{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T05:04:32Z","timestamp":1789707872763,"version":"4.0.1"},"reference-count":40,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T00:00:00Z","timestamp":1789171200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2022YFA1105403"],"award-info":[{"award-number":["2022YFA1105403"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012245","name":"Science and Technology Planning Project of Guangdong Province","doi-asserted-by":"publisher","award":["2021A1515110916"],"award-info":[{"award-number":["2021A1515110916"]}],"id":[{"id":"10.13039\/501100012245","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Guangdong Province Key Program of Discipline","award":["2021ZDJS091"],"award-info":[{"award-number":["2021ZDJS091"]}]},{"name":"Wuyi University-Hong Kong-Macao Joint Research and Development Fund","award":["2022WGALH14"],"award-info":[{"award-number":["2022WGALH14"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>COVID-19, caused by SARS-CoV-2, remains a global health challenge because of viral evolution and immune escape. Although current therapies primarily target viral entry and replication, agents that directly interfere with the Spike receptor-binding domain (S-RBD) remain limited. Here, we combined virtual screening with biological validation to identify compounds capable of interfering with S-RBD function. A total of 3014 compounds from a customized drug library were screened by molecular docking. Candidate binding and functional activity were subsequently evaluated using cellular thermal shift assays, surface plasmon resonance, immunoprecipitation, immunofluorescence, and pseudovirus-entry assays against 2019-nCoV, Delta, and Omicron pseudoviruses. DOTAP chloride (KD = 49.94 \u03bcM), cefotiam hexetil hydrochloride (KD = 142.26 \u03bcM), melittin (KD = 34.98 \u03bcM), and teicoplanin (KD = 73.58 \u03bcM) showed detectable binding to the S-RBD and inhibited Spike-mediated pseudovirus entry. Molecular docking suggested that these interactions were mediated by potential binding modes involving hydrogen bonds and \u03c0-interactions. The compounds interfered with S-RBD\/hACE2 colocalisation and inhibited pseudovirus entry with variant-dependent efficacy. DOTAP chloride (25 \u03bcM) inhibited entry of the 2019-nCoV and Omicron pseudoviruses, whereas the other three compounds showed activity across the tested variants. These findings identify four compounds with RBD-binding and entry-inhibition properties for further development as entry inhibitors.<\/jats:p>","DOI":"10.3390\/ijms27188136","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T12:09:51Z","timestamp":1789387791000},"page":"8136","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Identification of Four Compounds with S-RBD-Binding and Pseudovirus Entry-Inhibitory Activity"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-4523-1035","authenticated-orcid":false,"given":"Jingjie","family":"Zheng","sequence":"first","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-4537-2606","authenticated-orcid":false,"given":"Shitao","family":"Wang","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuqing","family":"Zhou","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiman","family":"Lin","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingsong","family":"Guan","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4215-6092","authenticated-orcid":false,"given":"Yao","family":"Wang","sequence":"additional","affiliation":[{"name":"Engineering Research Center in Ministry of Education for Innovative Drugs of Traditional Chinese Medicine and Zhuang Yao Medicine, Guangxi University of Chinese Medicine, Nanning 530001, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1737-6130","authenticated-orcid":false,"given":"Jianglin","family":"Fan","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, South China Institute of Large Animal Models for Biomedicine, School of Pharmacy and Food Engineering, Wuyi University, Jiangmen 529020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1056\/NEJMoa2001017","article-title":"A Novel Coronavirus from Patients with Pneumonia in China, 2019","volume":"382","author":"Zhu","year":"2020","journal-title":"N. 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