The activation effect of boric acid as an activator is good,and we investigate the best activation conditions for the boric acid impregnation method.To represent the structural characteristics and adsorption performan...The activation effect of boric acid as an activator is good,and we investigate the best activation conditions for the boric acid impregnation method.To represent the structural characteristics and adsorption performance of the Stellera Chamaejasme based carbon molecular sieves,we use Brunner-Emmet-Teller(BET)measurements,scan-ning electron microscope(SEM),Raman spectra(Raman),X-ray diffraction(XRD),and adsorption property measurement.When the loading ratio was 0.68:1,the specific surface area was 532.21 m^(2)/g,the total pore volume was 0.24 cm 3/g,the average pore size was 1.81 nm,the adsorption value of methylene blue was 145.28 mg/g,and the adsorption value of iodine was 713.33 mg/g,the results showed that boric acid had better activation effect.The carbon molecular sieves made from Stellera Chamaejasme and activated with boric acid produce two peaks on the aperture distribution graph that are densely distributed in the micropore range.This indicates that boric acid’s pore-forming tendency is primarily micropore.展开更多
遮荫是影响植物种子萌发和幼苗定居的重要环境因素。为了探明遮荫对高寒草地狼毒(Stellera chamaejasme)种苗定居的影响,本研究在其原生境下开展人工控制试验,探究了狼毒种子在不同遮荫高度(10 cm, 15 cm, 20 cm)和不同遮荫方位(东向、...遮荫是影响植物种子萌发和幼苗定居的重要环境因素。为了探明遮荫对高寒草地狼毒(Stellera chamaejasme)种苗定居的影响,本研究在其原生境下开展人工控制试验,探究了狼毒种子在不同遮荫高度(10 cm, 15 cm, 20 cm)和不同遮荫方位(东向、西向、南向、北向)下的出苗和幼苗定居表现。结果表明:不同遮荫处理均显著降低了高寒草地土壤表层温度(P<0.05),增加了土壤含水量(P<0.05);不同高度遮荫处理均能不同程度地降低狼毒种子出苗率和成苗率。与对照相比,东向、南向和北向遮荫处理对狼毒种子出苗率均无显著影响,而西向遮荫处理能显著降低狼毒出苗率(P<0.05);狼毒的成苗率在各方位遮荫处理下无显著性差异,均为100%。本研究表明,遮荫是影响狼毒种苗定居的重要环境因子。因此,维持高寒草地植物群落在一定的高度水平,可有效遏制狼毒种苗定居和种群扩散。展开更多
Methanol extract of Stellera chamaejasme L wasassessed for antitumor activity by an antitumor activebioassay against murine leukemia P388 in vivo. Thebioassay-directed separation of the extract furnishedseven diterpen...Methanol extract of Stellera chamaejasme L wasassessed for antitumor activity by an antitumor activebioassay against murine leukemia P388 in vivo. Thebioassay-directed separation of the extract furnishedseven diterpene compounds (stellerarin, stelleramacrin,gnidimacrin, pimelea factor P2, subtoxin, huratoxin,simplexin ) and two biflavanone compounds (neochemae-jasmin A and B). Among them, gnidimacrin, stellerarinand stelleramacrin (a novel compound) were found tohave high antitumor and cytotoxic activities against P388,L1210 and K562 in vivo and in vitro. The results suggestedthat the diterpene compounds were the potent anti-tumor principles of Stellera chamaejame L展开更多
A new biflavonoid, stelleranol, was isolated from the roots of Stellera chamaejasme L.. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.
A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots o...A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots of Stellera chamaejasme L. together with known chamaechromone. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.展开更多
Gnidimacrin, a diterpene compound, isolated from the methanol extract of Stellera, chamaejasme L., showed significant antitumor activities against mouse leukemia P-388 and L-1210 in vivo, such as Lewis lung carcinoma,...Gnidimacrin, a diterpene compound, isolated from the methanol extract of Stellera, chamaejasme L., showed significant antitumor activities against mouse leukemia P-388 and L-1210 in vivo, such as Lewis lung carcinoma, B-16 melanoma and Colon cancer 26. It showed ILSs of 40%.49% and 41% at the dosages of 0.01-0.02 mg/kg ip,respectively. Gnidimacrin strongly inhibited cell Proliferation of human cancer cell lines such as leukemia K562, stomach cancers Kato-III, MKN-28, MKN-45, and mouse leukemia L-1210 by the MTT assay and colony forming assay in vitro. The IC50 of gnidimacrin was 0.007-0.00012 μg/ml. It is concluded that gnidimacrin is the principal antitumor element in Stellera chemaejasme L. with strong antitumor activities.展开更多
Steller chamaejasme L.(S. chamaejasme for short) is one of the most noxious unpalatable weeds in China, which has been frequently reported its negative interaction(i.e. competition and allelopathy) with other herbaceo...Steller chamaejasme L.(S. chamaejasme for short) is one of the most noxious unpalatable weeds in China, which has been frequently reported its negative interaction(i.e. competition and allelopathy) with other herbaceous species in grasslands. This study compared species diversity, biomass and sexual reproduction of herbaceous plants in meadows with S. chamaejasme and in open meadows without S. chamaejasme in overgrazing meadows on the Tibetan Plateau in China to determine whether positive facilitation exist between S. chamaejasme and other herbaceous species under livestock's overgrazing. The results showed that there are more herbaceous species in meadows with S. chamaejasme than those in open meadows(35s and30s, respectively). Diversity index and above-ground biomass were also significantly higher in meadows with S. chamaejasme. There were 39%(11/28) of all species with sexual reproduction found in meadows with S. chamaejasme, which was 7 times more than those in open meadows. Our study showed that S. chamaejasme could provide biotic refuge for neighboring plants and preserve plant diversity from livestock's overgrazing in alpine meadows on the Tibetan Plateau. It also suggested that inter-specific facilitation between S. chamaejasme and other herbaceous species may play a key role in overgrazing alpine meadows.展开更多
基金Graduate Innovation Project of Qinghai University for Nationalities(2021XJXS12)Graduate Innovation Project of Qinghai University for Nationalities(12M2021018).
