dihydrogranaticin

(1R,4S,13R)-1,3,4,6,7,9,10,11-Octahydro-4α,5,12,13-tetrahydroxy-3α,7α-dimethyl-6,11-dioxo-1,4-ethanonaphtho[2,3-c:6,7-c']dipyran-9β-acetic acid