Published by De Gruyter

Volume 87 Issue 9-10

Issue of Pure and Applied Chemistry

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Contents
Journal Overview

Publicly Available October 7, 2015

Frontmatter

Page range: i-iv

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Conference papers

Publicly Available September 11, 2015

A brief illustrated history on sunscreens and sun protection

Federico Svarc

Page range: 929-936

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Abstract

Nobody exactly knows when human beings begun protecting their skin from the sun. Our dark-skinned ancestors in Africa had the benefit of natural melanin to avoid sunburn. With migration to cooler regions, humans clothed themselves to avoid frost, losing their protective pigmentation. For cultural reasons, occidentals continued to cover their body up to the XIX th century. After World War I fashion wanted tanned bodies. Oils without protection to UV radiation were used. In 1935 Eugène Schueller, founder of L’Oreal, formulated the first radiation filtering product, “ Ambre Solaire Huile ” . Benjamin Green produced for the soldiers battling in the Pacific a red jelly substance as a physical blocker. The hazards of sun overexposure were already apparent. The product boomed under the brand Coppertone. In 1946 Franz Greiter developed the “ Gletscher Cr é me ” . In 1956 R. Schulz introduced the concept of the sun protection factor (SPF). All those products protected only against UVB radiation, whose main visible result is erythema. There was still no concern on the more penetrating UVA radiation, and skin cancer prevention nor on several other contemporary issues. Today we benefit from very high SPF products with broad UV protection. Solubility limitations and sensorial properties make them difficult to formulate and stabilize.

Publicly Available September 19, 2015

Simulation of sunscreen performance

Bernd Herzog, Uli Osterwalder

Page range: 937-951

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Abstract

Sunscreens are used to protect the human skin against harmful effects of solar UV radiation. The most important quantity characterizing sunscreen performance is the sun protection factor (SPF). At the stage of development of new sun protection formulations quick and inexpensive methods for estimation of the UV screening performance are highly desirable. The most convenient approach towards this goal is given by computational simulations. Models for the calculation of the SPF employ the same algorithm as used with in vitro SPF measurements, but replace the transmittance measurement by the calculation of the overall absorbance of the UV filters in an irregular sunscreen film. The simulations require a database with quantitative UV extinction spectra of the relevant UV filters as well as a mathematical description of the film irregularity. The simulation algorithm implies also the consideration of photodegradation properties of the UV filters in the sunscreen composition. Besides using such simulations for designing new sunscreen formulations, the calculations can also support the understanding of sunscreen performance in general.

Publicly Available September 24, 2015

Sunscreens of red algae from Patagonia: a biotechnological perspective

Nelso P. Navarro

Page range: 953-960

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Abstract

Red algae can synthesize UV-absorbing mycosporine-like amino acid (MAA) compounds to minimize the damage caused by UV radiation. MAAs are molecules with low molecular weight and absorption maxima in the UV region (310–360 nm). Combined with their antioxidant activities, these features suggest a potential application in the prevention and therapeutic treatment of afflictions related to free-radical production and UV irradiation in humans. However, the use of MAAs in biotechnological products is limited by the low concentrations of these compounds in macroalgae harvested from the wild. Thus, species with high MAA concentrations are desirable. Information on red algae from Patagonia generally shows low concentrations of MAAs. However, increased MAA or at least changes in individual MAA concentration have been observed in certain species under stressful conditions. Additionally, methanolic extracts show an interesting absorption in the UVB region in certain red algae species, such as Lophurella hoockeriana .

Publicly Available September 24, 2015

In vitro photoprotection and antioxidant capacity of Sphagnum meridense extracts, a novel source of natural sunscreen from the mountains of Colombia

Juan C. Mejía-Giraldo, Cecilia Gallardo, Miguel A. Puertas-Mejía

Page range: 961-970

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Abstract

Excessive ultraviolet radiation can cause skin cancer and related health problems in humans. Traditionally, organic and inorganic sunscreens have been used to minimize these effects. Besides, some phenolic compounds present in plants play an important role as photoprotectors. Sphagnum meridense (L), found in Colombia, is continuously exposed to sunlight on high mountain ecosystems. In this work, we evaluated the potential of S. meridense extracts to be applied as UVA-UVB filter in cosmetic formulations and its antioxidant capacity. The mixture acetone-37% hydrochloric acid (1%, v/v) showed the best polyphenol content and UVA-UVB absorption coefficient. These extracts also exhibited promissory UVAPF values, UVA/UVB ratio, critical wavelength (λ c ) and antioxidant capacity in vitro, comparable to that of conventional sunscreens.

