scholarly journals 3-Pyridinols and 5-pyrimidinols: Tailor-made for use in synergistic radical-trapping co-antioxidant systems

2013 ◽  
Vol 9 ◽  
pp. 2781-2792 ◽  
Author(s):  
Luca Valgimigli ◽  
Daniele Bartolomei ◽  
Riccardo Amorati ◽  
Evan Haidasz ◽  
Jason J Hanthorn ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Aromatic Ring ◽  
Kinetic Data ◽  
Peroxyl Radicals ◽  
Antioxidant Systems ◽  
Phenolic Antioxidants ◽  
Substituted Phenols ◽  
Radical Trapping ◽  
Insight Into

The incorporation of nitrogen atoms into the aromatic ring of phenolic compounds has enabled the development of some of the most potent radical-trapping antioxidants ever reported. These compounds, 3-pyridinols and 5-pyrimidinols, have stronger O–H bonds than equivalently substituted phenols, but possess similar reactivities toward autoxidation chain-carrying peroxyl radicals. These attributes suggest that 3-pyridinols and 5-pyrimidinols will be particularly effectiveco-antioxidants when used in combination with more common, but less reactive, phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol (BHT), which we demonstrate herein. The antioxidants function in a synergistic manner to inhibit autoxidation; taking advantage of the higher reactivity of the 3-pyridinols/5-pyrimidinols to trap peroxyl radicals and using the less reactive phenols to regenerate them from their corresponding aryloxyl radicals. The present investigations were carried out in chlorobenzene and acetonitrile in order to provide some insight into the medium dependence of the synergism and the results, considered with some from our earlier work, prompt a revision of the H-bonding basicity value of acetonitrile to β2 H of 0.39. Overall, the thermodynamic and kinetic data presented here enable the design of co-antioxidant systems comprising lower loadings of the more expensive 3-pyridinol/5-pyrimidinol antioxidants and higher loadings of the less expensive phenolic antioxidants, but which are equally efficacious as the 3-pyridinol/5-pyrimidinol antioxidants alone at higher loadings.

scholarly journals Insight into the Secondary Metabolites of Geum urbanum L. and Geum rivale L. Seeds (Rosaceae)

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1219
Author(s):  
Marek Bunse ◽  
Peter Lorenz ◽  
Florian C. Stintzing ◽  
Dietmar R. Kammerer
Keyword(s):  
Fatty Acids ◽  
Phenolic Compounds ◽  
Unsaturated Fatty Acids ◽  
Asiatic Acid ◽  
Cosmetic Products ◽  
Nutritional Properties ◽  
First Time ◽  
Derivatives Of ◽  
Geum Urbanum ◽  
Insight Into

The present study aimed at the identification and quantitation of phenolic compounds, fatty acids, and further characteristic substances in the seeds of Geum urbanum L. and Geum rivale L. For this purpose, individual components of extracts recovered with MeOH, CH2Cl2, and by cold-pressing, respectively, were characterized by HPLC-DAD/ESI-MSn and GC/MS and compared with reference compounds. For both Geum species, phenolic compounds, such as flavonoids and gallic acid derivatives, and triterpenes, such as saponins and their aglycones, were detected. Surprisingly, both Geum species revealed the presence of derivatives of the triterpenoid aglycons asiatic acid and madecassic acid, which were characterized for the first time in the genus Geum. Furthermore, the fatty acids of both species were characterized by GC–MS after derivatization. Both species showed a promising fatty-acid profile in terms of nutritional properties because of high proportions of unsaturated fatty acids. Linoleic acid and linolenic acid were most abundant, among other compounds such as palmitic acid and stearic acid. In summary, the present study demonstrates the seeds of G. urbanum and G. rivale to be a valuable source of unsaturated fatty acids and bioactive phenolics, which might be exploited for nutritional and cosmetic products and for phytotherapeutic purposes.

