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为了系统研究中国南海软海绵属海绵 Halichondria sp.的化学成分,文章采用多种色谱方法分离纯化,从其氯仿萃取部位中分离得到了9个甾体类化合物,依据理化性质、波谱数据和文献对照的方法鉴定其结构.其结构分别鉴定为:1)3β-羟基-5,8,22-麦角甾三烯-7-酮;2)3β,5α-二羟基-7,22-麦角甾二烯-6-酮;3)3β,5α,6β-胆甾三醇;4)3β,5α,9α-三羟基-7,22-胆甾二烯-6-酮;5)3β-羟基-5-胆甾烯-6-酮;6)5α,8α-环二氧-6,22-麦角甾二烯-3β-醇;7)5α,8α-环二氧-6-胆甾烯-3β-醇;8)7,22-麦角甾二烯-3β,5α,3β-三醇;9)胆甾醇.本研究结果不仅丰富了软海绵属海绵的化学成分研究,而且将为软海绵属海绵的化学分类及甾体类化合物的进一步研究提供有利的理论依据. 相似文献
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应用色谱－质谱（GC－MS）方法分别鉴定了从广西海涠洲岛水域和海南省陵水县水域采集的莳萝曲网海绵Sigmadocia cymiformis的甾醇类化合物,涠洲岛水域的莳萝曲网海绵所含的旮醇类化合物主要是：胆甾－4，6－二烯3β－醇（1），27－降麦角甾5，22－二烯－3β－醇，（2），胆甾醇（3），（24S）－麦角甾5，22－二烯3β－醇（40，麦角甾5－烯C－3β－醇（5），麦角甾－2，22－二烯－3β－醇（6），豆甾醇（7），β－谷甾醇（8），麦角甾－4，24（28）－二烯－3－酮（9），柳珊瑚甾醇（10）；而陵水县水域的莳萝曲网海绵所含甾醇类化合物主要是：（3），（4），（5），（6），（8），胆甾－2，55－二烯－3β－醇（11），胆旨－3，5－二烯－7－酮（12），这是莳萝曲网海绵中甾醇类化合物组成的首次报道。 相似文献
3.
滨海湿地耐盐植物二色补血草化学成分研究 总被引：5，自引：0，他引：5
采用硅胶柱层析,Sephedex-LH-20凝胶层析,HPLC等方法,从滨海湿地耐盐植物二色补血草中分离得到了10个单体化合物。运用NMR,MS以及与文献对照,鉴定它们的结构分别为豆甾烷-3,6-二酮(1),豆甾-4烯-3,6-二酮(2),6β-羟基-豆甾-4-烯-3-酮(3),5α,8α-环二氧-24-甲基-胆-甾6,22E-二烯-3β-醇(4),5,α8α-环二氧-24-甲基-胆甾-6,9,22E-三烯-3β-醇(5),麦角-甾4,6,8(14),22E?四烯-3-酮(6),植醇(7),正十六烷酸(8),亚油酸(9),亚油酸单甘油酯(10)。化合物1~7和10为首次从该植物中分离得到。 相似文献
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本实验采用群体感应抑制(quorum sensing inhibitory, QSI)活性导向法, 对分离自山东威海近海底泥的真菌WH7-2开展代谢产物研究。综合菌落形态和转录间隔区 (Internal Transcribed Spacer, ITS)全序列分析, 菌株WH7-2鉴定为腐皮镰刀菌Fusarium solani。综合运用多种色谱方法, 从该真菌大米发酵产物的活性部位中分离得到11个化合物。分别鉴定为 (2E, 5E)-3, 5, 7-三甲基-2, 5-辛二烯酸 (1)、不饱和脂肪酸酯混合物 (2—4)、镰红菌素-3-甲醚 (5)、脱水镰红菌素 (6)、(22E)-5α, 8α-过氧化麦角甾-6, 22-二烯-3β-醇(7)、(22E)-5α, 8α-过氧化麦角甾-6, 9 (11), 22-三烯-3β-醇(8)、3β-羟基-胆甾-5-烯-7-酮 (9)、6β-羟基-胆甾-4-烯-3-酮 (10)和(22E)-胆甾-5, 22-二烯-3β-醇 (11)。其中不饱和脂肪酸酯混合物(2—4)具有QSI活性, 其他化合物无QSI活性。除5和6外, 其他化合物均为首次从腐皮镰刀菌F. solani中发现。 相似文献
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对采自海南文昌红树林根际土壤样品中分离到的真菌Penicillium sp. MA-37的次生代谢产物的化学成分进行了研究.利用硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析、制备薄层层析以及重结晶等分离方法并通过现代波谱技术共分离、鉴定了8个天然产物,分别为:氮-(2-甲氧基-4-羟基苯)-丙酰胺酸(1),氮-(2,4-二甲氧基苯)-丙酰胺酸(2),氮-(2,4-二甲氧基苯)-丙酰胺酸甲酯(3),(22E,24R)-麦角甾-5,7,22-三烯-3β-醇(4),(22E,24R)-麦角甾-4,6,8(14),22-四烯-3-酮(5),(22E,24R)-5α,8α-环二氧麦角甾-6,22-双烯-3β-醇(6), asperamide B (7), cis-4-hydroxy-6-deoxyscytalone (8);其中化合物1为新化合物,化合物2和3为新天然产物. 相似文献