Publicly Available September 11, 2015

Defect-rich ZnO quantum dots as a potential multifunctional sunscreen and cosmetic active ingredient

Adersh Asok, Ajit R. Kulkarni, Mayuri N. Gandhi

Page range: 971-977

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Abstract

In sunscreens, ZnO nanoparticles (NPs) are used as inorganic UV filter which have a prominent band edge emission in the UVA region (~385 nm). When applied to biological surface, this highly penetrating UVA emission from ZnO NPs would enhance the generation of reactive oxygen species resulting in oxidative stress. Therefore, the elimination of this harmful UVA emission from ZnO NPs are much sought after for the development of safer sunscreens. In this paper we introduce the use of defect-rich ZnO (D-ZnO) quantum dots (QDs) as a multifunctional active ingredient in sunscreen/cosmetic application. These D-ZnO QDs make use of their defect energy levels to emit in visible region by bypassing their harmful band edge emission at UVA region. The D-ZnO QDs also showed prominent visible luminescence which matches well with the autofluorescence of in vivo human skin. Hence, this visible luminescence could be useful for camouflaging, thereby enabling its potential as a biologically safe active ingredient for both cosmetic and UV screening applications.

Publicly Available September 10, 2015

Photochemistry and photophysics of mycosporine-like amino acids and gadusols, nature’s ultraviolet screens

Raul Losantos, Diego Sampedro, María Sandra Churio

Page range: 979-996

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Abstract

Mycosporine-like amino acids (MAAs) and related gadusols are among the most prominent examples of metabolites suggested to act as UV-sunscreens. This review illustrates how experimental and theoretical studies on model MAAs and gadusol offer a helpful description of the photoprotective mechanism at the molecular level. This knowledge may contribute to the rational design of chemical systems with predictable and tuneable response to light stimulus. Synthetic efforts to obtain MAAs and simplified related structures are also discussed.

Publicly Available October 7, 2015

Vitamin B2-sensitized degradation of the multifunctional drug Evernyl, in the presence of visible light – microbiological implications

Carolina Gambetta, Walter A. Massad, Andrea V. Nesci, Norman A. García

Page range: 997-1010

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Abstract

Taking into consideration the importance of the photooxidative effects in complex bio- environments, this paper reports on the visible-light-promoted interactions between Evernyl (methyl 2, 4-dihydroxy-3,6-dimethylbenzoate, Ev) and vitamin B2 (riboflavin, Rf). Ev is a phenolic derivative, transparent to visible light, that possesses important antimicrobial activity. This compound is the first known natural, complete and specific human androgen receptor antagonist. Ev is profusely employed in personal-care products and synthesized as a secondary metabolite by several lichen and plant species. In both sceneries, acting Ev as a cosmetic component for topic applications or as a lichen constituent, may Rf behave as a native visible-light absorber pigment. In this context, kinetic and mechanistic aspects of the Rf-sensitized photooxidation of Ev, has been studied in aqueous solution, irradiating with blue LED light (463–471 nm) and employing stationary and time resolved methods. Results indicate that Ev reacts with the photogenerated reactive oxygen species (ROS) singlet molecular oxygen with a rate constant of k r =1.1±0.2×10 6 M −1 s −1 . In parallel Ev also quenches the electronically excited singlet and triplet excited states of Rf with rate constants close to the difussion limit. As a result the ROS superoxide radical anion and hydrogen peroxide are generated and the latter subsequently reacts with Ev. Possible implications of these photoreactions on the antimicrobial activity of Ev have been investigated employing a Candida albicans (CA) strain, isolated from human skin infection. The simultaneous presence of Rf, Ev in a sub-MIC, and blue-light irradiation produced a significant antimycotic effect, attributed to ROS photogeneration.

