10 resultados para LOLIOLIDE


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首先,对虎眼万年青中化学成分进行了分离提取研究,采用柱层析和薄层层析等方法,并利用电喷雾质谱技术跟踪洗脱流分,首次从虎眼万年青氯仿提取物中分离得到两个新化合物。其一为单菇内酷loliolide,通过FT-ICRMS高分辨质谱、IR和NMR等手段对其结构进行了确定,并通过IHNMR和旋光法确定了其绝对构型。此外,还利用电喷雾多级串联质谱(ESI一MSn)技术对其质谱裂解规律进行了系统研究,其分析结果与NMR解析结果完全一致,建立了该类化合物结构解析的简便、快速的质谱新方法;另一化合物为生物碱类化合物,采用电喷雾多级串联质谱技术对其质谱裂解规律进行了详细研究,并对其结构进行了初步推断,进一步的NMR结构确定正在进行中。其次,对虎眼万年青多糖成分进行了分离提取研究,并结合体外抑瘤活性评价实验,确定了两种具有抑瘤生物活性的多糖成分OC一2一1一c和OC一2一卜d。并通过SDS凝胶电泳和糖基组成分析,初步证明了虎眼万年青中的活性多糖成分为阿拉伯半乳糖蛋白(AGPs),为进一步研究虎眼万年青抗肿瘤活性提供了基础数据和理论指导。此外,还对虎眼万年青中的微量元素及其溶出率进行了初步的研究,研究结果表明,其水煎液中Cu/Zn比值明显低于癌症患者血清中的Cu/Zn比值,因此,虎眼万年青可能有助于调节癌症患者体内的Cu、Zn平衡,从而达到抗癌目的;而虎眼万年青中Se、Ge含量很低,不能作为两种微量元素的药用来源。为了进一步研究抗癌药物的作用机理,我们采用电喷雾质谱技术,对三种临床疗效较好的抗癌药物与DNA相互作用进行了系统的研究,确定了复合物的化学计量比及其结合的特异性,并利用竞争实验方法,研究了抗癌药物的相对结合强度。质谱实验结果与液相行为完全一致,其中抗癌药物米托葱醒为首次利用质谱进行研究。最后,采用电喷雾质谱技术,对硝酸盐离子簇合物进行了详细研究,发现了双电荷簇合物离子,并且在离子簇合物中还发现了魔数规律的存在。利用电喷雾多级串联质谱技术,研究了双电荷簇合物离子的质谱裂解规律,并对其稳定性进行了分析。此外,还讨论了溶液浓度和毛细管温度对离子簇合物形成的影响规律。

