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Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies
Gabbanini, S.; Neba, J.N.; Matera, R.; Valgimigli, L. Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies. Molecules2024, 29, 2604.
Gabbanini, S.; Neba, J.N.; Matera, R.; Valgimigli, L. Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies. Molecules 2024, 29, 2604.
Gabbanini, S.; Neba, J.N.; Matera, R.; Valgimigli, L. Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies. Molecules2024, 29, 2604.
Gabbanini, S.; Neba, J.N.; Matera, R.; Valgimigli, L. Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies. Molecules 2024, 29, 2604.
Abstract
Chamazulene (CA) is an intensely blue molecule with a wealth of biological properties. In cosmetics chamazulene is exploited as a natural coloring and soothing agent. CA is unstable and tends to spontaneous degradation accelerated by light. We studied the photodegradation of CA upon controlled exposure to UVB-UVA irradiation by multi-ple techniques, including GC-MS, UHPLC-PDA-ESI-MS/MS and by direct infusion in ESI-MSn, which were matched to in silico mass spectral simulations to identify degra-dation products. Seven byproducts formed upon UVA exposure for 3 h at 70mW/cm2 (blue-to-green color change) were identified, including CA dimers and CA benzenoid which were not found on extended 6 h irradiation (green-to-yellow fading). Photosta-bility tests with reduced irradiance conducted in various solvents in the pres-ence/absence of air indicated highest degradation in acetonitrile in the presence of ox-ygen, suggesting a photo-oxidative mechanism. Testing in the presence of antioxidants (tocopherol, ascorbyl palmitate, hydroxytyrosol, bakuchiol, γ-terpinene, TEMPO and their combinations) indicated highest protection by tocopherol and TEMPO. Sun-screens ethylhexyl methoxycinnamate and particularly Tinosorb® S (but not octo-crylene) showed good CA photoprotection. Thermal stability tests indicated no degra-dation of CA in acetonitrile at 50°C in the dark for 50 days; however, accelerated deg-radation occurred in the presence of ascrorbyl palmitate.
Chemistry and Materials Science, Analytical Chemistry
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