鼬瓣花中的黄酮苷

从鼬瓣花甲醇提取物中分离得到4个黄酮苷类化合物,运用光谱技术鉴定了它们的结构,分别为洋芹素-7-O-(6″-O-p-羟基肉桂酰)-β-D-吡喃葡萄糖苷(1),洋芹素-7-葡萄糖苷(2),木犀草素-7-葡萄糖苷(3)和黄芩苷(4)。化合物1为首次从鼬瓣花属植物中分离获得。     

一点红黄酮成分的分析及含量测定

对一点红中黄酮类成分进行了定性分析和定量测定,结果表明,在一点红中含有黄酮、黄酮醇、二氢黄酮、二氢黄酮醇等多种黄酮类化合物,并以芦丁为标样,用分光光度法测出总黄酮含量为4．02％。     

欧亚旋覆花总黄酮提取与富集工艺研究

为研究欧亚旋覆花总黄酮的最佳提取与大孔吸附树脂富集工艺,采用不同溶剂、多种提取方法、L9(34)正交实验优化及AB-8大孔吸附树脂富集,结果表明其最佳提取工艺为用10倍量水为溶剂回流提取3次,每次1h,再结合AB-8大孔吸附树脂富集,以70%乙醇洗脱效果最佳,总黄酮回收率达90%,总黄酮含量达50%以上。此工艺简便可行,符合工业化生产要求。     

短叶假木贼中化学成分的分离和结构鉴定

从短叶假木贼(Anabasis brevifolia)的氯仿提取物中分离得到了9个化合物,经UVI、R、MS和NMR等波谱技术分析,并结合文献对照,确定其结构为-Ncis-feruloyltyramine(1)、N-trans-feruloyltyramine(2)、-Ncis-feruloyl-3-methoxytyramine(3)、-Ntrans-feruloyl-3-methoxytyramine(4)、3′,5,7-trihydroxy-4,′6-dimethoxy flavonoid(5)、eupatilin(6)、丁香脂素(7)、β-谷甾醇(8)、β-谷甾醇3-O-β-D-吡喃葡萄糖苷(9)。这些化合物均为首次从假木贼属(AnabasisL.)植物中分离得到。     

假苍耳的生活史进程中几种生理生化指标的变化

本文试图从生理生化的角度对假苍耳(Iva xanthifolia)生活史进程中可溶性糖类、赤霉素、单宁以及黄酮的变化进行探讨。通过对假苍耳在生长发育期间几种生理生化指标的测定,结果表明,在假苍耳生活史进程的不同阶段,其体内各种代谢产物的含量基本都在种子或芽阶段具有最高含量。此外,不同发育阶段可溶性还原糖含量的变化规律相似：芽＞花序＞苗＞成株＞种子。除在花序和苗阶段没有测到海藻糖,其他各阶段海藻糖的含量变化如下：芽＞成株＞种子。另外,只有在种子阶段检测到棉子糖,其含量为15.43 mg·g~(-1)。赤霉素含量的变化规律如下：种子＞芽≈苗≈花序＞成株。单宁含量的变化趋势：种子＞成株＞苗＞芽＞花序。黄酮含量的变化趋势：种子＞芽＞成株≈花序＞苗。值得注意的是,当单宁/黄酮的比值接近1时,植物体内需要的单宁和黄酮的含量则相对较低;相反,当单宁/黄酮的比值接近0时,植物体内需要的单宁和黄酮的含量则较高。     

Effect of total flavonoid in rabdosia rubescens on tolerant mice models under cerebral anoxia

ObjectiveTo study the protective effect of total flavonoid in rabdosia rubescens on BIT model by brain ischemic tolerance (hereinafter BIT) model of mice.MethodBIT model is used to block bilateral common carotid arteries and to copy BIT model of mice. After 10 min of transient ischemia for rats in preconditioning group, the mice in the nimodipine group and naoluotong capsule group were given the total flavonoid in rabdosia rubescens (300 mg/kg, 150 mg/kg, 75 mg/kg) for gavage, sham operation group, ischemia/reperfusion injury (hereinafter IRI) group and BIT group were fed with the same volume of 0.5% sodium carboxymethyl cellulose (CMC) once a day for 5 days. After administration for 1 h on day 5 (120 h), the rats in the other groups except for the sham operation group were treated with blood flow block for 30 min and reperfusion for 22 h. The serum NSE level were measured and the brain NO content and NOS activity changes was measured to observe the histopathological changes of brain tissue.ResultsBIT models of mice and in rats were both successfully replicated. The total flavonoid in rabdosia rubescens can decrease the mortality of mice, decrease serum NSE level, increase the content of NO and the activity of NOS in the brain tissue of mice, and improve the pathological damage of cortex and hippocampus of mice.ConclusionThe total flavonoid in rabdosia rubescens can stimulate an endogenous protective mechanism by inducing the release of low levels of cytokines NO and NOS, which reduces the release of serum NSE, relieves the brain tissue ischemia-reperfusion injury, and further improves the protection effect of ischemic preconditioning on brain injury. The damage of brain tissue ischemia and reperfusion, and further improve the ischemia Protective effect of preconditioning on brain injury.     

