Jolkinin was obtained as a tan amorphous powder and
characterized as an ellagitannin by the standard color
reactions with ferric chloride (dark blue) and sodium
nitrite-acetic acid (reddish brown).16 The 1H and 13C NMR
spectra exhibited signals due to a fully acylated hexopyranose along with aromatic and carboxyl carbon signals,
which is consistent with 2 being a hydrolyzable tannin. The
presence of galloyl and HHDP esters was suggested by the
1H and 13C NMR signals listed in the Experimental Section,
and hydrolysis of 2 in hot H2O to yield corilagin [1-Ogalloyl-3,6-(R)-HHDP-â-D-glucopyranose (3), Figure 1] confirmed the partial structure. This result showed not only
the location of the galloyl and HHDP esters on the â-Dglucopyranose ring but also R-atropisomerism of the HHDP
biphenyl bond.8,17