Valencia C.

[2α(2S,3S,4R,6R),3β,5α]-14-Hydroxy-19-oxo-3,2-[(tetrahydro-3,4-dihydroxy-6-methyl-2H-pyran-2,3-diyl)bis(oxy)]card-20(22)-enolide dihydrate (calactin), C₂₉H₃₉O₉.