ISOLATION AND CHARACTERIZATION OF AN ALIPHATIC SATURATED ESTER FROM Ipomoea carnea LEAVES

摘要

India has a rich traditional background in herbal medicines. Detailed accounts of remedies are given in texts like the Ayurveda and Rigveda. In the "Atharva Veda," one finds more varied use of drugs. Today there is a "Return to Nature" call in both advanced countries as well as countries like India. Plants still constitute one of the major raw materials for drugs for treating various ailments of humans, although there has been significant development in the field of synthetic drug chemistry and antibiotics [1]. Plants produce several straight-chain, branched-chain, aliphatic, and aromatic esters as secondary metabolites. Ipomoea belongs to the family Convolvulaceae and is represented by approximately 18 species in India [2]. One of the species is Ipomoea carnea. It is commonly called Besharam and Mahananda in Marathi. It is native to South America. I. carnea, locally known as Awier, occurs in tropical areas of the world such as North America, South America, Africa, Asia, and Australia [3]. It is available in ample amounts in all states of India due to its adaptation to Indian climatic conditions [4]. I. carnea is an exotic weed in Chattisghara, India, and only a few decades back it was introduced as Green Manure Crop [5]. It is a potential source of alternate feedback of biogas production and pulp for the paper industry [6-9]. There have been reports on the synergistic effect of insecticides with plant extracts of I. carnea against the malarial vector Anopheles stephensi [10]. Metschnikowia drosophilae, a new yeast species, was isolated from insects associated with flowers of I. carnea [11]. The presence of hexadecyl, octadecyl, and eicosyl esters of p-coumaric acid in the vine and root latex of sweetpotato [Ipomoea batatas (L.) Lam.] has been reported [12]. Compound 1 was isolated from an ethyl acetate extract prepared by a Soxhlet extractor using air shade-dried and pulverized leaves. Broad fractionation is performed using a column chromatographic technique. Compound 1 was isolated from the n-hexane-ethyl acetate (9.5:0.5) fraction, which was purified by repeated crystallization using a mixed solvent system. The structure was determined by spectral methods. Analysis reveals that compound 1 is octadecanoic acid eicosyl ester (eicosyl stearate). This compound was isolated for the first time from this plant source.