The glycosidal content of the different organs of Citrullus colocynthis.

A qualitative and qwantitative study of the glycosidnl content of the different organs and parts of Citrullus colocynthis SCHRAD. were undertaken. Qualitative study revealed the presence af a-elateri~r 2-D-glucopyranoside and its aglycone in all organs; cucurbitacin B, I , and'L (both free and glycosidal forms) in stents, leaves, and fruits. A suggested procedure for the estimation of a-elaterin glycoside was also given. The highest percentage of the glvcoside (0.22) was found in the pulp of the fruits and the lowest percentage in the roots (0.049). The seeds, stems, leaves and rind contain 0.18,0.17,0.15, and 0.08 percent respectively. The effect of drying on a-elaterin (glycoside) content of the pulp was also carried out. The obtained results showed that the best glycosidal content was obtained by cutting the fruits into 8 equal parts and drying in sun (30-3.5' C). The fruit of Citrullus colocynthis SCHRAD. is known to contain a mixture of glycosides (CI.AUS, 1967). NYLER and CHAPEL (1908) reported that the glycoside colocynthin, previously prepared by WALZ (1858), was isolated in a pure form from Cucumis'trigonus (Cucurbitaceae). The same author stated that this glycoside on hydrolysis, yielded an aglycone, called colocynthein o r a-elaterin, and glucose. Elaterin was also reported by POWER and MOORE (1910) to occur in the fruits o f Citrullus colocynthis and by D u r r (1934) to occur in the roots of the same plant. LAVIC et al. (1959) isolated a yellow glycoside from the fruits of colocynth and stated that the aglycone possessed anticancer activity. EL-KHADEM and ABDELRAHMAN (1962) prepared a-elaterin 2-D-glucopyranoside and showed that this glycoside contained one acetyl group. LAVIC and MERCULANDER (1964) prepared the glycosides of colocynth fruits and showed that its hydrolysates contained cucurbitacins L and I, while K ~ o s s and SCHINDLER (1966) showed that the colocynth fruits contained cucurbitacins D and L. AUTERHOFF and MULLER (1967) prepared the colocynthin glycoside and proved that it consisted of two main components viz. cucurbitacins I and E in glycosidal form. MURTY, VASUDEVAN and KHORANA (1970) showed that the fruits contain cucurbitacins B and E only. Owing to the variable contributions of previous authors, concerning the glycoD ow nl oa de d by : T hi em e E -B oo ks & E -J ou rn al s. C op yr ig ht ed m at er ia l. 294 Darwish Sayed, Balbaa and Afifi Planta medica Vol. 26 1974 sidal content of colocynth, it deemed necessary to carry out qualitative and quantitatvie studies of the glycosidal content of the different organs of colocynth plants viz., roots, stems, leaves and fruits (separated to seeds, pulp, and rind).