tailieunhanh - Study of dracaena angustifolia I - new spirostanol sapogenins from roots and rhizomes

The MeOH extract of Nam ginseng (roots and rhizomes of Dracaena angustifolia) afforded three new spirostanol sapogenins, named namogenins A-C (1-3). Their structures were determined on basis of spectral analyses and chemical methods. | Journal of Chemistry Vol. 42 1 P. 129 -131 2004 STUDY OF DRACAENA ANGUSTIFOLIA I - NEW SPIROSTANOL SAPOGENINS FROM ROOTS AND RHIZOMES Received 14-5-2003 TRAN LE QUAN1 TRAN KIM QUI1 SHIGETOSHI KADOTA2 1College of Natural Sciences National University Ho Chi Minh City Ho Chi Minh City institute of Natural Medicine Toyama Medical Pharmaceutical University Toyama Japan SUMMARY The MeOH extract of Nam ginseng roots and rhizomes of Dracaena angustifolia afforded three new spirostanol sapogenins named namogenins A-C 1 -3 . Their structures were determined on basis of spectral analyses and chemical methods. 1. INTRODUCTION 2. RESULTS AND DISCUSSION Dracaena angustifolia Roxb. Dracaenaceae is locally known as Nam ginseng ginseng from the South in Quang Nam province. Its underground parts are used as tonic and for treatment of leukemia 1 . In our continuing studies on Vietnamese medicinal plants we have examined the constituents of Nam ginseng D. angustifolia and isolated three new spirostanol sapogenins. This paper reports the isolation and structure elucidation of these new compounds. Air-dried roots and rhizomes of D. angusti-folia were extracted successively by refluxing MeOH 50 aqueous MeOH and water to give MeOH MeOH-H2O and H2O extracts respectively. The MeOH extract was subjected to Diaion HP-20 column chromatography CC . The MeOH eluate was further separated by a combination of silica gel and ODS column chromatographies and normal- and reversed-phase pTLC to afford three new compounds named namogenins A-C 1 - 3 . 3 1 R OH 25R S 2 R H 25S Negative-ion HRFABMS of 1 displayed a quasi-molecular ion at m z indicating the molecular formula C27H42O6. The 1H NMR spectrum of 1 showed signals ascribable to two tertiary methyls and three secondary methyls while the 13C NMR spectrum of 1 showed 129 twenty seven signals Table 1 . Analysis of the COSY and HMQC spectra together with the molecular formula suggested 1 to be a spirostane-type steroid but the H and 13C NMR .