Bifunctional Ligand Design for Stable Metal Complexation

Solution Overview

Problem

Current bifunctional ligands for radioimmunotherapy, magnetic resonance imaging, and iron depletion therapy face challenges such as slow complexation kinetics, instability, and non-specific distribution, limiting their clinical effectiveness in binding metals and targeting cancer cells effectively.

Innovation Solution

The development of stereoselective and regioselective synthesis methods for aziridinium ions to produce nucleophilic addition products, including bifunctional ligands like NE3TA and NBEA, which enable efficient preparation of key pharmaceutical precursors and metal complexes for improved binding and targeting capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If C-DOTA is used as a bifunctional ligand, then metal complex stability is improved, but complexation kinetics become too slow for clinical use

Engineering Contradiction:

Improvemetal complex stabilityVSAvoidcomplexation kinetics

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The ligand system is divided into two functional components: a macrocyclic C-DOTA unit providing stable metal binding, and a separate acyclic DTPA-like unit providing rapid complexation kinetics and functional group conjugation. This segmentation allows each component to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent merges the advantages of C-DOTA (stability) and DTPA (kinetics) into a single bifunctional ligand system. The combined ligand possesses both the macrocyclic DOTA moiety for stable metal chelation and the acyclic DTPA-like structure for rapid complexation and conjugation to targeting moieties.

Inventive Principle:

Principle #5Merging (Combining)

2Speed

If 1B4M-DTPA is used as a bifunctional ligand, then complexation kinetics are improved, but metal complex stability becomes insufficient

Engineering Contradiction:

Improvecomplexation kineticsVSAvoidmetal complex stability

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The ligand system is divided into two functional components: a macrocyclic C-DOTA unit providing stable metal binding, and a separate acyclic DTPA-like unit providing rapid complexation kinetics and functional group conjugation. This segmentation allows each component to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent merges the advantages of C-DOTA (stability) and DTPA (kinetics) into a single bifunctional ligand system. The combined ligand possesses both the macrocyclic DOTA moiety for stable metal chelation and the acyclic DTPA-like structure for rapid complexation and conjugation to targeting moieties.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If conventional bifunctional ligands are used, then metal binding is achieved, but tissue specificity and targeting effectiveness are reduced

Engineering Contradiction:

Improvemetal binding capabilityVSAvoidnon-specific distribution

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The bifunctional ligand is designed with multiple functions integrated into a single molecule: (1) metal binding through the DOTA macrocycle, (2) rapid complexation through the DTPA-like unit, (3) conjugation to targeting moieties (antibodies, peptides, etc.), and (4) potential for further derivatization. This multi-functionality enables the ligand to simultaneously achieve reliable metal binding and effective targeting.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Different portions of the ligand molecule are optimized for different functions: the macrocyclic DOTA portion is optimized for stable metal binding, while the acyclic DTPA-like portion is optimized for rapid complexation and conjugation chemistry. This local optimization of properties allows each region to perform its specific function effectively.

Inventive Principle:

Principle #3Local quality

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 methods enhance the synthesis of pharmaceuticals, allowing for faster, more stable complex formation and improved tissue specificity, leading to more effective diagnostic imaging and therapeutic outcomes, particularly in cancer treatment.

Implementation Method 1

nucleophilic ring opening reactions of aziridinium ions

Methodology Applied

Scientific EffectNucleophilic ring opening: Chemical Bonding

Implementation Method 2

stereoselective and regioselective synthesis of compounds

Methodology Applied

Scientific EffectStereoselective synthesis: Chemical Bonding

Implementation Method 3

bind either radioactive or non-radioactive metals

Methodology Applied

Scientific EffectMetal binding: Chemical Bonding

Implementation Method 4

bifunctional ligands that can bind the radionuclides

Methodology Applied

Scientific EffectChelation: Chemical Bonding

Data Source

PatentUS10189803B2Synthesis of therapeutic and diagnostic drugs centered on regioselective and stereoselective ring opening of aziridinium ions

Publication Date: 2019.01.29 CHONG HYUN-SOON PHD

AI summary

Stereoselective and regioselective synthesis of compounds via nucleophilic ring opening reactions of aziridinium ions for use in stereoselective and regioselective synthesis of therapeutic and diagnostic compounds.