Chemistry

The horse chestnut seeds are rich in saponins (3–5%) out of which thirty molecules are isolated and characterized. The principal biologically active component of horse chestnut seed extract is escin, mixture of acylated triterpene glycosides composed of crypto-, α- and β-escin. The two major glycosides in the escin mixture contain the aglycone protoescigenin, glucuronic acid, and two glucose molecules. The two aglycones differ only at the C-21 position (R) which is acylated by either angelic acid or tigilic acid. Along with escin, other compounds such as proanthocyanidin A2 and esculin were also reported (Fig. 1).

The anti-edema, anti-exudative, and vasoprotective actions are reported to be mainly due to escin. Orally and topically administered proanthocyanidin A2 is reported to have wound-healing actions. Esculin is reported to be useful in healthy microcirculation.

Escin

Proantocyanidin A2

Proanthocyanidin A2

Esculin

Figure 1. Chemical structures of bioactive molecules