Suppression and enhancement of non-native molecules within biological systems
Suppression and enhancement of non-native molecules within biological systems
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DOI：
10.1016/j.apsusc.2006.02.158
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发表时间：
2006-07-30
影响因子：
6.7
通讯作者：
Vickerman, J. C.
中科院分区：
文献类型：
--
作者：
Jones, E. A.;Lockyer, N. P.;Vickerman, J. C.
为了评估SIMS在生物系统中提供小分子分子信息的潜力，我们研究了不同生物化合物作为基质的作用。结果强调了一个事实，即分子的化学环境对其检测限有显著影响。这对组织切片和其他生物基质中药物和异种生物的成像具有重要意义。有机酸2,4,6-三羟基苯乙酮和二肽缬氨酸-缬氨酸的1:1混合物表明，一种化合物的[M + H]（+）离子几乎完全抑制可以由质子亲和力较高的化合物的存在引起。当两种类似的药物分子阿托品（一种中性分子）和异丙托溴铵（一种含季氮盐）与脑匀浆混合时，这一点的重要性得到了突出体现。阿托品[M + H]（+）离子表现出明显的抑制作用，而溴化依普拉托鸦片的[M - Br]（+）离子的检测强度可以通过其表面浓度的降低来解释。通过研究两种丰富的组织脂质胆固醇和双棕榈酰磷脂酰胆碱（DPPC）对与这些脂质混合检测的阿托品[M + H]（+）信号的影响，我们发现DPPC具有很强的抑制作用，这可能归因于气相质子转移。(c) 2006 Elsevier B.V.版权所有
With the aim of evaluating the potential of SIMS to provide molecular information from small molecules within biological systems, here we investigate the effect of different biological compounds as they act as matrices. The results highlight the fact that the chemical environment of a molecule can have a significant effect on its limit of detection. This has implications for the imaging of drugs and xenobiotics in tissue sections and other biological matrices.A 1: 1 mixture of the organic acid 2,4,6-trihydroxyacetophenone and the dipeptide valine-valine demonstrates that almost complete suppression of the [M + H](+) ion of one compound can be caused by the presence of a compound of higher proton affinity. The significance of this is highlighted when two similar drug molecules, atropine (a neutral molecule) and ipratropium bromide (a quaternary nitrogen containing salt) are mixed with brain homogenate. The atropine [M + H](+) ion shows significant suppression whilst the [M - Br](+) of ipratopium bromide is detected at an intensity that can be rationalised by its decreased surface concentration.By investigating the effect of two abundant tissue lipids, cholesterol and dipalmitoylphosphatidyl choline (DPPC), on the atropine [M + H](+) signal detected in mixtures with these lipids we see that the DPPC has a strong suppressing effect, which may be attributed to gas phase proton transfer. (c) 2006 Elsevier B.V. All rights reserved.