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Whittock AL, Turner MAP, Coxon DJL, Woolley JM, Horbury MD, Stavros VG. Reinvestigating the Photoprotection Properties of a Mycosporine Amino Acid Motif. Front Chem 2020; 8:574038. [PMID: 33102444 PMCID: PMC7546825 DOI: 10.3389/fchem.2020.574038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/26/2020] [Indexed: 12/28/2022] Open
Abstract
With the growing concern regarding commercially available ultraviolet (UV) filters damaging the environment, there is an urgent need to discover new UV filters. A family of molecules called mycosporines and mycosporine-like amino acids (referred to as MAAs collectively) are synthesized by cyanobacteria, fungi and algae and act as the natural UV filters for these organisms. Mycosporines are formed of a cyclohexenone core structure while mycosporine-like amino acids are formed of a cyclohexenimine core structure. To better understand the photoprotection properties of MAAs, we implement a bottom-up approach by first studying a simple analog of an MAA, 3-aminocyclohex-2-en-1-one (ACyO). Previous experimental studies on ACyO using transient electronic absorption spectroscopy (TEAS) suggest that upon photoexcitation, ACyO becomes trapped in the minimum of an S1 state, which persists for extended time delays (>2.5 ns). However, these studies were unable to establish the extent of electronic ground state recovery of ACyO within 2.5 ns due to experimental constraints. In the present studies, we have implemented transient vibrational absorption spectroscopy (as well as complementary TEAS) with Fourier transform infrared spectroscopy and density functional theory to establish the extent of electronic ground state recovery of ACyO within this time window. We show that by 1.8 ns, there is >75% electronic ground state recovery of ACyO, with the remaining percentage likely persisting in the electronic excited state. Long-term irradiation studies on ACyO have shown that a small percentage degrades after 2 h of irradiation, plausibly due to some of the aforementioned trapped ACyO going on to form a photoproduct. Collectively, these studies imply that a base building block of MAAs already displays characteristics of an effective UV filter.
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Affiliation(s)
- Abigail L Whittock
- Analytical Science Centre for Doctoral Training, Senate House, University of Warwick, Coventry, United Kingdom.,Department of Chemistry, University of Warwick, Coventry, United Kingdom
| | - Matthew A P Turner
- Department of Chemistry, University of Warwick, Coventry, United Kingdom.,Molecular Analytical Science Centre for Doctoral Training, Senate House, University of Warwick, Coventry, United Kingdom.,Department of Physics, University of Warwick, Coventry, United Kingdom
| | - Daniel J L Coxon
- Department of Chemistry, University of Warwick, Coventry, United Kingdom.,Department of Physics, University of Warwick, Coventry, United Kingdom.,Diamond Science and Technology Centre for Doctoral Training, University of Warwick, Coventry, United Kingdom
| | - Jack M Woolley
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
| | - Michael D Horbury
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, United Kingdom
| | - Vasilios G Stavros
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
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Holt EL, Stavros VG. Applications of ultrafast spectroscopy to sunscreen development, from first principles to complex mixtures. INT REV PHYS CHEM 2019. [DOI: 10.1080/0144235x.2019.1663062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Emily L. Holt
- Molecular Analytical Science Centre for Doctoral Training, Senate House, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
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Zhou HQ, Li L, Zhao Y, Wang HG, Zheng X. A combined experimental and density functional theory investigation of the hydrogen bonding of 2-cyclohexen-1-one and 3-methyl- 2-cyclohexen-1-one in solvents. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 208:32-39. [PMID: 30290292 DOI: 10.1016/j.saa.2018.09.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 08/07/2018] [Accepted: 09/24/2018] [Indexed: 06/08/2023]
Abstract
Hydrogen bonding is a weak chemical interaction widely existed in the variety of organic and biological molecules. As an important structural motif of pyrimidine bases, the solvent effect of the hydrogen bonding of 2-cyclohexen-1-one (CHO) and 3-methyl- 2-cyclohexen-1-one (3MCHO) and its effect on the frequency shift of the CO stretching mode were investigated by using the FT-Raman and UV absorption spectra and density functional theory calculations. The electronic transitions associated with the UV absorptions in different solvents were calculated at B3LYP-TD/6-31++G(d,p) level of theory and employing SCIPCM solvent model. The vibrational spectra of CHO and 3MCHO were assigned on the basis of the FT-Raman spectra in neat liquid and different solvents, the calculated vibrational spectra of monomer and CHO dimers, and the concentration dependent experiments of the band pair intensities. Hydrogen bonding energies of CHO-(H2O)n (n = 1,2) clusters were predicted. The results reveal that the CHO-(H2O)2 cluster and CHO monomer are respectively the major source of spectral observation in water and cyclohexane, while CHO dimmer and CHO monomer coexist in acetonitrile. The difference in the frequency of the νC=O stretching mode between 3MCHO monomer and CHO monomer in cyclohexane were explored.
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Affiliation(s)
- Hai Qiang Zhou
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, PR China
| | - Lei Li
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, PR China
| | - Yanying Zhao
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, PR China
| | - Hui Gang Wang
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, PR China
| | - Xuming Zheng
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, PR China.
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Woolley JM, Staniforth M, Horbury MD, Richings GW, Wills M, Stavros VG. Unravelling the Photoprotection Properties of Mycosporine Amino Acid Motifs. J Phys Chem Lett 2018; 9:3043-3048. [PMID: 29751729 DOI: 10.1021/acs.jpclett.8b00921] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Photoprotection from harmful ultraviolet (UV) radiation exposure is a key problem in modern society. Mycosporine-like amino acids found in fungi, cyanobacteria, macroalgae, phytoplankton, and animals are already presenting a promising form of natural photoprotection in sunscreen formulations. Using time-resolved transient electronic absorption spectroscopy and guided by complementary ab initio calculations, we help to unravel how the core structures of these molecules perform under UV irradiation. Through such detailed insight into the relaxation mechanisms of these ubiquitous molecules, we hope to inspire new thinking in developing next-generation photoprotective molecules.
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Affiliation(s)
- Jack M Woolley
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , U.K
| | - Michael Staniforth
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , U.K
| | - Michael D Horbury
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , U.K
| | - Gareth W Richings
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , U.K
| | - Martin Wills
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , U.K
| | - Vasilios G Stavros
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , U.K
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