Senna

Sennoside A is a rel-(9R,9'R)-9,9',10,10'-tetrahydro-9,9'-bianthracene-2,2'-dicarboxylic acid substituted with hydroxy groups at positions 4 and 4', beta-D-glucopyranosyloxy groups at positions 5 and 5', and oxo groups at positions 10 and 10'. The stereochemistry at positions 9 and 9' is either R,R or S,S, though the exact configuration is unknown. It belongs to the sennoside class and is an oxo dicarboxylic acid.