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1.
It has been reported that mycelia of the Cordyceps sinensis (CS) can function as an immunostimulant. However, the active constituents of the mycelia are not well known. In this study, we investigated which components of the mycelia of CS induce monocyte activation and then structurally analyzed the active components.  相似文献   

2.
Echinocystic acid (EA), a pentacyclic triterpene, was isolated and identified from the fruits of Gleditsia sinensis Lam. The protective effects of EA were evaluated in rat models with acute myocardial ischemia induced by isoproterenol and vasopressin. In the electrocardiogram of anesthetized rats, EA prevented the ST-segment depression induced by isoproterenol or vasopressin in a dose-dependently manner. Furthermore, the mRNA expression of Bcl-2 was analyzed by RT-PCR. EA shows an elevation of Bcl-2 mRNA level in infarcted tissue induced by isoproterenol in rats. These results demonstrated for the first time EA has a cardioprotective effect and may be a natural drug.  相似文献   

3.
Qi L  Liu CY  Wu WQ  Gu ZL  Guo CY 《Fitoterapia》2011,82(3):383-392
This study aimed to evaluate the radioprotective effect of flavonoids extracted from the seeds of Astragalus complanatus R.Br. (FAC) and their protective mechanism against radiation damage. FAC increased the survival rate of mice and made the damaged organ injured by 60Co γ-irradiation recovered to normal appearance with the mechanism of enhancing immune function and blood-producing function in vivo. The molecule mechanism of FAC against radiation is involved in the reduction of DNA injury and mutation in vitro. Eleven monomers of the FAC were analyzed by HPLC. These results seem to support the use of FAC in relieving radiation damage.  相似文献   

4.
Two new triterpene glycosides named ilexpublesnin A (1) and ilexpublesnin B (2) were isolated from the root of Ilex pubescens. Their structures were determined as 3-O-(β-d-xylopyranosyl)-28-O-(β-d-glucopyranosyl)-3β, 19α-dihydroxyurs-23-oxo-12-en-28-oic acid (1) and 28-O-(β-d-xylopyranosyl-(2 → 1)-β-d-glucopyranosyl)-3β, 19α-dihydroxyurs-23-oxo-12-en-28-oic acid (2) on the basis of chemical and spectroscopic methods.  相似文献   

5.
In this study, the stand level root respiration was estimated for two monoculture plantations: Acacia crassicarpa and Eucalyptus urophylla, based on in situ measurement of specific root respiration using simplified root chamber method. The respiration rates of fine roots (<5 mm) were significantly higher than those of coarse roots (>5 mm) for both A. crassicarpa and E. urophylla species. The root respiration of A. crassicarpa showed a clear seasonal pattern with a higher value in the wet season. For E. urophylla, the seasonal pattern was observed for fine roots but not for coarse roots. After determining the biomass of fine roots and coarse roots and their specific rates of respiration at different time points, root respiration at the stand level (Ra) was estimated using a direct up-scaling model. We found that the Ra accounted for 14% and 19% of total soil respiration (Rs) for A. crassicarpa and E. urophylla, respectively. The fine (RTf) and coarse (RTc) root respiration at the stand level accounted for about 47% and 53% of the Ra for A. crassicarpa, and accounted for 58% and 42% for E. urophylla. This suggests that coarse root respiration cannot be ignored when estimating the root respiration at the stand level. Our results showed that the Q10 values were more accurate in representing the temperature dependence when the confounding effect of soil moisture was considered. This study introduces an alternative approach to estimate stand level root respiration, but its reliability is largely dependent on the accuracy of root biomass quantification.  相似文献   