Strawberry dietary fiber functionalized with phenolic antioxidants from olives. Interactions between polysaccharides and phenolic compounds

2019 ◽  
Vol 280 ◽  
pp. 310-320 ◽  
Author(s):  
Alejandra Bermúdez-Oria ◽  
Guillermo Rodríguez-Gutiérrez ◽  
África Fernández-Prior ◽  
Blanca Vioque ◽  
Juan Fernández-Bolaños
Keyword(s):  
Phenolic Compounds ◽  
Dietary Fiber ◽  
Phenolic Antioxidants

scholarly journals Lignosulphonates as an Alternative to Non-Renewable Binders in Wood-Based Materials

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4196
Author(s):  
Sofia Gonçalves ◽  
João Ferra ◽  
Nádia Paiva ◽  
Jorge Martins ◽  
Luísa H. Carvalho ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Aromatic Ring ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Wood Adhesives ◽  
Renewable Source ◽  
Pressing Time ◽  
Value Added Products ◽  
Total Market

Lignin is a widely abundant renewable source of phenolic compounds. Despite the growing interest on using it as a substitute for its petroleum-based counterparts, only 1 to 2% of the global lignin production is used for obtaining value-added products. Lignosulphonates (LS), derived from the sulphite pulping process, account for 90% of the total market of commercial lignin. The most successful industrial attempts to use lignin for wood adhesives are based on using this polymer as a partial substitute in phenol-formaldehyde or urea-formaldehyde resins. Alternatively, formaldehyde-free adhesives with lignin and lignosulphonates have also been developed with promising results. However, the low number of reactive sites available in lignin’s aromatic ring and high polydispersity have hindered its application in resin synthesis. Currently, finding suitable crosslinkers for LS and decreasing the long pressing time associated with lignin adhesives remains a challenge. Thus, several methods have been proposed to improve the reactivity of lignin molecules. In this paper, techniques to extract, characterize, as well as improve the reactivity of LS are addressed. The most recent advances in the application of LS in wood adhesives, with and without combination with formaldehyde, are also reviewed.

scholarly journals Insight into transketolase of Pyropia haitanensis under desiccation stress based on integrative analysis of omics and transformation

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jianzhi Shi ◽  
Wenlei Wang ◽  
Yinghui Lin ◽  
Kai Xu ◽  
Yan Xu ◽  
...  
Keyword(s):  
Desiccation Tolerance ◽  
Integrative Analysis ◽  
Pyropia Haitanensis ◽  
Desiccation Stress ◽  
Integrated Analysis ◽  
Antioxidant Systems ◽  
Water Losses ◽  
Harsh Conditions ◽  
Insight Into ◽  
Better Than

Abstract Background Pyropia haitanensis, distributes in the intertidal zone, can tolerate water losses exceeding 90%. However, the mechanisms enabling P. haitanensis to survive harsh conditions remain uncharacterized. To elucidate the mechanism underlying P. haitanensis desiccation tolerance, we completed an integrated analysis of its transcriptome and proteome as well as transgenic Chlamydomonas reinhardtii carrying a P. haitanensis gene. Results P. haitanensis rapidly adjusted its physiological activities to compensate for water losses up to 60%, after which, photosynthesis, antioxidant systems, chaperones, and cytoskeleton were activated to response to severe desiccation stress. The integrative analysis suggested that transketolase (TKL) was affected by all desiccation treatments. Transgenic C. reinhardtii cells overexpressed PhTKL grew better than the wild-type cells in response to osmotic stress. Conclusion P. haitanensis quickly establishes acclimatory homeostasis regarding its transcriptome and proteome to ensure its thalli can recover after being rehydrated. Additionally, PhTKL is vital for P. haitanensis desiccation tolerance. The present data may provide new insights for the breeding of algae and plants exhibiting enhanced desiccation tolerance.

scholarly journals UVC light modulates vitamin C and phenolic biosynthesis in acerola fruit: role of increased mitochondria activity and ROS production

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marcela Cristina Rabelo ◽  
Woo Young Bang ◽  
Vimal Nair ◽  
Ricardo Elesbao Alves ◽  
Daniel A. Jacobo-Velázquez ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Vitamin C ◽  
Antioxidant Systems ◽  
Mitochondrial Activity ◽  
Postharvest Storage ◽  
Beneficial Effects ◽  
Transport Chain ◽  
Key Enzyme ◽  
Ultraviolet C

