Jiang Chengyu, Wang Li, Huang Xin, Zhu Song, Ma Chaoyang, Wang Hongxin
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.
School of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.
J Food Sci. 2021 Oct;86(10):4717-4729. doi: 10.1111/1750-3841.15894. Epub 2021 Sep 23.
(-)-Epigallocatechin-3-O-gallate(EGCG) was enzymatically modified to enhance the lipophilicity and the antioxidant property. The determination of optimal reaction conditions are as follows: Lipase DF "Amano" 15 and acetone were used as catalyst and solvent, respectively. Equal molar of EGCG and vinyl laurate (1:1); lipase addition of 6.0% (w/w of total substrates); reaction temperature of 50°C and reaction time of 96 h, which obtained the conversion rate of EGCG at 80.1%. The structure of EGCG lauroyl derivatives were 5″-O-lauroyl-EGCG, 3″,5″-2-O-lauroyl-EGCG, and 5',3″,5″-3-O-lauroyl-EGCG, identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and nuclear magnetic resonance (NMR). Compared with the logP of precursor EGCG (0.69 ± 0.03), the logP of EGCG lauroyl derivatives was 1.37 ± 0.19, 2.27 ± 0.33, and 3.28 ± 0.37, increasing by 0.98, 2.28, and 3.75 times, respectively (p < 0.05), suggesting the grafted fatty acid chains make EGCG derivatives more lipophilic, and the lipid solubility gradually increased as the number of substituents increased. Furthermore, EGCG lauroyl derivatives had excellent lipid oxidation than that of EGCG. The POVs (peroxide values) of soybean oil with mono-, di-, tri-lauroyl EGCG were significantly reduced by 42%, 47%, and 57% than that of EGCG at 21 days, respectively, indicating the antioxidative inhibition of these derivatives decreased with the increase in substituents. This indicates that these derivatives have broad prospects of the antioxidant application while improving their solubility properties in lipophilic environments/high-fat food. Practical Application: The lipophilic esterification reaction of EGCG catalyzed by new catalytic lipase DF "Amano" 15 was carried out in a non-aqueous solvent.Various reaction factors on a higher conversion rate of EGCG lauroyl derivatives were evaluated. The lipophilicity and antioxidant properties of EGCG lauroyl derivatives were much excellent than that of parent EGCG.
（-）-表没食子儿茶素-3-O-没食子酸酯（EGCG）经过酶促修饰以增强其亲脂性和抗氧化性能。最佳反应条件的确定如下：分别使用脂肪酶DF“Amano”15和丙酮作为催化剂和溶剂。EGCG与月桂酸乙烯酯等摩尔（1:1）；脂肪酶添加量为6.0%（占总底物的重量/重量）；反应温度为50°C，反应时间为96小时，此时EGCG的转化率为80.1%。通过高效液相色谱-质谱联用（HPLC-MS）和核磁共振（NMR）鉴定出EGCG月桂酰衍生物的结构为5″-O-月桂酰基-EGCG、3″,5″-2-O-月桂酰基-EGCG和5',3″,5″-3-O-月桂酰基-EGCG。与前体EGCG的logP（0.69±0.03）相比，EGCG月桂酰衍生物的logP分别为1.37±0.19、2.27±0.33和3.28±0.37，分别提高了0.98倍、2.28倍和3.75倍（p<0.05），表明接枝的脂肪酸链使EGCG衍生物更具亲脂性，且脂溶性随着取代基数量的增加而逐渐增加。此外，EGCG月桂酰衍生物的脂质氧化性能优于EGCG。在21天时，单、二、三月桂酰基EGCG的大豆油过氧化值（POV）分别比EGCG显著降低了42%、47%和57%，表明这些衍生物的抗氧化抑制作用随着取代基的增加而降低。这表明这些衍生物在改善其在亲脂性环境/高脂肪食品中的溶解性的同时，具有广阔的抗氧化应用前景。实际应用：新型催化脂肪酶DF“Amano”15催化EGCG在非水溶剂中进行亲脂性酯化反应。评估了各种反应因素对EGCG月桂酰衍生物较高转化率的影响。EGCG月桂酰衍生物的亲脂性和抗氧化性能远优于母体EGCG。
