- 學位論文
肉鹼及其相關化合物之新型微萃取法開發
Development of a new microextraction for L-carnitine and its relative compounds
摘要
肉鹼(3-羥基-4-三甲基氨丁酸)、丁基甜菜鹼(4-三甲基氨丁酸)及乙醯肉鹼(3-乙醯氧基-4-三甲基氨丁酸)是三種自然存在於人體內的四級銨物質。肉鹼是粒線體中脂肪酸氧化的重要輔助因子，因此被用來治療脂肪酸代謝不全的相關疾病，也用於輔助減肥。丁基甜菜鹼是人體內生性肉鹼的前驅物，和肉鹼的生合成有關聯。乙醯肉鹼為肉鹼之衍生物，其具有神經保護及清除自由基的功能。 在標準品中L-carnitine、acetyl-L-carnitine的定量範圍為10-2000 nM，在定量範圍有良好線性(r2>0.998)，偵測極限為4.5 fmol (S/N≧3)，並將建立之方法成功應用在化粧品、藥品及食品中。由於L-carnitine、butyrobetaine及acetyl-L-carnitine為人體內生性物質，因此本實驗以標準添加法進行人體血漿中含量之定量分析，所得健康人體血漿中分析物濃度範圍分別為肉鹼：43.25-47.67 μM、丁基甜菜鹼：1.08-1.27 μM、乙醯肉鹼：2.79-6.65 μM。本方法的線性(r2>0.996)及再現性佳(斜率及截距RSD分別小於7.41%及9.06%)。顯示本研究成功地將反相液液微萃取法應用於肉鹼、丁基甜菜鹼及乙醯肉鹼等水溶性待測物的分析。
並列摘要
L-Carnitine (3-Hydroxy-4-trimethylammoniobutanoic acid), butyrobetaine (4-trimethylammoniobutanoic acid), acetyl-L-carnitine (3-acetyloxy-4-trimethylammoniobutanoic acid) are three quaternary ammonium compounds which exist naturally in the human body. Due to L-carnitine is an important cofactor for fatty acid oxidation in the mitochondria, it is used as a drug for patients with fatty acid metabolism deficiency and also as an adjuvant for losing weight. Butyrobetaine is a precursor of endogenous L-carnitine, which is relative to biosynthesis of L-carnitine. Acetyl-L-carnitine, the derivative of L-carnitine, possesses neuroprotection and the capacity to decrease the production of free radicals. For application of cosmetic, pharmaceuticals and food, the linear response was ranged from 10-2000 nM for L-carnitine and acetyl-L-carnitine with good correlation coefficient (r2>0.998) in standard solution. The detection limits of two analytes were 4.5 fmol. Because L-carnitine, betyrobetaine, and acetyl-L-carnitine are endogenous in human, we used standard addition method as a quantitative method and applied this method to human plasma successfully. The concentration of L-carnitine is in the range from 43.25 to 47.67 μM in health volunteers. In human plasma, butyrobetaine and acetyl-L-carnitine are in the range from 1.08 to 1.27 μM and 2.79 to 6.65 μM, respectively. The linearity (r2>0.996) and reproducibility of standard addition method were good enough for quantitation. The results showed that iDLLME combined the proposed method were successfully developed for analysis of water-soluble compounds, such as L-carnitine, butyrobetaine, and acetyl-L-carnitine.