The invention relates to stable preparations of saponin nanovesicles, which can encapsulate active biological or chemical materials such as drugs, pesticides, vitamins, minerals and nutrients, and protect them. The preparations can be used, for example, in agricultural, pesticidal, dermatological and cosmetic compositions. The saponins per se can further be used as adjuvants for irrigation water. The invention further relates to novel saponins extracted from Balanites aegyptiaca.