Submit to Molecules Review for Molecules Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Natural and Artificial Photoprotective Agent

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Photochemistry".

Deadline for manuscript submissions: closed (30 November 2020) | Viewed by 70455

Share This Special Issue

Special Issue Editor

Dr. Diego Sampedro

E-Mail Website
Guest Editor

Departamento de Química, Universidad de La Rioja, Logroño, Spain
Interests: photochemistry; photophysics; molecular photoswitches; computational chemistry; organic synthesis; sunscreens; energy storage
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Solar light is fundamental for life on Earth, but the more energetic UV radiation coming from the Sun is a very dangerous agent due to the direct or indirect harm that it can cause on living organisms. Every life form in our planet has developed its own tools to avoid or minimize the damages caused by intense solar radiation. Evolution has guided the selection of compounds acting as photoprotective agents and also the use of repairing mechanisms after photodamage. Thus, many different chemical species have been isolated and identified in a wide variety of organisms.

Especially relevant is the preparation of new, artificial compounds (usually inspired by natural products) used in a variety of applications, including human skin. The development of more efficient sun-care products is not only a matter of intense scientific exploration. It is also a field with a great economic potential and public health impact.

This Special Issue covers all aspects of photoprotective agents either coming from natural sources or synthesis. Contributions dealing with the isolation, synthesis, and characterization of new compounds, photophysical and photochemical studies on different structures, and the use of photoprotective agents in different applications are welcome. Synthesis, computational studies, spectroscopic techniques, formulations, and final applications will be considered.

Dr. Diego Sampedro
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Photoprotection
Sunscreens
Photochemistry
Photophysics
Skin care

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (11 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Editorial

Jump to: Research, Review

2 pages, 173 KiB

Open AccessEditorial

Natural and Artificial Photoprotective Agents

by Diego Sampedro

Molecules 2021, 26(4), 1189; https://doi.org/10.3390/molecules26041189 - 23 Feb 2021

Viewed by 1827

Abstract

Sunlight has a long list of positive effects on living beings [...] Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

Research

Jump to: Editorial, Review

30 pages, 13067 KiB

Open AccessArticle

Zn(ferulate)-LSH Systems as Multifunctional Filters

by Gustavo Pereira Saito, Ana Carolina Lanfredi Matsumoto, Renata Pires Assis, Iguatemy Lourenço Brunetti, Marco Aurélio Cebim and Marian Rosaly Davolos

Molecules 2021, 26(8), 2349; https://doi.org/10.3390/molecules26082349 - 17 Apr 2021

Cited by 2 | Viewed by 2367

Abstract

Excessive UV solar radiation exposure causes human health risks; therefore, the study of multifunctional filters is important to skin UV protective ability and also to other beneficial activities to the human organism, such as reduction of reactive oxygen species (ROS) responsible for cellular damages. Potential multifunctional filters were obtained by intercalating of ferulate anions into layered simple metal hydroxides (LSH) through anion exchange and precipitation at constant pH methods. Ultrasound treatment was used in order to investigate the structural changes in LSH-ferulate materials. Structural and spectroscopic analyses show the formation of layered materials composed by a mixture of LSH intercalated with ferulate anions, where carboxylate groups of ferulate species interact with LSH layers. UV-VIS absorption spectra and in vitro SPF measurements indicate that LSH-ferulate systems have UV shielding capacity, mainly UVB protection. The results of reactive species assays show the ability of layered compounds in capture DPPH^•, ABTS^•+, ROO^•, and HOCl/OCl⁻ reactive species. LSH-ferulate materials exhibit antioxidant activity and singular optical properties that enable their use as multifunctional filters. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Graphical abstract

14 pages, 2099 KiB

Open AccessArticle

¹⁵N NMR Shifts of Eumelanin Building Blocks in Water: A Combined Quantum Mechanics/Statistical Mechanics Approach

by Leonardo Bruno Assis Oliveira, Tertius L. Fonseca and Benedito J. C. Cabral

Molecules 2020, 25(16), 3616; https://doi.org/10.3390/molecules25163616 - 9 Aug 2020

