吉米沙星、巴洛吉米沙星、妥舒沙星等氟喹诺酮类药物的光化学性质及其对生物分子的光敏损伤研究

发布时间：2018-04-20 21:07

本文选题：氟喹诺酮 + 激光光解　；参考：《中国科学院研究生院（上海应用物理研究所）》2015年博士论文

【摘要】：氟喹诺酮类药物(fluoroquinolones,FQs)是临床上广泛应用的抗菌药物,具有高效、广谱、廉价等优点。此类药物分子有着相似的吡啶酮酸结构,通过抑制DNA旋转酶,阻断细菌DNA的复制来发挥抗菌作用,然而其光敏毒性等副作用在一定程度上阻碍了FQs的发展。吉米沙星(gemifloxacin,GEFX)、巴洛沙星(balofloxacin,BFX)、帕株沙星(pazufloxacin,PAX)和妥舒沙星(tosufloxacin,TSFX)都属于FQs类抗菌素,它们对生物分子的光敏损伤机理仍不甚明确。本文利用激光光解、脉冲辐解、稳态光照、紫外-可见吸收光谱等瞬态和稳态技术手段对其光化学性质以及光敏毒性机理进行了详细研究,为进一步研究此类药物分子结构与光敏毒性之间的关系以及新一代FQs药物的研发提供了理论依据。本文研究了吉米沙星三重激发态(3GEFX*)和妥舒沙星三重激发态(3TSFX*)的光化学性质。利用激光光解技术,确定了中性水溶液中3GEFX*和3TSFX*的最大吸收峰位置。研究了3GEFX*和3TSFX*与萘普生(NAP)之间的能量转移反应,测定了速率常数分别为1.2×108和1.3×109 dm3 mol-1 s-1,确定GEFX三重激发态的能量为266 k J mol-1。研究了3GEFX*和3TSFX*与2’-脱氧鸟苷酸-5’-单磷酸盐(d GMP)、色氨酸(Trp H)、酪氨酸(Typ OH)、N,N,N’,N’-四甲基-对-二苯胺(TMPD)、阿魏酸(FCA)之间的反应机理,测定了上述反应的速率常数。通过设计竞争反应,分别利用TMPD和FCA作为给电子体指示剂,证明了3GEFX*和3TSFX*都是通过电子转移的方式光敏损伤DNA。本文还利用脉冲辐解技术研究了GEFX与水合电子(eaqˉ)、羟基自由基(?OH)以及叠氮自由基(N3?)之间的反应,得到了GEFX阴离子自由基、中性自由基和阳离子自由基的特征吸收峰,提出了反应机理并测定了瞬态反应的速率常数。利用稳态光照和凝胶电泳技术研究了在不同气氛、不同光照时间、不同浓度条件下GEFX对蛋白质的光敏损伤并提出了损伤机理。在对BFX光化学性质的研究中,本文利用紫外-可见吸收与荧光发射光谱分析研究了BFX的p H效应及变化规律,测定了其p Ka值。激光光解实验表明BFX光致电离效应强烈,通过对其光致电离机理的研究,证明BFX的光致电离为单光子过程。利用脉冲辐解研究了BFX与?OH、eaqˉ和N3?之间的瞬态反应,测得BFX阴阳离子吸收峰的位置以及反应的速率常数。通过设计竞争反应研究了巴洛沙星阳离子自由基对生物分子的损伤作用。稳态光照和凝胶电泳实验证明,有氧条件下BFX造成蛋白质的光敏损伤是I型反应和II型反应协同作用的结果。本文利用激光光解研究了PAX三重激发态与溶菌酶(Lyso)和FCA之间的反应机理,测定了电子转移反应速率常数。通过设计竞争反应,利用稳态光照和凝胶电泳分析研究了抗氧化剂FCA对于Lyso光敏损伤的保护作用,结果表明FCA能够有效抑制FQs光敏氧化造成的蛋白质分子交联,减弱蛋白质分子的光敏损伤。研究结果为进一步研究抗氧化剂对于蛋白质的保护作用机理提供了理论依据。通过上述实验,本文研究了GEFX、BFX和TSFX的光化学性质以及相关瞬态粒子的动力学性质,确定了GEFX、BFX和TSFX光敏氧化DNA、氨基酸和蛋白质的反应类型和瞬态反应速率常数,提出了损伤机理,并初步研究了抗氧化剂对生物分子光敏损伤的保护机制。
[Abstract]:Fluoroquinolones (FQs) is a widely used antibacterial drug in clinic. It has the advantages of high efficiency, broad-spectrum and cheap. It has similar structure of pyridoolone acid. It inhibits the replication of DNA by inhibiting the replicating of the bacterial DNA. However, the side effects such as photosensitive toxicity are hindered to some extent. The development of FQs. Jimmy floxacin (gemifloxacin, GEFX), balofloxacin (BFX), pazufloxacin (PAX) and dofloxacin (tosufloxacin, TSFX) are all FQs antibiotics. The mechanism of their photosensitive damage to biomolecules is still not clear. This paper uses laser photolysis, pulse radiolysis, steady state illumination, ultraviolet visible absorption light. The photochemical properties and the mechanism of photosensitive toxicity were studied in detail, such as spectra and other transient and steady-state techniques, which provided a theoretical basis for further study of the relationship between molecular structure and photosensitive toxicity of such drugs, as well as the development of a new generation of FQs drugs. The three heavy excitation state (3GEFX*) and the three weight of dofloxacin were studied in this paper. The photochemical properties of the excited state (3TSFX*). The maximum absorption peak position of 3GEFX* and 3TSFX* in neutral aqueous solution was determined by laser photodissociation. The energy transfer reaction between 3GEFX* and 3TSFX* and naproxen (NAP) was studied. The rate constants were 1.2 * 108 and 1.3 * 109 DM3 mol-1 S-1 respectively, and the energy of GEFX three excited state was 2. 