[Objective] This study aimed to investigate the chemical constituents of Dendrobium thyrsiflorum and determine its bioactive compounds. [Method] The compounds were extracted by 95% alcohol and isolated by column chrom...[Objective] This study aimed to investigate the chemical constituents of Dendrobium thyrsiflorum and determine its bioactive compounds. [Method] The compounds were extracted by 95% alcohol and isolated by column chromatography on silica gel and Sephadex LH-20. Their structures were identified by spectroscopic analysis(1H NMR and13 C NMR). [Result] Seven compounds were obtained and identified as 4, 7-dihydroxy-2-methoxy-9, 10-dihydrophenan-threne(1), syringaldehyde(2),moscatin(3), gigantol(4), batatasin III(5), tristin(6) and stigmasterol(7). [Conclusion] Compounds 1 and 2 were isolated from this medicinal plant for the first time.展开更多
Lithologically, two kinds of chert can be recognized in the Middle-Upper Permian from the Tieqiao section in Laibin area, Guangxi, i.e., calcic chert occurring mainly in the Maokou Formation and pure chert mainly in t...Lithologically, two kinds of chert can be recognized in the Middle-Upper Permian from the Tieqiao section in Laibin area, Guangxi, i.e., calcic chert occurring mainly in the Maokou Formation and pure chert mainly in the Wujiaping Formation. Geochemical data show that both kinds of chert contain very low A1203 （0-0.23%） and TiO2 （0.001%-0.024%） and low ZREE （0.55-19.94 ppm, averaging 9.97 ppm）, as well as high ratio of Fe2O3/TiO2 （17-443, averaging 111） and low ratio of A1203/（Al2O3＋Fe203） （0-0.26, averaging 0.09）. Given that the average value Ce anomalies in chert deposited in the ridge-proximal environment is about 0.29, and that in the pelagic environment is about 0.60, the low Ce anomalies in the Tieqiao chert （0.24-0.46, averaging 0.35） imply that they were deposited in an ocean basin with influence of submarine hydrothermal fluid and no input of terrigenous materials. The vertical variation of the silica abundance in strata （SAIS） in the Middle-Upper Permian strata, together with the Eu anomalies and the ratios of ∑REE/Fe, indicates a relationship between the hydrothermal activity and the Emeishan basalt eruption, and that submarine hydrothermal activity was stronger in the Upper Permian （the Wujiapingian Stage） than in the Middle Permian （the Maokou Stage）.展开更多
基金Supported by Grants from the National Natural Science Foundation of China(No.21202066)the Natural Science Foundation of Yunnan Province,China(No.2012FB156)the Open Research Foundation of Yunnan Key Laboratory of Pharmacology for Natural Products(No.2014G011)
文摘[Objective] This study aimed to investigate the chemical constituents of Dendrobium thyrsiflorum and determine its bioactive compounds. [Method] The compounds were extracted by 95% alcohol and isolated by column chromatography on silica gel and Sephadex LH-20. Their structures were identified by spectroscopic analysis(1H NMR and13 C NMR). [Result] Seven compounds were obtained and identified as 4, 7-dihydroxy-2-methoxy-9, 10-dihydrophenan-threne(1), syringaldehyde(2),moscatin(3), gigantol(4), batatasin III(5), tristin(6) and stigmasterol(7). [Conclusion] Compounds 1 and 2 were isolated from this medicinal plant for the first time.
基金supported by National Basic Research Program of China (Grant No. 2005CB422101)
文摘Lithologically, two kinds of chert can be recognized in the Middle-Upper Permian from the Tieqiao section in Laibin area, Guangxi, i.e., calcic chert occurring mainly in the Maokou Formation and pure chert mainly in the Wujiaping Formation. Geochemical data show that both kinds of chert contain very low A1203 （0-0.23%） and TiO2 （0.001%-0.024%） and low ZREE （0.55-19.94 ppm, averaging 9.97 ppm）, as well as high ratio of Fe2O3/TiO2 （17-443, averaging 111） and low ratio of A1203/（Al2O3＋Fe203） （0-0.26, averaging 0.09）. Given that the average value Ce anomalies in chert deposited in the ridge-proximal environment is about 0.29, and that in the pelagic environment is about 0.60, the low Ce anomalies in the Tieqiao chert （0.24-0.46, averaging 0.35） imply that they were deposited in an ocean basin with influence of submarine hydrothermal fluid and no input of terrigenous materials. The vertical variation of the silica abundance in strata （SAIS） in the Middle-Upper Permian strata, together with the Eu anomalies and the ratios of ∑REE/Fe, indicates a relationship between the hydrothermal activity and the Emeishan basalt eruption, and that submarine hydrothermal activity was stronger in the Upper Permian （the Wujiapingian Stage） than in the Middle Permian （the Maokou Stage）.
