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561.
杜仲叶中总黄酮物质超声提取的研究 总被引:16,自引:1,他引:15
采用醇提法、超声提取法探讨了从杜仲叶中提取总黄酮类物质的最佳工艺。试验结果表明:通过单因素试验和正交试验,超声提取效果最好。其最佳条件是:用浓度为400%、按料液比1:60的比例的乙醇浸泡24h,再用超声提取45min,其杜仲叶中总黄酮类物质的提出率可达25.43%。 相似文献
562.
Argania spinosa (L.) Skeels is a tree that plays a crucial role in the rural and urban economy of Morocco. Not only is the tree used in traditional
medicine but its fruits contain almonds used to prepare an edible oil, its leaves are utilized to feed cattle, and its wood
is used as fuel. In addition the tree is particularly well-adapted to arid lands and could hence be used to limit the desert
progression that is threatening subtropical African countries. Consequently a program aimed at a better understanding of all
the aspects and uses of the argan tree is currently being carried out in Morocco. This review summarizes the results gathered
so far on the phytochemical and pharmacological activity of A. spinosa.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
563.
The majority of in vitro assays on biological activities of flavonoids have used the aglycone form as the test compound. This form is readily available
from commercial sources and comparable approaches have been used for testing efficacy of drugs. This paper presents the hypothesis
that aglycones are only transiently present in vivo at significant concentrations at specific sites. The pathway of metabolism of flavonoids in mammals in vivo, focusing on aglycone formation, is examined to facilitate better design in the future of in vitro cell culture experiments. In vitro experiments using flavonoids and cultured cells require careful consideration of absorption and bioavailability for their
appropriate interpretation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
564.
通过对水稻 4号染色体一段 32 3kb的序列测定和分析 ,在其中 56kb的区域内发现了一个由 7个编码二氢黄酮醇还原酶 (DFR)类似蛋白基因组成的基因簇。这 7个基因在基因簇中串联排列 ,每个基因都由 6个外显子和 5个内含子组成。这 7个基因的预测蛋白质序列都和DFR以及BANYULS蛋白序列类似。DFR和BANYULS都是植物次生代谢类黄酮醇生物合成途径中的结构基因 ,它们的缺失或突变都会造成植物花色素合成代谢的不正常。RT PCR实验证明这 7个基因在水稻的 5个组织中表达不同。文中讨论了这 7个基因的结构和功能特性以及它们的进化关系。 相似文献
565.
高空气球搭载实验对鸡冠花黄酮类化合物成分的影响 总被引:14,自引:0,他引:14
利用高空气球搭载了2个品种鸡冠花(Celosia cristataL.)的种子,进行空间诱变处理,飞行高度为40.112km,飞行时间近4h,回收后播种栽培,采收子一代(SP1)花序,将各组样品花序的乙醇提取物与Mg HCl,Zn HCl,1?Cl3-乙醇液,2%AlCl3-乙醇液,1%NaOH进行显色反应,呈现黄酮类化合物性质特征颜色,又以槲皮素,山柰酚,异鼠李素为对照品,采用HPLC法测定分析了各搭载组花序中黄酮醇的含是,并与地面对照组比较,结果表明,2个品种鸡冠花搭载组花序黄酮醇总量分别为0.859%,0.864%,比对照组分别提高90.04%,142.02%。高空环境诱变处理对鸡冠花花序中黄酮类化合物合成产生了显著效应。 相似文献
566.
北柴胡茎叶总黄酮抗流感病毒的作用 总被引:31,自引:0,他引:31
北柴胡 (BupleurumchinenseDC .)茎叶总黄酮 (TFB) 0 .0 9g kg剂量组对乙型流感病毒 (B 京防 98 76 )感染小鼠具有明显的保护作用 (P <0 .0 5 ) ,0 .0 3g kg和 0 .0 9g kg剂量组能明显降低乙型流感病毒 (B 京防 98 76 )感染小鼠肺指数值 (P <0 .0 5 ,P <0 .0 1) ,肺指数抑制率分别为 2 0 .5 %和 2 5 .4 %。组织病理学检查结果表明 ,TFB各剂量组与模型组比较 ,肺部病变均明显减轻 ,其中以TFB高剂量组肺部总体病变程度最轻 ,疗效最好。 相似文献
567.