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钮子瓜(Zehneria maysorensis Arn.)是一种常用的中草药,其性味苦、凉,主要功效为清热利湿、散风止痛,主治膀胱炎、头痛。体外活性筛选实验表明,袋花忍冬(Lonicera saccata Rehd.)95%乙醇提取物的乙酸乙酯部分对血管紧张素转化酶显示较强的抑制活性。为明确钮子瓜的药用物质基础和袋花忍冬中具有ACE抑制活性的成分,首次对两个植物的成分进行了研究。 1. 从钮子瓜95%乙醇提取物中主要通过色谱方法首次分离了14个化合物,通过波谱方法鉴定为(2S,3S,4R,10E)-2-[(2R)-2-羟基二十四烷酰基氨基]-10-十八烷-1,3,4-三醇(1)、(2S,3S,4R)-2-二十四烷酰基氨基-十八烷-1,3,4-三醇 (2)、胡萝卜苷(3)、swertish (4)、苯甲酸(5)、水杨酸(6)、loliolide (7)、胸腺嘧啶(8)、尿嘧啶(9)、(23Z)-9,19-环阿尔廷-23-烯-3β,25-二醇(10)、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇(11)、十六烷酸 1-甘油酯(12)、大豆脑苷Ⅰ(13)和(22E,24S)-24-甲基-5α-胆甾-7,22-二烯-3β,5α,6β-三醇(14)。其中化合物4为一黄酮碳苷,具有旋转异构现象,有止痛作用;化合物6具有抗炎、镇痛、减热的活性,它们可能是钮子瓜药用物质基础的一部分。 2. 从袋花忍冬95%乙醇提取物中首次分离并鉴定了16个已知化合物:胡萝卜苷(3)、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇(11)、十六烷酸 1-甘油酯(12)、E-p-coumaryl behenate (15)、谷甾醇(16)、2,6-dihydroxyhumula-3(12), 7(13),9(E)-triene (17)、环阿尔廷-25-烯-3β,24ξ-二醇 (18)、二十四烷酸 (19)、2,4-二羟基-3,6-二甲基苯甲酸甲酯 (20)、乌苏酸 (21)、柚皮素 (22)、木犀草素 (23)、柏双黄酮(24)咖啡酸 (25)、洋芹素(26)和木犀草素-7-O-β-D-葡萄糖苷 (27)。其中木犀草素(23)和咖啡酸(25)含量较高,它们为抑制ACE活性的成分。 3.综述了黄酮碳苷的旋转异构现象。 Zehneria maysorensis is a folk medicine for the treatment of cystitis and headache. The ethyl acetate soluble fraction of the 95% ethanol extract of Lonicera saccata showed obvious ACE inhibitory activity in vitro. To reveal their active constitutents, they were subjected to chemically study. From the 95% ethanol extract of the whole plants of Zehneria maysroensis fourteen compounds were isolated for the first time. On the basis of spectral data and/or by comparison with authentic samples, they were characterized to be (2S,3S,4R,10E)-2-[(2R)-2-hydroxytetracosanoylamino]-10-octadecene-1,3,4-triol (1), (2S,3S,4R)-2-tetracosanoylamino-1,3,4-octadecanetriol (2), daucosterol (3), swertish (4), benzoic acid (5), salicylic acid (6), loliolide (7), thymine (8), uracil (9), (23Z)-9,19-cycloart-23-ene-3β,25-diol (10), (20S,22E,24R)-5α,8α-epidioxy-ergosta- 6,22-diene-3β-ol (11), 2,3-dihydroxypropyl hexadecoate (12), soya-cerebroside (13) and (22E,24S)-24-methyl-5α-cholesta-7,22-diene-3β,5α,6β-triol (14). Compound 4, a C-glycosylflavone, showed a very interesting rotational isomerism. Compounds 4 and 6 may be the active constituents of Zehneria maysorensis considering their sedative and anti-inflammation activity, respectively. From the whole plants of Lonicera saccata, sixteen compounds were isolated for the first time. On the basis of spectral data and/or by comparison with authentic samples, they were identified to be daucosterol (3), (20S,22E,24R)-5α,8α-epidioxy- ergosta-6,22-diene-3β-ol (11), 2,3-dihydroxypropyl hexadecoate (12), E-p-coumaryl behenate (15), β-sitosterol (16), 2,6-dihydroxyhumula-3(12),7(13),9(E)-triene (17), cycloart-25-ene-3β,24ξ-diol (18), tetracosanoic acid (19), methyl 2,4-dihydroxy- 3,6-dimethylbenzoate (20), ursolic acid (21), naringenin (22), luteolin (23), cupressuflavone (24), caffeic acid (25), apigenin (26) and luteolin-7-O-β-D- glucopyranoside (27). Luteolin (23) and caffeic acid (25) were the ACE inhibitory active constituents. Rotational isomerism for C-glycosylflavonoid was reviewed.

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虎眼万年青(Ornithogalum caudatum Ait)俗名珍珠草,为百合科虎眼万年青属多年生草本植物.其原产非洲南部,我国北方有栽培.民间用其全草或球茎入药,主要用于消炎和抗癌.从该属植物中曾分离得到胆甾烷苷和降胆甾烷苷类成分.

