Solid-state fluorodensitometric quantitation of arylnaphthalene lignan lactones of Cleistanthus collinus.

Arylnaphthalene lignan lactones are naturally occurrmg dimers in Plants and known to have potential use in medicine 1,2. A few of them are reported to be highly to&; others find use as antioxidants and insecticides3. Cleistanthus col1inu.y (Roxb.) Benth. & Hookf. (family: Euphorbiaceae) is a highly poisonous plant. All parts of it are reported to be toxic and employed as a suicidal, homicidal, cattle and fish poison and for procuring criminal abortion4+. Chemical characterization of different parts of the plant has led to the isolation and identification of certain lignan lactones including diphyllin, cleistanthin A, cleistanthin B and collinusin7,*. Although the poisonous nature of the plant has been establishedg, the compound(s) responsible for the toxicity is not known. Nevertheless, few reports on the medicinal properties of the lignan lactones have appeared*JO-I*. While information on the structures and biological activities of the constituents is available, there are little data on the quantitative analytical aspects. Methods reported in the literature cover only the qualitative identification of C. collinus from poisoned visceral materials and chromatographic systems for the separation of the lignan lactones13J4. Based on the photometric properties (including fluorescence under UV irradiation) of the four compounds mentioned above, we previously developed spectraphotometric and spectrofhrorometric methods 15J6. The present paper deals with an improved technique, namely, the solid-state fluorodensitometric quantitation of diphyllin, cleistanthin A, B and collinusin -the major arylnaphthalene lignan lactones of C. coZlinusafter their thin-layer chromatographic (TLC) separation. While the earlier methods require TLC and subsequent concentration of the CornpoundS, the present method is a direct one. The variation in the fluorescence characteristics of the compounds in solution and on silica gel (TLC) has also been studied and is utilized to enable a better quantitation.