568.
Yan Li Chun Chen Chunping Zhang Jingyu Duan Qunli Wei 《Journal of biomolecular structure & dynamics》2017,35(6):1189-1199
Human serum albumin (HSA) is the major transport protein affording endogenous and exogenous substances in plasma. It can affect the behavior and efficacy of chemicals in vivo through the binding interaction. AKR (3-O-α-l-arabinofuranosyl-kaempferol-7-O-α-l-rhamnopyranoside) is a flavonoid diglycoside with modulation of estrogen receptors (ERs). Herein, we investigated the binding interaction between AKR and HSA by multiple fluorescence spectroscopy and molecular modeling. As a result, AKR specifically binds in site I of HSA through hydrogen bonds, van der Waals force, and electrostatic interaction. The formation of AKR–HSA complex in binding process is spontaneously exothermic and leads to the static fluorescence quenching through affecting the microenvironment around the fluorophores. The complex also affects the backbone of HSA and makes AKR access to fluorophores. Molecular modeling gives the visualization of the interaction between AKR and HSA as well as ERs. The affinity of AKR with HSA is higher than the competitive site marker Warfarin. In addition, docking studies reveal the binding interaction of AKR with ERs through hydrogen bonds, van der Waals force, hydrophobic, and electrostatic interactions. And AKR is more favorable to ERβ. These results unravel the binding interaction of AKR with HSA and mechanism as an ERs modulator. 相似文献
569.
Solution NMR structure of RHE_CH02687 from Rhizobium etli: A novel flavonoid‐binding protein 下载免费PDF全文
Chunjie Liang Jiang Zhu Rui Hu Theresa A. Ramelot Michael A. Kennedy Maili Liu Yunhuang Yang 《Proteins》2017,85(5):951-956
We report the solution NMR structure of RHE_CH02687 from Rhizobium etli. Its structure consists of two β‐sheets that together with two short and one long α‐helix form a hydrophobic cavity. This protein shows a high structural similarity to the prokaryotic protein YndB from Bacillus subtilis, and the eukaryotic protein Aha1. NMR titration experiments confirmed that RHE_CH02687, like its homolog YndB, interacted with flavonoids, giving support for a biological function as a flavonoid sensor in the symbiotic interaction between R. etli and plants. In addition, our study showed no evidence for a direct interaction between RHE_CH02687 and HtpG, the R. etli homolog of Hsp90. Proteins 2017; 85:951–956. © 2016 Wiley Periodicals, Inc. 相似文献
570.
Zübeyir Huyut Şükrü Beydemir İlhami Gülçin 《Journal of biochemical and molecular toxicology》2017,31(9)
Carbonic anhydrases (CAs, E.C.4.2.1.1) play a critical role in many important physiological events and treatment of some diseases. Flavonoids or phenolic compounds have been discovered as novel CAs inhibitors instead of the traditional sulfonamides, with different binding to CAs, pro‐drug activities, and new inhibition mechanisms. Here, we investigated the inhibition effects of some flavonoids including malvin, callistephin, oenin, pelargonin, silychristin, and 1‐(4‐methoxyphenyl)‐2‐methyl‐3‐nitro‐1‐H‐indol‐6‐ol (ID‐8) against hCA I and II, which purified from human erythrocytes by affinity column chromatography. Both hCA isoenzymes were inhibited by flavonoids, with IC50 and Ki values in the range of 2.34 nM to 346.5 μM and 51.01–99.55 μM for hCA I and 86.60–750.00 μM for hCA II, respectively. These results showed that flavonoids especially malvin and oenin effectively inhibited hCA I and II isoenzymes. Hence, they may be used as an effective CA inhibitor in medical applications for treatment of certain diseases such as glaucoma, in the future. 相似文献