A new sesquiterpene ester (Malkangunin) and three sesquiterpene alkaloids (Celapanin, Celapanigin, Celapagin) were isolated from Celastrus paniculatus Willd. The complete structure and stereochemistry of Malkangunin, a sesquiterpene tetra-ol of the β-dihydroagarofurane type two of whose hydroxyls being esterified with acetic and benzoic acids, is discussed. The alkaloids described here are derived from a new sesquiterpene tetra-ol (Celapanol) which is alternately esterified with acetic, benzoic, nicotinic and β-furoic acids. © 1975.