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1.
Two new triterpenoids, 3β, 15α, 21β, 23-tetrahydroxy-12-oleanen-28-oic acid (1), 3β, 6α, 21β, 23-tetrahydroxy-12-oleanen-28-oic acid (2), together with seven known compounds, viz., paeonol (3), 3, 4-dihydroxybenzoic acid (4), scosoletin (5), anthraquinones chrysophanol (6), 4H-1-benzopyran-4-one, 5, 7-dihydroxy-2-methyl (7), β-sitosterol (8) and stigmasterol glucoside (9) were isolated by the chromatography of the silica gel, RP-18 and Sephadex-LH 20 from the EtOAc extract of Neonauclea sessilifolia (Roxb.) Merr. ( Rubiaceae ). Their structures were elucidated based on spectral analysis including 1D-, 2D-NMR (HMQC, HMBC), IR and EIMS. Among them, compound 6 was shown to possess inhibitory activity on the growth of Mycobacterium tuberculosis (Zopf) Lehmann et Neumann with a minimum inhibitory amount of 25 礸, compounds 2 and 4 also showed weak inhibitory activities on the growteof M. tuberculosis.  相似文献   

2.
无柄新乌檀中的三萜   总被引:1,自引:0,他引:1  
采用活性跟踪的方法对无柄新乌檀(Neonauclea sessilifolia (Roxb.)Merr.)枝干的乙醇提取物进行结核杆菌活性检测。利用硅胶柱层析、Sephadex-LH20和反相硅胶RPl8柱层析,从具有活性的乙酸乙酯部分分得9个化合物,利用一维、二维核磁共振技术(HMQC,HMBC)并结合质谱与红外光谱,将它们鉴定为3β,15α,21β,23-tetrahydroxy-12-oleanen-28-oic acid(1)、3β,6α,21β,23-tetrahydroxy-12-oleanen-28-oic acid(2)、单皮酚(3)、3,4-二羟基苯甲酸(4)、东茛菪内酯(5)、葸醌大黄酚(6)、5,7-二羟基-2-甲基吡喃酮(7)、β-谷甾醇(8)和^5.22 △-豆甾醇-β-D-葡萄糖苷(9)。其中化合物1和2是两个新化合物。体外抗结核杆菌试验表明,化合物6对结核杆菌(Mycobacterium tuberculosis(Zopf)Lehmannet Neumann)具有一定的抑制效果,用量在25μg时出现抑菌圈:化合物2与4具有微弱的抑制活性。  相似文献   

3.
近无柄金丝桃中的黄酮类化合物   总被引:2,自引:0,他引:2  
在抗癌活性筛选结果指导下,对近无柄金丝桃(Hypericum subsessile N.Robson)有活性的部位同步进行了化学成分的分离纯化。首次从该植物中得到6个黄酮类化合物,经理化性质和波谱分析,分别鉴定为槲皮素(quercetin,1)、槲皮甙(quercitrin,2)、异槲皮甙(isoquercitrin,3)、芦丁(rutin,4)、山柰酚(kaempferol,5)、I3,Ⅱ8—双芹菜甙元(I3,Ⅱ8-biapigenin,6)。  相似文献   

4.
为建立海南习用药材无柄灵芝的质量标准,依据《中国药典》2015年版中药质量标准研制的要求,对无柄灵芝药材的性状、鉴别、检查、浸出物、灰分、含量测定等项目进行研究。本研究明确了无柄灵芝药材的性状和显微结构特征,建立了专属的薄层鉴别方法;规定无柄灵芝多糖含量不得低于0.40%、三萜与甾醇含量不得低于0.40%、水分不得超过18.0%、总灰分不得超过4.0%、浸出物不得低于2.0%,为无柄灵芝药材质量控制及资源开发利用提供科学依据。  相似文献   

5.
从无柄新乌檀乙醇浸膏的正丁醇部位分离得到7个已知配糖体化合物,经波谱分析为:喹诺酸-3-O-β-D-葡萄吡喃糖基(28→1)-β-D-葡萄吡喃糖酯(1),齐墩果酸-(28→1)-β-D-葡萄吡喃糖酯(2),熊果酸-(28→1)-β-D-葡萄吡喃糖酯(3),喹诺酸-3-O-β-D-葡萄吡喃糖基-(1→3)-6-去氧-β-葡萄吡喃糖苷(4),齐墩果酸-3-O-β-D-吡喃木糖基-(1→2)-β-D-葡萄吡喃糖基-28-O-β-D-葡萄吡喃糖酯(5),番木鳖甙(6),7-甲氧基-龙胆苦甙(7)。这些化合物均为首次从该属中分离得到。  相似文献   

