Dryopteris crassirhizoma Nakai (Dryopteridaceae), a thick-stemmed wood fern, is a semi-evergreen plant mainly distributed in North and Northeast China. It is of great value in horticultural and medicinal applications. In this study, five β-tocopherol derivatives, drycrasspherols A–E (1–5), with three kinds of skeletons, were isolated from the rhizomes of Dryopteris crassirhizoma. Compounds 1–2 represent the basic architecture featuring a phenol motif fused with the phytyl-type diterpene via a pyran ring, compounds 3–4 possess an unprecedented tetracyclic system in which a 4-methylcyclohexanone is incorporated into the base unit of 1. Interestingly, compound 5 is a novel dimer constructed from two monomers via a pyran ring to form a pentacyclic system. These structures were elucidated by comprehensive spectroscopic data and quantum chemical electronic circular dichroism (ECD) calculations. Importantly, compound 1 exhibited the comparable anti-respiratory syncytial virus activity with an IC₅₀ value of 6.50 ± 1.25 μM to the positive control ribavirin. This study suggested the rhizomes of D. crassirhizoma as well as the β-tocopherol derivatives had new potential applications in pharmaceutical industry.

中井蕨（Dryopteridaceae）是一种粗茎木蕨类植物，是一种半常绿植物，主要​​分布在华北和东北地区。它在园艺和医药应用中具有重要价值。在这项研究中，5β生育酚衍生物，drycrasspherols A-E（1 - 5），具有三种骨架，从根茎分离鳞毛贯众。化合物1 - 2代表基本结构，其特征是苯酚基序通过吡喃环与植基型双萜融合，化合物3 - 4具有前所未有的四环体系，其中 4-甲基环己酮结合到1 . 有趣的是，化合物5是一种新型二聚体，由两个单体通过吡喃环构成五环体系。通过综合光谱数据和量子化学电子圆二色性 (ECD) 计算阐明了这些结构。重要的是，化合物1表现出与阳性对照病毒唑相当的抗呼吸道合胞病毒活性，IC ₅₀值为 6.50 ± 1.25 μM。该研究表明，粗骨木的根茎以及β-生育酚衍生物在制药工业中具有新的潜在应用。