tailieunhanh - Phytochemical Investigation of Alpinia globosa (Lour.) Horaninov, Zingiberaceae

B-Sitosterol, stigmasterol and a minor compound 5,6-dehydrokawain were isolated from the ethanol extract of the rhizomes of Alpinia globosa, a medicinal plant of Vietnam. The paper provides characteristic spectra and HPLC profile of the natural -pyrone 5,6- dehydrokawain that would be useful for the purpose of fast determination of this bioactive compound in plant extracts. | Journal of Chemistry Vol. 42 3 P. 376 - 378 2004 PHYTOCHEMICAL INVESTIGATION OF ALPINIA GLOBOSA Lour. HORANINOV ZINGIBERACEAE Received 25-7-2003 PHAN MINH GIANG PHAN TONG SON Faculty of Chemistry College of Natural Science Vietnam National University Hanoi SUMMARY -Sitosterol stigmasterol and a minor compound 5 6-dehydrokawain were isolated from the ethanol extract of the rhizomes of Alpinia globosa a medicinal plant of Vietnam. The paper provides characteristic spectra and HPLC profile of the natural a-pyrone 5 6-dehydrokawain that would be useful for the purpose of fast determination of this bioactive compound in plant extracts. Alpinia globosa Lour. Horaninov Zingibe-raceae is a perennial herb reaching m in height. The plant prefers moist soil and shadow 1 - 3 . In Vietnam the fruits of A. globosa are used in the treatment of stomach ache diarrhoea and dysentery. Its rhizomes and seeds are also effective against vomiting 3 . There is no report on chemical constituents and biological activities of A. globosa. The ethanol extract of the rhizomes of A. globosa was partitioned between H2O and n-hexane and ethyl acetate successively and then the organic layers were evaporated to remove the solvents in vacuo. The n-hexane soluble fraction was subjected to Si column chromatography and preparative high perfomance liquid chromatography HPLC see Experimental Section . -sitosterol and stigmasterol were isolated in high yield from non-polar fractions collected from the first Si gel chromatographic column and identified in a 1 1 mixture on the basis of 1H NMR and 13C NMR spectral data. From a more polar fraction a pale yellow compound 1 mp 136 - 137oC was isolated after purification with preparative RP HPLC. Its molecular formula was assigned as C14H12O3 by EIMS 70 eV and 376 ESIMS spectra. The styryl moiety of 1 was evidenced from the signals at S 5H m 1H d J 16 Hz 1H d J 16 Hz in 1H NMR and 1C 1C 2C 2C 1C all d 1C s in