Effects of growing location on the contents of secondary metabolites in the leaves of four selected superior clones of Eucommia ulmoides

The interior quality of an herbal medicine is determined by its secondary metabolites. Secondary metabolites that are contained in medicinal plants may be different in types, contents, and proportions of the constituents because of the differences in production locations. Four excellent clones of Eucommia ulmoides, Qinzhong No. 1 to 4, which have been selected from 40 clones from all over China, were planted in 6 main cultivation locations. The contents of secondary metabolites, including chlorogenic acid, flavonoids and geniposidic acid contained in the leaves of each clone were measured. Gray correlation and path analysis were conducted among the contents of secondary metabolites and environmental factors, such as altitude, annual sunshine duration, annual precipitation, and annual average temperature. The results showed that environmental factors had significant impacts on the contents of secondary metabolites of the 4 clones. High degrees of association were found between altitude, annual average temperature in the locations tested and the contents of chlorogenic acid and flavonoids, between the annual sunshine duration, annual average temperature and the contents of geniposidic acid. Altitude and annual average temperature are key environmental factors for the accumulation of chlorogenic acid and flavonoids, while annual sunshine duration and annual average temperature are key ones for geniposidic acid. Altitude and annual average temperature were significantly and positively correlated to the contents of chlorogenic acid and flavonoids (P < 0.05). Annual sunshine duration was significantly and positively correlated to the content of geniposidic acid (P < 0.05), while annual average temperature was significantly and negatively correlated to the content of geniposidic acid (P < 0.05). No significant correlation was observed between the annul precipitation and the contents of each secondary metabolite. It was concluded that from the view of the contents of the secondary metabolites, Lueyang in Shaanxi Province, Lingbao in Henan Province, and Zunyi in Guizhou Province are preferable for the cultivation of E. ulmoides in China.     

青稞4-香豆酸辅酶A连接酶基因4CL的克隆及表达分析

为了进一步了解4-香豆酸辅酶A连接酶(4-coumarate:CoA ligase;4CL)基因在黄酮合成中的作用,利用RT-PCR和cDNA末端快速扩增技术(rapid amplification of cDNA ends,RACE)获得了青稞4CL基因(Hv4CL)的cDNA全长序列,并利用实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)技术,对该基因在青稞4个胚乳发育时间段茎、叶和花中的表达情况进行研究。结果表明,Hv4CL基因cDNA序列全长2 107bp,该序列包含一个完整的开放阅读框(ORF,1 662bp),编码553个氨基酸。Hv4CL与小麦同源性最高(96%),且该蛋白序列中包含2个保守的box,即AMP结合盒:boxⅠ(SSGTTGLPKGV)和boxⅡ(GEICIRG)。qRT-PCR分析结果表明:4CL基因在青稞不同发育时期、不同组织的表达丰度不同,在茎中表达量最高,其次是叶和籽粒。     

胡椒叶抗氧化物质提取条件初探

采用系统溶剂提取法处理胡椒叶,确定了胡椒叶的乙醇提取相和水提取相具有较强的DPPH自由基清除能力和较高的多酚含量;通过对胡椒嫩叶、完全稳定叶和老叶的乙醇和水提取液的DPPH自由基清除能力和多酚含量的测量,得出胡椒嫩叶的多酚含量较高,抗氧化活性较高,老叶次之;采用不同浓度的乙醇水溶液常温搅拌浸提胡椒老叶,得出50%左右的乙醇水溶液提取液具有较强的清除自由基能力,较高的多酚含量(5.4 g/100g)和黄酮类化合物含量(0.8 g/100g)。     

超声波辅助提取铜锤玉带草茎叶黄酮类化合物的工艺研究

[目的]研究超声波辅助提取铜锤玉带草茎叶黄酮类化合物的最优工艺。[方法]以浓度70%乙醇为溶剂,采用超声波作辅助提取设备,通过单因子试验确定影响黄酮类化合物提取的主要因素及其最佳水平范围,并通过L9(34)正交试验确定最优提取条件。[结果]影响铜锤玉带草茎叶黄酮类化合物提取的因素主次为:超声波功率浸提温度提取时间料液比;最优工艺条件为:超声波功率350 W,浸提温度60℃,提取时间30 min,料液比1∶20(g/ml);在该工艺条件下,铜锤玉带草茎叶黄酮类化合物的含量为38.437 mg/g。[结论]试验得出的最优工艺条件可为铜锤玉带草的开发利用提供依据。     

植物天然成分黄酮类化合物的提取方法

黄酮类化合物是广泛存在于植物体的一大类天然活性成分,具有多种药理和保健作用,在食品、药品、保健品等方面得到广泛应用。对黄酮类化合物提取方法的研究现状进行了综述,并对其发展前景进行了展望。     

Flavonoid mixture ameliorates increase in erythrocyte osmotic fragility and malondialdehyde concentration induced by Trypanosoma brucei brucei-infection in Wistar rats