66 K J mol-1. was used to study the reaction mechanism between 3GEFX* and 3TSFX* and 2 'deoxy guanosine monophosphate (D GMP), tryptophan (Trp H), tyrosine (Typ OH), H' - four methyl - to - two aniline and ferulic acid. The progeny indicator proves that both 3GEFX* and 3TSFX* are photosensitive damage DNA. through electron transfer, and the reaction between GEFX and hydrous electrons (EAQ), hydroxyl radical (? OH) and azido radical (N3?) is also studied by pulse radiolysis technology, and the characteristics of GEFX anion radical, neutral radical and cationic radical are obtained. The reaction mechanism was proposed and the rate constant of the transient reaction was measured. The photosensitive damage of GEFX to protein in different atmospheres, different illumination time and different concentration conditions was studied by steady state light and gel electrophoresis. In the study of the photochemical properties of BFX, the UV visible absorption was used in this paper. The P H effect and the change law of BFX were studied with the fluorescence emission spectrum analysis. The P Ka value was measured. The laser photodissociation experiment showed that the photoionization effect of BFX was strong. Through the study of its photoionization mechanism, the photoionization of BFX was a single photon process. The transient reaction between BFX and OH, EAQ and N3? Was studied by the pulse radiolysis, and the B was measured. The location of the absorption peak of FX and the rate constant of the reaction. The damage effect of the free radical of barloxacin cationic radical on the biological molecules was studied by designing a competitive reaction. The steady-state light and gel electrophoresis experiments showed that the photosensitive damage of the protein caused by BFX under the aerobic condition was the result of the synergistic effect of the I type reaction and the II type reaction. The reaction mechanism between PAX three heavy excited state and lysozyme (Lyso) and FCA was studied by laser photolysis. The rate constant of electron transfer reaction was measured. The protective effect of antioxidant FCA on the photosensitivity of Lyso was studied by designing the competitive reaction and using steady-state light and gel electrophoresis. The results showed that FCA could effectively inhibit the photosensitivity of FQs. The results of the study provide a theoretical basis for the further study of the mechanism of the protective action of antioxidants to proteins. The photochemical properties of GEFX, BFX and TSFX and the kinetic properties of the related transient particles are studied by these experiments. GEFX, B is determined. FX and TSFX photosensitive oxidation of DNA, the type of reaction of amino acids and proteins and the rate constant of transient reaction, put forward the mechanism of damage, and preliminarily studied the protective mechanism of antioxidants on the photosensitive damage of biomolecules.

【学位授予单位】：中国科学院研究生院（上海应用物理研究所）
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ465

【参考文献】