Introduction: The SARS-CoV-2 pandemic has revealed a deficiency in antiviral agents. Plants, traditionally used for respiratory infections, are valuable sources of antiviral compounds. Such a plant is the Sideritis L. taxa (mountain tea), traditionally used against cold and cough.

Objectives: Accordingly, this study aimed to investigate the potential protective effects of dichloromethane extracts from Sideritis species against SARS-CoV-2.

Materials and methods: Eight Sideritis extracts were tested in an in vitro pretreatment assay to assess the protective effect against SARS-CoV-2. Therefore, infectious virus particles were pre-incubated with the extract, then incubated with Vero E6 cells to finally measure cell viability as a surrogate for virus infection. Untargeted analyses (GC-MS and LC-PDA-HRESIMS) were performed to determine metabolite profiles.

Results: Using an orthogonal approach that combines untargeted metabolomics and biological data from a screening assay, we characterized the phytochemical profiles of the different extracts and prioritized samples for targeted isolation. The dichloromethane extract of Sideritis cypria exhibited a notable protective effect. Untargeted analysis revealed coumarins as key compounds, with varying amounts across Sideritis species. Accordingly, fractionation of extract resulted in the isolation of two coumarin derivatives. Structure elucidation was performed using one- and two-dimensional nuclear magnetic resonance experiments. The coumarin, more abundant in S. cypria, demonstrated a slight protective effect in the SARS-CoV-2 pretreatment assay.

Conclusion: This study highlights the antiviral effects of Sideritis taxa, although further investigations are necessary to clarify the full potential of the herb. Additionally, the methodology presented herein can serve as a valuable resource for future phytochemical investigations focused on coumarin content within Sideritis genus.

Keywords: GC–MS; Lamiaceae; antiviral effect; metabolite profile; mountain tea.

© 2025 The Author(s). Phytochemical Analysis published by John Wiley & Sons Ltd.

简介： SARS-CoV-2大流行揭示了抗病毒药物的不足。植物传统上用于治疗呼吸道感染，是抗病毒化合物的重要来源。例如石松属（Mountain Tea）植物，在传统医学中被用来对抗感冒和咳嗽。

目的： 因此，本研究旨在调查石松属物种二氯甲烷提取物对SARS-CoV-2的潜在保护效果。

材料与方法： 八种石松属植物的提取物在体外预处理试验中进行了测试，以评估其对抗SARS-CoV-2的保护作用。因此，在将感染病毒颗粒与提取物预先孵育后，再将其与Vero E6细胞共同孵育，最后通过测量细胞活力作为病毒感染的替代指标。未靶向分析（GC-MS和LC-PDA-HRESIMS）被用来确定代谢谱。

结果： 采用一种结合无目标代谢组学和筛选试验中所得生物学数据的正交方法，我们对不同提取物的植物化学特征进行了表征，并优先选择了用于靶向分离的样本。来自Sideritis cypria的二氯甲烷提取物显示出显著的保护作用。未靶向分析揭示了香豆素为关键化合物，在石松属物种中含量各异。因此，提取物分馏导致两个香豆素衍生物的分离。结构解析使用了一维和二维核磁共振实验。在S. cypria中更为丰富的香豆素，在SARS-CoV-2预处理试验中显示出轻微的保护作用。

结论： 本研究突显了石松属植物的抗病毒效果，尽管仍需进一步的研究来阐明其全部潜力。此外，本文提出的方法可以作为未来针对石松属中的香豆素含量进行植物化学研究的重要资源。

关键词： GC–MS; 唇形科; 抗病毒效果; 代谢谱; 山茶。

© 2025 The Author(s). Phytochemical Analysis published by John Wiley & Sons Ltd.