Mulberry leaves contain various bioactive constituents and are widely used as traditional medicine and food in Asia. In this study, mulberry leaves were processed by solid-state fermentation (SSF) using a mixture microbial of , , , and . The effects of SSF on the metabolite profile, antioxidant activity, and α-glucosidase inhibitory activity (GIA) of mulberry leaves were investigated. UPLC–QQQ–MS/MS-based widely targeted metabolomic analysis showed the detection of 11 classes of metabolites. SSF drastically influenced the metabolites of mulberry leaves. A total of 441 differential metabolites were identified after SSF, with 165 metabolites remarkably up-regulated and 276 metabolites of mulberry leaves drastically down-regulated during fermentation. The main types of differential metabolites were phenolic acids and flavonoids. Furthermore, SSF significantly increased the levels of total phenolics and flavonoids, and enhanced the scavenging activities of DPPH radical and ABTS·, reducing power, ferrous ion chelating ability, ferric reducing antioxidant power, and α-glucosidase inhibitory activity of mulberry leaves. In conclusion, our study revealed that SSF remarkably improved the phytochemical components of mulberry leaves, thereby contributing to the enhancement of antioxidant and α-glucosidase inhibitory activities.

中文翻译：

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基于UPLC-QQQ-MS/MS的固态发酵桑叶的广泛靶向代谢组学分析、抗氧化和α-葡萄糖苷酶抑制活性


桑叶含有多种生物活性成分，在亚洲被广泛用作传统药物和食品。在本研究中，使用 、 、 和 的混合微生物通过固态发酵 (SSF) 加工桑叶。研究了 SSF 对桑叶代谢谱、抗氧化活性和 α-葡萄糖苷酶抑制活性 (GIA) 的影响。基于 UPLC-QQQ-MS/MS 的广泛靶向代谢组学分析显示检测到 11 类代谢物。 SSF极大地影响了桑叶的代谢产物。 SSF后共鉴定出441个差异代谢物，其中165个代谢物在发酵过程中显着上调，276个代谢物在发酵过程中显着下调。差异代谢物主要类型为酚酸类和黄酮类化合物。此外，SSF显着提高了桑叶总酚和黄酮类化合物的含量，增强了桑叶DPPH自由基和ABTS·的清除活性、还原力、亚铁离子螯合能力、铁还原抗氧化能力和α-葡萄糖苷酶抑制活性。总之，我们的研究表明，SSF 显着改善了桑叶的植物化学成分，从而有助于增强抗氧化和 α-葡萄糖苷酶抑制活性。