排序方式: 共有17条查询结果,搜索用时 15 毫秒
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报道从中国南海网胰藻Hydroclathrus clathratus中分离得到3个单体化合物,经过MS,IR,1HNMR,13CNMR(DEPT),HMQC和HMBC等波谱技术鉴定为:(6R,7aS)-6-羟基-4,4,7a-三甲基-2,4,5,6,7,7a-六氢苯并呋喃-2-酮(1),1-(2-脱氧-β-D-呋喃核糖)-5-甲基-1,2,3,4-四氢嘧啶-2,4-二酮(2),尿嘧啶(3),并通过X射线单晶衍射实验确定化合物1的立体结构,其中化合物1是首次从自然界中分离得到. 相似文献
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Q1234+134是1982年在室女座星系团区域内发现的一颗类星体。本文介绍了用UK Schmidt的物端棱镜巡天和美国Palomar山天文台5m望远镜的分光观测结果;列出了全部的发射线和它们的红移值Ze=2.364±0.002;对吸收光谱进行了分析,给出了29根吸收线和两个较可靠的吸收线红移系统(ZaⅠ=2.279,ZaⅡ=2.249)及一个可能系统(ZaⅢ=1.734)。最后,对本文的结果进行了讨论。 相似文献
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Tao Li Ping-Lin Li Xiang-Chao Luo Xu-Li Tang Guo-Qiang Li 《Tetrahedron letters》2019,60(30):1996-1998
Three new dibromopyrrole alkaloids, 9-N-methylcylindradine A (1), 1-N-methylugibohlin (2), nemoechine H (3), together with one known dibromopyrrole alkaloid N-methyldibromoisophakellin (4) were isolated from the South China Sea sponge Agelas nemoechinata. Their structures were elucidated by comprehensive spectroscopic methods including HRESIMS and NMR, and the absolute configuration of compound 1 was further confirmed by comparison of optical rotation. Compound 3 exhibited moderate cytotoxic activity against K562 and L-02 with IC50 values of 6.1 μM and 12.3 μM, respectively. 相似文献
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3-(1-Ethyl-1H-indole-3-carbonyl)aminopropionic acid has been synthesized by alkylation of 3-(1H-indole-3-carbonyl)aminopropionic acid methyl ester with bromoethane,follo-wed by saponifying and acidating,in 89.0% yield.Its crystal structure was gotten and determined by X-ray diffraction method.The crystal is of orthorhombic,space group P212121 with a = 8.9490(12),b = 11.1010(15),c = 13.0475(18) ,V = 1296.2(3) 3,Z = 4,Dc = 1.334 g/cm3,λ = 0.71073 ,μ(MoKα) = 0.095 mm-1,Mr = 260.29 and F(000) = 552.The structure was refined to R = 0.0306 and wR = 0.1445 for 2612 observed reflections with I 2σ(I).In the crystal structure,molecules are linked to each other through hydrogen bonds of N(2)-H(2)···O(1) and O(3)-H(3)···O(1),generating a three-dimensional network. 相似文献
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表面接枝分子印迹聚合物微球的合成及评价 总被引:5,自引:0,他引:5
将聚苯乙烯-二乙烯苯微球表面功能基化, 引入引发转移终止剂(initiator-transfer-terminator agent, iniferter), 以活性自由基聚合方式研究了球形树脂表面合成印迹聚合物的方法. 在紫外光引发下, 以左旋麻黄碱为印迹分子, 甲基丙烯酸为功能单体, 在接枝Iniferter后的微球表面进行分子印迹聚合物接枝实验, 并使用不同的反应条件, 探讨了表面接枝印迹层微球制备条件对于识别能力的影响. 平衡吸附的结果表明, 表面接枝聚苯乙烯-二乙烯苯微球对于印迹分子具有亲和能力及选择性, 其识别能力来自于印迹得到的识别位点. 相似文献
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Methyl 3-(5-bromo-1-ethyl-1H-indole-3-carbonyl)aminopropionate has been syn-thesized by the acylation of 5-bromo-3-trichloroacetylindole with β-alanine methyl ester,followed by alkylation with ethyl iodide,in 82.6% yield.Its crystal structure was gotten and determined by X-ray diffraction method.The crystal is of monoclinic,space group P2 1 /c with a=11.7927(8),b=14.9342(8),c=9.0060(5),β=101.558(6)°,V=1553.93(16)3,Z=4,D c=1.510 g/cm 3,λ=0.71073,μ(MoKα)=2.656 mm-1,M r=353.22 and F(000)=720.The structure was refined to R=0.0401 and wR=0.0825 for 1704 observed reflections with I > 2σ(I).In the crystal structure,intermolecular N(2)-H(2)···O(1) hydrogen bond and weak intermolecular bonds (C(1)-H(1) O(1) and C(10)-H(10B) O(2)) are formed,and π-π stacking also exists. 相似文献
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报道了1-(4-硝基苯)-3-(2-吡嗪)-三氮烯(NPPT)的合成及与锌(Ⅱ)的显色反应。在非离子表面活性剂TritonX-100存在下,于pH8.8的KCl,H3BO3-NaOH缓冲介质中,NPPT与锌(Ⅱ)形成4∶1的黄棕色络合物,在465nm处有一最大吸收,表观摩尔吸光系数为3.15×104L·mol-1.cm-1,10mL溶液中,锌(Ⅱ)量在0—0.56μg范围内符合比尔定律。方法用于葡萄糖酸锌口服溶液中微量锌的测定,测定结果与AAS法相符。 相似文献
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