Oseltamivir acid D3 (GS 4071 D3) is a deuterium labeled Oseltamivir acid. Oseltamivir acid, the active metabolite of Oseltamivir phosphate, is an orally bioavailable, potent and selective inhibitor of influenza virus neuraminidase (IC50=2 nM) with activity against both influenza A and B viruses[1][2].
[1]. Li W, et al. Identification of GS 4104 as an orally bioavailable prodrug of the influenza virus neuraminidase inhibitor GS 4071. Antimicrob Agents Chemother. 1998 Mar;42(3):647-53.
[2]. Ghosh GC, et al. Oseltamivir carboxylate, the active metabolite of oseltamivir phosphate (Tamiflu), detected in sewage discharge and river water in Japan. Environ Health Perspect. 2010 Jan;118(1):103-7.