Chevalone B is a meroterpenoid metabolite isolated from the fungus, Eurotium chevalieri, by Thai researchers in 2011. The pentacyclic ring system of chevalone B is formed by closure of ring D via coupling of the 4-hydroxy pyrone tautomer to the exo-alkene. This gives chevalone B a distinctly different UV spectrum from chevalone C which couples through the 2-hydroxypyrone isomer. Chevalone B has weak activity against some tumor cell lines.