6.
用天然群落枯枝落叶浸提液浸种与其它处理方法进行伯乐树种子发芽试验,试验分室内和大田萌发试验,室内又进行了不同浸提液、不同激素处理、不同温度处理对伯乐树种子发芽的影响.结果表明:(1)蒸馏水浸种发芽率>伯乐树群落枯枝落叶浸提液浸种发芽率>罗浮栲群落枯枝落叶浸提液浸种发芽率,但差异不大;其中蒸馏水处理的种子发芽率最高(69.2%).(2)以200mg· L-1 GA3浸种12 h发芽率最高,达到80.0%.GA3浸种的伯乐树种子发芽率>蒸馏水浸种的发芽> IAA浸种的发芽率.(3)大田试验的发芽率与室内试验发芽率基本接近;其中酒精浸提液处理的种子发芽率较高,达70.4%.(4)伯乐树发芽最适宜温度是20~25℃.发芽开始后第10~26天为发芽高峰期;发芽可持续32天.(5)在20℃条件下第7-14天腐烂率较高;随着温度的升高,高腐烂率出现的时间推迟,但发芽率相对降低.  相似文献   

7.
Polygonum cuspidatum root has been traditionally used for the treatment of dental diseases in Korea. The purpose of this study was to evaluate effects of P. cuspidatum root on the development of dental caries, especially its effects against bacterial viability and caries-inducing factors of Strptococcus mutans and Strptococcus sobrinus. Among methanol extract of P. cuspidatum root and its fraction tested, ethyl acetate fraction, composed of polydatin, resveratrol, anthraglycoside B, and emodin, showed inhibitory effects on glycolytic acid production and glucosyltransferase activity of S. mutans and S. sobrinus in addition to antibacterial activities.  相似文献   

8.
Efforts in Europe to convert Norway spruce (Picea abies) plantations to broadleaf or mixed broadleaf-conifer forests could be bolstered by an increased understanding of how artificial regeneration acclimates and functions under a range of Norway spruce stand conditions. We studied foliage characteristics and leaf-level photosynthesis on 7-year-old European beech (Fagus sylvatica) and pedunculate oak (Quercus robur) regeneration established in open patches and shelterwoods of a partially harvested Norway spruce plantation in southwestern Sweden. Both species exhibited morphological plasticity at the leaf level by developing leaf blades in patches with an average mass per unit area (LMA) 54% greater than of those in shelterwoods, and at the plant level by maintaining a leaf area ratio (LAR) in shelterwoods that was 78% greater than in patches. However, we observed interspecific differences in photosynthetic capacity relative to spruce canopy openness. Photosynthetic capacity (A1600, net photosynthesis at a photosynthetic photon flux density of 1600 μmol photons m−2 s−1) of beech in respect to the canopy gradient was best related to leaf mass, and declined substantially with increasing canopy openness primarily because leaf nitrogen (N) in this species decreased about 0.9 mg g−1 with each 10% rise in canopy openness. In contrast, A1600 of oak showed a weak response to mass-based N, and furthermore the percentage of N remained constant in oak leaf tissues across the canopy gradient. Therefore, oak photosynthetic capacity along the canopy gradient was best related to leaf area, and increased as the spruce canopy thinned primarily because LMA rose 8.6 g m−2 for each 10% increase in canopy openness. These findings support the premise that spruce stand structure regulates photosynthetic capacity of beech through processes that determine N status of this species; leaf N (mass basis) was greatest under relatively closed spruce canopies where leaves apparently acclimate by enhancing light harvesting mechanisms. Spruce stand structure regulates photosynthetic capacity of oak through processes that control LMA; LMA was greatest under open spruce canopies of high light availability where leaves apparently acclimate by enhancing CO2 fixation mechanisms.  相似文献   

9.
A new glycocerebroside (1), along with one reported one (2), was isolated from the ethanol extract of Sagina japonica (Caryophyllaceae) and was fully characterized. The structures of two compounds were identified as (2S, 3S, 4R, 8E)-1-(β-D-glucopyranosyl-3, 4-dihydroxy-2-[(R)-2′- hydroxypalmitoyl]amino-8-heptadecaene (1) and (2S, 3R, 8E)-1-(β-D-glucopyranosyl-3-hydroxy-2-[(R)-2′-hydroxypalmitoyl]amino-8-octadecaene (2) by using spectroscopic methods (1H, 13C, and 2D NMR, MS) and chemical degradation.  相似文献   

