Ultrafast Nonadiabatic Photoisomerization Dynamics Mechanism for the UV Photoprotection of Stilbenoids in Grape Skin
Yanan Shi1, Xiaoying Zhao1, Chao Wang1
1Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China.
Abstract:
Natural UV photoprotection plays a vital role in physiological protection. It has been reported that UVC radiation can make resveratrol (RSV) and piceatannol (PIC) accumulate in grape skin. In this work, we demonstrated that RSV and PIC could significantly absorb UVA and UVB, and confirmed their satisfactory photostability. Furthermore, we clarified the UV photoprotection mechanism of typical stilbenoids of RSV and PIC for the first time by using combined femtosecond transient absorption (FTA) spectroscopy and time-dependent density functional theory (TD-DFT) calculations. RSV and PIC can be photoexcited to the excited state after UVA and UVB absorption. Subsequently, the photoisomerized RSV and PIC quickly relax to the ground state via nonadiabatic transition from the S1 state at a conical intersection (CI) position between potential energy surfaces (PESs) of S1 and S0 states. This ultrafast trans-cis photoisomerization will take place within a few tens of picoseconds. As a result, the UV energy absorbed by RSV and PIC could be dissipated by an ultrafast nonadiabatic photoisomerization process.
More Related Videos
10:08High-Throughput Analysis of Non-Photochemical Quenching in Crops Using Pulse Amplitude Modulated Chlorophyll Fluorometry
Published on: July 6, 2022
10:03Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in...
UV–Vis Spectroscopy: Molecular Electronic Transitions
Radical Autoxidation
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
