Kamińska B, Majewska K, Skwierawska A, Kozłowska-Tylingo K
Department of Chemistry and Technology of Functional Materials, Gdansk University of Technology Narutowicza 11/12 80-233 Gdansk Poland
Department of Pharmaceutical Technology and Biochemistry, Gdansk University of Technology Narutowicza 11/12 80-233 Gdansk Poland.
RSC Adv. 2018 Jun 29;8(42):23648-23656. doi: 10.1039/c8ra02631a. eCollection 2018 Jun 27.
Degradation of pentoxifylline (PTX) by sodium peroxydisulfate (SPDS) assisted by UV irradiation has been investigated in deionized water. The treatment was more favorable over direct photolysis or peroxydisulfate oxidation alone. The effects of various parameters, including different dosage of oxidant agent, PTX concentration, initial solution pH levels, and the presence of inorganic ions like chloride, nitrate and carbonate have been evaluated. The rate of PTX decomposition depends on the oxidant agent dose. The highest degradation was determined at pH 10.5, which can be explained by the generation of additional hydroxyl radicals (HO˙) in the reaction between sulfate radicals and hydroxide ions. The presence of inorganic ions, especially the carbonate ions quench valuable sulfate radicals and have successfully retarded the PTX decomposition. Six PTX oxidation products were identified using UPLC-QTOF-MS for trials in a basic environment. The main degradation product (3,7-dimethyl-6-(5-oxohexyloxy)-3,7-dihydro-2-purin-2-one) was isolated by column chromatography and identified by HNMR and LC MS analyzes.
在去离子水中研究了过二硫酸钠（SPDS）在紫外线照射辅助下对己酮可可碱（PTX）的降解情况。该处理方法比单独的直接光解或过二硫酸盐氧化更具优势。评估了各种参数的影响，包括不同剂量的氧化剂、PTX浓度、初始溶液pH值以及氯离子、硝酸根离子和碳酸根离子等无机离子的存在。PTX的分解速率取决于氧化剂剂量。在pH 10.5时降解程度最高，这可以通过硫酸根离子与氢氧根离子反应生成额外的羟基自由基（HO˙）来解释。无机离子的存在，尤其是碳酸根离子会淬灭有价值的硫酸根自由基，并成功延缓了PTX的分解。在碱性环境中进行的试验中，使用超高效液相色谱-四极杆飞行时间质谱（UPLC-QTOF-MS）鉴定出六种PTX氧化产物。通过柱色谱法分离出主要降解产物（3,7-二甲基-6-(5-氧代己氧基)-3,7-二氢-2-嘌呤-2-酮），并通过核磁共振氢谱（HNMR）和液相色谱-质谱（LC MS）分析进行鉴定。
