瓯柑果皮类黄酮提取纯化及其功能活性评价

Extraction and Purification Processes of Flavonoids from Ougan(Citrus suavissima Hort.Ex Tanak)Peel and Its Biological Activity Evaluation

为提高瓯柑果皮类黄酮提取物中类黄酮的含量及评估其功能活性,该研究优化冻干瓯柑果皮类黄酮的超声辅助乙醇法提取和大孔树脂纯化工艺,并评价其主要功能活性。结果显示,在40%乙醇、液料比30:1(mL/g)、超声功率400 W、60℃条件下提取60 min得到的粗提物中总黄酮含量最高,为(118.94±2.29)mg/g;AB-8大孔树脂最佳纯化工艺为上样浓度3.50 mg/mL、上样流速0.75 mL/min、乙醇洗脱溶剂浓度60%和洗脱流速0.75 mL/min,纯化后提取物中类黄酮的纯度提高约3.07倍;类黄酮提取物中主要含有新橙皮苷、川陈皮素、橙皮苷、橘皮素、枸橘苷、柚皮苷和5-去甲川陈皮素,纯化后各主要类黄酮化合物含量均有所提高且总量为粗提物的2.63倍;纯化后的类黄酮提取物在2,2-联氨-双-3-乙基苯并噻唑啉-6-磺酸(2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS)阳离子自由基、1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl,DPPH)自由基和羟自由基清除和铁还原能力,以及对α-葡萄糖苷酶的抑制作用方面均表现出更高的活性。研究表明瓯柑果皮类黄酮提取物有较好的抗氧化和降糖活性,且纯化后的能力更强。

In order to improve flavonoids content and assess functional activity of flavonoids extract from Ougan(Citrus Suavissima Hort.Ex Tanak)peel,the ultrasound assisted ethanol extraction and macroporous resin purification process of flavonoids from freeze-dried Ougan peel were optimized,and their functional activities were comparatively evaluated.Results showed that the highest flavonoid content(118.94±2.29)mg/g,in the extract was obtained under the conditions of 40%ethanol,30:1(mL/g)in liquid to material ratio,and 400 W,60℃and 60 min for ultrasound power,temperature and time,respectively.The optimal purification process for AB-8 macroporous resin was as follows:sample concentration,sample flow rate,elution solvent,and elution flow rate were 3.5 mg/mL,0.75 mL/min,60%ethanol,and 0.75 mL/min,respectively.The purity of flavonoid in the extract after purification was enhanced around 3.07 folds.The flavonoids extract mainly contained neohesperidin,nobiletin,hesperidin,tangeretin,poncirin,naringin and 5-demethylnobiletin,and their respective content was increased and the total amount was enhanced in 2.63 folds after purification.The purified flavonoids extract exhibited higher activities in scavenging 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)(ABTS)cation radical,1,1-diphenyl-2-picrylhydrazyl(DPPH)radical and hydroxyl radicals,and ferric ion reducing antioxidant power(FRAP),as well as inhibitory activity onα-glucosidase.The study indicated that flavonoids extract from Ougan peel had high antioxidative and in vitro hypoglycemic activities with higher abilities after purification.