The Influence of Styrenes on the Metabolism of Neurotransmitter Serotonin in Monkey Brain.

用C18反相高效液相色谱法对100℃煮沸24h的超纯水进行分离，得到抑制单胺氧化酶a (MAOA) 5 -羟色胺降解活性的单一组分。考察了乙腈浓度为30%时的洗脱效果。通过红外光谱和拉曼光谱分析发现，MAOA抑制部位的主要成分为含苯环的低分子量化合物。C <13>和H^1核磁共振进一步研究表明，该化合物是一个苯环和一个季碳分子，FTIR再次研究表明苯环上有一个取代基。通过TOFMS、GCMS和LCMS对该化合物进行了精确的分子质量测定，结果表明其苯环数不是1个，而是2个或3个。在上述结果的基础上，我们研究了MAOA的商业候选抑制剂（过氧化苯甲酰、苯甲酸钠、苯甲酸、邻苯二甲酸、苯甲酸和苯甲酸酐）是否会抑制MAOA的活性。在浓度为1 μg/ml时，各化合物均无抑制MAOA活性的作用。超纯水提取的抑制组分对猴脑线粒体中MAOA同工酶的活性有较强的抑制作用，但对MAOA同工酶的活性无明显抑制作用。在大鼠脑线粒体中，MAOA和MAOB均不受该组分的抑制。此外，我们还检测了MAOA抑制部分对猴和大鼠脑乙酰胆碱酯酶的影响，在各组织中均未发现抑制作用。

Ultrapure water boiled at 100℃ for 24hr with commercial styrene polymers was fractionated by C18 reversed phase HPLC to obtain a single component which inhibited the serotonine degradation activity of MAOA(monoamine oxidase A). The inhibition fraction eluted at acetonitrile concentration of 30% was examined. We reported that a major component of the MAOA inhibitory fraction was low molecular weight chemical compound with a benzene ring by FTIR and Raman spectroscopy. Further investigation by C^<13> and H^1 NMR revealed that the chemical compound was a benzene ring with a quaternary carbon molecule and re-investigation by FTIR suggested that benzene ring had one substituent. This compound was examined by means of TOFMS, GCMS and LCMS to obtain precise molecular mass and these results suggested that numbers of benzene ring was not one, but two or three.On the basis of the results above, we investigated whether the commercial candidates for MAOA inhibitor (benzoyl peroxide, sodium benzoate, benzoic acid, phthalic acid, benzoin and benzoic anhydride) would inhibit MAOA activity. Any compound did not inhibit MAOA activity at the concentration of 1 μg/ml. Extracted inhibition fraction from polystyrene with ultrapure water strongly inhibited the activity of MAOA but not the activity of MAOB, which was a MAOA isozyme, in monkey brain mitochondria. In rat brain mitochondria, both MAOA and MAOB were not inhibited by the fraction. Furthermore, we examined effects of MAOA inhibition fraction on acetylcholinesterase in monkey and rat brain no inhibition were observed in each tissue.