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1.
GC-O与GC-MS联用法鉴定香竹竹叶中关键气味活性物质   总被引：3，自引：1，他引：2  
实验运用SDE方法对香竹竹叶中挥发性物质进行提取,利用GC-O与GC-MS联用的法方对其中气味活性物质进行定性分析,共鉴定出29种气味活性物质.研究发现,对香竹竹叶的特征性气味起关键性作用的化合物种类主要有醇(9种)、醛(9种)、萜类化合物(5种)、酮(3种)、酯类(2种)和含硫化合物(2种).香竹竹叶中重要的气味活性化合物为2-甲基丁醛(黑巧克力味),嘧啶(刺激味,辛辣味),2-甲基噻吩(刺鼻汽油味),己醛(青草味),糠醛(烤香、肉香),3-己烯醛(青草味),1-庚烯-3-醇(青草味、刺激味),乙二硫醚(刺激味、咸菜味),3-甲硫基丙醛(煮土豆味、煮肉味),2-甲基-3-呋喃硫醇(甜香),辛醛(花香,绿草,橘皮味),橙花醇/香叶醇(橘子味、花香).  相似文献   

2.
双稠哌啶类生物碱分子结构与杀线活性间关系   总被引：19，自引：2，他引：19  
赵博光 《林业科学》1998,34(5):61-68
使用培养基法和棉球法测定了苦豆碱、野靛碱、甲基野靛碱、苦参碱对松材线虫的杀线活性。两种生测方法测得的结果一致,表明苦豆碱的杀线活性最强,其ｌｏｇ（１／ＩＤ５０）（ｍｏｌ／棉球）＝８．６７,与文献中用同样方法测定的对松材线虫杀线活性的其它７种双稠哌啶类生物碱的杀线活性相比较,它也是最强。本文提出了双稠哌啶类生物碱对松材线虫的杀线活性强弱主要受其分子结构中官能团对的类型及其中的官能团的类型控制的假说。根据这一假说,推测了具高杀线活性的生物碱的分子结构。  相似文献   

3.
以异长烯酮为原料,通过缩合、亲核取代和环化等手段合成了11种新型异长叶烯基噻唑类化合物,同时采用1H NMR、13C NMR、LC-MS和FT-IR对化合物进行了鉴定,从而确定了化合物的结构。对目标化合物进行了抑菌活性实验,结果表明:(E)-4-(4-甲氧基苯基)-2-(2-(1,1,5,5-四甲基-3,4,5,6-四氢-1H-2,4a-亚甲基-7(2H)-亚基)肼基)噻唑(2e)与(E)-4-(4-甲基苯基)-2-(2-(1,1,5,5-四甲基-3,4,5,6-四氢-1H-2,4a-亚甲基-7(2H)-亚基)肼基)噻唑(2g)对细菌(大肠杆菌与金黄色葡萄球菌)具有较好的抑制效果,最低抑菌质量浓度(MIC)为7.8 mg/L。(E)-4-氯苯基-2-(2-(1,1,5,5-四甲基-3,4,5,6-四氢-1H-2,4a-亚甲基-7(2H)-亚基)肼基)噻唑(2b)对真菌(白念球菌与热带假丝酵母)抑制效果优于其他化合物,其MIC值为15.6 mg/L。采用噻唑蓝(MTT)法对目标化合物进行了人体肝癌细胞(HepG 2)抗癌活性测试,化合物2g(IC50=43.9±0.9 mg/L)对HepG 2具有较好的抗癌活性。  相似文献   

4.
以诺蒎酮为原料,合成了新型的4-吡啶基-2-氨基嘧啶类化合物,并探索了该类化合物的抑菌和抗虫活性。诺蒎酮分别与吡啶-3-甲醛和吡啶-4-甲醛在乙醇钠催化作用下缩合制得3-(3'-吡啶)亚甲基诺蒎酮(2a)和3-(4'-吡啶)亚甲基诺蒎酮(2b),2a和2b在叔丁醇钾催化作用下与盐酸胍经环化反应,得到新型吡啶基嘧啶类化合物5,6,7,8-四氢-4-(3'-吡啶基)-7,7-二甲基-6,8-桥亚甲基喹唑啉-2-胺(3a)和5,6,7,8-四氢-4-(4'-吡啶基)-7,7-二甲基-6,8-桥亚甲基喹唑啉-2-胺(3b)。采用1H NMR、13C NMR、IR、MS和HRMS对化合物3a和3b的结构进行了表征,探讨了化合物3a和3b的抑菌活性和对萝卜蚜虫(Lipaphis erysimi)和紫薇长斑蚜虫(Tinocallis kalawaluokalani)的杀虫活性。结果表明,合成的化合物对细菌和真菌具有较好的抑制效果,其中3b对枯草芽孢杆菌(Bacillus subtilis)有较强的抑制作用,最低抑菌浓度为7.80μg/m L。化合物对蚜虫均表现出较好的杀虫活性,在50 mg/L的浓度下对蚜虫的致死率可达60%以上。通过分析化合物的抗虫活性,为开拓松节油的深加工应用提供理论依据。  相似文献   

