A spin trap
BMPO is a cyclic nitrone spin trap agent, it is a water-soluble white solid which makes BMPO purification easier than other spin trap agents. Even after prolonged storage at 220°C, there was no artificial signal formation from aqueous solutions containing BMPO (25–100 mM). BMPO offers several advantages over the existing spin traps in the detection and characterization of thiyl radicals, hydroxyl radicals, and superoxide anions in biological systems. One of the perceived advantages of BMPO is that the BMPO/?OOH adduct does not readily decay nonenzymatically to the BMPO/?OH adduct. [1]
The in vitro experiment took advantage of Rabbit aortic segments, which were treated with ADR and incubation with 0.1 M BMPO, a novel solid superoxide spin trap. Results showed that BMPO-hydroxyl radical adduct was detected in supernatants upon 10-min incubation of aortic segment with incremental doses of ADR.[2] Time-dependent changes in the ESR spectra of superoxide adducts of BMPO was generated in a xanthine/xanthine oxidase incubation system. BMPO superoxide adducts did not decay to the corresponding hydroxyl adducts. Results also indicate that the BMPO superoxide adduct is persistent. The decay kinetics of BMPO/?OOH also demonstrate this feature. In this system, the ESR spectrum of the BMPO/?OOH adduct could be detected even up to 35 min. Although BMPO/?OOH is intrinsically more stable, it is likely to be enzymatically reduced to BMPO/?OH in biological systems.[1]
参考文献:
[1]. Zhao H, Joseph J, Zhang H, Karoui H, Kalyanaraman B. Synthesis and biochemical applications of a solid cyclic nitrone spin trap: a relatively superior trap for detecting superoxide anions and glutathiyl radicals. Free Radic Biol Med. 2001 Sep 1;31(5):599-606.
[2]. Duquaine D, Hirsch GA, Chakrabarti A, Han Z, Kehrer C, Brook R, Joseph J, Schott A, Kalyanaraman B, Vasquez-Vivar J, Rajagopalan S. Rapid-onset endothelial dysfunction with adriamycin: evidence for a dysfunctional nitric oxide synthase. Vasc Med. 2003 May;8(2):101-7.
BMPO是一种环状硝酮自旋捕集剂，它是一种水溶性白色固体，比其他自旋捕集剂更容易提纯BMPO。即使在 220°C 下长时间储存后，含有 BMPO (25-100 mM) 的水溶液也不会形成人工信号。在检测和表征生物系统中的硫自由基、羟基自由基和超氧阴离子方面，BMPO 与现有的自旋陷阱相比具有多项优势。 BMPO 的明显优势之一是 BMPO/?OOH 加合物不易非酶分解为 BMPO/?OH 加合物。 [1]
体外实验利用了兔主动脉节段，这些节段经过 ADR 处理并与 0.1 M BMPO（一种新型固体超氧化物自旋陷阱）一起孵育。结果表明，在主动脉段与递增剂量的 ADR 孵育 10 分钟后，在上清液中检测到 BMPO-羟基自由基加合物。 [2]在黄嘌呤/黄嘌呤氧化酶孵育系统中产生 BMPO 超氧化物加合物的 ESR 光谱的时间依赖性变化。 BMPO 超氧化物加合物不会分解为相应的羟基加合物。结果还表明 BMPO 超氧化物加合物具有持久性。 BMPO/?OOH 的衰变动力学也证明了这一特征。在这个系统中，BMPO/?OOH 加合物的 ESR 光谱甚至可以检测到长达 35 分钟。尽管 BMPO/?OOH 本质上更稳定，但它可能在生物系统中被酶促还原为 BMPO/?OH。[1]
| Cell experiment [1]: | |
|
Cell lines |
Human normal lymphocytes and MEC-1 leukemia cells |
|
Preparation Method |
Cells were irradiated with UV radiation (290 – 315 nm). Then add 20 μl of BMPO to 80μ l cell suspension (20 mM), then mixed in an eppendorf tube. After that, transferred the mixture to microhaematocrit capillaries and sealed with Paraffin. Then put it into EPR Pyrex tubes and inserted into the cavity of a Bruker EMX-131 X-band spectrometer. |
|
Reaction Conditions |
The final concentration of BMPO is 100 mM. Samples were exposed to UVB radiation (290-315 nm) and to UVA radiation (315-400 nm) for 3 and 10 min at 47.7 and 159 mJ/cm2 and 53.7 mJ/cm2. The spectrometer was operated at ~9.5 GHz, while the spectra were recorded at room temperature. |
|
Applications |
BMPO combined with EPR spectroscopy provides detection and identification of cellular ROS. Which might contribute to the understanding of some fundamental mechanisms leading to oxidative stress or damage in biological systems. |
|
参考文献: [1]. Tepe ?am S, et al. Tea extracts protect normal lymphocytes but not leukemia cells from UV radiation-induced ROS production: An EPR spin trap study. Int J Radiat Biol. 2015 Aug;91(8):673-80. |
|
动态评分
0.0