采收期对代料栽培桑黄子实体活性成分含量和抗氧化活性的影响

桑黄孔菌属Sanghuangporus 是一类具有重要药用价值的大型真菌,目前被国际公认为抗肿瘤效果最好的真菌之一。本研究以桑黄孔菌属中的杨树桑黄Sanghuangporus vaninii、鲍姆桑黄S. baumii为研究对象,通过测定代料栽培原基形成后第30、45、60、75、90天子实体多糖、三萜、总黄酮、总酚含量和抗氧化活性（ABTS和FRAP）,探究采收期对桑黄子实体活性成分含量和抗氧化活性的影响。结果表明,除杨树桑黄三萜含量外,采收期对上述6个指标均产生了极显著的影响。在多糖含量上,鲍姆桑黄在原基形成后75d时急剧升至最大,在原基形成后90d时有所下降;而杨树桑黄在原基形成后45、60、75d均维持较高水平。在三萜含量上,鲍姆桑黄在原基形成后30d时即达最大值,此后缓慢下降,而杨树桑黄则不同采收期差异不显著。关于总黄酮含量、总酚含量和抗氧化活性（ABTS、FRAP）,鲍姆桑黄和杨树桑黄均在原基形成后30、45、60d维持较高水平,在原基形成后75、90d急剧下降。相关性分析结果表明,总黄酮含量、总酚含量、抗氧化活性（ABTS、FRAP）两两极显著正相关。鲍姆桑黄多糖含量与其上述4指标呈显著或极显著负相关,与三萜相关不显著。杨树桑黄多糖含量与其上述4指标相关不显著,与三萜含量呈显著负相关。主成分分析与聚类分析结果一致,表现为原基形成后30、45、60d的子实体聚为一类,原基形成后75、90d的子实体聚为另一类。适时采收,有利于桑黄活性成分含量和抗氧化活性的提升。研究结果为桑黄代料栽培适时采收、质量控制、药材质量综合评价提供了科学参考。

Effects of harvest time on content of active components and antioxidant activities of fruiting bodies of Sanghuangporus cultivated with substitute materials

Sanghuangporus is currently recognized as one of valuable medicinal macrofungi with antitumor activity. The effects of harvest time on the content of active components (polysaccharide, total triterpenes, flavonoids and phenols) and antioxidant activity (ABTS and FRAP) of fruiting body were investigated on 30th, 45th, 60th, 75th, and 90th day after primordium formation of Sanghuangporus vaninii and S. baumii cultivated with sawdust medium. The result showed that harvest time significantly effected the content of polysaccharide, total triterpenes, flavonoids and phenols, and antioxidant activity (ABTS and FRAP) of the tested strains with the exception of the content of triterpenes of S. vaninii. The polysaccharide content of S. baumii increased sharp to the maximum on 75th day after primordium formation, and decreased slightly on 90th day, while that of S. vaninii maintained a high level on 45th, 60th and 70th day. The triterpene content of S. baumii reached the maximum value on 30th day, and then decreased slowly, while the triterpene content of S. vaninii had no significant change during whole harvest period. The total flavonoid and phenolic content, and antioxidant activities (ABTS and FRAP) of S. baumii and S. vaninii maintained a high level on 30th, 45th, and 60th day, and decreased sharp on 75th and 90th day. Correlation analysis showed positive correlation between the content of total flavonoid and phenols, and antioxidant activities of ABTS and FRAP. The polysaccharide content of S. baumii was significantly negatively correlated with the total flavonoid and phenolic content and ABTS and FRAP antioxidant activities, but not significantly correlated with the triterpenoid content. The polysaccharide content of S. vaninii has no significant correlation with the total flavonoid and phenolic content and antioxidant activities of ABTS and FRAP, but had a significant negative correlation with the triterpene content. The result of principal component analysis is consistent with that of cluster analysis, manifesting that the fruiting bodies formed on 30th, 45th and 60th day after primordium formation were grouped into one group, and the fruiting bodies formed on 75th and 90th day were grouped into another group. These results indicate that timely harvest is beneficial to the increase of active component content and antioxidant activity of Sanghuangporus fruiting body.