5.
从小叶臭黄皮(Clausena excavata Burm F.)的茎和叶中分离得到10个单萜基香豆素,分别鉴定为7-((E)-3'-甲基-4'-(8'-羰基-7',9'-烯-呋喃)-2'-烯)-香豆素(1)、7-((E)-3'-甲基-4'-(7'-甲基-8'-羰基-6'-烯-呋喃)-2'-烯)-香豆素(2)、7-((E)-3'-甲基-4'-(7'-甲基-6'-亚甲基-8'-羰基-呋喃)-2'-烯)-香豆素(3)、7-((E)-3'-甲基-4'-(9'-羟基-8'-羰基-6'-烯-呋喃)-2'-烯)-香豆素(4)、7-(3'-甲基-4'-(7'-甲基-8'-羰基-6'-烯-呋喃)-2',3'-环氧丁烷)-香豆素(5)、7-(3'-甲基-4'-(9'-羟基-8'-羰基-6'-烯-呋喃)-2',3'-环氧丁烷)-香豆素(6)、7-(3'-甲基-4'-(7'-甲基-7'-羟基-8'-羰基-6'-烯-呋喃)-2',3'-环氧丁烷)-香豆素(7)、7-(3'-甲基-4'-(7'-甲基-8'-羰基-呋喃)-2',3'-环氧丁烷)-香豆素(8)、5'-羟基葡萄内酯(9)和7-((E)-7'-羟基-3',7'-二甲基-2',5'-二烯)-香豆素(10),2个四降三萜,鉴定为11β-羟基-1α-乙酰基黄柏酮(11)、11β-羟基黄柏酮(12)和1个木脂素,鉴定为(-)-丁香脂素(13)。其中化合物11和13为首次从该植物中分离得到。测定了化合物1、2、3、11和12对癌细胞株A549、Hela和BGC-823的细胞毒活性,及其对白色念珠菌(Candida albicans)、金黄色葡萄球菌(Staphylococcus aureus)的抑菌活性。结果显示,化合物1对Hela和A549均有细胞毒活性,其半数抑制质量浓度(IC_(50))值分别为11.26和13.55 mg/L,化合物3对BGC-823有细胞毒活性,其IC_(50)值为16.65 mg/L,5个化合物对白色念珠菌和金黄色葡萄球菌均没有抗菌活性。  相似文献   

6.
为了寻求无公害的杀虫剂,设计合成了系列新型的含有去氢枞酸骨架的1,3,4-噻二唑衍生物。利用1H NMR、IR、MS和元素分析等手段对所合成新化合物进行了分析和表征。探讨了化合物对棉铃虫(Helicoverpa armigera)、玉米螟(Ostrinia nubilalis)和小菜蛾(Plutella xylostella)的杀虫活性。研究表明在200 mg/L质量浓度下,化合物N-(5-去氢枞基-1,3,4-噻二唑-2-基-)-N'-苯基硫脲(3a)和N-(5-去氢枞基-1,3,4-噻二唑-2-基-)-N'-间甲基苯基硫脲(3c)对棉铃虫具有良好的杀虫活性,防效率分别达到93.3%和83.3%,而化合物N-(5-去氢枞基-1,3,4-噻二唑-2-基-)-N'-邻甲基苯基硫脲(3b)、N-(5-去氢枞基-1,3,4-噻二唑-2-基-)-N'-间甲基苯基硫脲(3c)、N-(5-去氢枞基-1,3,4-噻二唑-2-基-)-N'-对甲基苯基硫脲(3d)和N-(5-去氢枞基-1,3,4-噻二唑-2-基-)-N'-对氯苯基硫脲(3i)对玉米螟具有一定的杀虫活性,防效率分别为66.7%、66.7%、73.3%和60%;此外,对化合物构效关系也进行了讨论,发现苯环上4位取代基对棉铃虫和玉米螟的防效率贡献分别为HCH3ClCF3OCH3Br=F和CH3ClBrFH=CF3OCH3。  相似文献   

