To provide a new adjuvant relating fields of an adjuvant and an immunostimulator.
There is provided a compound in which a lipophilic moiety such as a lipid, a fatty acid, polyethylene glycol or a terpene is covalently bound with a non-acylated or a de-acylated triterpene saponin via a carboxyl group existing on 3-O-glucuronic acid of triterpene saponin. The binding of the lipophilic moiety with the 3-O-glucuronic acid of saponin such as a saponin derived from Quillaja desacylsaponin, lucyoside P or Gypsophila, Saponaria and Acanthophyllum enhances the adjuvant effect of humoral or cell mediated immunity. In addition, the binding of the lipophillic moiety of non-acylated or de-acylated saponin with the 3-O-glucuronic acid residue gives a saponin analog which can be more easily purified, less toxic and chemically more stable than the original saponin, and having a comparative or more favorable adjuvant property.
Takaaki Yasumura
Natsuki Morishita