(2R)-3-[(2S,6R,8S,11R)-2-[(E,2R)-4-[(2S,2'R,4R,4aS,6R,8aR)-4-hydroxy-2-[(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undecan-2-yl]butyl]-3-methylidenespiro[4a,7,8,8a-tetrahydro-4H-pyrano[2,3-e]pyran-6,5'-oxolane]-2'-yl]but-3-en-2-yl]-11-hydroxy-4-methyl-1,7-dioxaspiro[5.5]undec-4-en-8-yl]-2-hydroxy-2-methylpropanoic acid (2R)-3-[(2S,6R,8S,11R)-2-[(E,1R)-3-[(2S,2'R,4R,4aS,6R,8aR)-4-hydroxy-2-[(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undecan-2-yl]butyl]-3-methylene-spiro[4a,7,8,8a-tetrahydro-4H-pyrano[2,3-e]pyran-6,5'-tetrahydrofuran]-2'-yl]-1-methyl-prop-2-enyl]-11-hydroxy-4-methyl-1,7-dioxaspiro[5.5]undec-4-en-8-yl]-2-hydroxy-2-methyl-propanoic acid (2R)-3-[(2S,6R,8S,11R)-2-[(E,1R)-3-[(2S,2'R,4R,4aS,6R,8aR)-4-hydroxy-2-[(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undecan-2-yl]butyl]-3-methylene-2'-spiro[4a,7,8,8a-tetrahydro-4H-pyrano[2,3-e]pyran-6,5'-tetrahydrofuran]yl]-1-methylprop-2-enyl]-11-hydroxy-4-methyl-1,7-dioxaspiro[5.5]undec-4-en-8-yl]-2-hydroxy-2-methylpropanoic acid (2R)-3-[(2S,6R,8S,11R)-2-[(E,1R)-3-[(2S,2'R,4R,4aS,6R,8aR)-4-hydroxy-2-[(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undecan-2-yl]butyl]-3-methylene-spiro[4a,7,8,8a-tetrahydro-4H-pyrano[2,3-e]pyran-6,5'-tetrahydrofuran]-2'-yl]-1-methyl-prop-2-enyl]-11-hydroxy-4-methyl-1,7-dioxaspiro[5.5]undec-4-en-8-yl]-2-hydroxy-2-methyl-propionic acid (2R)-3-[(2S,6R,8S,11R)-2-[(E,2R)-4-[(2S,2'R,4R,4aS,6R,8aR)-4-hydroxy-2-[(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undecan-2-yl]butyl]-3-methylidene-spiro[4a,7,8,8a-tetrahydro-4H-pyrano[2,3-e]pyran-6,5'-oxolane]-2'-yl]but-3-en-2-yl]-11-hydroxy-4-methyl-1,7-dioxaspiro[5.5]undec-4-en-8-yl]-2-hydroxy-2-methyl-propanoic acid O4511_SIGMA Okadaic acid from Prorocentrum concavum Okadaic acid OKA (2R)-2-hydroxy-3-{(2S,5R,6R,8S)-5-hydroxy-8-[(2R,3E)-4-((2R,4a'R,5R,6'S,8'R,8a'S)-8'-hydroxy-6'-{(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undec-2-yl]butyl}-7'-methylideneoctahydro-3H,3'H-spiro[furan-2,2'-pyrano[3,2-b]pyran]-5-yl)but-3-en-2-yl]-10-methyl-1,7-dioxaspiro[5.5]undec-10-en-2-yl}-2-methylpropanoic acid CHEBI:44658 O9381_SIGMA Probes1_000180