A theoretical study of the UV absorption of 4-methylbenzylidene camphor: from the UVB to the UVA region

Silva, Luís Pinto da; Ferreira, Paulo J.O.; Miranda, Margarida S.; Silva, Joaquim C. G. Esteves da

doi:10.1039/c4pp00392f

Cited by 9 publications

(5 citation statements)

References 44 publications

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“…The percentage of initial UVA PF and AUC values range from 103.5 to 87.0% and 94.0 to 79.6% respectively. Especially compound 3d is characterized by functional photostability very similar to that of 4-MBC which is considered a photostable UV-filter [48]. The analysis of chromatograms and mass spectra of selected compounds indicates that in macrogol formulations the compounds behave as in methanol solutions.…”

Section: Resultsmentioning

confidence: 99%

Discovery of Novel UV-Filters with Favorable Safety Profiles in the 5-Arylideneimidazolidine-2,4-dione Derivatives Group

et al. 2019

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Effective protection from the harmful effects of UV radiation may be achieved by using sunscreens containing organic or inorganic UV filters. The number of currently available UV filters is limited and some of the allowed molecules possess limitations such as systemic absorption, endocrine disruption properties, contact and photocontact allergy induction, and low photostability. In the search for new organic UV filters we designed and synthesized a series consisting of 5-benzylidene and 5-(3-phenylprop-2-en-1-ylidene)imidazolidine-2,4-dione (hydantoin) derivatives. The photoprotective activity of the tested compounds was confirmed in methanol solutions and macrogol formulations. The most promising compounds possessed similar UV protection parameter values as selected commercially available UV filters. The compound diethyl 2,2′-((Z)-4-((E)-3-(4-methoxyphenyl)allylidene)-2,5-dioxoimidazolidine-1,3-diyl)diacetate (4g) was characterized as an especially efficient UVA photoprotective agent with a UVA PF of 6.83 ± 0.05 and favorable photostability. Diethyl 2,2′-((Z)-4-(4-methoxybenzylidene)-2,5-dioxo- imidazolidine-1,3-diyl)diacetate (3b) was the most promising UVB-filter, with a SPFin vitro of 3.07 ± 0.04 and very good solubility and photostability. The main photodegradation products were geometric isomers of the parent compounds. These compounds were also shown to be non-cytotoxic at concentrations up to 50 µM when tested on three types of human skin cells and possess no estrogenic activity, according to the results of a MCF-7 breast cancer model.

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Section: Resultsmentioning

confidence: 99%

Discovery of Novel UV-Filters with Favorable Safety Profiles in the 5-Arylideneimidazolidine-2,4-dione Derivatives Group

et al. 2019

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“…In view of the attention that nowadays is given to protection against solar radiation and the potential of photothermal materials, it is not surprising that over the years increasingly more studies have been reported that focus on these aspects. The development of spectroscopic techniques that enable such studies over a wide range of wavelengths, encompassing time scales ranging from femtoseconds to days and longer, and under a large variety of environmental conditions [18][19][20][21][22][23][24][25][26][27] in combination with advanced quantum chemical calculations [28][29][30][31][32][33] has from this point of view contributed significantly to the body of knowledge that is currently available.…”

Section: Introductionmentioning

confidence: 99%

Elucidating the photoprotective properties of natural UV screening agents: ZEKE–PFI spectroscopy of methyl sinapate

Fan

Finazzi

Buma

2022

Phys. Chem. Chem. Phys.

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“…Computationally, to the best of our knowledge, there are two computational works that focus on exploring ground‐state structures and absorption spectra of 4MBC . The photophysical mechanism of 4MBC is not studied.…”

Section: Introductionmentioning

confidence: 99%

Photophysics of a UV‐B Filter 4‐Methylbenzylidene Camphor: Intersystem Crossing Plays an Important Role

Fang

Chang

et al. 2018

ChemPhysChem

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4-Methylbenzylidene camphor (4MBC) is a frequently used ultraviolet (UV) filter in commercial sunscreens, which is experimentally found to undergo efficient intersystem crossing to triplet manifolds followed by predominant radiationless decay to the ground state. However, its photophysical mechanism is unclear. Herein, we have employed combined CASPT2 and CASSCF methods to study the spectroscopic properties, geometric and electronic structures, conical intersections and crossing points, and excited-state deactivation channels of 4MBC. We have found that the V( ππ*) state is populated with large probability in the Franck-Condon region. Starting from this state, there are two efficient nonradiative relaxation processes to populate the ππ* state. In the first one, the V( ππ*) state decays to the V'( ππ*) state. The resultant V'( ππ*) state further jumps to the nπ* state by internal conversion at the ππ*/ nπ* conical intersection. Then, the nπ* state hops to the ππ* state through an efficient nπ*→ ππ* intersystem crossing process. In the second one, the V( ππ*) state can diabatically relax along the photoisomerization reaction coordinate. In this process, a ππ*/ nπ* crossing point helps the ππ* system decay to the nπ* state, which further decays to the ππ* state through internal conversion at the nπ*/ ππ* conical intersection. Once the ππ* state is formed, a nearly barrierless relaxation path drives the ππ* system to hop to the S state via the ππ*/S crossing point. Our current work not only rationalizes recent experimental observations but also enriches our photophysical knowledge of UV filters.

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A theoretical study of the UV absorption of 4-methylbenzylidene camphor: from the UVB to the UVA region

Cited by 9 publications

References 44 publications

Discovery of Novel UV-Filters with Favorable Safety Profiles in the 5-Arylideneimidazolidine-2,4-dione Derivatives Group

Discovery of Novel UV-Filters with Favorable Safety Profiles in the 5-Arylideneimidazolidine-2,4-dione Derivatives Group

Elucidating the photoprotective properties of natural UV screening agents: ZEKE–PFI spectroscopy of methyl sinapate

Photophysics of a UV‐B Filter 4‐Methylbenzylidene Camphor: Intersystem Crossing Plays an Important Role

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