文摘The activation effect of boric acid as an activator is good,and we investigate the best activation conditions for the boric acid impregnation method.To represent the structural characteristics and adsorption performance of the Stellera Chamaejasme based carbon molecular sieves,we use Brunner-Emmet-Teller(BET)measurements,scan-ning electron microscope(SEM),Raman spectra(Raman),X-ray diffraction(XRD),and adsorption property measurement.When the loading ratio was 0.68:1,the specific surface area was 532.21 m^(2)/g,the total pore volume was 0.24 cm 3/g,the average pore size was 1.81 nm,the adsorption value of methylene blue was 145.28 mg/g,and the adsorption value of iodine was 713.33 mg/g,the results showed that boric acid had better activation effect.The carbon molecular sieves made from Stellera Chamaejasme and activated with boric acid produce two peaks on the aperture distribution graph that are densely distributed in the micropore range.This indicates that boric acid’s pore-forming tendency is primarily micropore.
文摘遮荫是影响植物种子萌发和幼苗定居的重要环境因素。为了探明遮荫对高寒草地狼毒(Stellera chamaejasme)种苗定居的影响,本研究在其原生境下开展人工控制试验,探究了狼毒种子在不同遮荫高度(10 cm, 15 cm, 20 cm)和不同遮荫方位(东向、西向、南向、北向)下的出苗和幼苗定居表现。结果表明:不同遮荫处理均显著降低了高寒草地土壤表层温度(P<0.05),增加了土壤含水量(P<0.05);不同高度遮荫处理均能不同程度地降低狼毒种子出苗率和成苗率。与对照相比,东向、南向和北向遮荫处理对狼毒种子出苗率均无显著影响,而西向遮荫处理能显著降低狼毒出苗率(P<0.05);狼毒的成苗率在各方位遮荫处理下无显著性差异,均为100%。本研究表明,遮荫是影响狼毒种苗定居的重要环境因子。因此,维持高寒草地植物群落在一定的高度水平,可有效遏制狼毒种苗定居和种群扩散。
文摘Methanol extract of Stellera chamaejasme L wasassessed for antitumor activity by an antitumor activebioassay against murine leukemia P388 in vivo. Thebioassay-directed separation of the extract furnishedseven diterpene compounds (stellerarin, stelleramacrin,gnidimacrin, pimelea factor P2, subtoxin, huratoxin,simplexin ) and two biflavanone compounds (neochemae-jasmin A and B). Among them, gnidimacrin, stellerarinand stelleramacrin (a novel compound) were found tohave high antitumor and cytotoxic activities against P388,L1210 and K562 in vivo and in vitro. The results suggestedthat the diterpene compounds were the potent anti-tumor principles of Stellera chamaejame L
文摘A new biflavonoid, stelleranol, was isolated from the roots of Stellera chamaejasme L.. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.
文摘A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots of Stellera chamaejasme L. together with known chamaechromone. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.
文摘Gnidimacrin, a diterpene compound, isolated from the methanol extract of Stellera, chamaejasme L., showed significant antitumor activities against mouse leukemia P-388 and L-1210 in vivo, such as Lewis lung carcinoma, B-16 melanoma and Colon cancer 26. It showed ILSs of 40%.49% and 41% at the dosages of 0.01-0.02 mg/kg ip,respectively. Gnidimacrin strongly inhibited cell Proliferation of human cancer cell lines such as leukemia K562, stomach cancers Kato-III, MKN-28, MKN-45, and mouse leukemia L-1210 by the MTT assay and colony forming assay in vitro. The IC50 of gnidimacrin was 0.007-0.00012 μg/ml. It is concluded that gnidimacrin is the principal antitumor element in Stellera chemaejasme L. with strong antitumor activities.
基金funded by the National Natural Science Foundation of China (Grant Nos. 31100360, 31200378, 31000233)
文摘Steller chamaejasme L.(S. chamaejasme for short) is one of the most noxious unpalatable weeds in China, which has been frequently reported its negative interaction(i.e. competition and allelopathy) with other herbaceous species in grasslands. This study compared species diversity, biomass and sexual reproduction of herbaceous plants in meadows with S. chamaejasme and in open meadows without S. chamaejasme in overgrazing meadows on the Tibetan Plateau in China to determine whether positive facilitation exist between S. chamaejasme and other herbaceous species under livestock's overgrazing. The results showed that there are more herbaceous species in meadows with S. chamaejasme than those in open meadows(35s and30s, respectively). Diversity index and above-ground biomass were also significantly higher in meadows with S. chamaejasme. There were 39%(11/28) of all species with sexual reproduction found in meadows with S. chamaejasme, which was 7 times more than those in open meadows. Our study showed that S. chamaejasme could provide biotic refuge for neighboring plants and preserve plant diversity from livestock's overgrazing in alpine meadows on the Tibetan Plateau. It also suggested that inter-specific facilitation between S. chamaejasme and other herbaceous species may play a key role in overgrazing alpine meadows.
