title: Ultrafast Photoprotecting Sunscreens in Natural Plants.
abstract: We explore the ultrafast photoprotective properties of a series of sinapic acid derivatives in a range of solvents, utilizing femtosecond transient electronic absorption spectroscopy. We find that a primary relaxation mechanism displayed by the plant sunscreen sinapoyl malate and other related molecular species may be understood as a multistep process involving internal conversion of the initially photoexcited 1(1)ππ* state along a trans-cis photoisomerization coordinate, leading to the repopulation of the original trans ground-state isomer or the formation of a stable cis isomer.
authors.forename: Lewis A
authors.initials: LA
authors.lastname: Baker
authors.forename: Michael D
authors.initials: MD
authors.lastname: Horbury
authors.forename: Simon E
authors.initials: SE
authors.lastname: Greenough
authors.affiliation: Chaire Agro-Biotechnologies Industrielles (ABI), AgroParisTech , F-51100 Reims, France.|UMR GMPA, AgroParisTech, INRA , F-78850 Thiverval-Grignon, France.|UMR IJPB, AgroParisTech, INRA , F-78026 Versailles, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Allais
authors.affiliation: Department of Chemistry, Purdue University , West Lafayette, Indiana 47907-2084, United States.
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Walsh
authors.forename: Scott
authors.initials: S
authors.lastname: Habershon
authors.forename: Vasilios G
authors.initials: VG
authors.lastname: Stavros
mesh_terms: D017360:Arabidopsis / Q000737:chemistry*; D001688:Biological Products / Q000737:chemistry*; D002934:Cinnamates / Q000737:chemistry*; D003373:Coumaric Acids / Q000737:chemistry*; D008293:Malates / Q000737:chemistry*; D015394:Molecular Structure; D010666:Phenylpropionates / Q000737:chemistry*; D055668:Photochemical Processes; D013056:Spectrophotometry, Ultraviolet; D013473:Sunscreening Agents / Q000737:chemistry*; D013997:Time Factors
chemical_list: C079164:2-O-sinapoylmalate; D001688:Biological Products; D002934:Cinnamates; D003373:Coumaric Acids; D008293:Malates; D010666:Phenylpropionates; D013473:Sunscreening Agents; C006605:antithiamine factor; C073734:sinapinic acid
keywords: UV-B; excited-state dynamics; plant sunscreens; solution phase; ultrafast photochemistry