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1.
人心果乳汁成分的定性分析   总被引:14,自引:6,他引:8  
对人心果果实乳汁水提取液、石油醚提取液及乙醇提取液化学成份的化学分析结果表明,人心果果实乳汁中含有氨基酸、多肽、蛋白质、糖类、酚类、黄酮类、生物碱、甾体、萜类、有机酸、鞣质、挥发油等化学成分;可能含有皂甙、强心甙、油脂等化学成分;不含苯醌类、香豆素、内酯类化合物等化学成分。其中萜类是最值得开发利用的一类化学物质。  相似文献   

2.
太白米化学成分初步研究   总被引:1,自引:0,他引:1  
对假百合属植物太白米茎叶、大鳞茎、小鳞茎3部分做化学成分系统预试,显示含有生物碱、皂甙、强心甙、黄酮、酚性成分、挥发油、甾体及萜类、糖类、有机酸、氨基酸等物质,但各成分的含量在植物不同部位存在差异。  相似文献   

3.
蝙蝠葛茎叶中化学成分的研究   总被引:7,自引:0,他引:7  
初步确定了蝙蝠葛茎叶所含化学成分,结果表明,其中含有生物碱、甾体成分、内酯、香豆素及其甙类、酸性成分、鞣质、油脂、糖类及氨基酸、蛋白质。并对其粗总生物碱含量进行测定,生物碱含量达0.69%。  相似文献   

4.
香椿化学成分的初步研究   总被引:35,自引:2,他引:33  
采用系统预试法,对香棒化学成分进行了初步的定性检验。结果表明,香椿嫩叶、叶中含有黄酮、萜类、蒽醌、皂甙、鞣质、生物碱等重要药用成分;香椿种子内含有醛、酮、萜类、皂甙、甾体和挥发油等,而挥发油中含有单质硫、硫华。本文对香椿可能具有的药用功效和环保功效进行了探讨。  相似文献   

5.
板栗壳化学成分的初步研究   总被引:25,自引:0,他引:25  
通过系统预试和单项预试,初步确定了板栗壳中含有酚类、有机酸、糖、多糖(或甙类)、内酯、香豆素、鞣质、甾体(或三萜)和黄酮等成分。  相似文献   

6.
紫椴花和果实化学成分及其地理变异   总被引:1,自引:0,他引:1  
采集不同地点紫椴花和果实,通过系统预试验,检测出紫椴花及花蕾中含有较多的酚类、糖和甙类,还检测到黄酮类化合物、蛋白质、香豆素及强心甙等,在花蕾中还含有少量鞣质.紫椴果实中含有酚类、糖和甙类,还含有少量黄酮化合物、香豆素和鞣质.对不同纬度和海拔紫椴花和果实中可溶性糖、总酚和黄酮的含量进行分析,发现3类化学成分含量随纬度、海拔的变化存在一定的变化规律.除花中总酚含量差异不显著外,紫椴花和果实中其他化学成分含量随着纬度升高而降低,随着海拔升高而增高.紫椴花中可溶性糖含量明显高于果实,其他化学成分在花和果实中的含量接近.化学成分含量聚类分析与遗传距离聚类分析比较表明:化学成分含量变异在纬度上是不连续的,在海拔梯度上是连续的.  相似文献   

7.
目前为止,从山核桃(Carya cathayensis)外果皮中提取的化学成分达60种多种,具有应用潜力的有效成分20多种,主要为生物碱类、醌类、黄酮类、酚类和酸类等具有生物活性的成分,具有抗菌消炎、抗氧化、镇痛、抗肿瘤及染色等作用。但是,化学提取手段仍需不断地深入研究,同时,缺少对于抗癌用途有效成分和药理作用的系统实验。  相似文献   

8.
中国沙棘果实化学成分初步研究   总被引:6,自引:0,他引:6  
采用系统预试法,对中国沙棘果皮渣所含化学成分进行了定性检验,并测定了油脂和黄酮含量。结果表明,中国沙棘果实含有鞣质,有机酸,酚类,黄酮类、挥发油及油脂,并且油脂和黄酮含量较高。  相似文献   

9.
柿叶化学成分及其抑菌活性研究   总被引:9,自引:0,他引:9  
对柿叶的化学成分进行了定性分析和抗菌活性的研究.通过系统预试,初步确定柿叶中含有生物碱、皂苷、氨基酸、多肽、有机酸、酚类和鞣质、糖类、甾体、总黄酮、强心苷、蒽醌、挥发油等物质.抑制活性试验结果显示:乙醇提取物和乙酸乙酯萃取物对供试的6种细菌有较强的抑制作用;水相对供试的5种真菌有较强的抑制作用,而且对细菌有较小抑制作用;石油醚相对真菌和细菌几乎无抑制作用;正丁醇萃取物对细菌有不同程度的抑制作用,而对真菌无抑制作用.用不同质量浓度的乙酸乙酯提取物进行抑菌活性试验,结果显示:质量浓度越高,其抑菌能力越强,而且,在不同质量浓度下,对测试的6个细菌的抑制活性的大小顺序不一致.  相似文献   

10.
鸡屎藤地上部分化学成分的初步研究   总被引:5,自引:2,他引:5  
通过系统预试和单项预试,初步确定鸡尿藤地上部分含有酚类,有机酸,生物碱,氨基酸、多肽(或蛋白质)、糖、多糖(或甙类)、黄酮及其甙类、甾醇(或三萜)和挥发油等成分。  相似文献   

11.

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.  相似文献   

12.

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.  相似文献   

13.

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.  相似文献   

14.

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.  相似文献   

15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。  相似文献   

16.

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.  相似文献   

17.
18.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.  相似文献   

19.
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.  相似文献   

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