Salimon Jumat, Salih Nadia, Abdullah Bashar Mudhaffar
School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia.
J Biomed Biotechnol. 2012;2012:693848. doi: 10.1155/2012/693848. Epub 2012 Jan 19.
Linoleic acid (LA) is converted to per-carboxylic acid catalyzed by an immobilized lipase from Candida antarctica (Novozym 435). This per-carboxylic acid is only intermediate and epoxidized itself in good yields and almost without consecutive reactions. Monoepoxide linoleic acid 9(12)-10(13)-monoepoxy 12(9)-octadecanoic acid (MEOA) was optimized using D-optimal design. At optimum conditions, higher yield% (82.14) and medium oxirane oxygen content (OOC) (4.91%) of MEOA were predicted at 15 μL of H(2)O(2), 120 mg of Novozym 435, and 7 h of reaction time. In order to develop better-quality biolubricants, pour point (PP), flash point (FP), viscosity index (VI), and oxidative stability (OT) were determined for LA and MEOA. The results showed that MEOA exhibited good low-temperature behavior with PP of -41(°)C. FP of MEOA increased to 128(°)C comparing with 115(°)C of LA. In a similar fashion, VI for LA was 224 generally several hundred centistokes (cSt) more viscous than MEOA 130.8. The ability of a substance to resist oxidative degradation is another important property for biolubricants. Therefore, LA and MEOA were screened to measure their OT which was observed at 189 and 168(°)C, respectively.
亚油酸(LA)在南极假丝酵母固定化脂肪酶(诺维信435)的催化下转化为过羧酸。这种过羧酸只是中间体,自身环氧化产率良好,几乎没有连续反应。单环氧化亚油酸9(12)-10(13)-单环氧-12(9)-十八碳烯酸(MEOA)采用D-最优设计进行优化。在最佳条件下,预测在15μL过氧化氢、120mg诺维信435和7小时反应时间时,MEOA的产率较高(82.14%)且环氧乙烷氧含量(OOC)适中(4.91%)。为了开发质量更好的生物润滑剂,测定了LA和MEOA的倾点(PP)、闪点(FP)、粘度指数(VI)和氧化稳定性(OT)。结果表明,MEOA表现出良好的低温性能,倾点为-41℃。MEOA的闪点升至128℃,而LA的闪点为115℃。同样,LA的粘度指数为224,通常比MEOA的130.8粘性高几百厘沲(cSt)。物质抵抗氧化降解的能力是生物润滑剂的另一个重要特性。因此,对LA和MEOA进行了筛选以测量它们的氧化稳定性,分别在189℃和168℃观察到。