Gelidoside

1H,3H-Pyrano[3,4-c]pyran-1-one,5-ethenyl-4,4a,5,6-tetrahydro-4a-hydroxy-6-[[2,3,6-tri-O-acetyl-4-O-[3-(b-D-glucopyranosyloxy)-2-hydroxybenzoyl]-b-D-glucopyranosyl]oxy]-, (4aR,5R,6S)-(9CI)