ICP-MS测定两种一枝黄花中12种微量元素

为确定两种一枝黄花中微量元素的差异,建立了微波消解-ICP-MS法,测定加拿大一枝黄花与一枝黄花中Ca、Mg、P、Fe、Mn、Ni、Cu、Zn、Se、Cr、Hg和Pb12种微量元素。方法的加标回收率为95.2%～107.1%,相对标准偏差在2.5%～8.9%之间,检出限在0.002～0.057μg.L-1之间,该方法具有良好的准确度和精密度。分析结果表明,加拿大一枝黄花与一枝黄花均含有Ca、Mg、P、Mn和Fe元素,前者中Ca、Cr、Mn、Zn、Pb、Ni含量较高,而后者中的Mg、P、Fe、Cu、Se含量较高。     

Food processing by animals: do beavers leach tree bark to improve palatability?

Beavers store and consume tree parts in the bodies of water where they live. We examined whether such soaking renders food more palatable by leaching out undesirable compounds. In experiment 1, saplings of red maple, Acer rubrum (RM), were first soaked in a pond for periods of 2, 18, and 36 days, then offered to free-ranging beavers. Soaking for two days rendered RM slightly more acceptable to beavers. To further examine the time window around two days, RM sticks were soaked in distilled water in the laboratory for 1, 2, 4, and 6 days before presenting them to beavers (experiment 2). In experiment 3, twigs of three species were placed on land. Beavers placed RM in the water for 1 to 3 days before consuming the twigs. In experiment 4, sticks were provided in the water at Cranberry Lake Biological Station (CLBS). Most quaking aspen (QA) was consumed during the first night, and most witch hazel, Hamamelis virginiana (WH), during the third night. At Allegany State Park (ASP), no such difference was found. Twigs were provided in the water in experiment 5. At ASP, WH was taken after three days in the water, and at CLBS little WH was consumed, and only during the third night. A meta-analysis of all experiments shows that relatively more WH is consumed after two days than any other species. Experiment 6 traced the time beavers left their own harvested branches in the water. Unlike other tree species, WH remained in the water for two to four days before being consumed. Experiment 7 measured the phenolics leached into water from RM twigs and small pieces of bark soaked for 10 and 8 days, respectively. Shredded bark lost 50–60% of leachable phenolics into the water, and twigs 70–80%. We conclude that beavers can use water to leach undesirable compounds from their food. Although this effect was not robust, our study is the first of its kind.     

Anthocyanins and other polyphenolics in American elderberry (Sambucus canadensis) and European elderberry (S. nigra) cultivars

BACKGROUND: Ten genotypes representing two elderberry species, Sambucus canadensis L. (eight genotypes) and S. nigra L. (two genotypes), were examined for their anthocyanins (ACY), total phenolics (TP),°Brix, titratable acidity (TA), and pH over two growing seasons. RESULTS: Overall, fruit generally had higher ACY, TP, ACY/TP,°Brix, and pH in 2005 than 2004. All samples of S. canadensis had similar anthocyanin profiles to one another, but were distinctly different from S. nigra. Both species had cyanidin‐based anthocyanins as major pigments. Previously unreported anthocyanins were identified in some samples in this study. Trace levels of delphinidin 3‐rutinoside were present in all elderberry samples except cv. ‘Korsør’. Also, petunidin 3‐rutinoside was detected in cvs ‘Adams 2’, ‘Johns’, ‘Scotia’, ‘York’, and ‘Netzer’ (S. canadensis). The identified polyphenolics of both species were mainly composed of cinnamic acids and flavonol glycosides. The major polyphenolic compounds present in S. canadensis were neochlorogenic acid, chlorogenic acid, rutin, and isorhamnetin 3‐rutinoside, while chlorogenic acid and rutin were found to be major polyphenolic compounds in S. nigra. CONCLUSION: Sufficient variability was seen among these genotypes to suggest that a successful breeding program could be carried out to improve levels of the various compounds evaluated in this study. Copyright © 2007 Society of Chemical Industry     

加拿大一枝黄花在改良锰尾渣中的生长与重金属富集特性

采用盆栽法研究锰尾渣改良对外来植物加拿大一枝黄花(Solidago canadensis)的生长及其富集金属的影响.基质全为锰尾渣时,加拿大一枝黄花的株高、生物量和叶绿素含量小于对照,但差异不显著.锰尾渣经土壤改良后,其株高、生物量和叶绿素含量都显著大于对照.锰尾渣胁迫增强其体内SOD活性.随锰尾渣含量增加,其根系活力先增加而后下降.除T100处理(锰尾渣未经改良)外,在其它处理中,其根系耐性指数均大于1.其根部能富集锰和镉,其地上部分铅含量为1089.45～1731.10mg/kg,铅转运系数大于1.因此,加拿大一枝黄花具有铅富集植物的特性.实验结果表明加拿大一枝黄花对锰尾渣耐性较强,能富集锰、镉和铅;土壤改良锰尾渣有利其生长.加拿大一枝黄花竞争排斥性强,会造成生境退化,因此,植被重建时,要加强对其管理.     

