounds were able to downregulate p-STAT3.