Cationic Phenalenone Derivative for Microbial Inactivation

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Solution Overview

Problem

Current photosensitizers for photodynamic inactivation of microorganisms, such as 1H-phenalen-1-one and sulfonated 1H-phenalen-1-one, have low affinity for microorganisms and insufficient inactivation due to limited diffusion of singlet oxygen, leading to treatment challenges with resistant pathogens.

Innovation Solution

Development of a 1H-phenalen-1-one derivative with a specific radical structure, -(CH2)k-X, where k is 1 to 4 and X contains neutral or positively charged nitrogen atoms, which enhances singlet oxygen production and affinity for microorganisms, allowing for efficient inactivation upon irradiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If 1H-phenalen-1-one and sulfonated 1H-phenalen-1-one are used as photosensitizers, then singlet oxygen yield is high, but affinity for microorganisms is low

Engineering Contradiction:
Improvesinglet oxygen yieldVSAvoidaffinity for microorganisms
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by introducing a cationic head group (containing nitrogen with positive charge) at one end of the molecule while maintaining the phenalenone core structure. This creates a localized positive charge that specifically interacts with negatively charged microorganism surfaces, thereby improving affinity without altering the singlet oxygen generating capability of the phenalenone moiety.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention creates a composite molecular structure combining the phenalenone photosensitizer core with a cationic head group (such as pyridinium, imidazolium, or triphenylphosphonium). This composite structure integrates two functional elements: the phenalenone for singlet oxygen generation and the cationic group for microorganism targeting, thereby achieving both high singlet oxygen yield and high affinity simultaneously.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If singlet oxygen is used for inactivation, then oxidation capability is strong, but diffusion distance is limited

Engineering Contradiction:
Improveoxidation capabilityVSAvoiddiffusion distance
Core Design Contradiction:
Object-affected harmful factorsVSLength of moving object

Solution Approach 1:

The cationic head group acts as an intermediary that facilitates the delivery of the phenalenone photosensitizer to the microorganism surface. By electrostatic attraction to negative charges on microorganism membranes, the intermediary group ensures close proximity positioning, allowing singlet oxygen to act on target molecules without requiring long-distance diffusion.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If complex molecular structure photosensitizers are used, then photodynamic activity is high, but manufacturing complexity increases

Engineering Contradiction:
Improvephotodynamic activityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the photodynamic function (phenalenone core) with the targeting function (cationic head group) into a single molecular entity. This consolidation eliminates the need for separate application steps and simplifies manufacturing by providing a ready-to-use photosensitizer that combines both activities in one compound.

Inventive Principle:
Principle #5Merging (Combining)

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 1H-phenalen-1-one derivative achieves a high log 10 reduction factor of microorganisms, reducing their viability by at least 99.99% through the generation of reactive oxygen species, effectively addressing the limitations of existing photosensitizers.

Implementation Method 1

Two different photooxidative processes play a crucial role in this process. The excited photosensitizer can cause the formation of reactive oxygen species (ROS), which can include radicals such as superoxide anions, hydrogen peroxide, or hydroxyl radicals, and/or excited molecular oxygen, such as singlet oxygen.

Methodology Applied
Scientific EffectPhotooxidation: Photo-oxidation

Implementation Method 2

The prerequisites for photooxidative inactivation are, firstly, the presence of a sufficient amount of oxygen and, secondly, the localization of a so-called photosensitizer, which is excited by light of a specific wavelength.

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP2678035B1Phenalene-1-one derivatives, method for producing same and use thereof
Publication Date: 2019.04.10 TRIOPTOTEC GMBH
  • EP2678035B1 patent drawingFigure 1A~1B
  • EP2678035B1 patent drawingFigure 2A~2B
  • EP2678035B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a compound of formula (1): where R1 through R8, which can be identical or different from each other, each are selected from of the group comprising hydrogen and the radical -(CH2)k-X, where k is a whole number from 1 to 20 and where X is an organic radical comprising a) at least one neutral, protonizable nitrogen atom and/or b) at least one positively charged nitrogen atom, under the provision that at least 1 radical R1 through R8 is not hydrogen. The invention further relates to the production and use of said compound.