7.
指出了假海桐(Pittosporopsis kerrii)是西双版纳热带雨林林下的优势植物,为探讨其花气味及传粉昆虫多样性,针对其开花特性、花气味及访花昆虫进行了相关研究。结果表明:假海桐开花早,种群内花期持续时间长,主要集中在2～3月份,单花期3～4d,单株盛花期8～10d。访花昆虫54种,大蜜蜂(Apis dorsata)是最为优势的传粉昆虫。鉴定出花气味的13种化合物,主要由萜类、脂肪酸衍生物和芳香族化合物三大类构成,含量最高的是α-甲基-α-[4-甲基-3-戊烯基]环氧乙烷基甲醇。传粉后花气味中没有化合物消失,但有2种化合物含量显著减少、3种化合物含量显著增加,并新增1种化合物。深入研究传粉前后含量变化大,对优势传粉昆虫具引诱活性的化合物,有助于揭示林下假海桐的传粉繁殖特点,为热带雨林物种保护提供依据。  相似文献   

8.
以漆酚为原料,通过对其邻二酚羟基进行醚化反应,在其侧链尾部引入异羟肟酸基团,在苯环或脂肪链引入硝基、羟基等官能团,合成了3种新型亚甲基醚漆酚异羟肟酸衍生物,分别是亚甲基醚漆酚异羟肟酸(化合物1)、8'-羟基亚甲基醚漆酚异羟肟酸(化合物2)和6-硝基亚甲基醚漆酚异羟肟酸(化合物3)。用1 H NMR,13C NMR和MS等方法对所合成的化合物进行结构表征。采用分子对接研究了化合物与组蛋白去乙酰化酶-2(HDAC2)的作用模式,结果表明:3种化合物均能很好地与HDAC2的活性口袋结合,可与氨基酸(His145、Tyr308、Glu103和Asp104等)残基形成氢键相互作用,并能与活性口袋底部的Zn^2+形成稳定螯合。采用试剂盒AK-501检测化合物对HDAC2的抑制活性,结果表明:化合物2和3对HDAC2的抑制效果要优于化合物1,其半数抑制质量浓度(IC50)值和阳性药SAHA(0.20 mg/L)的相当,化合物1,2和3对HDAC 2的IC 50分别为0.33,0.29和0.24 mg/L。  相似文献   

9.
滇牡丹是我国西南特有的野生牡丹,属于濒危物种,在观赏、新品种培育及药用等方面均具有重要的开发前景和利用价值。为研究滇牡丹果荚中的抗氧化活性物质,用其乙酸乙酯萃取物中化合物清除DPPH能力研究了其抗氧化能力,并通过TLC、1H-NMR和13C-NMR对具有抗氧化活性物质进行分析。结果表明,滇牡丹果荚乙酸乙酯萃取物中有多种单体化合物,其中有8种含量较多,用于测定其抗氧化能力,并且仅有2种化合物具较强的抗氧化活性,其余6种化合物不具抗氧化活性。具有抗氧化活性的化合物分别是2,6-二羟基-4-甲基苯甲酸乙酯和邻羟基苯甲酸丙酯。  相似文献   

10.
本研究以巴东县皱皮木瓜为试验材料,用水蒸气蒸馏法提取成熟期干燥条件下皱皮木瓜的挥发油和脂肪酸,用GC-MS获得其挥发油和脂肪酸各成分的总离子流图谱,结合计算机检索技术对化合物进行结构鉴定,分离鉴定了挥发油70个化合物,结果表明,其相对含量≥5%的成分为L-抗坏血酸-2,6-二棕榈酸酯、α-金合欢烯、3-辛基-顺式环氧己烷基甲酯、亚油酸乙酯;分离鉴定脂肪酸成分15个,其相对含量≥5%的成分为14-甲基-十五酸甲酯、邻苯二甲酸二异丁酯、十八酸甲酯、顺-别香橙烯、[1S-(1α,3Aβ,4α,8Aβ)]-十氢-4,8,8-三甲基-9-亚甲基-1,4-亚甲基奥-长叶烯。试验证明皱皮木瓜中所含的高级不饱和脂肪酸在降血脂、抗氧化、抗炎等多个方面显示出显著的药理活性。  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.
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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   

20.
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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