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Combined micropaleontological and geochemical analyses of the high-sedimentation gravity core M-4G provided new centennial-scale paleoceanographic data for sapropel S1 deposition in the NE Aegean Sea during the Holocene Climatic Optimum. Sapropel layer S1a (10.2–8.0 ka) was deposited in dysoxic to oxic bottom waters characterized by a high abundance of benthic foraminiferal species tolerating surface sediment and/or pore water oxygen depletion (e.g., Chilostomella mediterranensis, Globobulimina affinis), and the presence of Uvigerina mediterranea, which thrives in oxic mesotrophic-eutrophic environments. Preservation of organic matter (OM) is inferred based on high organic carbon as well as loliolide and isololiolide contents, while the biomarker record and the abundances of eutrophic planktonic foraminifera document enhanced productivity. High inputs of terrigenous OM are attributed to north Aegean borderland riverine inputs. Both alkenone-based sea surface temperatures (SSTs) and δO18G. bulloides records indicate cooling at 8.2 ka (S1a) and ~7.8 ka (S1 interruption). Sapropelic layer S1b (7.7–6.4 ka) is characterized by rather oxic conditions; abundances of foraminiferal species tolerant to oxygen depletion are very low compared with the U. mediterranea rise. Strongly fluctuating SSTs demonstrate repeated cooling and associated dense water formation, with a major event at 7.4 ka followed by cold spells at 7.0, 6.8, and 6.5 ka. The prominent rise of the carbon preference index within the S1b layer indicates the delivery of less degraded terrestrial OM. The increase of algal biomarkers, labile OM-feeding foraminifera and eutrophic planktonic species pinpoints an enhanced in situ marine productivity, promoted by more efficient vertical convection due to repeated cold events. The associated contributions of labile marine OM along with fresher terrestrial OM inputs after ~7.7 ka imply sources alternative/additional to the north Aegean riverine borderland sources for the influx of organic matter in the south Limnos Basin, plausibly related to the inflow of highly productive Marmara/Black Sea waters.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Lipid compositions of sediments recovered during Ocean Drilling Program Leg 175 in the eastern South Atlantic reflect a variety of oceanographic and climatological environments. Most of the identified lipids can be ascribed to marine sources, notably haptophytes, eustigmatophytes, dinoflagellates, archaea, and diatoms. Elevated concentrations of cholesterol suggest zooplankton herbivory, characteristic for sites influenced by upwelling. At these sites, sulfurized highly branched isoprenoids from diatoms are also present in high amounts. Sterols, sterol ethers, hopanoids, and midchain hydroxy fatty acids could also be detected. Terrigenous lipids are n-alkanes, fatty acids, n-alcohols, and triterpenoid compounds like taraxerol and -amyrine. n-Alkanes, fatty acids, and n-alcohols are derived from leaf waxes of higher land plants and transported to the sea by airborne dust or fresh water. Triterpenoid compounds are most probably derived from mangroves and transported solely by rivers. Lipid compositions below the Congo low-salinity plume are strongly influenced by terrigenous material from the Congo River. Elevated organic carbon contents and predominantly marine lipid distributions at the Angola margin may indicate a highly productive plankton population, probably sustained by the Angola Dome. Sedimentary lipids in the Walvis Basin contain an upwelling signal, likely transported by the Benguela Current. Sedimentary lipids off Lüderitz Bay and in the southern Cape Basin are dominated by plankton lipids in high to intermediate amounts, reflecting persistent and seasonal upwelling, respectively.

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Surface sediments from the eastern South Atlantic were investigated for their lipid biomarker contents and bulk organic geochemical characteristics to identify sources, transport pathways and preservation processes of organic components. The sediments cover a wide range of depositional settings with large differences in mass accumulation rates. The highest marine organic carbon (OC) contributions are detected along the coast, especially underlying the Benguela upwelling system. Terrigenous OC contributions are highest in the Congo deep-sea fan. Lipid biomarker fluxes are significantly correlated to the extent of oxygen exposure in the sediment. Normalization to total organic carbon (TOC) contents enabled the characterization of regional lipid biomarker production and transport mechanisms. Principal component analyses revealed five distinct groups of characteristic molecular and bulk organic geochemical parameters. Combined with information on lipid sources, the main controlling mechanisms of the spatial lipid distributions in the surface sediments are defined, indicating marine productivity related to river-induced mixing and oceanic upwelling, wind-driven deep upwelling, river-supply of terrigenous organic material, shallow coastal upwelling and eolian supply of plant-waxes.

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Free and ester-bound lipid biomarkers were analysed in oxidised and unoxidised parts of four distinct turbidites from the Madeira Abyssal Plain (MAP), which contained 1 to 2% organic carbon homogeneously distributed throughout the turbidites at the time they were deposited. These turbidites are well suited to study the effects of oxic degradation on lipid biomarkers without the complicating influence of varying organic matter sources, sedimentation rates, or bioturbation. One sample from the oxidised turbidite was compared with two samples from the unoxidised part of each turbidite. Postdepositional oxic degradation decreased concentrations of biomarkers by several orders of magnitude. The ester-bound lipids were degraded to a far lesser extent than their free counterparts were. The extent of degradation of different compounds differed substantially. Within a specific class of biomarkers, degradation also took place to a different extent, altering their distributions. This study shows that oxic degradation of the organic matter may have a profound effect on the biomarker fingerprint and may result in a severe bias in, for example, the interpretation of organic matter sources and the estimation of the palaeoproductivity of specific groups of phytoplankton.