Thin layer chromatographic studies of the pungent principles of Ceylon chillies (Capsicum species)

Abstract

There are many varieties of cultivated chillies in Ceylon and the pungency of the fruit varies markedly with species, colour and size. A thin layer chromatographic study has been undertaken of the hot principles of Capsicum species found in Ceylon. This study shows that there are three compounds in Capsicum species other than capsaicin (vanillyl amide of isodeeenoic acid) which give similar colour reactions as capsaicin. In Capsicum annuum, variety grossum, the hot principle, capsaicin is not detected by this method but instead, two other compounds are present which in a concentrated extract are responsible for the pungency of the fruit. Major variations in the relative concentrations of those pungent principles as determined semi-quantitatively, in the different varieties of Ceylon chillies have been discussed. Kosuge, Inagaki & Uchare (1) using paper-chromatographic techniques separated two pungent principles from certain Japanese species of Capsicum. One of these compounds was the vanillyl amide of 6 -- iso decenoic acid. By the reduction of noneoic acid, Kosuge, Inagaki & Ino (2) showed that the other pungent principles was the vanillyl amide of 8-methyl nonaoic acid. Jentzch, Pock & Kubelka (3) showed the occurrence of homedihydrocapsaicin and dihydrocapsaicin in Capsicum species. A thin layer chromatographic method was described by Spanyar & Blazovich (4) for the determination of capsaicin in ground paprika. The workers tested more than ten solvent system described in the literature for the separation of capsaicin, and reported that the best solvent system for the separation of capsaicin was chloroform - ethanol (99 : 1 v/v). This paper gives the results of a qualitative study of the hot principles (capsaicins) of Ceylon chillies. Extraction was carried out according to the method of North (5). The capsaicins were extracted with peroxide free diethyl ether. The ethereal extract was treated with purified kerosene and finally partitioned with an aqueous solution of 60% acetone, which