Synthetic TLR4 Agonists with C3 Dehydroxylation

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Solution Overview

Problem

Current TLR4 agonists, such as MPL and AGPs, have limitations including chemical heterogeneity and complex synthesis processes, which affect their efficacy and usability as vaccine adjuvants and immunostimulants.

Innovation Solution

Development of novel synthetic compounds, specifically those of formula 1, which are more effective TLR4 receptor agonists with simpler and more industrially scalable synthesis processes, eliminating the need for hydroxyl groups on C3 and using non-hydroxylated myristic acid chains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If monophosphoryl lipid A (MPL) is used as TLR4 agonist, then immunostimulatory activity is maintained, but chemical heterogeneity and complex synthesis processes occur

Engineering Contradiction:
Improveimmunostimulatory activityVSAvoidchemical heterogeneity and synthesis complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent modifies the chemical structure of lipid A by changing specific parameters (removing hydroxyl groups at C3 position, adjusting acyl chain composition) to create a homogeneous synthetic compound that maintains immunostimulatory activity while eliminating chemical heterogeneity and simplifying synthesis processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention focuses on specific local modifications of the lipid A molecule, particularly at the C3 position where hydroxyl groups are removed and specific acyl chains are introduced, creating a targeted structural change that improves manufacturability while preserving biological activity

Inventive Principle:
Principle #3Local quality

2Reliability

If AGPs (Corixa compounds) are used as TLR4 agonists, then potent agonist activity is achieved, but synthesis processes become complex

Engineering Contradiction:
Improveagonist activityVSAvoidsynthesis process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex synthesis steps from the AGP production process by using a simplified approach that avoids the need for multiple protection and deprotection steps, directly synthesizing the compound without hydroxyl groups at C3 position

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of building up the complex structure step-by-step through conventional synthesis, the invention inverts the approach by starting with a simpler core structure and adding only the necessary components, thereby reducing synthesis complexity while maintaining agonist activity

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If natural LPS is used as TLR4 agonist, then strong activation effect is obtained, but excessive toxicity occurs

Engineering Contradiction:
Improveactivation effectVSAvoidtoxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful toxicity of natural LPS into a benefit by selectively removing the toxic hydroxyl groups at C3 position while retaining the essential activating structure, thereby reducing toxicity while maintaining or improving activation effect

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention creates a simplified copy of the lipid A structure that lacks the toxic hydroxyl groups at C3 position, producing a analogue that maintains the essential TLR4 activation function while eliminating the harmful toxic effects

Inventive Principle:
Principle #26Copying

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 new compounds, such as FP11, demonstrate enhanced TLR4 agonist activity with improved tolerability and reduced toxicity, offering potential as effective vaccine adjuvants and immunostimulants with streamlined synthesis.

Implementation Method 1

Lipid A agonistic activity is based on its binding affinity (ability to bind) to the TLR4 co-receptor, Myeloid Differentiation factor 2, MD-2

Methodology Applied
Scientific EffectBinding affinity: Chemical Bonding

Implementation Method 2

MPL is a molecule identical to lipid A, but with the C 1 position stripped of the phosphate group through chemical modification

Methodology Applied
Scientific EffectChemical modification: Chemical Bonding

Implementation Method 3

AGPs are comprised of a monosaccharide unit linked by glycosidation to a unit of an aminoalkyl aglycone N-acylate

Methodology Applied
Scientific EffectGlycosidation: Chemical Bonding

Implementation Method 4

Also compound SDZ MRL 953 demonstrated a potent activity in stimulating the release of inflammatory cytokines like interleukin-6 (IL-6), interleukin-8 (IL-8) and TNF-α factor

Methodology Applied
Scientific EffectCytokine release:

Data Source

PatentEP3707147B1New synthetic agonists of TLR4 receptor
Publication Date: 2025.03.05 UNIV DEGLI STUDI DI MILANO BICOCCA
  • EP3707147B1 patent drawingFigure 1A~2B
  • EP3707147B1 patent drawingFigure 3
  • EP3707147B1 patent drawingFigure 4A~4H

AI summary

The present invention relates to new synthetic molecules with agonist activity of human Toll-like Receptor 4 (TLR4), compositions comprising them and uses thereof for the treatment of diseases in which it is useful to induce or increase an immune response. The compounds have general formula (1), wherein R1 is a saturated C8-C16 aliphatic chain having a =0 on C1, said chain being free from -OH substituents on C3, wherein R2 is a saturated C8-C16 aliphatic chain having a =O on C1, said chain being free from -OH substituents on C3, wherein R3 is a saturated C8-C16 aliphatic chain having a =O on C1, said chain being free from -OH substituents on C3; wherein R4 is a hydrogen atom (H) or a phosphate group (PO4 2-).