115219-90-4 Cyclobut(6,7)indeno(4,5-b)pyran-3-carboxylic acid, 2,5,6,6a,6b,7,8,9,9a,9b-decahydro-6a,8,8-trimethyl-2,5-dioxo-, (6aR-(6aalpha,6bbeta,9abeta,9balpha))- Lentinellic acid