Cited by 3 | Viewed by 2471

Abstract

Theoretical results for the magnetic shielding of protonated and unprotonated nitrogens of eumelanin building blocks including monomers, dimers, and tetramers in gas phase and water are presented. The magnetic property in water was determined by carrying out Monte Carlo statistical mechanics sampling combined with quantum mechanics calculations based on the gauge-including atomic orbitals approach. The results show that the environment polarization can have a marked effect on nitrogen magnetic shieldings, especially for the unprotonated nitrogens. Large contrasts of the oligomerization effect on magnetic shielding show a clear distinction between eumelanin building blocks in solution, which could be detected in nuclear magnetic resonance experiments. Calculations for a

π

-stacked structure defined by the dimer of a tetrameric building block indicate that unprotonated N atoms are significantly deshielded upon

π

stacking, whereas protonated N atoms are slightly shielded. The results stress the interest of NMR experiments for a better understanding of the eumelanin complex structure. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

16 pages, 2537 KiB

Open AccessArticle

The Lipoxin Receptor/FPR2 Agonist BML-111 Protects Mouse Skin Against Ultraviolet B Radiation

by Renata M. Martinez, Victor Fattori, Priscila Saito, Ingrid C. Pinto, Camilla C. A. Rodrigues, Cristina P. B. Melo, Allan J. C. Bussmann, Larissa Staurengo-Ferrari, Julia Rojo Bezerra, Josiane A. Vignoli, Marcela M. Baracat, Sandra R. Georgetti, Waldiceu A Verri Jr. and Rubia Casagrande

Molecules 2020, 25(12), 2953; https://doi.org/10.3390/molecules25122953 - 26 Jun 2020

Cited by 22 | Viewed by 3901

Abstract

Excessive exposure to UV, especially UVB, is the most important risk factor for skin cancer and premature skin aging. The identification of the specialized pro-resolving lipid mediators (SPMs) challenged the preexisting paradigm of how inflammation ends. Rather than a passive process, the resolution of inflammation relies on the active production of SPMs, such as Lipoxins (Lx), Maresins, protectins, and Resolvins. LXA4 is an SPM that exerts its action through ALX/FPR2 receptor. Stable ALX/FPR2 agonists are required because SPMs can be quickly metabolized within tissues near the site of formation. BML-111 is a commercially available synthetic ALX/FPR2 receptor agonist with analgesic, antioxidant, and anti-inflammatory properties. Based on that, we aimed to determine the effect of BML-111 in a model of UVB-induced skin inflammation in hairless mice. We demonstrated that BML-111 ameliorates the signs of UVB-induced skin inflammation by reducing neutrophil recruitment and mast cell activation. Reduction of these cells by BML-111 led to lower number of sunburn cells formation, decrease in epidermal thickness, collagen degradation, cytokine production (TNF-α, IL-1β, IL-6, TGF, and IL-10), and oxidative stress (observed by an increase in total antioxidant capacity and Nrf2 signaling pathway), indicating that BML-111 might be a promising drug to treat skin disorders. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

16 pages, 2346 KiB

Open AccessFeature PaperArticle

Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin Photoaging

by Diana I. S. P. Resende, Mariana C. Almeida, Bruna Maciel, Helena Carmo, José Sousa Lobo, Carlotta Dal Pozzo, Sara M. Cravo, Gonçalo P. Rosa, Aida Kane-Pagès, Maria do Carmo Barreto, Isabel F Almeida, Maria Emília de Sousa and Madalena M. M. Pinto

Molecules 2020, 25(12), 2782; https://doi.org/10.3390/molecules25122782 - 16 Jun 2020

Cited by 8 | Viewed by 4786

Abstract

Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

18 pages, 20703 KiB

Open AccessArticle

Characterization of Ethyl Acetate and Trichloromethane Extracts from Phoebe zhennan Wood Residues and Application on the Preparation of UV Shielding Films

by Fangya Pan, Lin Chen, Lu He, Yongze Jiang, Jinqiu Qi, Hui Xiao, Yuzhu Chen, Xingyan Huang, Hongling Hu, Lihua Tu, Tiantian Lin, Gang Chen, Jianfeng Hao, Yinlong Xiao and Jiulong Xie

