Two new tirucallane triterpenoids,2a-ethoxy-2,3-secotirucalla-2,29-epoxy-7-ene-23-oxo-3-oic acid(1)and(23E)-2a-hydroxytirucalla-7,23,25-triene-3-one(2),along with the known 2,3-secotirucalla-2,3;2,29-diepoxy-7-ene-3,2...Two new tirucallane triterpenoids,2a-ethoxy-2,3-secotirucalla-2,29-epoxy-7-ene-23-oxo-3-oic acid(1)and(23E)-2a-hydroxytirucalla-7,23,25-triene-3-one(2),along with the known 2,3-secotirucalla-2,3;2,29-diepoxy-7-ene-3,23-dione(3),were isolated from the leaves and twigs of Aphanamixis grandifolia.Their structures were elucidated by extensive NMR and MS data,and compound 3 was further confirmed by X-ray crystal diffraction analysis.Antimicrobial activities and insecticidal activities of these three compounds were also evaluated.Compound 1 showed good antimicrobial activity against Staphylococcus aureus with the MIC value of 1.56μg/mL,while compounds 1 and 2 showed insecticidal activity at 100 ppm,with the corrected mortality 79.1%and 60.6%,respectively.展开更多
To address the central question of how climate change influences tree growth within the context of climate will become warmer and drier in central Ontario, we used dendroclimatological analysis to understand the radia...To address the central question of how climate change influences tree growth within the context of climate will become warmer and drier in central Ontario, we used dendroclimatological analysis to understand the radial growth responses of four co-occurring hardwood species: sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britton), American beech (Fagus grandifolia Ehrh.), and red oak (Quercus rubra L.) to climatic variables in central Ontario, Canada. Ring width chronologies were developed for the target species within three regions (Algonquin Park, Haliburton, and North Bay) of the study area. Seven of the eleven chronologies exceeded the 0.85 expressed population signal (EPS) and were used for further analysis. Mean sensitivity and standard deviation values of the Ontario chronologies indicated lower sensitivity to climate fluctuations than in southern North America. Positive correlations with precipitation variables from the current and prior growing season supported previous studies in sugar maple, while a positive response to growing degree days suggested the importance of warmer temperatures and a longer growing season at the northern limit of the distribution range of sugar maple. Yellow birch ring width was correlated with precipitation from the previous growing season and from the end of the current growing season also suggesting that mature trees with deep root systems might utilize moisture from deep soil. Radial growth of American beech positively correlated to precipitation of the previous season, suggesting that the amount of moisture reserves stored in the previous year might affect growth in the following year. Drought stress at the start of the growing season for red oak had negative correlations with precipitation in August indicating possible cessation of cambial activity. This decline in growth process would also affect ring width of red oak the following year as expressed by negative correlations with mean annual temperature from the previous year. Abnormally, warm seasonal temperatures may be indicative of drought stress in red oak.展开更多
Objective:To evaluate the ethanol extract of Voacanga grandifolia for hepatoprotective and antioxidant potential against ethanol-induced liver toxicity in rats.Methods:Sprague-Dawley rats were administered ethanol(7 g...Objective:To evaluate the ethanol extract of Voacanga grandifolia for hepatoprotective and antioxidant potential against ethanol-induced liver toxicity in rats.Methods:Sprague-Dawley rats were administered ethanol(7 g/kg)and then treated with 100 and 200 mg/kg of Voacanga grandifolia extract.The phytochemical constituents and antioxidant potential of Voacanga grandifolia extract were evaluated by GC-MS and in vitro antioxidant assays.Biochemical indicators for liver damage and pro-apoptotic and antiapoptotic gene expression were determined using biochemical kits,ELISA,and qRT-PCR,respectively.Additionally,histopathological study of the liver was performed.Results:GC-MS identified propanoic acid,meso-erythritol,D-pinitol,myo-inositol,and hexadecanoic acid in Voacanga grandifolia extract.Voacanga grandifolia extract(100 and 200 mg/kg)increased the concentration of enzymatic antioxidants while diminishing the levels of inflammatory cytokines and biochemical indicators.qRT-PCR assay showed that Voacanga grandifolia extracts upregulated antiapoptotic gene expression while downregulating pro-apoptotic gene expression.Furthermore,the plant extract improved the hepatic architecture of ethanol-intoxicated rats.Conclusions:Voacanga grandifolia extract demonstrates hepatoprotective activity against alcohol-induced liver injury in rats and could be a potential hepatoprotective agent.展开更多
To the Editor: Dietary supplements and herbal products are an increasingly common source of drug-induced liver injury. An increasing number of case reports have suggested causative supplement-associated liver toxicity...To the Editor: Dietary supplements and herbal products are an increasingly common source of drug-induced liver injury. An increasing number of case reports have suggested causative supplement-associated liver toxicity. [1] Malva grandifolia is a plant which is frequently found in flower and vegetable gardens (Fig.). Mallow products are used展开更多
Four new limonoids, named aphanagranins A-D （1-4）, were isolated from the fruits ofAphanamixis grandi- folia. The new structures were determined by spectroscopic methods especially 1D and 2D NMR analysis, Aphana- gr...Four new limonoids, named aphanagranins A-D （1-4）, were isolated from the fruits ofAphanamixis grandi- folia. The new structures were determined by spectroscopic methods especially 1D and 2D NMR analysis, Aphana- granin A （1） possessed a rare four membered oxygen heterocyclic ring and its absolute configurations were deter- mined on the basis of the signal crystal X-ray diffraction analysis. Furthermore, compounds 1 and 2 showed weak activity toward brine shrimp （Artemia salina）.展开更多
基金This work was financially supported by grants from the National Basic Research Program of China(973 Program,2009CB522300 and 2009CB940900)National Natural Science Funding of China(31170332)the Young Academic and Technical Leader Raising Foundation of Yunnan Province(2010CI047).