The experiment was performed with the aim of investigating the effect of a flavonoid mixture, Daflon® 500 mg (DF) on the erythrocyte fragility and lipoperoxidative changes, induced by Trypanosoma brucei brucei infection in Wistar rats. Fifty adult male rats randomly divided into five groups of 10 animals each were used. Rats in the control group were administered (1 mL/kg) distilled water only, while the other groups were infected with T. brucei brucei and treated with Daflon® 500 mg and/or Diminazene aceturate. At the end of 5 weeks, EDTA-blood samples and serum samples were collected from the rats, and were used to determine erythrocyte osmotic fragility (EOF) and serum malondialdehyde (MDA) concentration respectively. The results showed that EOF and MDA concentration significantly (P < 0.05) increased in the infected untreated group when compared to the treatment groups. Treatment with Daflon® 500 mg and Diminazene aceturate significantly (P < 0.05) reduced trypanosome-induced increases in EOF and lipoperoxidative changes, suggesting possible antioxidant properties of Daflon® 500 mg and its therapeutic value in trypanosomosis.     

纤维素酶辅助法在植物黄酮类化合物提取中的应用(英文)

叙述了纤维素酶辅助法在黄酮类化合物提取中的提取机理,以及其在豆科、银杏科、芸香科、唇形科等植物中提取黄酮类化合物的应用;此外,对与其他技术结合的方法(纤维素酶-超声辅助法、纤维素酶-微波辅助法)在黄酮类化合物提取中的进展也作了描述。     

不同月份元宝枫叶内黄酮、绿原酸含量的变化

以5年生元宝枫苗为试材,用方差分析和多重比较的方法研究了元宝枫叶内黄酮、绿原酸含量及有关成分随月份的变化规律。结果表明:元宝枫叶内黄酮含量8月份最高,含量高达5.86%,绿原酸含量6月份最高,含量高达3.62%,SOD酶活性8月份最高,叶绿素含量6月份最高,可溶性糖含量9月份最高,月份不同其含量也不同,不同月份下,黄酮、绿原酸、叶绿素、可溶性糖含量均以a=0.01水平上差异极显著,而SOD酶活性以a=0.05水平上差异显著。     

Specific flavonoids as interconnecting signals in the tripartite symbiosis formed by arbuscular mycorrhizal fungi, Bradyrhizobium japonicum (Kirchner) Jordan and soybean (Glycine max (L.) Merr.)

Many legume plants benefit from the tripartite symbiosis of arbuscular mycorrhizal fungi (AMF) and rhizobia. Beneficial effects for the plant have been assumed to rely on increased P supply through the mycorrhizas. Recently, we demonstrated that P does not regulate the establishment of the tripartite symbiosis. Flavonoids appear to play a role as early signals for both rhizobia and AMF. Four soybean lines known to express different concentrations of the isoflavones genistein, daidzein and glycitein in the seed were used to test three hypotheses: (i) The establishment of the tripartite symbiosis is not dependent of a nutrient mediated effect; (ii) There is a positive correlation between seed isoflavone concentrations of different soybean lines and the progress of the tripartite symbiosis; (iii) Specific flavonoids control the establishment of the tripartite symbiosis in that a change in flavonoid root accumulation resulting from the development of one microbial partner can stimulate colonization of soybean roots by the other. Disturbed versus undisturbed soil treatments were produced to vary the potential for indigenous AMF colonization of soybean. In contrast, the potential for Bradyrhizobium was kept identical in both soil disturbance treatments. The uptake of P and Zn and the concentration of flavonoids in mycorrhizal soybean roots at 10 d after emergence were analysed either separately of Bradyrhizobium or in context of the tripartite symbiosis. Zinc nutrition did not differ between AMF treatments which supports the first hypothesis. The concentration of daidzein was at least four times greater in the root than in the seed reaching 3958±249 μg g⁻¹ dry across soybean lines. Coumestrol, which was absent in the seed, was synthesized to reach 2154±64 μg g⁻¹ dry. Conversely, the concentration of genistein was approximately three times smaller in the root that in the seed (301±15 μg g⁻¹ dry), while glycitein and formononetin were never detected. The establishment of the tripartite symbiosis was identical across soybean lines which does not support the second hypothesis. Concentrations of flavonoids were significantly greater in roots under disturbed soil, for which both symbioses were not as developed as in plants from undisturbed soil. This clearly supports the third hypothesis. This research provides the first data linking the function of different flavonoids to the establishment of the tripartite symbiosis, and suggests that these compounds are produced and released into the rhizosphere as a function of the colonization process.     

Nitrate alters the flavonoid profile and nodulation in pea (Pisum sativum L.)

A rhizosphere application of NO _inf3 ^sup- and/or naringenin affected the Pisum sativum — Rhizobium leguminosarum biovar viciae symbiosis. NO _inf3 ^sup- (5 mM) lowered while naringenin raised the nodulation status (nodule numbers and weight) and nodule efficiency (C₂H₂ reduction activity). However, the inhibitory effect of NO _inf3 ^sup- was to some extent alleviated when applied in combination with naringenin. The plant biomass was increased by the application of NO _inf3 ^sup- and naringenin, either alone or in combination, while a higher root: shoot ratio was observed only in the naringenin-treated plants. Root flavonoids are known to regulate the expression of nod genes; their high-performance liquid chromatography profile was influenced in different ways by NO _inf3 ^sup- and naringenin.