Figure 10.

Metabolic pathways of swertiamarin. 4,4a,5,6-Tetrahydro-4a-hydroxy-6-(tetrahydro-3,4,5-trihydroxy-6-(hydroxymethyl)-2H-pyran-2-yloxy)-5-vinylpyrano[3,4-c]pyran-(3H)-one (Swertiamarin). 3,6-Dihydro-4-(1-hydroxybut-3-en-2-yl)-2-oxo-2H-pyran-3-carbaldehyde (1), 2-(3,6-dihydro-3-(hydroxymethyl)-2-oxo-2H-pyran-4-yl)but-3-enal (2), 1-oxoisochroman-5-carbaldehyde (3), 1-oxoisochroman-5-carboxylic acid (4), 3,4-dihydro-5-vinylpyrano[3,4-c]pyridin-1-one (5), and 3,5,6,8-tetrahydro-3-methyl-8-oxopyrano[3,4-c]pyran-4-carbaldehyde (6) are the metabolites of swertiamarin.89