6.
被子植物胚柄研究进展   总被引:1,自引:0,他引:1  
胚柄在胚胎发育过程中是一个暂时性的结构, 但却起着为胚体提供营养和生长调节因子的作用。相对胚体而言, 胚柄具有细胞类型单一、结构相对独立及发育时间短等特点, 其在胚胎发育的基因调控和细胞命运决定研究中具有独特的优势。该文从胚柄的形成及特点、胚柄在胚胎发育中的作用、信号传递系统对胚柄的影响以及与胚柄相关基因的功能等方面进行综述, 以期为研究胚柄在胚胎发育过程中所起的作用以及胚柄的命运决定提供参考信息。  相似文献   

7.
大孔吸附树脂纯化无柄金丝桃茎部总黄酮工艺研究   总被引:1,自引:0,他引:1  
通过静态吸附筛选纯化无柄金丝桃茎部总黄酮的最佳树脂,并利用静态吸附解吸动力学确定纯化无柄金丝桃茎部总黄酮的工艺参数。实验结果显示AB8大孔吸附树脂为纯化总黄酮的最佳树脂。最佳工艺参数为:上样液浓度为1.30 mg/m L,体积为60 m L,p H=4.0,流速为1.00 m L/min,树脂柱径高比为1∶10,70%乙醇溶液(p H=7.0)为洗脱剂。经AB8树脂纯化,无柄金丝桃茎部总黄酮的纯度由30.26%提高到了55.70%,AB8大孔吸附树脂纯化无柄金丝桃茎部的总黄酮效果明显,其工艺参数简单可行。  相似文献   

8.
张修国  张天宇 《菌物学报》2002,21(3):324-326
来自山东泰安和安徽合肥匍柄霉属的两个新种分别命名为棉匍柄霉Stemphylium gossypii和莴苣匍柄霉Stemphylium lactucae.模式标本保存于山东农业大学植物病理系标本室(HSAUP).  相似文献   

9.
庄剑云  魏淑霞 《菌物学报》2001,20(4):449-453
本文报告了我国西部的四种柄锈菌。黑果茜草Rubia cordifolia var. pratensis上的西北柄锈菌Puccinia boreo-occidentalis被描述为新种。垂花报春Primula nutans上的北极柄锈菌P. arctica、车叶草Asperula aparine上的车叶草柄锈菌P. asperulae-aparines和黄水枝Tiarella polyphylla上的黄水枝生柄锈菌P. tiarellicola为中国新记录。根据我国的标本对每个种作了描述和讨论并附有孢子线条图。所有标本保藏在中国科学院菌物标本馆(HMAS)。  相似文献   

10.
胶州湾浮游桡足类时空分布   总被引:3,自引:1,他引:3  
根据2003年1月至12月在胶州湾所获得的浮游生物样品,已鉴定浮游桡足类28种,幼虫、幼体6类.分析了该海区浮游桡足类的分布﹑时空变化及其与生态环境因子的关系,同相关历史资料进行了比较,结果表明,浮游桡足类的种类组成单纯,生态属性以暖温带、近岸低盐种类为主.浮游桡足类的丰度分布具明显的月份变化,高峰在7月份,为181.61个/m3,最低在12月份,为23.53个/m3,全年平均为71.42个/m3.浮游桡足类丰度的平面分布不均匀,最大丰度在5号站,为132.62个/m3,最小丰度在8号站,为40.45个/m3,丰度平面分布的变化趋势基本是湾北部海域大于湾南部海域.浮游桡足类丰度的时空分布,主要种类的季节更替,近20a来的变化趋势基本相同,高峰出现时间的差异,是受温度年季变化差异因素的影响.浮游桡足类丰度的时空分布与海水温度和盐度密切相关,与温度的关系更重要于与盐度的关系.并且用胶州湾的调察资料证实了浮游桡足类对浮游植物的依存关系,浮游植物为浮游桡足类的生长、繁衍提供了饵料.  相似文献   

