紫色红曲霉Mp-21次级代谢产物抗氧化及抑制α-葡萄糖苷酶活性的研究

Antioxidation and inhibition of α-glucosidase activity of secondary metabolites of Monascus purpureus Mp-21

摘要:

【目的】紫色红曲霉（Monascus purpureus）Mp-21次级代谢产物的分离纯化与生物活性研究。【方法】综合运用硅胶柱、反相C₁₈柱和Sephadex LH-20凝胶柱等柱色谱分离技术对紫色红曲霉Mp-21的次级代谢产物进行分离纯化，运用波谱学技术（核磁共振和高分辨质谱技术）鉴定化合物的结构。对鉴定的化合物进行抗氧化与降血糖相关酶抑制活性的测定。【结果】从紫色红曲霉Mp-21次级代谢产物中鉴定出10个活性化合物，分别为FMOC-ALLO-THR（TBU）-OH（1）、quercetin（2）、hesperetin（3）、monascin（4）、monasphilone A（5）、oleanolic acid（6）、β-sitosterol（7）、ergosterol（8）、indole-3-carboxylic acid（9）、chlorogenic acid（10）。其中化合物1为新天然产物，补充了该化合物在自然界中的信息和有机波谱信息，化合物2、6、9、10首次在红曲菌科中发现。在体外清除O^2-、DPPH和OH^-自由基的抗氧化活性试验中，化合物2 （IC₅₀分别为5.07、4.84和27.39 μg/mL）表现出较强的抗氧化能力。通过电子顺磁共振技术验证了化合物2对DPPH和OH^-自由基具有较强的清除能力。化合物6对α-葡萄糖苷酶具有较强的抑制作用，IC₅₀为22.87μg/mL。【结论】紫色红曲霉Mp-21是极具开发性能的优质种质资源，具有开发成抗氧化、降血糖等功能性食品的潜力。

Abstract:

[Objective] To study the separation, purification and biological activity of secondary metabolites from Monascus purpureus Mp-21. [Methods] The secondary metabolites of Monascus purpureus Mp-21 were isolated and purified using silica gel column, RPC₁₈ column and Sephadex LH-20 gel column and other column chromatographic separation techniques, and the structure of the compound was identified by spectroscopy technique (NMR and HR-ESI-MS). The anti-oxidation and hypoglycemic-related enzyme inhibitory activities of the identified compounds were determined. [Results] Ten active compounds were identified from the secondary metabolites of Monascus purpureus Mp-21, namely FMOC-ALLO-THR(TBU)-OH (1), quercetin (2), hesperetin (3), monascin (4), monasphilone A (5), oleanolic acid (6), β-sitosterol (7), ergosterol (8)、indole-3-carboxylic acid (9) and chlorogenic acid (10). Among them, compound 1 is a new natural product, which complements the information of the compound in nature and the information of the organic spectrum. Compounds 2, 6, 9 and 10 are discovered from the Monascus for the first time. In the in vitro antioxidant activity tests of O^2-, DPPH and OH^- free radicals, compound 2 (IC₅₀ of 5.07, 4.84 and 27.39 μg/mL, respectively) showed strong antioxidant capacity. Electron paramagnetic resonance (EPR) showed that compound 2 had strong scavenging ability on DPPH and OH^-. Compound 6 had strong inhibitory activity on α-glucosidase with IC₅₀ of 22.87 μg/mL. [Conclusion] Monascus purpureus Mp-21 is a high-quality germplasm resource with high development performance, and has the potential to be developed into functional food such as antioxidant and hypoglycemic.