操纵茶树类黄酮3′-羟基化酶生物合成B环-3′,4′-二羟基黄酮类化合物

【目的】操纵茶树类黄酮3′-羟基化酶,生物合成B环-3′,4′-二羟基黄酮类化合物圣草酚、二氢槲皮素和槲皮素。【方法】构建了4个茶树类黄酮3′-羟基化酶基因(CsF3′H)和拟南芥的P450还原酶基因(ATR)融合表达质粒:SUMO-CsF3'H[7-517]::ATR1[49-688]3 AA、SUMO-CsF3'H[28-517]::ATR1[49-688]3 AA、SUMO-CsF3'H[7-517]::ATR2[75-711]3 AA和SUMO-CsF3'H[28-517]::ATR2[75-711]3 AA,分别转化大肠杆菌菌株TOP10、DH5α和BL21,获得12个转化菌株S1–S12;构建了茶树类黄酮3′-羟基化酶基因CsF3′H表达质粒p YES-Dest52-CsF3′H,转化酵母菌株WAT11,得到转化菌株S13;构建了茶树类黄酮3′-羟基化酶基因CsF3′H表达质粒pES-URA-CsF3′H,及茶树黄烷酮3-羟基化酶基因CsF3H与拟南芥黄酮醇合成酶基因At FLS的融合表达质粒pES-HIS-CsF3H::At FLS 9AA,二者共转化酵母菌株WAT11,获得转化菌株S14。【结果】转化SUMO-CsF3'H[28-517]::ATR1[49-688]3 AA质粒的TOP10菌株S6在25°C条件下发酵,转化效率最高,能将1000μmol/L柚皮素、二氢山奈酚和山奈酚,分别转化生成287.93μmol/L圣草酚、131.76μmol/L二氢槲皮素和188.62μmol/L槲皮素。发酵菌株S13能分别将1000μmol/L柚皮素、二氢山奈酚和山奈酚,最多能转化生成734.32μmol/L圣草酚、446.07μmol/L二氢槲皮素和594.64μmol/L槲皮素。喂食S14发酵菌株5 mmol/L的底物柚皮素,在发酵36–48 h中,最多能生成1412.16μmol/L圣草酚、490.25μmol/L山奈酚、445.75μmol/L槲皮素、66.75μmol/L二氢槲皮素和73.50μmol/L二氢山奈酚。【结论】本研究首次将茶树类黄酮3′-羟基化酶基因应用于B环-3′,4′-二羟基黄酮类化合物圣草酚、二氢槲皮素和槲皮素的生物合成。     

3个向日葵品种生长期内水分、蛋白质和总黄酮含量动态变化

本实验研究了3个向日葵品种在生长周期内茎、叶及茎叶混合样的水分、蛋白质和总黄酮含量的动态变化.结果表明:向日葵不同品种、不同生长期以及同一品种的不同部位的水分、蛋白质、总黄酮含量均存在差异.水分含量整体呈现下降趋势,且茎＞茎叶混合＞叶;蛋白质含量为叶＞茎叶混合样＞茎,其中高秆食用葵叶片中蛋白质含量为8.10g/100g...     

Flavonols: old compounds for old roles

Background

New roles for flavonoids, as developmental regulators and/or signalling molecules, have recently been proposed in eukaryotic cells exposed to a wide range of environmental stimuli. In plants, these functions are actually restricted to flavonols, the ancient and widespread class of flavonoids. In mosses and liverworts, the whole set of genes for flavonol biosynthesis – CHS, CHI, F3H, FLS and F3′H – has been detected. The flavonol branch pathway has remained intact for millions of years, and is almost exclusively involved in the responses of plants to a wide array of stressful agents, despite the fact that evolution of flavonoid metabolism has produced >10 000 structures.

Scope

Here the emerging functional roles of flavonoids in the responses of present-day plants to different stresses are discussed based on early, authoritative views of their primary functions during the colonization of land by plants. Flavonols are not as efficient as other secondary metabolites in absorbing wavelengths in the 290–320 nm spectral region, but display the greatest potential to keep stress-induced changes in cellular reactive oxygen species homeostasis under control, and to regulate the development of individual organs and the whole plant. Very low flavonol concentrations, as probably occurred in early terrestrial plants, may fully accomplish these regulatory functions.

Conclusions

During the last two decades the routine use of genomic, chromatography/mass spectrometry and fluorescence microimaging techniques has provided new insights into the regulation of flavonol metabolism as well as on the inter- and intracellular distribution of stress-responsive flavonols. These findings offer new evidence on how flavonols may have performed a wide array of functional roles during the colonization of land by plants. In our opinion this ancient flavonoid class is still playing the same old and robust roles in present-day plants.