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对采自广西涠州岛近海多管藻(Poiysiphonia urceolata)分离到的一株内生真菌EN-22的次生代谢产物的化学成分进行了研究.利用正相硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析、制备薄层层析(PTLC)以及重结晶等分离手段从该菌发酵液中分离得到15个化合物,通过一维、二维核磁共振技术、质谱技术等鉴定了所有化合物的结构,分别为:4-(4-喹啉)-4-羟基-2-丁酮(1),3-羟基-3-(2-氧丙基)吲哚-2-酮(2),3-吲哚乙醇(3),3-吲哚甲酸(4),2-羟基-3-吲哚丙酸(5),2-酮-3-吲哚乙醇(6),3,3-二吲哚-2-羟基-丙醇(7),β-咔啉(8),尿嘧啶(9),环-(S-脯氨酸-S-异亮氨酸)(10),(22E,24R)-3β,5α,9α-三羟基麦角甾-7,22-二烯-6-酮(11),(22E,24R)-5α,6α-环氧麦角甾-8,22-二烯-3β,7α-二醇(12),5α,6α-环氧-24(R)-甲基胆甾-7,22-二烯-3β-醇(13),胡萝卜苷(14),过氧化麦角甾醇(15);其中化合物1和2为新天然产物,并首次报道化合物1的碳谱数据. 相似文献
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综合运用正相和反相硅胶柱层析、Sephadex LH-20凝胶柱层析以及制备HPLC等分离方法,从1种中国南海海绵Xestospongia testudinaria中追踪分离抗肿瘤活性次级代谢产物。从95%乙醇提取物中分离获得8个单体化合物,通过NMR,MS等波谱技术鉴定其结构分别为:E-18,18-二溴-9,17-二烯-5,7-二炔硬脂酸甲酯(1),E-18,18-二溴-9,17-二烯-5,7-二炔硬脂酸乙酯(2),麦角甾-5,7,22-三烯-3-醇(3),麦角甾-4,6,8(14),22-四烯-3-酮(4),胆甾-4-烯-3-酮(5),3-吲哚醛(6),3-吲哚酸(7)和5-吲哚醛(8)。其中,化合物2-5和8为首次从该属海绵中分离得到。化合物1对肿瘤细胞株HCT116和A549显示较强的抑制活性。 相似文献
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从南海圆裂短足软珊瑚(Cladiella krempfi)中分离出12个甾体化合物,分别鉴定为:1,2-[1',3',4']oxodithiin-pregna-20-en-3-one(1);19-nor-4-methylpregna-1,3,5(10),20-tetraen-1-ol(2);pregna-1-en-3-one-20-ol(3);pregna-1,7-dien-20-ol-3-one(4);pregna-5,20-dien-3-O-α-fucopyranoside(5);pregna-20-en-3-O-α-fu-copyranoiside(6);孕甾-1,20-二烯-3-酮(7);孕甾-1,4,20-三烯-3-酮(8);24-甲基-5α-胆甾-7,22-二烯-3β,5,6β-三醇(9);26-甲基-24-亚甲基胆甾-5烯-3β-醇(10);胆甾-5-烯-3β醇(11);β-谷甾醇(12).化合物1～6系首次从Cladiella属软珊瑚中获得的孕甾类化合物.对所获得化合物的生源途径进行了初步讨论. 相似文献
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从采自大连近海的红藻鸭毛藻（Symphyocladia latiuscula）中分离到一株肉座菌目真菌（Hypocreales sp．），对其发酵代谢产物的化学成分进行了研究。利用正相硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析、制备薄层层析（PTLC）以及重结晶等分离手段，并通过一维、二维核磁共振技术、质谱技术等从该菌发酵液中分离鉴定了10个化舍物：双酚A（1）；邻羟基苯甲酸（2）；吲哚甲酸（3）；吲哚乙酸（4）；N-乙酰色胺（5）；（22E，24R）-麦角甾-7，9，22三烯-3β-醇（6）；过氧化麦角甾醇（7）；（22E，24R）-5α，6α-环氧麦角甾-8，22-二烯-3β，7α-二醇（8）；（22E，24R）-麦角甾-7，22-二烯-6β-甲氧基-3β，5α-二醇（9）；啤酒甾醇（10）。这些化合物均为首次从该菌中分离得到，其中化合物1为首次作为天然产物分离得到。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested. 相似文献
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G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
17.
The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments. 相似文献
18.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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