一株柴胡红景天中内生真菌的抗氧化活性

对柴胡红景天中一株具有抗氧化活性的内生真菌Rb-R-1进行研究,获得其分类地位并评价抗氧化活性强弱。结果表明:这株真菌为Ascomacota门Hypocreales目Neonectria属的N.ramulariae真菌,具有较强的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、羟自由基(·OH)、超氧阴离子自由基(O2-·)、NO2-清除能力和Fe2+螯合能力,IC50值分别为8.86、4.40、9.65、16.53、1.91 mg/m L;其发酵产物中总酚和总黄酮含量分别达18.12、22.48 mg/g。发酵条件优化结果表明,在以乳糖为碳源、牛肉膏为氮源、装液量90 m L/250 m L、p H 7.0、25℃条件下培养10 d时,内生真菌Rb-R-1发酵产物对DPPH自由基的清除率最大,达到93.12%;总酚和总黄酮含量最高,分别为19.14 mg/g和28.25 mg/g。

An Endophytic Fungus with Antioxidant Activity from Rhodiola bupleuroides

In this study, we reported for the first time an endophytic fungus, named Rb-R-1, with antioxidant activity
isolated and identified from Rhodiola bupleuroides. The isolate Rb-R-1 was affiliated to Neonectria ramulariae
belonging to the order Hypocreales in the phylum Ascomacota. The fungus possessed high scavenging activities against
1,1-diphenyl-2-picrylhydrazyl (DPPH), ·OH, O2-· and NO2- radicals and Fe2+ chelating activity, with half maximal
inhibitory concentration (IC50) of 8.86, 4.40, 9.65, 16.53 and 1.91 mg/mL, respectively. The contents of total phenolics
and total flavonoids in the concentrated culture supernatant of Rb-R-1 were 18.12 and 22.48 mg/g, respectively. The
optimal culture conditions that provided maximal DPPH radical scavenging rate (93.12%) were determined as lactose as
the carbon source, beef extract as the nitrogen source, initial pH 7.0, 90 mL of the medium in a 250-mL flask and 25 ℃.
In the meantime, the maximal contents of total phenolics and total flavonoids of 19.14 and 28.25 mg/g, respectively, were
obtained under these culture conditions.