不同品种嘉宝果叶提取物的酚类成分及生物活性分析

【目的】研究3个品种嘉宝果叶提取物的酚类成分和生物活性，为嘉宝果叶的开发利用提供参考依据。【方法】测定大红钻、保利斯塔和乔尼尔3个嘉宝果品种的叶片提取物总酚和黄酮含量，利用超高效液相色谱—串联质谱法 （UPLC-MS/MS）分析提取物的酚类成分，并测定提取物的抗氧化活性 ［1,1-二苯基-2-三硝基苯肼自由基 （DPPH·）、2,2'-联氮-双 （3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基 （ABTS+）、超氧阴离子自由基 （O₂-·）清除能力及总抗氧化能力］和降糖活性 （α-葡萄糖苷酶抑制活性、 α-淀粉酶抑制活性），对总酚含量与生物活性的相关性进行分析。【结果】 3个品种嘉宝果叶提取物的总酚和黄酮含量分别为458.78~535.51 mg GAE/g和99.46~233.42 mg RE/g，总酚含量以乔尼尔最高，黄酮则以大红钻最高。大红钻和保利斯塔叶片的酚类成分以没食子酸、鞣花酸、儿茶素和表儿茶素含量较高，乔尼尔则以没食子酸、鞣花酸和槲皮素-3-O-葡萄糖苷含量较高。乔尼尔叶提取物的DPPH·和ABTS+清除能力最强，半数清除浓度（IC₅₀）分别为8.48和77.02 μg/mL，其总抗氧化能力也最强，为0.922 mmol/g； O₂-·清除能力、 α-葡萄糖苷酶抑制活性和α-淀粉酶抑制活性则以保利斯塔最强， IC₅₀分别为0.893 mg/mL、 14.96 μg/mL和57.42 μg/mL。相关分析结果显示，总酚含量与DPPH·、 ABTS+和O₂-·清除能力均呈极显著正相关（P<0.01），与总抗氧化能力呈显著正相关（P<0.05），与降糖活性相关性不显著 （P>0.05）。【结论】 3个品种嘉宝果叶提取物的酚类含量和成分存在差异，乔尼尔的综合抗氧化能力最强，降糖活性则以保利斯塔最强，但均是开发抗氧化和降血糖健康产品的良好来源。

Phenolic components and biological activity analysis of extracts from leaves of different cultivars of jaboticaba

【Objective】To study phenolic components and biological activity of extracts from leaves of 3 cultivars of jaboticaba，so as to provide reference for the development and utilization of jaboticaba leaves.【Method】 Content of total phenols and flavonoids content in extracts from leaves of 3 cultivars of jaboticaba，Dahongzuan，Paulista and Qiaonier were determined.The extracted phenolic components were analyzed by ultra-high performance liquid chromatography and the triple-quadrupole tandem mass spectrometry（UPLC-MS/MS）.Then the antioxidant activity［scavenging abilities of 1-diphenyl-2-trinitrophenyl hydrazine free radical（DPPH·），diammonium 2,2'-azino-bis（3-ethylbenzothiazoline-6-sulfonate）free radical（ABTS+），superoxide anion free radical（O₂-· ）and their total antioxidant capacity］and hypoglycemic activity（inhibition on α-glucosidase and α-amylase）were determined.Furthermore，correlations between content of total phenols and biological activities were analyzed.【Result】 Content of total phenols and flavonoids in extracts from leaves of the 3 jaboticaba cultivars were 458.78-535.51 mg GAE/g and 99.46-233.42 mg RE/g respectively.Content of total phenols in Qiaonier leaf was the highest，while content of flavonoids in Dahongzuan leaf was the highest.The main phenolic components in Dahongzuan and Paulista leaves were gallic acid，ellagic acid，catechin and epicatechin，while those in Qiaonier were gallic acid，ellagic acid and quercetin-3-O-glucoside.Extract of Qiaonier leaf had the strongest DPPH·and ABTS+ scavenging abilities，their median inhibition concentration（IC₅₀）were 8.48 and 77.02 μg/mL，and it also had the highest total antioxidant ability，which was 0.922 mmol/g.Meanwhile，Paulista had the strongest scavenging ability on O₂-·and inhibition activities on α-glucosidase and α-amylase and the IC₅₀ were 0.893 mg/mL，14.96 μg/mL and 57.42 μg/mL respectively.The correlation analysis indicated that content of total phenols was extremely，significantly and positively correlated with DPPH·，ABTS+，O₂-·scavenging abilities（P<0.01），and it had significantly positive correlation with the total antioxidant capacity（P<0.05），while no significant correlation between content of total phenols and hypoglycemic activity （P>0.05）was found.【Conclusion】There are differences of content of total phenols and phenolic components in extracts from the leaves of 3 cultivars of jaboticaba.Qiaonier has the highest comprehensive antioxidant ability，while Paulista have the strongest hypoglycemic activity.Leaves of 3 cultivars of jaboticaba are good sources for develo-ping antioxidant and hypoglycemic products.