化学实验研究论文英文

原文：. 9-[2-(3-Carboxy-9,10-diphenyl)anthryl]-6-hydroxy-3H-xanthen-3-ones (DPAXs) The most widely used 1O2 trap is 9,10-diphenylanthracene (DPA), which reacts rapidly and specifically with 1O2 to form a thermostable endoperoxide at a rate of k = M1 s1. The decrease in absorbance at 355 nm is used as a measure of the formation of the endoperoxide. However, DPA derivatives are not very sensitive probes because the detection is based on the measurement of absorbance [79]. Umezaka et al. [79] fused DPA with a fluorophore (fluorescein) aiming to associate the first’s reactive characteristics with the second’s fluorescent characteristics. Fluorescein was chosen as fluorophore since it has a high fluorescence quantum yield in aqueous solution and is able to be excited at long wavelength. From this fusion resulted 9-[2-(3-carboxy-9,10-diphenyl)anthryl]-6- hydroxy-3H-xanthen-3-ones (DPAXs) (Fig. 11) [79]. Thus, DPAXs were the first chemical traps for 1O2 that permitted fluorescence detection. They react with 1O2 to produce DPAX endoperoxides (DPAX-EPs) (Fig. 11). DPAXs themselves scarcely fluoresce, while DPAXEPs are strongly fluorescent. The mechanism accounting for the diminution of fluorescence in DPAXs and its enhancement in DPAX-EPs remain unclear [79]. The fluorescence intensity of fluorescein derivatives is known to be decreased under acidic conditions as a consequence of the protonation of the phenoxide oxygen atom. In order to stabilize the fluorescence intensity at physiological pH, electron-withdrawing groups wereincorporated at the 2- and 7-positions of the xanthene chromophore, leading to Cl (DPAX-2) and F (DPAX-3) (Fig. 11). This modification lowered the pKa value of the phenolic oxygen atom [79]. DPAX-2 was used to detect the production of 1O2 from two different generation systems: the MoO4 2/H2O2 system and the 3-(4-methyl-1-naphthy)propionic acid endoperoxide (EP-1) system, which act at different pH values ( and , respectively). In both cases an increase of the probe’s fluorescence was verified when in contact with the generating system. These results confirmed DPAXs’ advantage when detecting 1O2 in neutral or basic aqueous solutions [79]. The behaviour of this probe towards H2O2, !NO and O2 ! was also studied, but no change in the intensity of the fluorescence was observed for any of these reactive species. These facts corroborate the specificity of this probe for 1O2 [79]. The detection of 1O2 in biological samples was also investigated. With this purpose, DPAX-2 diacetate (DPAX-2-DA) was prepared, since it was considered to be more permeable to cells. DPAX-2-DA is hydrolysed by intracellular esterases to generate DPAX-2. Both DPAX-2 and DPAX-2DA were tested and compared in the same assay systems. However, cells were stained similarly in both cases. This observation probably means that DPAX-2 itself is also membranepermeable [79].译文：420. 91-[2-(3-羧基-9,10-二苯)anthryl]-6 羟基3h-xanthen-3-酮 (dpaxs)使用最广泛的1o2阱9,10-diphenylanthracene(政治部) 而迅速的反应,特别是与1o2形成耐热endoperoxide的增长率为k=米1秒1. 减少,为355nm,是用来衡量形成的过氧化物. 不过,政治部衍生不是很敏感的探针,因为检测是基于测量吸光度[79]. umezakaetal. [79]fused审批与fluorophore(fluorescein)以准第一功的特点与第二的荧光特性. fluorescein被选为fluorophore,因为它具有较高的荧光量子产率在水溶液中,并能 兴奋长波长. 由此导致的融合 91-[2-(3-羧基-9,10-二苯)anthryl]-6 - 羟基3h-xanthen-3酮(dpaxs)(图11)[79]. 因此,dpaxs被化学第一陷阱1o2允许荧光检测. 他们的反应与1o2出示dpaxendoperoxides(dpax-eps)(图11). dpaxs自己scarcelyfluoresce,而dpaxeps强烈的荧光. 机制的会计核算窄化荧光dpaxs及其增强dpax-办事仍不清楚[79]. 荧光强度的荧光素衍生物已知是减少酸性条件下,随着大量的质子 该phenoxide氧原子. 为了稳定的荧光强度,在生理pH, 电子撤组wereincorporated在2-和7点位置的xanthene生色 通往cl(dpax-2)和F(dpax-3)(图11). 这个修改降低pKa值的酚氧原子〔79〕. dpax-2检测生产1o2从两个不同的发电系统: 该moo42/过氧化氢体系和3-(4-甲基-1-萘基)丙酸endoperoxide(ep-1)系统, 该法在不同pH值(和美元). 在这两种情况下,提高了探头的荧光验证时接触的发电系统. 这些调查结果证实dpaxs的优势,在检测1o2在中性或碱性溶液[79]. 该行为此探针对双氧水,! NO和O2! 还研究, 但不改变强度的荧光染色任何这些活性物种. 这些事实证实特异性这种探针1o2[79]. 检测1o2生物样品中为. 为了这个目的,dpax-2diacetate(dpax-2-da)制成的,因为它被认为是更容易接受细胞. dpax-2-daishydrolysedbyintracellularesterases产生dpax-2. 双方dpax-2dpax-2da试验,比较在同一实验系统. 但是,细胞染色同样,在这两种情况. 这个观察可能意味着dpax-2本身也是membranepermeable[79].

