| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1987: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1986: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
The Seeds of Pharbitis nil and Iponoea muricata are well known to be important prugative crude drugs which contain so-called "resin glycosid". Chemical investegations on resin glycosides were iniated as early as in the middle of 19th century. They are classigied two groups,i.e.ether-soluble"jalapin"and insoluble"convolvulin"and considered to be high molecular(up to about 10000) complex glycolipids which affords vareous organic and glycosidic acids by saponification.However. any pure resin glycoside has not so far been isolated and the chemical studies have been confined only to cahracterization of the component organic acids and glycosidic acid yielded by alkaline hydrolysis of crude resin glycoside.
Very recently,we succeeded,at the first time,in isolation and characterization of four and six genuine resin glycosides,which belong to "jalapin",from i. orizabensis and I. muricata,respectively. All of them posess novel macrocyclic ester structure composed of one mole of glycosidic acid co
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mbined by several organic acids (repeating unit). In this study,1.Pharbitin,so-called"convolvulin"of the seeds of P. nil shows only broad sigle peak,on vareous kinds of TLC and HPLC and it was suggested that free carboxy acid residue presens in the molecule.Therefore,it was treated with CH_2N_2 yielded separable mixture of the methyl ester. Preparative HPLC gave 10 compounds and they were respectively characterized to be methy1 esters of repeating unit by means of negative ion FAB-MS, H-, C-NMR and partial alkaline hybrolysis. The study on the genuine resin glycosides are in progress. 2. Two minor resin glycosides were isolated from I. muricata and characterized as macrocyclic esters being characteristic to "jalapin". 3. Of the component organic acids and hydroxy fatty acids of I.muricata and P.nil,2-methylbutyric, nilic and jalapinolic acids have one or two chiral carbons.Their absolute configurations were determined, respectively, to be 2S-,2R,3R-(in the case of I.orizabensis, 2S,3S-) and 11R-configuration. In abbition to previous studies, these results affords the full structures of the resin glycosides so far characterized. Less
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