1
|
Vinod Mouli MSS, Mishra AK. Flavin based supramolecular gel displaying multi-stimuli triggered sol-gel transition. Org Biomol Chem 2023. [PMID: 37377152 DOI: 10.1039/d3ob00720k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Herein, we report the design and synthesis of an amphiphilic flavin analogue as a robust low molecular weight gelator involving minimal structural modification. Four flavin analogues were evaluated for their gelation capabilities and the flavin analogue with antipodal positioning of the carboxyl and octyl functionalities was found to be the most efficient gelator with the minimum gelation concentration being as low as 0.03 M. A wide range of solvents were used for gelation studies suggesting its widespread applicability. Morphological, photophysical and rheological characterization studies were performed to fully characterize the nature of the gel. Interestingly, reversible multiple stimuli responsive sol-gel transition was observed with changing pH and redox activity, while metal screening showed specific transition in the presence of ferric ions. The gel was able to differentiate between ferric and ferrous species with well-defined sol-gel transition. The current results potentially offer a redox-active flavin-based material as a low molecular weight gelator for the development of next-generation materials.
Collapse
Affiliation(s)
- M S S Vinod Mouli
- Department of Chemistry, Indian Institute of Technology-Hyderabad, Kandi, 502284, Sangareddy, India.
| | - Ashutosh Kumar Mishra
- Department of Chemistry, Indian Institute of Technology-Hyderabad, Kandi, 502284, Sangareddy, India.
| |
Collapse
|
2
|
Ribes J, Bourdeau Y, Rascol E, Bestel I, Badarau E. Enhancing the photosensitizing activity of natural flavins: Tuning the heavy-atom effect in the isoalloxazine series. Bioorg Med Chem 2023; 81:117210. [PMID: 36791612 DOI: 10.1016/j.bmc.2023.117210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023]
Abstract
Structure-photosensitizing activity relationships for a series of flavin analogues were investigated with the final goal of identifying the most potent photosensitizer in these series. The main structural modifications involved the introduction of various halogen atoms in C7- and/or C8-positions on the isoalloxazine ring. These compounds were synthesized by reacting judiciously-functionalized anilines with alloxan. The SAR trends showed that the photosensitizing activity increased with the size of the halogen atoms, confirming the importance of the heavy-atom effect on the photosensitizer's activity. The halogens in C8 were more active than the di-substituted halogens, which in turn were more active than the C7-substituted equivalents. However, even if the photosensitizing activity is slightly less important for the 7- compared to the 8-substituted derivatives, the 7-haloisoalloxazines are promising photosensitizers, as they present a better cellular toxicity profile than the 8-substituted analoges. The photosensitizing activity perfectly correlated with the determined fluorescence for the same compounds. Except for the dihalogeno derivatives, all the compounds were not toxic up to a 50 μM range.
Collapse
Affiliation(s)
- Jonathan Ribes
- University of Bordeaux, CNRS, CBMN, UMR 5248, Institute of Chemistry and Biology of Membranes & Nano-objects (CBMN), Allée Geoffroy Saint Hilaire, Bât B14, 33600 Pessac, France
| | - Yann Bourdeau
- University of Bordeaux, CNRS, CBMN, UMR 5248, Institute of Chemistry and Biology of Membranes & Nano-objects (CBMN), Allée Geoffroy Saint Hilaire, Bât B14, 33600 Pessac, France
| | - Estelle Rascol
- University of Bordeaux, CNRS, CBMN, UMR 5248, Institute of Chemistry and Biology of Membranes & Nano-objects (CBMN), Allée Geoffroy Saint Hilaire, Bât B14, 33600 Pessac, France
| | - Isabelle Bestel
- University of Bordeaux, CNRS, CBMN, UMR 5248, Institute of Chemistry and Biology of Membranes & Nano-objects (CBMN), Allée Geoffroy Saint Hilaire, Bât B14, 33600 Pessac, France
| | - Eduard Badarau
- University of Bordeaux, CNRS, CBMN, UMR 5248, Institute of Chemistry and Biology of Membranes & Nano-objects (CBMN), Allée Geoffroy Saint Hilaire, Bât B14, 33600 Pessac, France.
| |
Collapse
|
3
|
Pavlovska T, Král Lesný D, Svobodová E, Hoskovcová I, Archipowa N, Kutta RJ, Cibulka R. Tuning Deazaflavins Towards Highly Potent Reducing Photocatalysts Guided by Mechanistic Understanding - Enhancement of the Key Step by the Internal Heavy Atom Effect. Chemistry 2022; 28:e202200768. [PMID: 35538649 PMCID: PMC9541856 DOI: 10.1002/chem.202200768] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Indexed: 11/11/2022]
Abstract
Deazaflavins are well suited for reductive chemistry acting via a consecutive photo-induced electron transfer, in which their triplet state and semiquinone - the latter is formed from the former after electron transfer from a sacrificial electron donor - are key intermediates. Guided by mechanistic investigations aiming to increase intersystem crossing by the internal heavy atom effect and optimising the concentration conditions to avoid unproductive excited singlet reactions, we synthesised 5-aryldeazaflavins with Br or Cl substituents on different structural positions via a three-component reaction. Bromination of the deazaisoalloxazine core leads to almost 100 % triplet yield but causes photo-instability and enhances unproductive side reactions. Bromine on the 5-phenyl group in ortho position does not affect the photostability, increases the triplet yield, and allows its efficient usage in the photocatalytic dehalogenation of bromo- and chloroarenes with electron-donating methoxy and alkyl groups even under aerobic conditions. Reductive powers comparable to lithium are achieved.
Collapse
Affiliation(s)
- Tetiana Pavlovska
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - David Král Lesný
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - Eva Svobodová
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - Irena Hoskovcová
- Department of Inorganic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - Nataliya Archipowa
- Institute for Biophysics and Physical BiochemistryUniversity of RegensburgD-93053RegensburgGermany
| | - Roger Jan Kutta
- Institute of Physical and Theoretical ChemistryUniversity of RegensburgD-93053RegensburgGermany
| | - Radek Cibulka
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| |
Collapse
|