Effect of Processing and Storage on The Antioxidant Activity of Frozen and Pasteurized Shadblow Serviceberry (Amelanchier canadensis)

Serviceberry fruits were pasteurised in glass jars at two temperatures, 85 and 100°C, while another batch was packed in polyethylene bags and frozen at a temperature of ?20 ± °C. Processed fruits were stored for 10 months: frozen fruit at ?20 ± 1°C; and pasteurised fruit at room temperature without access to light. Refrigerated storage and pasteurization lowered the DPPH antioxidant activity of serviceberry fruit. In the former, the change was not great, whilst pasteurisation caused an approximately twofold increase in EC50. On the basis of total anthocyanin content and total polyphenolic content measurements, it would appear that the antioxidant properties of serviceberry were affected mainly by anthocyanins. Pasteurising at 100°C allowed slightly better preservation of these compounds during long-term storage.     

加拿大一枝黄花化学成分的研究

目的分离和鉴定加拿大一枝黄花Solidago canadensis的化学成分。方法用色谱技术分离、纯化,通过理化常数和波谱分析鉴定化合物结构。结果从乙醇提取物中分离鉴定了7个化合物,分别为2-羟基-6-甲氧基苯甲酸(Ⅰ)、3-甲酰吲哚(Ⅱ)、3β,4α-二羟基-6β-当归酰-13Z-烯-15,16-克罗烷内酯(Ⅲ)、3β,4α-二羟基-6β-巴豆酰-13Z-烯-15,16-克罗烷内酯(Ⅳ)、α-菠菜甾醇(Ⅴ)、山柰酚(Ⅵ)和槲皮素(Ⅶ)。结论化合物Ⅱ为首次从该属植物中分离得到,化合物Ⅰ、Ⅲ～Ⅴ均为首次从该种植物中分离得到。     

Beaver assisted river valley formation

We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in‐channel beaver dams. Our data show a 1.7‐m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient‐rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de‐watered following the dam breach by high stream flows, protecting the deposited sediment from future re‐mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re‐occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. Copyright © 2010 John Wiley & Sons, Ltd.     

小蓬草精油活性组分分析

利用气相色谱-质谱法对水蒸气蒸馏提取小蓬草精油的挥发性组分进行了分析,匹配度83%以上的活性组分有5种,其中4种为萜类化合物(柠檬烯、α-佛手柑油烯、顺式-β-金合欢烯、反式-β-金合欢烯)。通过纸上种子发芽的生物测定试验,结果表明,小蓬草精油对受体植物青菜、白菜、小麦、高粱种子萌发具有抑制作用,小蓬草精油对4种受体植物种子萌发具有50%抑制作用的丙酮溶液的适宜浓度IC₅₀分别为0.4、0.6、0.4、0.8 g/L。精油的活性组分主要有柠檬烯等萜类化合物、2,3-二甲基-4(3H)-喹唑啉酮等酮类化合物。     

加拿大一枝黄花制备高吸水性树脂的研究

加拿大一枝黄花(Solidago canadensis L.)是在我国分布广泛的入侵植物,其纤维素含量高。利用加拿大一枝黄花作为原料制备接枝丙烯酸钠,并对原料预处理、丙烯酸单体与纤维的比例、引发剂用量以及交联剂用量对产物吸水性能的影响进行了研究。结果表明在丙烯酸单体与纤维素的质量比为12∶1,反应温度为75℃,引发剂质量为0.1g,交联剂质量为0.0025g时,制得的高吸水性树脂吸水倍率可达到556.8g/g,其合成时间短,为加拿大一枝黄花的利用与处置寻找了新的途径。     

加杨雄花序挥发油化学成分分析

采用水蒸气蒸馏法提取出加杨雄花序挥发油，运用GC—MS技术，结合计算机检索对其化学成分进行分析鉴定，用色谱峰面积归一化法计算各组分的相对含量。分离出72个组分，鉴定了其中62个组分，占总挥发油量的80．271％。加杨雄花序的挥发性成分的为愈创醇(8．843％)，[3s-(3α，3aβ，5α)]-1，2，3，3a，4，5，6，7-八氢化-α，α，3，8-四甲基-5-奥(7．128％)，(2R-cis)-1，2，3，4，4a，5，6，7-八氢化-α，α，4a,8-四甲基-2-萘甲醇(5．722％)，二十七烷(5．407％)等。