只要300字左右的？几千字的要不要？

In contrast to the fluorescent response of ZTRS to metal ionsin aqueous solutions, in 100% CH3CN Zn2+ and Cd2+ result inblue-shifted emissions with the maximum wavelength changefrom 481 to 430 and 432 nm, respectively (Supporting Information,Figures S4, S5); however, the addition of Zn2+ and Cd2+to ZTRS in 100% DMSO cause red-shifted emissions with themaximum wavelength change from 472 to 512 and 532 nm,respectively (Supporting Information, Figures S6, S7). TheFigure 1. Influence of pH on the fluorescence of ZTRS in acetonitrile/water (50:50, v/v). Excitation wavelength: 360 nm. [ZTRS] ) 10 μM. (a) . Inset: The fluorescence intensity at 483 nm as a function of pH; (b) pH . Inset: The ratiometric fluorescence changes as a function of 2. (a) Fluorescence spectra of 10 μM ZTRS in the presence of various metal ions in aqueous solution (CH3CN/ M HEPES (pH ) ) 50:50).Excitation at 360 nm. (b) Fluorescence spectra of ZTRS in the presence of different concentrations of Zn2+. The inset shows the Job plot evaluated fromthe fluorescence with a total concentration of 10 μ of other HTM ions results in blue-shift in emissionsin both CH3CN and DMSO (Supporting Information, FiguresS8, S9). However, a small blue-shift of the absorption maximumof ZTRS in CH3CN, DMSO, and aqueous solution uponaddition of Zn2+ and Cd2+ (Supporting Information, FiguresS10-S15) indicates that the red-shifted emission does not resultfrom the deprotonation of amide NH group, because thedeprotonation of the NH group conjugated to 1,8-naphthalimidewould cause a red-shift in absorption spectra. 18h,25a Thesespectral data suggest that ZTRS binds Zn2+ and Cd2+ indifferent tautomeric forms, depending on the solvent and metalions (Scheme 3); ZTRS complexes both Zn2+ and Cd2+ in theamide tautomer in CH3CN, and the imidic acid tautomer inDMSO predominantly. However, other HTM ions bind to theamide tautomer in both CH3CN and evidence for the amide and imidic acid tautomericbinding modes (Scheme 3) is provided by 1H NMR titrationexperiments of ZTRS with Zn2+ and Cd2+ in CD3CN (SupportingInformation, Figures S16, S17) and DMSO-d6 (SupportingInformation, Figures S18, S19), 2D NOESY of ZTRS/Zn2+ (1:1 complex) in CD3CN (Figures 3, Supporting Information,Figures S20, S21) and DMSO-d6 (Figures 3, S22-23),and IR spectra of ZTRS/Zn2+ (1:1 complex) in CH3CN(Supporting Information, Figure S24) and DMSO (SupportingInformation, Figure S25). As a reference, the binding propertiesof ZTF with Zn2+ were also examined by means of 1H NMRand IR spectra.与ZTRS与含水溶液中金属离子的荧光响应相反，在100％CH3CN中，Cd2＋和Zn2＋产生最大波长从481分别变化到430和432nm的蓝移发射（支持信息的图S4和S5）；然而，向100％DMSO中的ZTRS添加Cd2＋和Zn2＋会引起最大波长从472分别变化到512和532nm的红移发射（支持信息的图S6和S7）。添加其他HTM离子会引起在CH3CN和DMSO中发射的蓝移（支持信息的图S8、S9）。不过，在添加Cd2＋和Zn2＋时，在CH3CN、DMSO以及含水溶液中的ZTRS的吸收谱小的蓝移（支持信息的图S10－S15）表明，红移发射不是因为酰胺NH基团去质子化的结果，因为与1,8萘二甲酰亚胺共轭的NH基团的去质子化会引起吸收谱的红移18h,25a。这些光谱数据告诉我们，ZTRS根据溶剂和金属离子（方案3）以不同的互变异构形式与Cd2＋和Zn2＋结合；ZTRS主要与CH3CN中酰胺互变异构体中的Cd2＋和Zn2＋络合，以及与DMSO中亚氨酸互变异构体中的Cd2＋和Zn2＋络合。可是，其他离子与CH3CN和DMSO中的酰胺互变异构体结合。 关于酰胺和亚胺酸互变异构结合模式（方案3）的进一步证据由ZTRS的氢核磁共振（1H NMR）滴定实验，用CD3CN（支持信息的图S16、S17）和DMSO-d6（支持信息的图S18、S19）中的Cd2＋和Zn2＋，CD3CN（图3，支持信息的图S20/S21）和DMSO-d6（图3，S22、S23）中的ZTRS/Zn2+（1：1络合物）的2维相关核磁共振谱（2D NOESY），以及CH3CN（支持信息的图S24）和DMSO（支持信息的图25）中ZTRS/Zn2+（1：1络合物）的红外光谱提供。作为参考，ZTF与Zn2＋的结合性质也用1H NMR和红外光谱进行了研究。