Cb. Mei et al., PREPARATIONS OF GINSENOSIDE RG(1) IMMUNOGEN AND I-125 LABELED ANTIGEN, Journal of radioanalytical and nuclear chemistry, 206(2), 1996, pp. 201-203
This work began with the side chain of ginsenoside Rg(1) which was ace
tylized with Ac2O-Pyr and oxidized by OsO4 and NaIO4 to give ginsenosi
de Rg(1) aldehyde(2), which was further converted into an unsaturated
ester(3) by Wittig-Horner reaction. The unsaturated ester(3) was treat
ed with N2H4 and HNO2 to yield Rg(1) azide(4) which was directly conju
gated with BSA to give immunogen: ginsenoside Rg(1)-BSA conjugate(5).
This azide(4) was conjugated with tyramine to give ginsenoside Rg(1)-t
yramine conjugate which was labelled with free (NaI)-I-125 by CH-T to
yield I-125-labeled antigen: gensenoside Rg(1)-I-125-tyramine(6). The
labelling rate was 40%-50% and specific activity was 3.0-4.0 MBq/mu g.