10.
GAPDH is a typical structural protein in eukaryote organism, which plays an important role involved in the biosynthesis of cell composition and the expression of genetic information. In order to reveal the biological function of GAPDH in the growth and development of Eucalyptus, 3 genes were obtained and named as EC-GAP1, EC-GAP2 and EC-GAP3 by amplification with primers for GAPDH genes conserved regions and RACE method from the young leaf of Eucalyptus camaldulensis. The bioinformatics analysis suggested that the proteins encoded by corresponding genes owned the typical conserved domains of GAPDH and showed high homology with those of other plant species.  相似文献   

11.
以杜仲叶片cDNA为模板,采用反转录RCR及RACE技术分离出DXR基因cDNA全长。序列分析结果表明该基因序列全长1 814 bp,共编码478个氨基酸,推导的蛋白质分子量为51.71 kD,理论等电点5.79,命名为EuDXR。推导的EuDXR蛋白质序列具有植物DXR酶的5个典型基序,并预测出26个潜在的功能位点。系统进化树分析表明EuDXR蛋白与玉米、水稻亲缘关系最近,其次为橡胶、拟南芥、烟草。  相似文献   

12.
[目的]克隆马尾松谷胱甘肽过氧化物酶基因,并对其进行功能研究。[方法]采用RACE技术克隆基因c DNA序列,实时荧光定量PCR检测基因在马尾松干旱胁迫下的表达模式,花序浸泡法转化拟南芥,并对转基因与野生型拟南芥的生长表型和根系生长进行分析。利用荧光显微镜技术对转基因拟南芥不定根进行GFP荧光检测。[结果]克隆到1个871 bp的GPX基因全长c DNA序列,命名为Pm GPX6。Pm GPX6包括513 bp的完整开放阅读框,编码170个氨基酸残基。Pm GPX6蛋白与油松Pt GPX蛋白同源性达95%。Pm GPX6在马尾松根中高表达,茎、叶中表达量低。在干旱胁迫下,Pm GPX6在根、茎、叶中的表达量均在第15天达到最大,随后出现下降趋势。过表达Pm GPX6与野生型拟南芥植株在正常水分条件下表型与根长差异不大,但在干旱胁迫下,转基因植株根系更长。转基因拟南芥根在蓝色光激发下能发出强烈的绿色荧光,表明Pm GPX6基因能高效表达。[结论]推测Pm GPX6可能参与马尾松干旱胁迫应答。  相似文献   

13.
Shi L  Fu YL  Chen KS 《Fitoterapia》2007,78(4):298-301
CTPS-01, a water-soluble polysaccharide, was obtained from the root of Cudrania tricuspidata and estimated to have an average molecular weight of 5.9 x 10(3) and to be composed of glucose residues, solely. It contains an average repeating unit of decasaccharide, having a backbone consisting of 1,4-linked alpha-D-glucopyranosyl residues, to which a side chain consisting of terminal and 1,4-linked alpha-D-glucopyranosyl residues is attached at position O-6 of the branching residues.  相似文献   

14.
Climate changes induced by the anthropogenic alteration of the atmospheric radiative balance are expected to change the productivity and composition of forest ecosystems. In Europe, the Mediterranean is considered one of the most vulnerable regions according to climatic forecasts and simulations. However, although modifications in the inter-specific competition are envisaged, we still lack a clear understanding of the ability of the Mediterranean vegetation to adapt to climate changes. We investigated how two co-occurring tree species commonly used in afforestation programmes, the native Abies alba Mill. and the nonnative Picea abies L. Karst., adapt to climate change by assessing their growth performance and physiological responses in relation to past climate variability. Growth was addressed by analysing tree-ring width and carbon and oxygen stable isotopes. Statistical relationships between isotopic value and monthly climate data suggest that the two species underwent ecophysiological adaptation to Mediterranean climatic constraints. These adaptations are also expressed in the ring-width data. Based on the carbon isotope ratio reflecting the stomatal response to drought, we found that the precipitation in the first period of the growing season, i.e. early spring, is a major factor influencing the annual growth of A. alba, which although native, proved to be sensitive to drought. P. abies, on the other hand, showed a higher tolerance to summer drought stress. These findings should help define criteria for sustainability and effective forest conservation in the Mediterranean region.  相似文献   

