不同成熟度树葡萄果实醇提取物抗氧化和抑制α-葡萄糖苷酶活性研究

Studies on Antioxidant and α-Glucosidase Inhibitory Activities of Ethanol Extracts from Peels and Seeds of Jaboticaba at Different Maturities

摘要:

为探究树葡萄果皮和种籽的抗氧化和对α-葡萄糖苷酶活性的抑制作用，采用比色法测定了不同成熟度树葡萄果皮和种籽70%乙醇提取物的总多酚和总黄酮含量，并分析了他们与抗氧化活性和α-葡萄糖苷酶活性抑制作用的相关性。结果表明，绿果皮的总多酚含量最高（95.96 mg g^-1 DW），红果皮的最低（18.31 mg g^-1 DW）；绿果籽的总黄酮含量最高（43.48 mg g^-1 DW），紫果籽的最低（16.50 mg g^-1 DW）；抗氧化活性及对α-葡萄糖苷酶活性抑制作用均以绿果皮的最强，紫果籽的最弱。树葡萄果皮/籽清除·OH自由基能力均高于抗坏血酸，对α-葡萄糖苷酶活性抑制作用均强于阿卡波糖；其总多酚和总黄酮含量与抗氧化能力显著正相关（P<0.05），抗氧化能力与对α-葡萄糖苷酶活性的抑制作用呈显著正相关（P<0.05）。因此，树葡萄绿果的总多酚及总黄酮含量较高，抗氧化活性、对α-葡萄糖苷酶活性的抑制作用较强，可用于天然抗氧化剂和α-葡萄糖苷酶抑制剂的开发。

关键词:树葡萄;总多酚;总黄酮;抗氧化;α-葡萄糖苷酶

Abstract:

In order to investigate the antioxidant and α-glucosidase inhibitory activities of jaboticaba (Myrciaria cauliflora) fruits at different maturities, the contents of total polyphenols (TP) and total flavonoids (TF) of 70% ethanol extracts from its peels and seeds were measured, and the correlation of TP, TF with antioxidant capacity and α-glucosidase inhibitory activity was analyzed. The results showed the contents of TP and TF, antioxidant capacity and α-glucosidase inhibitory activity in peels and seeds of jabuticaba at different maturities had obviously difference. The contents of TP and TF ranged from 18.31 to 95.96, 16.50 to 43.48 mg g^-1DW, respectively. The content of TP was the highest in peels at green fruit stage, the lowest in peels at red fruit stage, while the content of TF was the highest in seeds at green fruit stage, the lowest in seeds at purple fruit stage. The peels of green fruits had the highest antioxidant capacity, while the seeds of purple fruits showed the lowest level. The capacity of scavenging ·OH of all extracts with EC₅₀ ranged from 0.260 6 to 1.280 4 g DW L^-1 was stronger than that of ascorbic acid (EC₅₀=2.659 0 g DW L^-1). The IC₅₀ value of α-glucosidase inhibitory activity ranged from 1.134 0 to 11.414 1 mg DW L^-1 showed lower than that of acarbose (IC₅₀=3 133.47 mg L^-1). The contents of TP and TF had positively significant correlation with the antioxidant capacity (P < 0.05), as well as α-glucosidase inhibitory activity and scavenging capacity of free radicals, such as DPPH·, ·OH and ABTS⁺. Therefore, the jaboticaba fruits at green stage were a good source of natural antioxidants and α-glucosidase inhibitors, due to its high contents of TP and TF, great antioxidation and strong inhibition on α-glucosidase.

Key words:Jaboticaba;Total polyphenol;Total flavonoid;Antioxidant capacity;α-Glucosidase inhibitory activity