文摘Two new tirucallane triterpenoids,2a-ethoxy-2,3-secotirucalla-2,29-epoxy-7-ene-23-oxo-3-oic acid(1)and(23E)-2a-hydroxytirucalla-7,23,25-triene-3-one(2),along with the known 2,3-secotirucalla-2,3;2,29-diepoxy-7-ene-3,23-dione(3),were isolated from the leaves and twigs of Aphanamixis grandifolia.Their structures were elucidated by extensive NMR and MS data,and compound 3 was further confirmed by X-ray crystal diffraction analysis.Antimicrobial activities and insecticidal activities of these three compounds were also evaluated.Compound 1 showed good antimicrobial activity against Staphylococcus aureus with the MIC value of 1.56μg/mL,while compounds 1 and 2 showed insecticidal activity at 100 ppm,with the corrected mortality 79.1%and 60.6%,respectively.
文摘To address the central question of how climate change influences tree growth within the context of climate will become warmer and drier in central Ontario, we used dendroclimatological analysis to understand the radial growth responses of four co-occurring hardwood species: sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britton), American beech (Fagus grandifolia Ehrh.), and red oak (Quercus rubra L.) to climatic variables in central Ontario, Canada. Ring width chronologies were developed for the target species within three regions (Algonquin Park, Haliburton, and North Bay) of the study area. Seven of the eleven chronologies exceeded the 0.85 expressed population signal (EPS) and were used for further analysis. Mean sensitivity and standard deviation values of the Ontario chronologies indicated lower sensitivity to climate fluctuations than in southern North America. Positive correlations with precipitation variables from the current and prior growing season supported previous studies in sugar maple, while a positive response to growing degree days suggested the importance of warmer temperatures and a longer growing season at the northern limit of the distribution range of sugar maple. Yellow birch ring width was correlated with precipitation from the previous growing season and from the end of the current growing season also suggesting that mature trees with deep root systems might utilize moisture from deep soil. Radial growth of American beech positively correlated to precipitation of the previous season, suggesting that the amount of moisture reserves stored in the previous year might affect growth in the following year. Drought stress at the start of the growing season for red oak had negative correlations with precipitation in August indicating possible cessation of cambial activity. This decline in growth process would also affect ring width of red oak the following year as expressed by negative correlations with mean annual temperature from the previous year. Abnormally, warm seasonal temperatures may be indicative of drought stress in red oak.
文摘Objective:To evaluate the ethanol extract of Voacanga grandifolia for hepatoprotective and antioxidant potential against ethanol-induced liver toxicity in rats.Methods:Sprague-Dawley rats were administered ethanol(7 g/kg)and then treated with 100 and 200 mg/kg of Voacanga grandifolia extract.The phytochemical constituents and antioxidant potential of Voacanga grandifolia extract were evaluated by GC-MS and in vitro antioxidant assays.Biochemical indicators for liver damage and pro-apoptotic and antiapoptotic gene expression were determined using biochemical kits,ELISA,and qRT-PCR,respectively.Additionally,histopathological study of the liver was performed.Results:GC-MS identified propanoic acid,meso-erythritol,D-pinitol,myo-inositol,and hexadecanoic acid in Voacanga grandifolia extract.Voacanga grandifolia extract(100 and 200 mg/kg)increased the concentration of enzymatic antioxidants while diminishing the levels of inflammatory cytokines and biochemical indicators.qRT-PCR assay showed that Voacanga grandifolia extracts upregulated antiapoptotic gene expression while downregulating pro-apoptotic gene expression.Furthermore,the plant extract improved the hepatic architecture of ethanol-intoxicated rats.Conclusions:Voacanga grandifolia extract demonstrates hepatoprotective activity against alcohol-induced liver injury in rats and could be a potential hepatoprotective agent.
文摘To the Editor: Dietary supplements and herbal products are an increasingly common source of drug-induced liver injury. An increasing number of case reports have suggested causative supplement-associated liver toxicity. [1] Malva grandifolia is a plant which is frequently found in flower and vegetable gardens (Fig.). Mallow products are used
文摘Four new limonoids, named aphanagranins A-D （1-4）, were isolated from the fruits ofAphanamixis grandi- folia. The new structures were determined by spectroscopic methods especially 1D and 2D NMR analysis, Aphana- granin A （1） possessed a rare four membered oxygen heterocyclic ring and its absolute configurations were deter- mined on the basis of the signal crystal X-ray diffraction analysis. Furthermore, compounds 1 and 2 showed weak activity toward brine shrimp （Artemia salina）.