AbstractThe effects of ultraviolet-C light (UVC) on vitamin C and phenolic compounds in acerola during postharvest storage were investigated in order to elucidate the mechanism inducing the antioxidant systems. The fruits, stored at 10 °C for 7 days after a hormetic UVC irradiation (two pulses of 0.3 J/cm2), showed significantly less degradation of vitamin C and phenolic compounds than the control without the UVC challenge. UVC activated the L-galactono-1,4-lactone dehydrogenase (GalDH), a key enzyme for vitamin C biosynthesis, and altered the composition of phenolic compounds, through phenolic biosynthesis, in acerola during postharvest storage. UVC also induced reactive oxygen species (ROS) productions at immediate (day 0) and late (day 7) times during postharvest storage through the mitochondrial electron transport chain and NADPH oxidase, respectively. Results suggest that UVC helps in the retention of vitamin C and phenolic content in acerola by altering ascorbic acid and phenolic metabolism through an increase in mitochondrial activity and a ROS-mediated mechanism. Data showed the beneficial effects of UVC on maintenance of nutraceutical quality in acerola during postharvest storage and supplied new insights into understanding the mechanism by which UVC irradiation enhance the antioxidant system in fruits.

Organic compounds in municipal landfill leachates

2000 ◽  
Vol 42 (7-8) ◽  
pp. 323-333 ◽  
Author(s):  
N. Paxéus
Keyword(s):  
Waste Management ◽  
Organic Compounds ◽  
Organic Wastes ◽  
Phosphate Esters ◽  
Phenolic Antioxidants ◽  
Chlorinated Phenols ◽  
Substituted Phenols ◽  
Landfill Leachates ◽  
The Third ◽  
Municipal Landfill

Leachates from three municipal landfills in the Göteborg area of western Sweden were characterised in terms of their content of individual organic compounds. Two of the investigated landfills were still in use during the time of this study. The third landfill was closed down in the mid-seventies. More than 200 individual organic compounds and classes of compounds were identified in the leachate with concentrations ranging from less than one up to several hundred μg/L. Among the compounds common to all three landfills were plasticizers (phthalates, benzenesulfonamides), phosphate esters, substituted phenols, chlorinated phenols, phenolic antioxidants and siloxanes as well as the compounds formed during the degradation of organic wastes (dihydro-dioxin, pyrazines and several sulphur-containing odorous volatiles). Dioxanes and dioxolans found in the leachates have not been previously reported. Compounds originated from previously disposed oil contaminated wastes dominate the leachate from an old closed landfill. Its replacement, a new regional landfill has a leachate dominated by alcohols and ethers. This difference is attributed to regional measures in waste management.

scholarly journals In Vitro and Ex Vivo Chemopreventive Action of Mauritia flexuosa Products

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Joilane Alves Pereira-Freire ◽  
George Laylson da Silva Oliveira ◽  
Layana Karine Farias Lima ◽  
Carla Lorena Silva Ramos ◽  
Stella Regina Arcanjo-Medeiros ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Ex Vivo ◽  
Peroxyl Radicals ◽  
Palm Tree ◽  
Mauritia Flexuosa ◽  
Before And After ◽  
Scavenger Action ◽  
Ruminant Animals ◽  
By Products

Mauritia flexuosa (Arecaceae), known as “Buriti,” is a Brazilian palm tree with high economic potential for local communities. Herein, we investigated the phytochemistry profile and antioxidant potential of M. flexuosa fruits and determined the bioaccessibility of phenolic compounds. Peels revealed upper values for phenols, flavonoids, carotenoids, tannins, and ascorbic acid when compared to the pulps and endocarps. All samples showed capacity to scavenger free radicals (0.5, 1.0, 2.0, 4.0, and 8.0 mg/mL) but peels presented higher scavenger action in all methods explored. Phenolic compounds identified by HPLC displayed reduced bioaccessibility after in vitro simulated gastrointestinal digestion for pulp (38.7%), peel (18.7%), and endocarp (22.3%) extracts (P<0.05). Buriti fruits also protected rat blood cells against lysis induced by peroxyl radicals. We demonstrated the promising chemopreventive potentialities of M. flexuosa fruits and their by-products and peels with higher quantities of bioactive compounds and phenolic substances before and after in vitro bioaccessibility investigation. In Brazil, these parts are discarded or underused, mainly as feed for ruminant animals. Consequently, it is extremely important to explore nutritional characteristics of these by-products for human/livestock foods and to install biofriendly techniques and sustainable biotechnology handling of natural resources.

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