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目的:为获得大量的9,10-二羟基硬脂酸(Dihydroxy Stearic Acid,DHSA),应用质谱、红外光谱及核磁共振解析验证合成物为DHSA。方法:实验于2007-01/05在解放军总医院营养科实验室完成。在烧瓶中加入油酸后,再加入甲酸、过氧化氢,并不断搅拌。在整个反应过程中维持反应温度在40℃,反应四五小时后,反复水洗油层并收集。在油层中加入3mol/L NaOH溶液25mL,于100℃水浴加热1h,趁热加入3mol/L HCl50mL,剧烈搅拌,析出白色沉淀。用水反复清洗使清洗液pH值为中性,收集沉淀物。在沉淀物中加入体积分数为0.95的乙醇10mL,加热溶解,抽滤,将滤液于0℃析出结晶,抽滤,将抽滤物用体积分数为0.95的乙醇10mL加热溶解,于0℃结晶,抽滤。同样方法再结晶2次,最后得到白色结晶物,晾干,收率68.8%。将结晶物分别上FTS-65A红外光谱仪、ISONS EA1108型元素分析仪,Varian INOVA 600型核磁共振仪,安捷伦XCR-trap液相质谱(LC-MS)联用仪进行分析和结构鉴定。结果:①LC-MS分析提示合成的DHSA经过多次重结晶后,纯度较高,可达95%。MS分析提示DHSA相对分子质量为315.1,与理论值316.48相近。②DHSA元素分析实验值C68.78%,H11.53%,与理论值C68.77%,H11.58%接近。③红外光谱分析提示DHSA为含有两个羟基的十八碳长链脂肪酸。④核磁共振的氢谱和碳谱均证实合成的化合物为9,10-二羟基十八碳脂肪酸。结论:合成的DHSA经过3次重结晶后,纯度可95%以上,质谱、红外光谱及核磁共振解析结果证实合成的化合物是9,10-二羟基硬脂酸。
OBJECTIVE: To obtain a large amount of 9,10-dihydroxy stearic acid (DHSA), DHSA was confirmed by MS, FT-IR and 1H NMR. Methods: The experiment was performed at the Laboratory of Nutrition, PLA General Hospital from January 2007 to January 05. After adding oleic acid to the flask, add formic acid, hydrogen peroxide, and stirring constantly. The reaction temperature was maintained at 40 ° C throughout the reaction. After four to five hours of reaction, the oil layer was repeatedly washed with water and collected. Add 25mL of 3mol / L NaOH solution to the oil layer and heat in water bath at 100 ℃ for 1h, add 50mL of 3mol / L HCl while hot and stir vigorously to precipitate white precipitate. Repeated washing with water to make the pH value of the cleaning solution is neutral, collecting sediment. 10 mL of ethanol with a volume fraction of 0.95 was added to the precipitate, dissolved by heating, and suction filtered. The filtrate was crystallized at 0 ° C. and filtered with suction. The filtrate was heated and dissolved in 10 mL of ethanol having a volume fraction of 0.95 and crystallized at 0 ° C., Filter. The same method recrystallized twice, and finally get a white crystal, dried, yield 68.8%. The crystals were respectively analyzed by FTS-65A infrared spectrometer, ISONS EA1108 elemental analyzer, Varian INOVA 600 nuclear magnetic resonance apparatus and Agilent XCR-trap liquid chromatography mass spectrometry (LC-MS). Results: ①LC-MS analysis showed that the purity of DHSA was up to 95% after repeated recrystallization. MS analysis suggested that the relative molecular mass of DHSA was 315.1, similar to the theoretical value of 316.48. ②DHSA elemental analysis of experimental values C68.78%, H11.53%, and the theoretical value of C68.77%, H11.58% close. (3) The infrared spectrum analysis indicated that DHSA is an octadecane long chain fatty acid containing two hydroxyl groups. ④ hydrogen nuclear magnetic resonance and carbon spectra confirmed the synthesis of compounds as 9,10- dihydroxy octadecyl fatty acids. Conclusion: The purity of DHSA can be above 95% after 3 times of recrystallization. The result of MS, IR and 1H NMR showed that the synthesized compound was 9,10-dihydroxystearic acid.