Publicly Available September 15, 2015

Combined heterogeneous metal/organic catalysts for eco-friendly synthesis

Armando Córdova

Page range: 1011-1019

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Abstract

The interplay and synergistic cooperation between homogeneous and heterogeneous catalyst systems is of utmost importance in nature. It is also applied in chemical synthesis. Here, it can allow for new reactivity, which is not possible by the employment of a single catalyst, and promote the catalysis of multiple transformations in a one-pot sequence. This could overall lead to novel reactions and the development of sustainable chemistry. In this context, a versatile and broad synergistic strategy for the selective synthesis of valuable molecules with variable complexity and under eco-friendly conditions is disclosed. It is based on integrated heterogeneous metal/organo multiple relay catalysis, which is performed in a single reaction vessel, and allows for the assembly of complex molecules (e.g., heterocycles and carbocycles) with up to three quaternary stereocenters in a highly enantioselective fashion from simple alcohols and air/O 2 .

Publicly Available September 8, 2015

Amino acid sequence controls the self-assembled superstructure morphology of N-acetylated tri-β³-peptides

Rania S. Seoudi, Annette Dowd, Mark Del Borgo, Ketav Kulkarni, Patrick Perlmutter, Marie-Isabel Aguilar, Adam Mechler

Page range: 1021-1028

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Abstract

Peptides based on unnatural β 3 -amino acids offer a versatile platform for the design of self-assembling nanostructures due to the folding stability of the 14-helix and the high symmetry of the side chains inherent in this geometry. We have previously described that N-terminal acetylation (Ac-) forms a supramolecular self-assembly motif that allows β 3 -peptides to assemble head-to-tail into a helical nanorod which then further bundles into hierarchical superstructures. Here we investigate the effect of the topography of the 14-helical nanorod on lateral self-assembly. Specifically, we report on the variations in the superstructure of three isomeric peptides comprising the same three β 3 -amino acid residues: β 3 -leucine (L), β 3 -isoleucine (I) β 3 -alanine (A) to give peptides Ac-β 3 [LIA], Ac-β 3 [IAL] and Ac-β 3 [ALI]. AFM imaging shows markedly different superstructures for the three peptides. Well defined synchrotron far-infrared spectra reveal uniform geometries with a high degree of similarity between the isomeric peptides in the amide modes of the 400–650 wavenumber range. Far-IR also confirms that the C-terminal carboxyl group is free in the assemblies, thus it is solvated in the dispersant. Hence, the differences in the superstructures formed by the fibers are defined primarily by van der Waals energy minimization between the varied cross sectional morphologies of the core nanorods.

Publicly Available August 26, 2015

Bioinspired infrared detection using thermoresponsive hydrogel nanoparticles

Zhen Luo, Jun Chen, Qingchen Shen, Jiaqing He, Hao Shan, Chengyi Song, Peng Tao, Tao Deng, Wen Shang

Page range: 1029-1038

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Abstract

The development of high performance uncooled infrared (IR) detection and imaging systems will greatly expand the application of IR technology in broad areas such as transportation, environmental monitoring, and medical care. Inspired by the superior IR detection capability of beetle Melanophila acuminata , we explored the potential use of hydrogel nanoparticles (NPs) in uncooled IR detection system. In the system, the absorption of the incoming IR radiation by the temperature-sensitive hydrogel NPs, together with water, induces the volume change of the hydrogel NPs, similar to the volume change of the biofluid inside the sensillae receptors in M. acuminata caused by the IR radiation. This volume change results in the change of optical readout (transmittance in this study) in visible range and provides the sensitive detection of the IR radiation. In this work, poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM- co -AAc)) copolymer NPs with different sizes were synthesized and their IR sensing performances were studied in detail. The correlation between the NP size and concentration and the IR sensing property was also discussed in the paper. This work helps enhance the understanding of the response of hydrogel NPs under IR radiation, and offers a potential material system for uncooled IR detection that is inspired by M. acuminata . The direct use of transmittance of the NP solution as the readout for IR detection also provides a simple and sensitive IR detection approach for low cost and portable industrial applications.

