Pyrazolo[4,3-d]pyrimidines Bind Colchicine Site Tubulin
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Solution Overview
Problem
Current microtubule targeting agents face limitations in treating cancer due to multidrug resistance, particularly in tumors with overexpressed P-glycoprotein and β-III tubulin, where there is a need for effective colchicine site binding agents to overcome resistance mechanisms.
Innovation Solution
Development of pyrazolo[4,3-d]pyrimidine compounds and their pharmaceutical compositions that bind to the colchicine site on tubulin, inhibiting microtubule assembly and circumventing resistance mechanisms, with specific alkyl and halogen substitutions enhancing binding affinity and efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional microtubule targeting agents are used, then microtubule assembly can be inhibited, but resistance mechanisms (P-glycoprotein overexpression and β-III tubulin) reduce efficacy
Solution Approach 1:
The patent modifies the chemical structure of colchicine site binding agents by introducing specific substituents (R1, R2, R3 groups with various configurations) to change the molecular parameters of the drug. These structural parameter changes enable the compounds to maintain binding affinity at the colchicine site while evading resistance mechanisms mediated by P-glycoprotein and β-III tubulin, thereby improving antitumor efficacy in resistant cell lines
Solution Approach 2:
The invention introduces specific local modifications to the colchicine molecule structure, including substituents at defined positions (R1, R2, R3) with specific chemical properties. These localized structural changes create compounds that selectively interact with the colchicine site on tubulin while being less susceptible to efflux by P-glycoprotein and maintaining activity against β-III tubulin containing microtubules
2Reliability
If colchicine site binding agents are developed to overcome resistance, then efficacy in resistant tumors improves, but structural complexity of the compounds increases
Solution Approach 1:
The patent systematically varies specific parameters of the colchicine derivative structure (substituents R1, R2, R3 at defined positions) to optimize activity against resistant cell lines. By controlling and modifying only specific molecular parameters rather than completely redesigning the molecule, the invention achieves improved efficacy while managing structural complexity
Solution Approach 2:
The invention applies local modifications to specific regions of the colchicine molecule (N-terminal region with R1, C-terminal region with R2 and R3) rather than uniform complexity throughout. This localized approach to molecular design allows the compounds to maintain essential binding features while introducing resistance-overcoming properties at specific sites
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
The pyrazolo[4,3-d]pyrimidine compounds demonstrate improved inhibition of tubulin assembly and colchicine binding, effectively overcoming resistance mechanisms, with enhanced activity in cancer cell lines resistant to traditional microtubule targeting agents.
Implementation Method 1
bind to the colchicine site on tubulin, inhibiting microtubule assembly
Data Source
AI summary
A compound of Formula II, or optionally a salt or a hydrate of the compound of Formula II is provided:wherein R1 is selected from the group consisting of a hydrogen, an alkyl group having from one to six carbon atoms, an aryl group, and a heteroaryl group; R2 is selected from the group consisting of an alkyl group having from one to six carbon atoms, a hydrogen, a NRaRb group wherein Ra is either a hydrogen or an alkyl group having from one to six carbon atoms and Rb is either a hydrogen or an alkyl group having from one to six carbon atoms, an aryl group, a heteroaryl group, and a halogen; R is an alkyl group having from one to six carbon atoms; and Ar is selected from the group consisting of an alkyl group having from one to six carbon atoms, a substituted aryl, and a substituted heteroaryl.