Molecules 2020, 25(5), 1145; https://doi.org/10.3390/molecules25051145 - 4 Mar 2020

Cited by 10 | Viewed by 3914

Abstract

In this work, ethyl acetate (EA) and trichloromethane (TR) extracts were extracted from Phoebe zhennan wood residues and the extracts were then applied to the preparation of UV shielding films (UV-SF). The results revealed that substances including olefins, phenols and alcohols were found in both EA and TR extracts, accounting for about 45% of all the detected substances. The two extracts had similar thermal stability and both had strong UV shielding ability. When the relative percentage of the extract is 1 wt% in solution, the extract solution almost blocked 100% of the UV-B (280–315 nm), and UV-A (315–400 nm). Two kinds of UV-SF were successfully prepared by adding the two extracts into polylactic acid (PLA) matrix. The UV-SF with the addition of 24 wt% of the extractive blocked 100% of the UV-B (280–315 nm) and more than 80% of the UV-A (315–400 nm). Moreover, the UV shielding performance of the UV-SF was still stable even after strong UV irradiation. Though the addition of extracts could somewhat decrease the thermal stability of the film, its effect on the end-use of the film was ignorable. EA extracts had less effect on the tensile properties of the films than TR extracts as the content of the extract reached 18%. The results of this study could provide fundamental information on the potential utilization of the extracts from Phoebe zhennan wood residues on the preparation of biobased UV shielding materials. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

Review

Jump to: Editorial, Research

16 pages, 1210 KiB

Open AccessReview

Photoprotective Role of Neoxanthin in Plants and Algae

by Chiara Giossi, Paulo Cartaxana and Sónia Cruz

Molecules 2020, 25(20), 4617; https://doi.org/10.3390/molecules25204617 - 11 Oct 2020

Cited by 31 | Viewed by 4799

Abstract

Light is a paramount parameter driving photosynthesis. However, excessive irradiance leads to the formation of reactive oxygen species that cause cell damage and hamper the growth of photosynthetic organisms. Xanthophylls are key pigments involved in the photoprotective response of plants and algae to excessive light. Of particular relevance is the operation of xanthophyll cycles (XC) leading to the formation of de-epoxidized molecules with energy dissipating capacities. Neoxanthin, found in plants and algae in two different isomeric forms, is involved in the light stress response at different levels. This xanthophyll is not directly involved in XCs and the molecular mechanisms behind its photoprotective activity are yet to be fully resolved. This review comprehensively addresses the photoprotective role of 9′-cis-neoxanthin, the most abundant neoxanthin isomer, and one of the major xanthophyll components in plants’ photosystems. The light-dependent accumulation of all-trans-neoxanthin in photosynthetic cells was identified exclusively in algae of the order Bryopsidales (Chlorophyta), that lack a functional XC. A putative photoprotective model involving all-trans-neoxanthin is discussed. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

36 pages, 6485 KiB

Open AccessReview

Unravelling the Photoprotective Mechanisms of Nature-Inspired Ultraviolet Filters Using Ultrafast Spectroscopy

by Temitope T. Abiola, Abigail L. Whittock and Vasilios G. Stavros

Molecules 2020, 25(17), 3945; https://doi.org/10.3390/molecules25173945 - 28 Aug 2020

Cited by 34 | Viewed by 5696

Abstract

There are several drawbacks with the current commercially available ultraviolet (UV) filters used in sunscreen formulations, namely deleterious human and ecotoxic effects. As a result of the drawbacks, a current research interest is in identifying and designing new UV filters. One approach that has been explored in recent years is to use nature as inspiration, which is the focus of this review. Both plants and microorganisms have adapted to synthesize their own photoprotective molecules to guard their DNA from potentially harmful UV radiation. The relaxation mechanism of a molecule after it has been photoexcited can be unravelled by several techniques, the ones of most interest for this review being ultrafast spectroscopy and computational methods. Within the literature, both techniques have been implemented on plant-, and microbial-inspired UV filters to better understand their photoprotective roles in nature. This review aims to explore these findings for both families of nature-inspired UV filters in the hope of guiding the future design of sunscreens. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

