Ribeiro Bárbara, Valentão Patrícia, Baptista Paula, Seabra Rosa M, Andrade Paula B
REQUIMTE/Serviço de Farmacognosia, Faculdade de Farmácia, Universidade do Porto, R. Aníbal Cunha, 164, 4050-047 Porto, Portugal.
Food Chem Toxicol. 2007 Oct;45(10):1805-13. doi: 10.1016/j.fct.2007.03.015. Epub 2007 Mar 30.
The phenolic compounds and the organic acids composition of the edible beefsteak fungus Fistulina hepatica was determined by HPLC/DAD and HPLC/UV, respectively. The results showed a profile composed by five phenolic compounds (caffeic, p-coumaric and ellagic acids, hyperoside and quercetin) and six organic acids (oxalic, aconitic, citric, malic, ascorbic and fumaric acids). The quantification of the identified compounds revealed that ellagic acid (ca. 49.7%) and malic acid (ca. 57.9%) are the main compounds in this species. In a general way the phenolic profile revealed to be more constant than the organic acids one and could be more useful for the quality control of the species. Beefsteak fungus was also investigated for its capacity to act as a scavenger of DPPH() radical and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid). Good results were obtained against DPPH in a concentration-dependent manner. Beefsteak fungus also displayed good activity against superoxide radical, achieved by its capacity to act as both scavenger and xanthine oxidase inhibitor. A prooxidant effect was noticed for hydroxyl radical, which may be due to its capacity for iron ions reduction. Little ability for iron chelation was also observed. Beefsteak fungus showed a weak protective effect against hypochlorous acid.
分别采用高效液相色谱-二极管阵列检测法（HPLC/DAD）和高效液相色谱-紫外检测法（HPLC/UV）测定了食用牛排菌（肝色牛排菌）中的酚类化合物和有机酸成分。结果显示，其成分包括5种酚类化合物（咖啡酸、对香豆酸、鞣花酸、金丝桃苷和槲皮素）和6种有机酸（草酸、乌头酸、柠檬酸、苹果酸、抗坏血酸和富马酸）。对已鉴定化合物的定量分析表明，鞣花酸（约49.7%）和苹果酸（约57.9%）是该物种中的主要化合物。总体而言，酚类成分比有机酸成分更稳定，可能对该物种的质量控制更有用。还研究了牛排菌作为二苯代苦味酰基自由基（DPPH）和活性氧（超氧自由基、羟基自由基和次氯酸）清除剂的能力。在清除DPPH方面取得了良好的结果，且呈浓度依赖性。牛排菌对超氧自由基也表现出良好的活性，这是通过其作为清除剂和黄嘌呤氧化酶抑制剂的能力实现的。对于羟基自由基，观察到了促氧化作用，这可能是由于其还原铁离子的能力。还观察到其铁螯合能力较弱。牛排菌对次氯酸显示出较弱的保护作用。
