1. De Clercq, E. & Li, G. Approved antiviral drugs over the past 50 years. Clin. Microbiol. Rev. 29, 695–747 (2016).
2. Gogineni, V., Schinazi, R. F. & Hamann, M. T. Role of marine natural products in the genesis of antiviral agents. Chem. Rev. 115, 9655–9706 (2015).
3. Hori, M., Takita, T., Koyama, G., Takeuchi, T. & Umezawa, H. A new antibiotic, Formycin. J. Antibiot. (Tokyo) 17, 96–99 (1964).
4. Takeuchi, T., Iwanaga, J., Aoyagi, T. & Umezawa, H. Antiviral effect of formycin and formycin B. J. Antibiot. (Tokyo) 19, 286–287 (1966).
5. Sawa, T., Fukagawa, Y., Homma, I., Takeuchi, T. & Umezawa, H. Mode of inhibition of coformycin on adenosine deaminase. J. Antibiot. (Tokyo) 20, 227–231 (1967).