IUPAC Technical Reports

Publicly Available July 29, 2015

Brief guide to the nomenclature of inorganic chemistry

Richard M. Hartshorn, Karl-Heinz Hellwich, Andrey Yerin, Ture Damhus, Alan T. Hutton

Page range: 1039-1049

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Abstract

This IUPAC Technical Report (PAC-REP-14-07-18) is one of a series that seeks to distil the essentials of IUPAC nomenclature recommendations. The present report provides a succinct summary of material presented in the publication Nomenclature of Inorganic Chemistry – IUPAC Recommendations 2005 . The content of this report will be republished and disseminated as a four-sided lift-out document (see supplementary information) which will be available for inclusion in textbooks and similar publications.

Publicly Available July 2, 2015

Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)

Matthias Thommes, Katsumi Kaneko, Alexander V. Neimark, James P. Olivier, Francisco Rodriguez-Reinoso, Jean Rouquerol, Kenneth S.W. Sing

Page range: 1051-1069

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Abstract

Gas adsorption is an important tool for the characterisation of porous solids and fine powders. Major advances in recent years have made it necessary to update the 1985 IUPAC manual on Reporting Physisorption Data for Gas/Solid Systems. The aims of the present document are to clarify and standardise the presentation, nomenclature and methodology associated with the application of physisorption for surface area assessment and pore size analysis and to draw attention to remaining problems in the interpretation of physisorption data.

About this journal

Since 1960, the International Union of Pure and Applied Chemistry (IUPAC) has made available to chemists everywhere a large amount of important chemical information published in the journal Pure and Applied Chemistry.

We are sad to announce the passing of Hugh Burrows, Editor-in-Chief of PAC between 2014-2022, and offer our deepest condolences to his family and friends. Hugh passed away surrounded by his loved ones on March 12, 2023. He left a big gap in our community and will be sorely missed. To honor Hugh's many contributions to IUPAC and our journal we plan to publish a more extensive obituary in the next issue of PAC. Please join us for a minute of silence dedicated to Hugh.

In 2020 we celebrated Pure and Applied Chemistry's 60th anniversary!
As part of these celebrations, we are offering free access to the virtual issue of PAC: 60 seminal papers published in PAC over the past 60 years

Pure and Applied Chemistry is the official monthly Journal of IUPAC, with responsibility for publishing works arising from those international scientific events and projects that are sponsored and undertaken by the Union. The policy is to publish highly topical and credible works at the forefront of all aspects of pure and applied chemistry, and the attendant goal is to promote widespread acceptance of the Journal as an authoritative and indispensable holding in academic and institutional libraries.

The objectives of the Journal are:

to publish papers based upon authoritative lectures presented at IUPAC sponsored conferences, symposia and workshops.
to publish papers or collections of papers by invitation, as special topic features.
to publish IUPAC Recommendations on nomenclature, symbols and units.
to publish IUPAC Technical Reports on standardization, recommended procedures, collaborative studies, data compilations, etc.

Volume 87 Issue 9-10

Issue of Pure and Applied Chemistry

Frontmatter

A brief illustrated history on sunscreens and sun protection

Abstract

Simulation of sunscreen performance

Abstract

Sunscreens of red algae from Patagonia: a biotechnological perspective

Abstract

In vitro photoprotection and antioxidant capacity of Sphagnum meridense extracts, a novel source of natural sunscreen from the mountains of Colombia

Abstract

Defect-rich ZnO quantum dots as a potential multifunctional sunscreen and cosmetic active ingredient

Abstract

Photochemistry and photophysics of mycosporine-like amino acids and gadusols, nature’s ultraviolet screens

Abstract

Vitamin B2-sensitized degradation of the multifunctional drug Evernyl, in the presence of visible light – microbiological implications

Abstract

Combined heterogeneous metal/organic catalysts for eco-friendly synthesis

Abstract

Amino acid sequence controls the self-assembled superstructure morphology of N-acetylated tri-β3-peptides

Abstract

Bioinspired infrared detection using thermoresponsive hydrogel nanoparticles

Abstract

Brief guide to the nomenclature of inorganic chemistry

Abstract

Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)

Abstract

Amino acid sequence controls the self-assembled superstructure morphology of N-acetylated tri-β³-peptides