桑叶7种黄酮类成分同时测定及其抑制α-糖苷酶活性的研究

Study on relation of seven flavonoids from mulberry leafs and their inhibition of α-glucosidase activities

关键词:  桑叶  黄酮类  α-糖苷酶抑制活性

Key words:  mulberry leafs  flavonoids ingredients  α-glucosidase inhibitory activity

摘要:

[目的] 测定桑叶7种黄酮类成分含量与其α-糖苷酶抑制活性，考察黄酮类成分与降糖活性关系，阐明桑叶"经霜为上"的科学内涵。[方法] 基于正交实验对桑叶提取方法进行优化，采用高效液相色谱（HPLC）法对不同采收期及不同产地桑叶7种黄酮类成分进行含量测定；采用酶标法对桑叶样品α-糖苷酶抑制活性进行测定。[结果] 桑叶最佳的提取条件为80%甲醇、超声30 min、料液比1：20；建立了桑皮苷A、隐绿原酸、芦丁、异槲皮苷、紫云英苷、槲皮素和山奈酚7种黄酮类成分同时测定HPLC方法。[结论] 建立了同时测定桑叶中7种黄酮类成分的HPLC方法，且本方法精密度、重复性、稳定性、加样回收率良好；发现不同产地桑叶7种黄酮类成分总含量与其α-糖苷酶抑制活性呈正相关关系，本研究为桑叶"经霜为上"的科学内涵阐明，桑叶的临床应用、质量控制及桑叶资源的二次开发提供参考。

Abstract:

[Objective] HPLC method was established for simultaneous determination of seven flavonoids ingredients and exploring the relationship between the total content of seven flavonoids and α-glucosidase inhibitory activity. [Methods] Orthogonal test was used to optimize extracting method of mulberry leaf. The HPLC method was established and validated to simultaneously determine seven flavonoids ingredients (mulberroside A, cryptochlorogenic acid, rutin, isoquercitrin, astragaline, quercitrin, kaempferol) in mulberry leaf. [Results] The optimal extracting conditions were that 0.5 g of mulberry leaf powder was extracted with 10 mL of 80% methanol (methanol-water) in ultrasonic bath for 30 min. The content of Rutin, Quercetin, Kaempferol, Isoquercitrin, Astragalin, Cryptochlorogenin acid, Mulberroside A are simultaneously determined by HPLC. [Conclusion] The established method is stable, repeatable and has good recovery. The seven flavonoids ingredients can be a reference for the strenth of α-glucosidase inhibitory activity. The results can provide a reference for quality control, clinical application, exploitation of mulberry leaf whose quality is better after Frost Desent