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甘草次酸及衍生物的质谱研究 总被引:1,自引:0,他引:1
本文用EI质谱、高分辨质谱及快原子轰击正、负离子质谱研究了7种甘草次酸衍生物的质谱裂解机理。 相似文献
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本文综述了快原子轰击质谱方法在糖甙类的分子量、甙的裂解规律、立体异构现象研究中的应用及底物的影响。 相似文献
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Thushara Diyabalanage Vanisree Mulabagal Gary Mills David L. DeWitt Muraleedharan G. Nair 《Food chemistry》2008
The black poplar mushroom, Agrocybe aegerita is a popular edible mushroom with reported anti-tumor properties. A bioactivity-guided investigation gave positive results for ceramide (1), methyl-β-d-glucopyranoside and α-d-glucopyranoside, along with already reported linoleic acid and its methyl ester. The structure elucidation of the above was accomplished by NMR and mass spectral methods. The ceramide (1) inhibited cyclooxygenase enzymes, COX-1 and -2, by 43 and 92.3%, respectively at 25 μg/ml (34.4 μM). The 50% inhibition concentration (IC50) of compound 1 against COX-2 was 5.3 μg/ml (7.3 μM). Similarly, its anti-cancer potential was investigated against five human cancer cell lines in vitro and it was found to inhibit the proliferation of stomach, breast and CNS cancer cell lines at 26.9, 23.2 and 39.1%, respectively, at 100 μg/ml (139 μM) concentration. This is the first report of the isolation of ceramide from A. aegerita and its COX and tumor cell proliferation inhibitory activities. This suggested that the consumption of A. aegerita would assist in alleviating inflammatory conditions, as well as reducing the development of the above cancers. 相似文献
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用快原子轰击质谱法分析磺化琥珀酸二烷基酯钠盐类表面活性刘,可以得到丰富的正、负准分子离子,nm±Na,但是缺乏碎片离子对其烷基提供有价值的结构信息。为此,先将磺化琥珀酸酯盐通过水解转化为相应的醇,然后用电子轰击质谱法鉴定该产物,这样可以得到烷基的特征结构。用以上方法证明Aerosol MA是磺化琥珀酸二(1—甲基戊酯)钠盐,而不是如文献所述是相应的2—甲基戊酯化合物。 相似文献
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本文报道12个合成的胞壁酰肽及其类似物的FABMS。所有化合物都出现质子化分子离子[M+H]^+和[M+Na]^+峰,碎片离子的形成主要是由MH^+脱水或脱保扩基,可以清晰地观察到序离子,另外由分子离子失去完整的吡喃糖可生成乳酸肽链离子。 相似文献
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本文报道了两类稀土异羟肟酸配合物的正、负离子快原子轰击质谱(FABMS),通过分析FABMS特征离子讨论了配合物溶液中的配体交换反应及离解反应。 相似文献
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本文报道了标题簇合物阴离子[V2Fe2S4(Me2dtc)5]-在FAB质谱条件下,存在两种不同的质谱断裂方式:(1)保持簇阴离子骨架,逐步失去配体Me2dtc或其它碎片NMe2而生成的各级碎片离子;(2)破坏簇阴离子[V2Fe2S4(Me2dic)5]的骨架,即沿簇阴离子的薄弱的M(金属)-S(无机硫)键,劈裂为两个亚簇而产生的碎片离子,以及由碎片重组反应而生成的碎片离子m/z296(8.47%)Fe(Me2dtc)2.本文还讨论了簇阴离子在簇解还原过程中,金属原子及其簇芯表观氧化态变化。 相似文献