AbstractMonoglycerides of erucic acid (C22:1, Δ13), prepared by conventional methods, were reacted with caprylic acid (octanoic acid, C8.0) by using lipases as catalysts with the intention of synthesizing a triglyceride that contains two molecules of caprylic acid and one molecule of erucic acid (caprucin). The reaction was carried out by mixing lipase powder, a small quantity of water, and the reactants in a temperature‐controlled stirred batch reactor. Organic solvents or emulsifying agents were not required. When the nonspecific lipase fromPseudomonas cepacia was used, a yield of approximately 37% caprucin was obtained, together with a complex mixture of di‐ and triglycerides that resulted from the random transesterification of the erucic acid. The fatty acid‐specific lipase fromGeotrichum candidum promoted minimal transesterification of erucic acid and resulted in a yield of 75% caprucin and approximately 10% interesterification products. Lipase fromCandida rugosa exhibited a similar, although less pronounced, specificity to that fromG. candidum and promoted more transesterification of erucic acid. Optimum conditions forG. candidum lipase were at 50°C and an initial water content of 5.5%. After the reaction, erucic acid was converted to behenic acid by hydrogenation, thereby converting caprucin into caprenin, a commercially available low‐calorie triglyceride.
摘要 用传统方法制备的芥酸(C22:1,Δ13)单甘酯,通过使用脂肪酶作为催化剂与辛酸(辛酸,C8.0)反应,目的是合成一种含有两分子辛酸和一分子芥酸的甘油三酯(caprucin)。反应是在一个温控搅拌间歇式反应器中将脂肪酶粉末、少量水和反应物混合后进行的。无需使用有机溶剂或乳化剂。当使用来自头孢假单胞菌的非特异性脂肪酶时,可获得约 37% 的辣椒素产量,以及芥酸随机酯交换反应产生的二甘油酯和三甘油酯的复杂混合物。来自念珠菌(Geotrichum candidum)的脂肪酸特异性脂肪酶促进了芥酸的最小酯交换反应,得到了 75% 的辣椒素和大约 10% 的酯交换产物。白色念珠菌的脂肪酶与念珠菌的脂肪酶具有相似的特异性,但不那么明显,而且能促进更多的芥酸酯交换反应。念珠菌脂肪酶的最佳条件是温度为 50°C,初始含水量为 5.5%。反应后,芥酸通过氢化转化为山嵛酸,从而将辣椒素转化为辣椒素,这是一种市售的低热量甘油三酯。