A great deal of thermally instable form photoisomerization products will be formed from the thermally stable form of the plant sunscreens sinapate esters upon ultraviolet radiation. To reveal the photoisomerization mechanism of the -isomer, we explore the photodynamics of a model plant sunscreen methyl sinapate (MS) in the form in organic solution. The high photoisomerization quantum yield of the -isomer results in the relatively higher photostability of -MS. By utilizing femtosecond transient absorption spectroscopy and quantum chemical calculation, we propose that an adiabatic relaxation competes with nonadiabatic relaxation for the excited-state form of methyl sinapate. These results suggest that the photoprotection mechanism of the form of sinapate esters is significantly different from that of the form of sinapate esters and plays an important role in the overall photoprotection effect.
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http://dx.doi.org/10.1021/acs.jpclett.9b01651 | DOI Listing |
Chem Biodivers
March 2024
Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt.
Felicia abyssinica L., family Asteraceae, is widely used in folk medicine. This represents the first study to investigate its phytoconstituents and pharmacological effects.
View Article and Find Full Text PDFJ Nat Prod
August 2023
Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
The roots of are recognized as a rich source of protoberberine and aporphine alkaloids, but the non-alkaloidal metabolites in this plant are underexplored. The present study investigated the chemical composition of the plant roots using untargeted metabolomics-based molecular networking and MS2LDA motif annotation, revealing the presence of a characteristic fragment motif related to several sinapoyl-functionalized metabolites. Guided by the targeted motif, two new sinapic acid-ecdysteroid hybrids, named 3--sinapoyl makisterone A () and 2--sinapoyl makisterone A (), were isolated.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2022
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
As a prominent derivative of a natural sunscreen, methyl sinapate is an ideal candidate to provide fundamental insight into strategies on how to come to a rational design of artificial sunscreen filters with improved photoprotective properties. Here, static and time-resolved Zero Kinetic Energy-Pulsed Field Ionization (ZEKE-PFI) photoelectron spectroscopy has been used to study the spectroscopy and decay pathways of its electronically excited states. We find that different conformers are subject to distinct structural changes upon electronic excitation, and trace the structural changes that occur upon excitation back to the character of the LUMO.
View Article and Find Full Text PDF3 Biotech
January 2022
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), No 11 Fucheng Street, Haidian District, Beijing, 100048 China.
Unlabelled: In this study, a novel feruloyl esterase (BpFae) from B1213 was purified, biochemically characterized, and applied in releasing ferulic acid from wheat bran. The molecular mass of BpFae was approximately 60 kDa by SDS-PAGE, and the enzyme was a homomultimer in solution. BpFae displayed maximum activity at pH 4.
View Article and Find Full Text PDFJ Sci Food Agric
March 2022
Institute of Food Chemistry, Gottfried Wilhelm Leibniz University, Hannover, Germany.
Background: The use of rapeseed protein for human nutrition is primarily limited by its strong bitterness, which is why the key bitter compound, kaempferol 3-O-(2‴-O-sinapoyl-β-sophoroside), is enzymatically degraded.
Results: Mass spectrometry analyses of an extract from an untreated rapeseed protein isolate gave three signals for m/z 815 [M-H]. The predominant compound among the three compounds was confirmed as kaempferol-3-O-(2‴-O-sinapoyl-β-sophoroside).
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