15.
Two new withanolides named mandragorolide A (1) and mandragorolide B (2) were isolated from the MeOH extract of the whole plant of Mandragora officinarum of Jordanian origin, along with five known withanolides namely larnaxolide A (3), withanolide B (4), datura lactone 2 (5), withanicandrin (6) and salpichrolide C (7). Compound 3 has been reported only once before, from the leaves of Larnax glabra. This is the first report of withanolides of different biogenetic types from the genus Mandragora. Isolation of known fatty compounds, coumarins, sterols and tropane alkaloids was also achieved in this study.  相似文献   

16.
应用RT-PCR和RACE法从麻疯树总RNA中分离出pepc基因全长cDNA,长度为3 142 bp,阅读框2 898 bp,编码965个氨基酸,在GenBank中登录,序列号为EU069413。它的氨基酸序列与蓖麻、陆地棉、橙、大豆、花生、烟草、油菜、拟南芥的氨基酸同源性分别为94.94%、92.46%、90.60%、90.50%、90.50%、88.33%、84.61%、82.44%。该基因编码了pepc基因家族中的pepc1,蛋白属于C3型PEPC。推测了pepc编码蛋白分子量为110.6 kD,并对其稳定性、二级结构、疏水性等特性进行了分析,最后确定了该蛋白的功能位点和结构域。  相似文献   

17.
Bioassay-directed separation of the chloroform extracts from the air-dried aerial part of Alhagi pseudalhagi (M.B.) led to the isolation of a new isoflavonolignan (1), together with five known isoflavones (26) (Fig. 1). Their structures were identified on the basis of spectral analysis of NMR, MS, IR, UV and CD spectral evidences. The quinone reductase (QR) inducing activities of the extracts and compound 1 were evaluated and the new isoflavonolignan (1) exhibited moderate quinone reductase (QR) inducing activity for hepa lclc7 cells.  相似文献   

18.
对欧洲黑杨α-expansin基因PnEXPA1的SNP多态性与水分利用效率相关性状稳定碳同位素比率(δ13C)进行了关联分析。利用SNaPshot技术对PnEXPA1基因内11个SNP位点进行了基因型分型,发现各SNP位点优势基因型均为纯合,且其频率高于杂合基因型。关联分析显示:SNP8和SNP12在采用单因素方差分析(ANOVA)和一般线性模型(GLM)2种方法时均与δ13C值显著关联。SNP8为exon 1内的无义突变,可解释6.620%的表型变异;而SNP12位于intron 1中,遗传贡献率为6.613%;这2个SNP位点与SNP9、SNP13共同位于一个高连锁不平衡(LD)的单倍型块中。SNP8与SNP12的TT基因型无性系均具有较高的δ13C值,为优势基因型。  相似文献   

19.
采用Wolbachia的通用引物、A大组和B大组的特异性引物对一种新的白蜡虫寄生蜂--长尾啮小蜂(Aprostocetus sp.)体内Wolbachia的wsp基因进行分子检测,所获得的基因片段分别命名为wApr、wAprB和wAprB,长度分别为620、566和463bp;基因序列分析表明:wApA、wAprB与w...  相似文献   

20.
Polycarpol, sitosterol and sitosterol-3-O-β-D-glucoside isolated for the first time from Piptostigma preussi (Annonaceae) occur regularly in some Annonaceae such as Piptostigma genus. Polycarpol exhibits interesting antitrypanosomal activity with an ED50 value of 5.11 µM on Trypanosoma brucei cells. Moreover, it inhibits T. brucei glycolytic enzymes GAPDH and PFK with IC50 values of 650 and 180 µM respectively.  相似文献   

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