55256-55-8 5H-Furo(3',2':4,5)furo(3,2-b)xanthen-5-one, 3a,12a-dihydro-6-hydroxy-9-(3-hydroxy-3-methylbutyl)-4-methoxy-, (3aS-cis)- Austocystin C BRN 1274590 CCRIS 2007