石榴籽油不同极性部位的分离、纳米乳制备及生物学活性

Isolation,nanoemulsion preparation and biological activity of pomegranate seed oil with different polarity

目的将石榴籽油(pomegranate seed oil,PSO)分离为不同极性部位,并比较生物活性。方法采用硅胶柱层析法分离出PSO甘油三酯(pomegranate seed oil triglyceride,PSO-TG)和甘油二酯(pomegranate seed oil diglycerides,PSO-DG),用无水乙醇提取PSO,制得富含多酚的PSO(polyphenol enriched pomegranate seed oil,P-PSO);用自由基清除法考察各油的抗氧化活性;采用滤纸片法检测油的抗菌能力;将4种油制成纳米乳,考察各纳米乳对α-糖苷酶和α-淀粉酶的抑制活性。结果PSO、PSO-DG、PSO-TG和P-PSO的极性顺序为P-PSO>PSO-DG>PSO>PSO-TG;对DPPH自由基清除率为P-PSO>PSO-TG>PSO>PSO-DG;PSODG对枯草芽胞杆菌(Bacillus subtilis)的抑制活性显著高于其余3种油(P<0.05),PSO对少孢哈萨克斯坦酵母(Kazachstania exigua)有最强的抗菌作用;纳米乳对α-糖苷酶和α-淀粉酶的抑制作用为PSO-DG>PSO>P-PSO>PSO-TG。结论油的极性影响着其对细菌质膜和细胞壁的穿透能力,以及与酶的亲和作用,是油发挥生物活性的关键因素。

Objective The pomegranate seed oil(PSO)into fractions with different polarities was isolated to compare their biological activities.Methods PSO triglyceride(PSO TG)and PSO diglyceride(PSO DG)were isolated by silica gel column chromatography,respectively.Polyphenol-enriched PSO(P-PSO)was prepared by extracting PSO with anhydrous ethanol.The antioxidant activity of the oils was estimated by the radical-scavenging method.The antibacterial capacity was assessed using the filter paper approach.The four oils were formulated into nanoemulsions,and the inhibitory effects of nanoemulsions againstα-glucoside andα-amylase were examined,respectively.Results The polarity order was P-PSO>PSO-DG>PSO>PSO-TG.The scavenging rate against DPPH radicals was P-PSO>PSO-TG>PSO>PSO-DG.PSO-DG had a significantly higher inhibitory effect than the other oils against Bacillus subtilis(P<0.05),while PSO possessed the strongest antibacterial activity against yeast(Kazachstania exigua).The inhibitory strength of nanoemulsions onα-glucoside andα-amylase was PSO-DG>PSO>P-PSO>PSOTG.Conclusion The polarity of oil could influence its capacity to penetrate through the plasma membrane and cell wall of bacteria,as well as its affinity with enzymes.It is a key factor in the biological activity of oil.