11.
Darwin's studies on barnacles, begun to satisfy his curiosity about specimens from the Beagle , but later extended to the large collections of other naturalists, lasted for 8 years and produced a set of definitive monographs. Darwin was particularly troubled over the taxonomy of two groups of acorn barnacles, Balanus tintinnabulum and B. amphitrite , which he ultimately classified as clusters of wellmarked varieties. Recent studies, based on established taxonomic methods or on statistical treatment of morphometric data, suggest these are clusters of full species and that the 'intermediate' forms are just phenotypic variants. Darwin was also troubled by the small chthamalid intertidal barnacles, which he eventually grouped as varieties of a world-wide species, Chthamalus stellatur. Gel electrophoresis and morphometrics now show this to be a heterogenous assemblage of distinct species, some very different, others closer together, all with restricted geographical range, but all showing extreme variability in the characters normally used for classification.
Darwin's difficulties with the classification of the highly varying barnacles, and his anatomical studies on these peculiar animals, must have had considerable influence on the development of his theories about natural selection, more than is usually acknowledged by writers on evolution. These 'lost years' were in fact a period of intense zoological enquiry, and Darwin's change in attitude with regard to species and variation in nature underwent a big change, as can be seen from the letters and from the differences between the early drafts written before the barnacle work and the later Natural Selection and The Origin. Whether we regard the difficult groups of Balanus as clusters of species or clusters of varieties, they still draw attention to evolutionary processes as in Darwin's day.  相似文献   

12.
Barnacles have very high accumulated trace metal body concentrations that vary with local trace metal bioavailabilities and represent integrated measures of the supply of bioavailable metals. Pioneering work in Chinese waters in Hong Kong highlighted the potential value of barnacles (particularly Balanus amphitrite) as trace metal biomonitors in coastal waters, identifying differences in local trace metal bioavailabilities over space and time. Work in Hong Kong has also shown that although barnacles have very high rates of trace metal uptake from solution, they also have very high trace metal assimilation efficiencies from the diet. High assimilation efficiencies coupled with high ingestion rates ensure that trophic uptake is by far the dominant trace metal uptake route in barnacles, as verified for cadmium and zinc. Kinetic modelling has shown that low efflux rate constants and high uptake rates from the diet combine to bring about accumulated trace metal concentrations in barnacles that are amongst the  相似文献   

13.
Barnacles have very high accumulated trace metal body concentrations that vary with local trace metal bioavailabilities and represent integrated measures of the supply of bioavailable metals. Pioneering work in Chinese waters in Hong Kong highlighted the potential value of barnacles (particularly Balanus amphitrite) as trace metal biomonitors in coastal waters,identifying differences in local trace metal bioavailabilities over space and time. Work in Hong Kong has also shown that although barnacles have very high rates of trace metal uptake from solution, they also have very high trace metal assimilation efficiencies from the diet. High assimilation efficiencies coupled with high ingestion rates ensure that trophic uptake is by far the dominant trace metal uptake route in barnacles, as verified for cadmium and zinc. Kinetic modelling has shown that low efflux rate constants and high uptake rates from the diet combine to bring about accumulated trace metal concentrations in barnacles that are amongst the highest known in marine invertebrates.  相似文献   

14.
Distribution patterns of epibiotic barnacles on green sea turtles were investigated in waters neighboring Okinawa, Japan. A number of barnacle species were found to coexist on the turtles and were classified into three genera: Chelonibia, Platylepas and Stomatolepas. Attachment sites on the turtles varied among the barnacle species, suggesting that there is niche partitioning with respect to their microhabitat selection. Turtle bodies offer a “patchy” environment for barnacles, so we also analyzed coexistence patterns in the context of an aggregation model. Within each genus, individual barnacles showed a clumped distribution. The different genera do not have mutually exclusive distribution patterns, but instead occur on the same turtle to various degrees. However, when turtles were divided into two size classes, both the level of aggregation and the degree of interspecific overlap among the barnacles was significantly lower on large turtles. We suggest that obtaining basic information on turtle epibionts will shed light on the biology of wild turtles, which is still largely unknown.  相似文献   

15.
Buschbaum  Christian 《Hydrobiologia》2000,440(1-3):119-128
On the extensive sedimentary tidal flats of the Wadden Sea, beds of the blue mussel Mytilus edulis represent the only major hard substratum and attachment surface for sessile organisms. On this substratum, the barnacle Semibalanus balanoides is the most frequent epibiont. In summer 1998, it occurred on over 90% of the large mussels (>45 mm shell length) and the dry weight of barnacles reached 65% of mussel dry weight. However, the extent of barnacle overgrowth is not constant and differs widely between years. Periwinkles (Littorina littorea) may reach densities >2000 m–2 on intertidal mussel beds. Field experiments were conducted to test the effect of periwinkle grazing on barnacle densities. An experimental reduction of grazing and bulldozing pressure by periwinkles resulted in increased recruitment of barnacles, while barnacle numbers decreased with increasing snail density. The highest numbers of barnacles survived in the absence of L. littorea. However, a lack of periwinkle grazing activity also facilitated settlement of ephemeral algae which settled later in the year. Field experiments showed that the growth rate of barnacles decreased in the presence of these ephemeral algae. Thus, L. littorea may reduce initial barnacle settlement, but later may indirectly increase barnacle growth rate by reducing ephemeral algae. It is suggested that periwinkle density may be a key factor in the population dynamics of S. balanoides on intertidal mussel beds in the Wadden Sea.  相似文献   

