COVID-19 has been a major global health concern for the past three years, and currently we are still experiencing coronavirus patients in the following years. The virus, known as SARS-CoV-2, shares a similar genomic identity with previous viruses such as SARS-CoV and MERS-CoV. To combat the pandemic, modern drugs discovery techniques such as in silico experiments for docking and virtual screening have been employed to design new drugs against COVID-19. However, the release of new drugs for human use requires two safety assessment steps consisting of preclinical and clinical trials. To bypass these steps, scientists are exploring the potential of repurposing existing drugs for COVID-19 treatment. This approach involves evaluating antiviral activity of drugs previously used for treating respiratory diseases against other enveloped viruses such as HPV, HSV, and HIV. The aim of this study is to review repurposing of existing drugs, traditional medicines, and active secondary metabolites from plant-based natural products that target specific protein enzymes related to SARS-CoV-2. The review also analyzes the chemical structure and activity relationship between selected active molecules, particularly flavonol groups, as ligands and proteins or active sites of SARS-CoV-2.

中文翻译：

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治疗 COVID-19 的药物发现研究最新进展：重新利用现有药物和现有天然生物活性分子

过去三年来，COVID-19 一直是全球主要的健康问题，目前我们在接下来的几年里仍然会遇到冠状病毒患者。该病毒被称为 SARS-CoV-2，与 SARS-CoV 和 MERS-CoV 等以前的病毒具有相似的基因组特征。为了抗击这一流行病，现代药物发现技术（例如用于对接和虚拟筛选的计算机实验）已被用来设计针对 COVID-19 的新药物。然而，用于人类使用的新药的发布需要两个安全评估步骤，包括临床前和临床试验。为了绕过这些步骤，科学家们正在探索重新利用现有药物用于治疗 COVID-19 的潜力。该方法涉及评估先前用于治疗呼吸道疾病的药物针对其他包膜病毒（例如 HPV、HSV 和 HIV）的抗病毒活性。本研究的目的是回顾现有药物、传统药物和来自植物天然产物的活性次生代谢物的重新利用，这些天然产物针对与 SARS-CoV-2 相关的特定蛋白酶。该综述还分析了所选活性分子（特别是黄酮醇基团）作为 SARS-CoV-2 配体和蛋白质或活性位点之间的化学结构和活性关系。