Fluoroneplanocin A-8N (Compound 3a) is an inhibitor targeting SAH hydrolase (IC50 = 1.51 µM) and viral RNA polymerase. Fluoroneplanocin A-8N exhibits broad-spectrum anti-SARS-CoV-2 and dengue virus activity, with EC50 values of 12.2 and 37.4 µM respectively. Fluoroneplanocin A-8N has no cytotoxicity. Fluoroneplanocin A-8N can be used for anti-positive-strand viruses[1].