The objective of this research was to synthesize and characterize a novel modified lipid which is composed of mainly oleic acid at sn-2 position and a hydrophobic essential amino acid derivative (N-acetyl-l-leucine) at sn-1(3) or sn-1, 3 positions. LC-MS-MS analysis indicated that the target modified lipid structure was obtained at the end of the developed reaction. Response surface methodology was applied to enhance a reliable empirical model for prediction and to optimize reaction conditions: reaction time (8 to 24 hr), reaction temperature (40 to 55 °C), and enzyme load (15 to 30 wt%). The percentage of total reaction products was found to be 28.5 at the optimum conditions of 54 °C, 8 hr and 15% (by mass) enzyme load. This result is closely correlated to the predicted highest total reaction product (29.3%) obtained by response surface methodology. The physical and thermal characteristics of the modified lipid and refined olive pomace oil were compared and found to be similar. Caloric value of modified lipid was decreased by 18.65% compared to that of refined olive pomace oil. A novel modified lipid which may have potential uses in healthy food industries was successfully produced with the incorporation of N-acetyl-l-leucine to 2-monoacylglycerol. PRACTICAL APPLICATION A novel modified lipid was synthesized by enzymatic incorporation of a "hydrophobic and essential amino acid derivative" into 2-monoacylglycerol. This modified lipid contains mainly oleic acid at sn-2 position and N-acetyl-l-leucine at sn-1,3 positions. The product behaved as an oil above 10 °C. Caloric value of the novel oil-like product was reduced by 18.65%. The modified lipid may have the potential for replacement with the oil in food products such as margarine, shortenings, salad dressing, and mayonnaise.

中文翻译：

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一种新型改性脂质：2-单酰基甘油与 N-乙酰基-l-亮氨酸的酶促酯化

本研究的目的是合成和表征一种新型修饰脂质，该脂质主要由 sn-2 位的油酸和 sn-1(3) 位的疏水性必需氨基酸衍生物 (N-乙酰基-l-亮氨酸) 或sn-1, 3 个位置。LC-MS-MS 分析表明，目标修饰的脂质结构在展开反应结束时获得。应用响应面方法来增强可靠的预测经验模型并优化反应条件：反应时间（8 至 24 小时）、反应温度（40 至 55 °C）和酶负荷（15 至 30 wt%）。在 54 °C、8 小时和 15%（按质量计）酶负荷的最佳条件下，发现总反应产物的百分比为 28.5。该结果与预测的最高总反应产物密切相关（29. 3%）通过响应面法获得。比较了改性脂质和精制橄榄果渣油的物理和热特性，发现它们是相似的。与精制橄榄渣油相比，改性脂质的热值降低了 18.65%。通过将 N-乙酰基-l-亮氨酸与 2-单酰基甘油结合，成功生产了一种可能在健康食品工业中具有潜在用途的新型改性脂质。实际应用通过将“疏水和必需氨基酸衍生物”酶促掺入2-单酰基甘油中来合成新型修饰脂质。这种修饰的脂质主要在 sn-2 位包含油酸，在 sn-1,3 位包含 N-乙酰基-l-亮氨酸。该产品在高于 10 °C 时表现为油。新型油状产品热值降低18.65%。