Try searching for...
SCFBio, IIT Delhi
Formula: C15H12O6 | Mol. Weight: 288.25 g/mol
IUPAC: 1,3-dihydroxy-5,6-dimethoxyxanthen-9-one
COC1=C(C2=C(C=C1)C(=O)C3=C(C=C(C=C3O2)O)O)OC