16.
Abstract

This paper evaluates the bioavailability of As, Cd, Cu, Mn, Hg, Ni and Zn in the coastal waters of the two most important bays in southern Spain (Cádiz and Algeciras). Concentrations of these metals were measured in the bodies of Balanus amphitrite barnacles in 2005 and 2006. Seawater samples were collected from the same sites as the barnacles to assess metal concentrations and to gain additional information on the environmental conditions. Analysis of variance (ANOVA) showed significant geographic differences in the local bioavailability of metals to the barnacles, as reflected in the concentrations of accumulated metals. Balanus amphitrite accumulates large amounts of metals, with high concentration factors for Zn, Cd, Cu and Mn, in relation to the concentrations in marine waters.  相似文献   

17.
18.
Despite strong selective pressure to optimize larval life history in marine environments, there is a wide diversity with regard to developmental mode, size, and time larvae spend in the plankton. In the present study, we assessed if adaptive hypotheses explain the distribution of the larval life history of thoracican barnacles within a strict phylogenetic framework. We collected environmental and larval trait data for 170 species from the literature, and utilized a complete thoracican synthesis tree to account for phylogenetic nonindependence. In accordance with Thorson's rule, the fraction of species with planktonic‐feeding larvae declined with water depth and increased with water temperature, while the fraction of brooding species exhibited the reverse pattern. Species with planktonic‐nonfeeding larvae were overall rare, following no apparent trend. In agreement with the “size advantage” hypothesis proposed by Strathmann in 1977, egg and larval size were closely correlated. Settlement‐competent cypris larvae were larger in cold water, indicative of advantages for large juveniles when growth is slowed. Planktonic larval duration, on the other hand, was uncorrelated to environmental variables. We conclude that different selective pressures appear to shape the evolution of larval life history in barnacles.  相似文献   

19.
中国沿岸小型鲸类误捕情况的调查   总被引:1,自引:0,他引:1  
报道了1994 ~1995 年对中国沿岸小型鲸类误捕情况的调查结果.调查表明,有误捕记录的小型鲸类主要有5 种,即江豚( Neophocaena phocaenoides) 、长喙真海豚( Delphinus capensis) 、瓶鼻海豚( Tursiopstruncatus) 、点斑原海豚(Stenella attenuata) 和伪虎鲸( Pseudorca crassidens) ,其中以江豚的误捕率最高.1994 年在山东、浙江、福建、广东、海南省和广西壮族自治区沿岸渔业误捕的小型鲸类约3045 ±2120 头,其中江豚的误捕量约2132 ±1484 头.误捕小型鲸类的渔具主要有拖网、刺网和张网.中国沿岸没有专门捕鲸的渔业方式.误捕的小型鲸类在沿岸居民的生活中不占重要地位,它们大部分被丢弃或廉价出售.目前尚不知道误捕对中国水域小型鲸种群影响的程度,但可能是造成数量下降原因之一.  相似文献   

20.
A review of reproductive strategies in cephalopods   总被引:11,自引:0,他引:11  
Cephalopod reproductive strategies are reviewed in order to clarify their current, confusing status. Based on the type of ovulation, spawning pattern and growth between egg batches or spawning periods, five comprehensive and flexible cephalopod reproductive strategies are defined. Accordingly, with these three factors the following classification is proposed. (a) Spawning once (formerly semelparity) consisting of simultaneous terminal spawning, with synchronous ovulation, monocyclic spawning and absence of growth between egg batches. (b) Spawning more than once (formerly iteroparity) including: (i) polycyclic spawning with egg-laying occurring in separate batches during the spawning season and growth occurring between production of egg batches and spawning seasons; (ii) multiple spawning, with group-synchronous ovulation, monocyclic spawning and growth between egg batches; (iii) intermittent terminal spawning, with group-synchronous ovulation, monocyclic spawning and no growth between egg batches; (iv) continuous spawning, with asynchronous ovulation, monocyclic spawning and growth between egg batches. Examples of species exhibiting each of these reproductive strategies are given. The large amount of inter-species variation in several life-history traits related to reproductive events is discussed.  相似文献   

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