After purification of crude TSE with Sephadex LH20, its
composition was found to be 25.2±0.9% (w/w) of metTSE
and 73.9±1.5% (w/w) of acTSE from three different
experiments. On the other hand, the content of polymeric
PA in crude TSE was about 88-95% (Table 2). These
results suggested that metTSE should contain a high
amount of polymeric PA. The content of polymeric PA in
metTSE was calculated by HPLC analysis using acTSE as
a standard and found to be about 79% (w/w). The 13C
NMR spectrum of metTSE was very similar to that of
acTSE, showing all the carbons necessary for polymeric
PA. Therefore, the main ingredient of metTSE was
confirmed to be condensed tannin similar to acTSE.