Abstract In this study, potential bioactive compounds in the products of the solid fermentation of the paper mulberry tree bark (Broussonetia papyrifera) with a white rot fungus (Perenniporia tephropora) were investigated. Fractionation of methanolic extracts from the fermented products of the bark led to the isolation of 10 known compounds, namely broussonin B (1), broussonin A (2), 7,4'-dihydroxy-3'-prenylflavan (3), cathayanon H (4), broussoflavonol B (5), isoliquiritigenin (6), broussochalcone B (7), glyasperin A (8), marmesin (9), and vomifoliol (10). Their structures were determined by spectroscopic analysis (including considerations of MS, 1H, 13C NMR, COSY, HMQC, and HMBC spectra) and compared with structures that had been published in the literature. Of these compounds identified, cathayanon H (4) and glyasperin A (8) were isolated for the first time from the paper mulberry tree. Vomifoliol (10) was produced from the bark only after fermentation with white rot fungi. It was observed that concentrations of marmesin (9) and vomifoliol (10) generally increased with an increase in fermentation time, whereas concentration of compounds 1‒8 in the fermented products decreased during the same period. Biological tests showed that the tyrosinase inhibitory activity of marmesin (9) (IC50 = 168.0 μM) was similar to that of arbutin, a well-known tyrosinase inhibitor, whereas vomifoliol (10) exhibited no tyrosinase inhibition activity at any concentration higher than 2 mM. Accordingly, both solids and the liquid broth left after fermentation of the paper mulberry tree bark with the aforementioned white rot fungus could be developed for potential use in industrial applications.

中文翻译：

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白腐真菌 Perenniporia tephropora 固体发酵后，来自 Broussonetia papyrifera 树皮的生物活性化合物

摘要 在这项研究中，研究了桑树皮 (Broussonetia papyrifera) 与白腐真菌 (Perenniporia tephropora) 固体发酵产物中的潜在生物活性化合物。从树皮发酵产物中分离甲醇提取物，分离出 10 种已知化合物，即布鲁松素 B (1)、布鲁松素 A (2)、7,4'-二羟基-3'-异戊二烯黄烷 (3)、cathayanon H (4)、布罗索黄酮 B (5)、异甘草素 (6)、布罗索查耳酮 B (7)、glyasperin A (8)、marmesin (9) 和 vomifoliol (10)。它们的结构是通过光谱分析（包括对 MS、1H、13C NMR、COSY、HMQC 和 HMBC 光谱的考虑）确定的，并与已发表在文献中的结构进行比较。在这些鉴定出的化合物中，cathayanon H (4) 和 glyasperin A (8) 是首次从纸桑树中分离得到。Vomifoliol (10) 仅在用白腐真菌发酵后才从树皮中产生。观察到，marmesin (9) 和 vomifoliol (10) 的浓度普遍随着发酵时间的增加而增加，而发酵产物中化合物 1-8 的浓度则在同一时期下降。生物学测试表明，marmesin (9) (IC50 = 168.0 μM) 的酪氨酸酶抑制活性与众所周知的酪氨酸酶抑制剂熊果苷相似，而 vomifoliol (10) 在任何高于 2 mM 的浓度下都没有酪氨酸酶抑制活性. 因此，