N -Hydroxypiridinedione: A Privileged Heterocycle for Targeting the HBV RNase H

• Published in: Molecules (Basel, Switzerland) Switzerland), 2024-06, Vol.29 (12), p.2942
• Main Authors: Moianos, Dimitrios, Makri, Maria, Prifti, Georgia-Myrto, Chiotellis, Aristeidis, Pappas, Alexandros, Woodson, Molly E, Tajwar, Razia, Tavis, John E, Zoidis, Grigoris
• Format: Article
• Language: English
• Subjects: anti-HBV agents; Antiviral Agents - chemistry; Antiviral Agents - pharmacology; Biological response modifiers; Care and treatment; Catalytic Domain - drug effects; Chemistry; Enzyme Inhibitors - chemical synthesis; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - pharmacology; Enzymes; Health aspects; Hep G2 Cells; Hepatitis B; hepatitis B virus; Hepatitis B virus - drug effects; Hepatitis B virus - enzymology; Humans; Interferon; Medical research; Medicine, Experimental; Molecular Docking Simulation; Molecular Structure; N-hydroxypyridinediones; oximes; Oximes - chemistry; Oximes - pharmacology; Patient compliance; Proteins; Ribonuclease; ribonuclease H; Ribonuclease H - antagonists & inhibitors; Ribonuclease H - metabolism; Structure-Activity Relationship; structure–activity relationships; Tetracycline; Tetracyclines; Vaccines; Virus Replication - drug effects
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29122942

Hepatitis B virus (HBV) remains a global health threat. Ribonuclease H (RNase H), part of the virus polymerase protein, cleaves the pgRNA template during viral genome replication. Inhibition of RNase H activity prevents (+) DNA strand synthesis and results in the accumulation of non-functional genomes, terminating the viral replication cycle. RNase H, though promising, remains an under-explored drug target against HBV. We previously reported the identification of a series of -hydroxypyridinedione (HPD) imines that effectively inhibit the HBV RNase H. In our effort to further explore the HPD scaffold, we designed, synthesized, and evaluated 18 novel HPD oximes, as well as 4 structurally related minoxidil derivatives and 2 barbituric acid counterparts. The new analogs were docked on the RNase H active site and all proved able to coordinate the two Mg ions in the catalytic site. All of the new HPDs effectively inhibited the viral replication in cell assays exhibiting EC values in the low μM range (1.1-7.7 μM) with low cytotoxicity, resulting in selectivity indexes (SI) of up to 92, one of the highest reported to date among HBV RNase H inhibitors. Our findings expand the structure-activity relationships on the HPD scaffold, facilitating the development of even more potent anti-HBV agents.