University of Maribor, Faculty of Chemistry and Chemical Engineering, Smetanova 17, 2000 Maribor, Slovenia.
J Pharm Biomed Anal. 2011 Jul 15;55(5):1010-6. doi: 10.1016/j.jpba.2011.04.003. Epub 2011 Apr 8.
The stability of trans-rosmarinic acid (trans-RA, an important phenolic compound with anti-oxidant, anti-inflammatory, anti-bacterial, and anti-viral properties) exposed to different stress conditions (daylight, higher temperatures, different solvents, and humidity) was investigated. Gas chromatography-mass spectrometry (GC-MS) was used to analyse the degraded samples, and structural identification of degradation products was assigned based upon MS fragmentation pattern. The GC-MS method was validated in terms of linearity, precision as repeatability, accuracy, limit of detection (LOD), limit of quantitation (LOQ) and recovery. The stability experiments were performed on pure trans-RA and on trans-RA present in commercially available rosemary extract. The cis-isomer of RA was the only degradation product. The results showed that trans-RA was readily isomerized into its cis-form within a few hours when dissolved in ethanol, methanol or tetrahydrofuran, and exposed to darkness or daylight at different temperatures. Isomerization took place to a greater extent in protic than in aprotic solvents. Trans-RA in the solid state was found to be stable for up to three months under all tested conditions. The described GC-MS method was also applied to the determination of trans-RA in eight different species of Lamiaceae family.
研究了反式迷迭香酸（trans-RA，一种具有抗氧化、抗炎、抗菌和抗病毒特性的重要酚类化合物）在不同应激条件（日光、较高温度、不同溶剂和湿度）下的稳定性。采用气相色谱-质谱联用（GC-MS）分析降解样品，并根据 MS 碎片模式对降解产物的结构进行了鉴定。该 GC-MS 方法在线性、精密度（重复性）、准确度、检测限（LOD）、定量限（LOQ）和回收率方面进行了验证。在纯反式 RA 和市售迷迭香提取物中存在的反式 RA 上进行了稳定性实验。结果表明，当反式 RA 溶解在乙醇、甲醇或四氢呋喃中，并在不同温度下暴露于黑暗或日光下时，其顺式异构体很容易在数小时内异构化为顺式，在质子溶剂中比在非质子溶剂中更容易异构化。固态反式 RA 在所有测试条件下可稳定长达三个月。还应用描述的 GC-MS 方法测定了 8 种唇形科植物中反式 RA 的含量。
