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槲皮素是一种具有多种生物活性的黄酮类化合物,可以预防和治疗肿瘤及心血管疾病。以槲皮素为先导物,合成了7个标题化合物,其中6个未见文献报道,目标产物结构经IR、~1HNMR、ESI-MS确证。采用MTT法,初步评价了7个目标化合物对人食管鳞癌细胞EC109、人食管鳞癌细胞EC9706、人胃癌细胞SGC7901及小鼠黑色素瘤细胞B16-F10这4株肿瘤细胞的体外增殖抑制作用。结果显示,槲皮素五乙酸酯对EC109和EC9706细胞抑制作用明显优于母药槲皮素和5-FU,是一个很有潜力的新型抗肿瘤候选化合物。 相似文献
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槲皮素是一种优良的天然抗氧化剂。以槲皮素为先导物,选择性对C环3位羟基进行修饰。以廉价的芦丁为原料,经苄基选择性保护、Williamson成醚反应,再经Pd/C催化加氢脱苄基得到5个槲皮素酰胺类衍生物,均未见文献报道,目标产物结构经IR、~1H NMR、~(13)C NMR、ESI-MS确证。采用DPPH法考察了5个目标化合物的抗氧化活性,结果显示,大部分目标化合物的SC_(50)小于槲皮素或与槲皮素相当,这表明3-OH不是槲皮素抗氧化活性的必需基团。采用MTT法考察了5个槲皮素酰胺类衍生物对人食管鳞癌细胞EC109、人食管鳞癌细胞EC9706、人胃癌细胞SGC7901及小鼠黑色素瘤细胞B16-F10的增殖抑制作用。结果显示,通过化学方法对槲皮素进行结构修饰后,其体外抗肿瘤活性增强。其中,化合物7-1对SGC7901的抑制作用(IC_(50)=67.228μmol/L)明显优于母药槲皮素(IC_(50)=91.115μmol/L)和5-FU(IC_(50)=78.236μmol/L),是一个很有潜力的新型抗肿瘤候选化合物。 相似文献
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以廉价芦丁为原料,经苄基化保护、酸水解得到中间体7,3′,4′-O-三苄基槲皮素,中间体与羧酸发生酯化反应,再经Pd/C催化加氢脱苄基得到10种标题化合物,均未见文献报道,目标产物结构经IR、~1HNMR、ESI-MS确证。采用DPPH法考察了10种标题化合物的抗氧化活性,结果显示,大部分标题化合物的SC_(50)小于槲皮素或与槲皮素相当。采用MTT法,评价了10种标题化合物对人胃癌细胞MGC-803、人食管癌细胞EC109、人前列腺癌细胞PC-3、人食管鳞癌细胞EC9706 4株肿瘤细胞的体外增殖抑制作用。结果显示,结构修饰后,标题化合物对肿瘤细胞的增殖抑制作用显著增强。 相似文献
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《化工之友》2008,(19)
目的探讨胎盘部位滋养细胞肿瘤的临床病理学特征、诊断及鉴别诊断。方法通过光镜观察和免疫组化检测分析1例胎盘部位滋养细胞肿瘤的临床病理学特征,并进行文献复习。结果巨检见肿瘤位于子宫后壁,呈息肉状突向宫腔并向宫壁浸润生长达浆膜层,组织学上肿瘤细胞较大,形态多样,异型性明显,以单核细胞为主,可见多核巨细胞,胞质嗜酸性或透亮,核分裂像易见,瘤组织中有广泛的纤维素样物质沉积,肿瘤细胞呈片状或条索状排列,向肌壁间和血管壁浸润生长。免疫组化HPL( )、HCG散在( )、PLAP( )、CKL( )、Actin(-)、HMB45(-)、S-100(-)。结论胎盘部位滋养细胞肿瘤是一种罕见肿瘤,其诊断主要依靠病理检查和免疫组化,肿瘤良恶性的判断对治疗及预后具有重要意义。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献
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