Phytosterols are regarded as compounds able to reduce total and low-density lipoprotein cholesterol in the blood, and their esterified derivatives could help to improve the effectiveness of this function. In the present study, the water/sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/isooctane reverse micelle (RM) system was set up as a reaction medium for Candida rugosa lipase AY30 (CRL AY30) to synthesize β-sitosterol laurate (β-SLE). The product was identified by TLC, FT-IR, and HPLC-APCI-QqQ-MS/MS and quantified by HPLC. Through stepwise optimization, it was found that CRL AY30 had the highest activity in the water/AOT/isooctane RM system where 50 mM PBS with a pH of 7.5 was adopted as water core to carry CRL AY30, and the proportion of [CRL AY30] (mg/mL), [water] (mM), and [AOT] (mM) was set in 3:375:25, respectively, in isooctane. After screened with single-factor experiments, the esterification reaction conditions in the CRL AY30-water/AOT/isooctane RM system were further optimized by the response surface method as follows: the mole ratio of β-sitosterol to lauric acid of 1:3.5 (25 mM β-sitosterol), the enzyme load of 18% (w/w total reactants), the reaction temperature of 47 °C, and the reaction time of 48 h. As a result, the maximum esterification rate was up to 88.12 ± 0.79%.

中文翻译：

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在水中/ AOT /异辛烷反胶束中通过假丝酵母脂肪酶AY30酶促合成β-谷甾醇月桂酸酯。

植物甾醇被认为是能够降低血液中总胆固醇和低密度脂蛋白胆固醇的化合物，它们的酯化衍生物可以帮助改善这种功能的有效性。在本研究中，将水/ 1,4-双-2-乙基己基磺基琥珀酸钠（AOT）/异辛烷反胶束（RM）系统设置为皱纹念珠菌脂肪酶AY30（CRL AY30）的反应介质，以合成β-谷甾醇月桂酸酯（β-SLE）。产物通过TLC，FT-IR和HPLC-APCI-QqQ-MS / MS鉴定并通过HPLC定量。通过逐步优化，发现CRL AY30在水/ AOT /异辛烷RM系统中具有最高的活性，其中以pH值为7.5的50 mM PBS作为水核心来承载CRL AY30，[CRL AY30]的比例（mg / mL），[水]（mM）和[AOT]（mM）分别在异辛烷中设定为3：375：25。通过单因素实验筛选后，通过响应面法进一步优化了CRL AY30-水/ AOT /异辛烷RM系统中的酯化反应条件，如下所示：β-谷甾醇与月桂酸的摩尔比为1：3.5（ 25 mMβ-谷甾醇），18％的酶负载（w / w总反应物），反应温度47°C，反应时间48 h。结果，最大酯化率高达88.12±0.79％。