molecules-logo

Journal Browser

Journal Browser

Natural Antioxidants, Dyes and Their Synthetic Analogs

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

Deadline for manuscript submissions: 31 May 2024 | Viewed by 5614

Special Issue Editor

Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
Interests: carotenoids; carbohydrates; organic synthesis; supramolecular organization; antioxidant activity

Special Issue Information

Dear Colleagues,

Beneficial properties of natural compounds can be improved by covalent or noncovalent chemical modifications. The modified derivatives may find useful applications in medical and material sciences. Antioxidant compounds, especially with an extended conjugated electron system, such as carotenoids or polyphenols, are proven radical scavengers and efficient agents against oxidative stress-related conditions. Nevertheless, these compounds are also promising candidates to create novel structures being organic conductive materials, molecular wires, or dyes with specific light-absorption properties, as well as amphipatic molecules with self-organization.

The aim of this Special Issue, “Natural Antioxidants, Dyes and Their Synthetic Analogs” is to collect the recent discoveries about the native or modified structures, including isolation, structure elucidation, chemical modification, (semi)synthesis, antioxidant studies, structure-activity relationship, synergic effects, delivery, supramolecular organization, electrochemical and spectroscopic properties, in silico calculations, and other related findings. Both original full research articles and reviews on these topics are welcome.

We look forward to your valuable contribution.

Dr. Veronika Nagy
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

  • carotenoids
  • terpenoids
  • (poly)phenols
  • porphyrins
  • polyenes
  • antioxidants

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

17 pages, 5083 KiB  
Article
Reaction with ROO• and HOO• Radicals of Honokiol-Related Neolignan Antioxidants
by Nunzio Cardullo, Filippo Monti, Vera Muccilli, Riccardo Amorati and Andrea Baschieri
Molecules 2023, 28(2), 735; https://doi.org/10.3390/molecules28020735 - 11 Jan 2023
Cited by 3 | Viewed by 1274
Abstract
Honokiol is a natural bisphenol neolignan present in the bark of Magnolia officinalis, whose extracts have been employed in oriental medicine to treat several disorders, showing a variety of biological properties, including antitumor activity, potentially related to radical scavenging. Six bisphenol neolignans [...] Read more.
Honokiol is a natural bisphenol neolignan present in the bark of Magnolia officinalis, whose extracts have been employed in oriental medicine to treat several disorders, showing a variety of biological properties, including antitumor activity, potentially related to radical scavenging. Six bisphenol neolignans with structural motifs related to the natural bioactive honokiol were synthesized. Their chain-breaking antioxidant activity was evaluated in the presence of peroxyl (ROO•) and hydroperoxyl (HOO•) radicals by both experimental and computational methods. Depending on the number and position of the hydroxyl and alkyl groups present on the molecules, these derivatives are more or less effective than the reference natural compound. The rate constant of the reaction with ROO• radicals for compound 7 is two orders of magnitude greater than that of honokiol. Moreover, for compounds displaying quinonic oxidized forms, we demonstrate that the addition of 1,4 cyclohexadiene, able to generate HOO• radicals, restores their antioxidant activity, because of the reducing capability of the HOO• radicals. The antioxidant activity of the oxidized compounds in combination with 1,4-cyclohexadiene is, in some cases, greater than that found for the starting compounds towards the peroxyl radicals. This synergy can be applied to maximize the performances of these new bisphenol neolignans. Full article
(This article belongs to the Special Issue Natural Antioxidants, Dyes and Their Synthetic Analogs)
Show Figures

Figure 1

12 pages, 1388 KiB  
Article
Quantitative Determination of Polyphenols and Flavonoids in Cistus × incanus on the Basis of IR, NIR and Raman Spectra
by Sonia Pielorz, Izabela Fecka, Karolina Bernacka and Sylwester Mazurek
Molecules 2023, 28(1), 161; https://doi.org/10.3390/molecules28010161 - 25 Dec 2022
Cited by 3 | Viewed by 1625
Abstract
Cistus is a plant that has been used in natural medicine for hundreds of years; it works primarily as an antioxidant and cleansing agent. Cistus × incanus leaves or herb can be an attractive source of polyphenols and flavonoids. The official protocols of [...] Read more.
Cistus is a plant that has been used in natural medicine for hundreds of years; it works primarily as an antioxidant and cleansing agent. Cistus × incanus leaves or herb can be an attractive source of polyphenols and flavonoids. The official protocols of active compound analysis relies on the extraction of compounds of interest from plant matter, which makes their determination long and costly. An analysis of plant material in its native state can be performed using vibrational spectroscopy. This paper presents a comparison of Raman spectroscopy, attenuated total reflection in mid-infrared and diffuse reflectance technique in the near-infrared region for the simultaneous quantification of total polyphenols (TPC) and flavonoids (TF) content, as well as the determination of FRAP antioxidant activity of C. incanus material. Utilizing vibrational spectra and using partial least squares algorithm, TPC and TF were quantified with the RSEPVAL errors in the 2.7–5.4% range, while FRAP antioxidant activity for validation sets was determined with relative errors ranged from 5.2 to 9.3%. For the analyzed parameters, the lowest errors of predictions were computed for models constructed using Raman data. The developed models allow for fast and precise quantification of the studied active compounds in C. incanus material without any chemical sample treatment. Full article
(This article belongs to the Special Issue Natural Antioxidants, Dyes and Their Synthetic Analogs)
Show Figures

Graphical abstract

19 pages, 3947 KiB  
Article
The Influence of Lactic Acid Fermentation on Selected Properties of Pickled Red, Yellow, and Green Bell Peppers
by Emilia Janiszewska-Turak, Dorota Witrowa-Rajchert, Katarzyna Rybak, Joanna Rolof, Katarzyna Pobiega, Łukasz Woźniak and Anna Gramza-Michałowska
Molecules 2022, 27(23), 8637; https://doi.org/10.3390/molecules27238637 - 06 Dec 2022
Cited by 3 | Viewed by 1774
Abstract
Red, yellow, and green peppers are vegetables rich in natural pigments. However, they belong to seasonal vegetables and need to be treated to prolong their shelf life. One new approach to processing vegetables is to pickle them using lactic acid bacteria. The use [...] Read more.
Red, yellow, and green peppers are vegetables rich in natural pigments. However, they belong to seasonal vegetables and need to be treated to prolong their shelf life. One new approach to processing vegetables is to pickle them using lactic acid bacteria. The use of such a process creates a new product with high health value, thanks to the active ingredients and lactic acid bacteria. Therefore, this study aimed to evaluate the effect of the applied strain of lactic acid bacteria (LAB) on the chemical properties, including the content of active compounds (pigments) and the physical properties of the peppers. Levilactobacillus brevis, Limosilactobacillus fermentum, and Lactoplantibacillus plantarum were used for fermentation and spontaneous fermentation. The pigments, polyphenols content, and antioxidant properties were determined in the pickled peppers, as well as sugar content, color, dry matter, texture properties, and the count of lactic acid bacteria. In all samples, similar growth of LAB was observed. Significant degradation of chlorophylls into pheophytins was observed after the fermentation process. No significant differences were observed in the parameters tested, depending on the addition of dedicated LAB strains. After the fermentation process, the vitamin C and total polyphenols content is what influenced the antioxidant activity of the samples. It can be stated that the fermentation process changed the red bell pepper samples in the smallest way and the green ones in the highest way. Full article
(This article belongs to the Special Issue Natural Antioxidants, Dyes and Their Synthetic Analogs)
Show Figures

Graphical abstract

Back to TopTop