Phosphoramidate Nucleotide Prodrugs for Liver Targeting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nucleoside monophosphates face challenges in efficiently being transported to therapeutic targets within cells, limiting their effectiveness as drug candidates, particularly due to the first phosphorylation step being rate-limiting when they reach the liver.
Innovation Solution
Development of novel phosphoramidate and cyclophosphate compounds that facilitate the delivery of monophosphate therapeutic agents, including unnatural nucleosides, by selectively targeting the liver through the hepatic portal vein, enhancing drug distribution and reducing side effects outside the liver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nucleoside monophosphates are used as drug candidates, then therapeutic effectiveness is limited, but the first phosphorylation step becomes rate-limiting when they reach the liver
Solution Approach 1:
The patent applies preliminary action by pre-attaching the phosphate group to the nucleoside analog to form a monophosphate prodrug. This preliminary phosphorylation bypasses the rate-limiting first phosphorylation step that would normally occur in the liver, allowing the compound to be directly utilized by viral polymerases or undergo further metabolism without being constrained by hepatic phosphorylation kinetics
Solution Approach 2:
The patent uses an intermediary approach by introducing a prodrug form (monophosphate ester) that serves as a mediator between the administered nucleoside analog and the active triphosphate form. This intermediary compound is designed to be selectively activated in target tissues (such as infected cells with high viral polymerase activity) rather than being rate-limited by liver phosphorylation, thereby improving therapeutic effectiveness while avoiding the productivity bottleneck of hepatic metabolism
2Quantity of substance
If prodrugs are designed to improve liver targeting, then drug distribution to liver is enhanced, but side effects outside the liver may increase
Solution Approach 1:
The patent applies local quality by designing prodrugs with specific chemical structures (cyclophosphate or phosphoramidate esters) that confer selective stability and activation characteristics. These prodrugs are engineered to be selectively activated in liver tissue or in cells infected with virus, while remaining relatively stable in other tissues. The local quality is achieved through selective susceptibility to phosphatases or esterases present in target tissues, thereby enhancing liver targeting without proportionally increasing systemic side effects
Solution Approach 2:
The patent employs parameter changes by modifying the chemical parameters of nucleoside analogs through prodrug conversion. The cyclophosphate and phosphoramidate esters alter the pharmacokinetic parameters including tissue distribution, metabolic stability, and activation kinetics. These parameter changes enable selective accumulation in liver tissue and controlled activation, improving the therapeutic index by enhancing efficacy in target tissue while limiting exposure and side effects in non-target tissues
Data Source
AI summary
Provided herein am phosphoramidate and cyclophosphate prodrug compounds of unnatural configuration nucleotide, their preparation, and their uses, such as treating liver diseases or nonliver diseases via intervening in the molecular pathways in the liver.