Chemical composition of Calotropis gigantea. Part II. Wax and resin components of the stem bark

Abstract

A study of the wax and resin components of the stem bark of Calotropis gigantea is described. They were separated into fractions by means of alcohol. The most sparingly soluble fraction consisted of esters of resinols with long chain (saturated and unsaturated) fatty acids. From the unsaponifiable matter by fractionating the acetates and the benzoates, α-and β-calotropeols and β-amyrin were obtained. Small quantities of a mixture of possibly tetracyclic triterpene compounds and traces of sterols were also found to be present. A subsequent fraction was aliphatic being made up of 90% of fatty acids (C₃₀ and near homologues) and 10% of hydrocarbons (C₃₁+C₃₃, etc). The most soluble fraction contained esters of triterpene alcohols with steam volatile fatty acids. By a process of direct crystallisation applied repeatedly a new substance, Giganteol acetate, could be obtained from this fraction. It yielded a new dihydric alcohol, Giganteol, having the formula C₃₀H₅₀O₂. An alcoholic extract of the wax-free stem bark yielded mineral matter consisting of citrates, chlorides and tartrates of sodium and potassium.