N-Substituted Hydroxamic Acids for Efficient HNO Donors
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Solution Overview
Problem
Current nitroxyl (HNO) donors for therapeutic applications face challenges such as low efficiency in generating HNO under physiological conditions, competition from unwanted reaction pathways, and the production of toxic byproducts like cyanide, necessitating the development of more reactive and physiologically compatible donors.
Innovation Solution
N-substituted hydroxamic acids with carbon-based leaving groups that generate nitrosocarbonyl intermediates under physiological conditions, allowing for efficient HNO production through O-deprotonation and subsequent hydrolysis, or through N-selective nitrosocarbonyl aldol reactions in organic solvents, producing N-substituted hydroxamic acid adducts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If N,O-bis-acylated derivatives of N-hydroxycyanamide are used as HNO donors, then HNO can be generated under enzymatic or basic conditions, but toxic cyanide is produced as a byproduct and the conditions are not physiologically compatible
Solution Approach 1:
The patent removes the cyanide-containing N-hydroxycyanamide moiety from the molecular structure and replaces it with N-substituted hydroxamic acid structures containing non-toxic carbon-based leaving groups. This extraction of the harmful cyanide component while retaining the HNO-generating capability resolves the contradiction between HNO production and toxic byproduct formation.
Solution Approach 2:
The patent changes the chemical structure parameters from N,O-bis-acylated N-hydroxycyanamide to N-substituted hydroxamic acids with specific leaving groups (X = CR2R3). This structural parameter change enables HNO generation under physiologically compatible conditions (neutral pH, no enzymatic activation required) while eliminating cyanide toxicity.
2Object-affected harmful factors
If O-acylated hydroxamic acids with arenesulfonyl leaving groups are used as HNO donors, then HNO can be generated under basic conditions, but less than 5% HNO is produced at neutral pH and the conditions are not physiologically relevant
Solution Approach 1:
The patent changes the leaving group parameter from arenesulfonyl to specific carbon-based groups (X = CR2R3 where R = H, alkyl, aryl, or heteroaryl). This parameter change dramatically increases HNO generation efficiency at neutral pH while maintaining non-toxic byproduct profiles, resolving the contradiction between safety and effectiveness.
Solution Approach 2:
The patent designs the N-substituted hydroxamic acid structure with pre-positioned carbon-based leaving groups that are optimized for spontaneous hydrolysis at neutral pH. This preliminary structural arrangement enables efficient HNO generation without requiring basic conditions, eliminating the trade-off between physiological compatibility and HNO yield.
3Productivity
If modified N,O-bis-acylated hydroxylamine derivatives with arenesulfonyl leaving groups are used, then HNO can be generated without enzymatic activation, but amide hydrolysis and acyl migration compete with HNO generation making the decomposition chemistry complicated
Solution Approach 1:
The patent extracts the problematic N,O-bis-acylated hydroxylamine structure that undergoes competing amide hydrolysis and acyl migration reactions. By replacing it with the simplified N-substituted hydroxamic acid structure, the patent eliminates these side reactions while maintaining enzymatic-independent HNO generation, thus resolving the complexity issue.
Solution Approach 2:
Instead of using the conventional N,O-bis-acylated structure that requires careful control to avoid side reactions, the patent inverts the approach by using N-substituted hydroxamic acids where the hydroxamic acid moiety itself is the active HNO-generating unit. This inversion simplifies the decomposition pathway to primarily HNO release without competing amide hydrolysis or acyl migration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These compounds achieve excellent yield of HNO in physiologically relevant conditions without toxic byproducts, enhancing the efficacy of nitroxyl therapy for conditions like cardiovascular diseases and cancer.
Implementation Method 1
In aqueous solutions, subsequent hydrolysis of the nitrosocarbonyl (Path A) generates a carboxylic acid and HNO in excellent yield.
Data Source
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AI summary
N-substituted hydroxamic acids with carbon-based leaving groups as efficient HNO donors are disclosed. Pharmaceutical compositions and kits comprising such compounds, and methods of using such compounds or pharmaceutical compositions also are disclosed.