analytical standard Synonym(s): (4a R ,5 R ,6 S )-5-Ethenyl-6-(β-D-glucopyranosyloxy)-4,4a,5,6-tetrahydro-4a-hydroxy1 H ,3 H -pyrano[3,4- c ]pyran-1-one; 4,4a,5,6-Tetrahydro-4aα-hydroxy-1-oxo-5β-vinyl-1 H ,3 H -pyrano[3,4-c]pyran-6-yl β-D-glucopyranoside; Swertiamarine;...