14 pages, 3820 KiB

Open AccessFeature PaperReview

Zeaxanthin and Lutein: Photoprotectors, Anti-Inflammatories, and Brain Food

by Barbara Demmig-Adams, Marina López-Pozo, Jared J. Stewart and William W. Adams III

Molecules 2020, 25(16), 3607; https://doi.org/10.3390/molecules25163607 - 8 Aug 2020

Cited by 56 | Viewed by 15294

Abstract

This review compares and contrasts the role of carotenoids across the taxa of life—with a focus on the xanthophyll zeaxanthin (and its structural isomer lutein) in plants and humans. Xanthophylls’ multiple protective roles are summarized, with attention to the similarities and differences in the roles of zeaxanthin and lutein in plants versus animals, as well as the role of meso-zeaxanthin in humans. Detail is provided on the unique control of zeaxanthin function in photosynthesis, that results in its limited availability in leafy vegetables and the human diet. The question of an optimal dietary antioxidant supply is evaluated in the context of the dual roles of both oxidants and antioxidants, in all vital functions of living organisms, and the profound impact of individual and environmental context. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Figure 1

14 pages, 4245 KiB

Open AccessReview

Sunscreen-Assisted Selective Photochemical Transformations

by Or Eivgi and N. Gabriel Lemcoff

Molecules 2020, 25(9), 2125; https://doi.org/10.3390/molecules25092125 - 1 May 2020

Cited by 4 | Viewed by 3641

Abstract

In this review, we describe a simple and general procedure to accomplish selective photochemical reaction sequences for two chromophores that are responsive to similar light frequencies. The essence of the method is based on the exploitation of differences in the molar absorptivity at certain wavelengths of the photosensitive groups, which is enhanced by utilizing light-absorbing auxiliary filter molecules, or “sunscreens”. Thus, the filter molecule hinders the reaction pathway of the least absorbing molecule or group, allowing for the selective reaction of the other. The method was applied to various photochemical reactions, from photolabile protecting group removal to catalytic photoinduced olefin metathesis in different wavelengths and using different sunscreen molecules. Additionally, the sunscreens were shown to be effective also when applied externally to the reaction mixture, avoiding any potential chemical interactions between sunscreen and substrates and circumventing the need to remove the light-filtering molecules from the reaction mixture, adding to the simplicity and generality of the method. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Graphical abstract

18 pages, 1835 KiB

Open AccessFeature PaperReview

Photoprotection and Skin Pigmentation: Melanin-Related Molecules and Some Other New Agents Obtained from Natural Sources

by Francisco Solano

Molecules 2020, 25(7), 1537; https://doi.org/10.3390/molecules25071537 - 27 Mar 2020

Cited by 170 | Viewed by 20640

Abstract

Direct sun exposure is one of the most aggressive factors for human skin. Sun radiation contains a range of the electromagnetic spectrum including UV light. In addition to the stratospheric ozone layer filtering the most harmful UVC, human skin contains a photoprotective pigment called melanin to protect from UVB, UVA, and blue visible light. This pigment is a redox UV-absorbing agent and functions as a shield to prevent direct UV action on the DNA of epidermal cells. In addition, melanin indirectly scavenges reactive oxygenated species (ROS) formed during the UV-inducing oxidative stress on the skin. The amounts of melanin in the skin depend on the phototype. In most phenotypes, endogenous melanin is not enough for full protection, especially in the summertime. Thus, photoprotective molecules should be added to commercial sunscreens. These molecules should show UV-absorbing capacity to complement the intrinsic photoprotection of the cutaneous natural pigment. This review deals with (a) the use of exogenous melanin or melanin-related compounds to mimic endogenous melanin and (b) the use of a number of natural compounds from plants and marine organisms that can act as UV filters and ROS scavengers. These agents have antioxidant properties, but this feature usually is associated to skin-lightening action. In contrast, good photoprotectors would be able to enhance natural cutaneous pigmentation. This review examines flavonoids, one of the main groups of these agents, as well as new promising compounds with other chemical structures recently obtained from marine organisms. Full article

(This article belongs to the Special Issue Natural and Artificial Photoprotective Agent)

► Show Figures

Journal Menu

Journal Browser

Natural and Artificial Photoprotective Agent

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (11 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI