MDPI - Publisher of Open Access Journals

14 pages, 1716 KB

Open AccessEditor’s ChoiceArticle

Mycosporine-like Amino Acids in Palmaria palmata (Rhodophyta): Specific Implication of Usujirene in Photoprotection

by Fanny Lalegerie, Valérie Stiger-Pouvreau and Solène Connan

Mar. Drugs 2024, 22(3), 121; https://doi.org/10.3390/md22030121 - 5 Mar 2024

Cited by 7 | Viewed by 5264

The effect of UV radiation on the accumulation of mycosporine-like amino acids (MAAs) and pigments was investigated on red macroalga Palmaria palmata cultivated for 21 days. The data were combined with the effect of NaNO₃ to further investigate the synthesis of these nitrogenous compounds. A progressive decrease in both total MAA and pigment contents was observed, with a positive effect of nitrate supply. Usujirene was the only MAA exhibiting a significantly increasing content when exposed to UV radiation, changing from 9% to 24% of the total MAA’s contribution, with no variation observed with NaNO₃. This suggests a specific induction or synthesis pathway of usujirene for photoprotection, while the synthesis of other MAAs could have been limited by an insufficient amount of UV radiation and/or irradiance. The photoprotective ability of some MAAs could have been impacted by nitrogen starvation over time, resulting in a limited synthesis and/or potential use of MAAs as a nitrogen source for red macroalgae. The data confirmed the multiple effects of environmental factors on the synthesis of MAAs while providing new insights into the specific synthesis of usujirene, which could find an application in the cosmetics sector as natural sunscreen or an anti-ageing agent. Full article

(This article belongs to the Special Issue Antiphotoaging and Photoprotective Compounds from Marine Environments)

► Show Figures

Graphical abstract

16 pages, 2366 KB

Open AccessArticle

Rapid Screening for Mycosporine-like Amino Acids (MAAs) of Irish Marine Cyanobacteria and Their Antioxidant Potential

by Norma Browne, Paz Otero, Patrick Murray and Sushanta Kumar Saha

Sustainability 2023, 15(4), 3792; https://doi.org/10.3390/su15043792 - 19 Feb 2023

Cited by 17 | Viewed by 3809

Abstract

The present study evaluated 53 Irish marine cyanobacteria intending to identify potential producers of mycosporine-like amino acids (MAAs) to meet the increasing demand for replacing chemical sunscreen with bio-sunscreen. The biodiscovery analysis using absorption spectra of methanolic extracts identified eight cyanobacteria as potential MAAs producers with a specific content of 0.114–0.511 A* mg DW⁻¹. Leptolyngbya tenuis SABC010201 was found to possess notably higher MAAs content. LC-MS analysis identified a total of eight different types of known MAAs (mycosporine-glutamicol, mycosporine-glutaminol-glucoside, mycosporine-serinol, mycosporine-taurine, palythine, palythine-threonine-sulphate, porphyra-334, and usujirene) in eight cyanobacteria, while four compounds were considered unknown UV-absorbing compounds with specific mass and absorption maximum. For example, two unknown compounds with, respectively, [M-H]^- values of 219.0557 and 289.0730 and lambda max of 314 and 326 nm, were detected in three cyanobacteria Leptolyngbya tenuis SABC010201, Phormidium angustissimum SABC020801, and Schizothrix sp. SABC022401. These two unknown compounds were named M-314 and M-326, respectively. Antioxidant activities of total MAAs of all cyanobacteria showed considerable amounts of DPPH, FRAP, and ORAC activities. Considering the specific MAAs content and antioxidant activities, Leptolyngbya africana SABC021601 was considered the best producer of MAAs. Full article

(This article belongs to the Special Issue Current Advances in Microalgal Biotechnology)

► Show Figures

Figure 1

14 pages, 2514 KB

Open AccessArticle

Investigating the Ultrafast Dynamics and Long-Term Photostability of an Isomer Pair, Usujirene and Palythene, from the Mycosporine-like Amino Acid Family

by Abigail L. Whittock, Jack M. Woolley, Nazia Auckloo, Christophe Corre and Vasilios G. Stavros

Molecules 2022, 27(7), 2272; https://doi.org/10.3390/molecules27072272 - 31 Mar 2022

Cited by 8 | Viewed by 4127

Abstract

Mycosporine-like amino acids are a prevalent form of photoprotection in micro- and macro-organisms. Using a combination of natural product extraction/purification and femtosecond transient absorption spectroscopy, we studied the relaxation pathway for a common mycosporine-like amino acid pair, usujirene and its geometric isomer palythene, in the first few nanoseconds following photoexcitation. Our studies show that the electronic excited state lifetimes of these molecules persist for only a few hundred femtoseconds before the excited state population is funneled through an energetically accessible conical intersection with subsequent vibrational energy transfer to the solvent. We found that a minor portion of the isomer pair did not recover to their original state within 3 ns after photoexcitation. We investigated the long-term photostability using continuous irradiation at a single wavelength and with a solar simulator to mimic a more real-life environment; high levels of photostability were observed in both experiments. Finally, we employed computational methods to elucidate the photochemical and photophysical properties of usujirene and palythene as well as to reconcile the photoprotective mechanism. Full article

(This article belongs to the Special Issue Rotational and Vibrational Probes of Biomolecular Structure and Dynamics)

► Show Figures

Figure 1

17 pages, 1365 KB

Open AccessArticle

Antiproliferative and Antioxidant Activities and Mycosporine-Like Amino Acid Profiles of Wild-Harvested and Cultivated Edible Canadian Marine Red Macroalgae

by Yasantha Athukorala, Susan Trang, Carmen Kwok and Yvonne V. Yuan

Molecules 2016, 21(1), 119; https://doi.org/10.3390/molecules21010119 - 21 Jan 2016

Cited by 62 | Viewed by 10428

Abstract

Antiproliferative and antioxidant activities and mycosporine-like amino acid (MAA) profiles of methanol extracts from edible wild-harvested (Chondrus crispus, Mastocarpus stellatus, Palmaria palmata) and cultivated (C. crispus) marine red macroalgae were studied herein. Palythine, asterina-330, shinorine, palythinol, porphyra-334 and usujirene MAAs were identified in the macroalgal extracts by LC/MS/MS. Extract reducing activity rankings were (p < 0.001): wild P. palmata > cultivated C. crispus = wild M. stellatus > wild low-UV C. crispus > wild high-UV C. crispus; whereas oxygen radical absorbance capacities were (p < 0.001): wild M. stellatus > wild P. palmata > cultivated C. crispus > wild low-UV C. crispus > wild high-UV C. crispus. Extracts were antiproliferative against HeLa and U-937 cells (p < 0.001) from 0.125–4 mg/mL, 24 h. Wild P. palmata and cultivated C. crispus extracts increased (p < 0.001) HeLa caspase-3/7 activities and the proportion of cells arrested at Sub G₁ (apoptotic) compared to wild-harvested C. crispus and M. stellatus extracts. HeLa cells incubated with wild P. palmata and cultivated C. crispus extracts also exhibited morphological changes characteristic of apoptosis (shrinkage, rounding). Thus, extracts rich in low-polarity usujirene and polar palythine and asterina-330 MAAs were antiproliferative as inducers of apoptosis in HeLa cells. Full article

(This article belongs to the Special Issue Antioxidants—A Risk-Benefit Analysis for Health)

► Show Figures

Figure 1

Search Results (4)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (4)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI