Anti-Markovnikov hydroallylation reaction of alkenes via scandium-catalyzed allylic C‒H activation

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Фев. 6, 2025

Compared with rare-earth (RE)…heteroatom interaction, RE…π frequently used in facilitating regio- and stereoselectivity of olefin polymerizations, is seldomly to trigger catalytic C - H functionalization. Here, we describe a direct anti-Markovnikov hydroallylation reaction styrene derivatives 1-aryl-2-alkyl alkenes α-alkenes by use interaction. This protocol provides straightforward atom-efficient route for the synthesis valuable chain elongated internal (65 examples, up 99% yield, > 19:1 E/Z ratio). The proceeds via an allylic Csp3‒H activation pathway initiated site-selective deprotonation assistance cationic imidazolin-2-iminato scandium alkyl species followed alkene insertion into resulting scandium-allyl bond. A amount Lewis base additives, such as amine tetrahydrofuran (THF) show significant effects on reactivity selectivity. mechanism elucidated experimental studies theoretical calculations.

Язык: Английский

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Nutritional Benefits of Lycopene and Beta‐Carotene: A Comprehensive Overview

Food Science & Nutrition, Год журнала: 2024, Номер 12(11), С. 8715 - 8741

Опубликована: Окт. 16, 2024

Certain carotene components, such as lycopene and beta-carotene, are found in tomatoes, carrots, sweet potatoes, etc. good for human health. It gives plants their distinctive red color. A class of lipid-soluble natural pigments known carotenoids is the precursor vitamin vital antioxidant defense against peroxides cells tissues. This review provides an overview current state knowledge research on sources, structures, physiochemical properties, absorption metabolism, functional advantages, prevention many diseases associated with beta-carotene. These antioxidants have been linked to a lower risk cardiovascular disease cancer, they also help draw pollinators flowers. Carrots potatoes rich sources which strengthens immune system improves eye The vivid color reproductive organs, including flowers fruits, caused by carotenoid, secondary metabolite that produced plastids. other health advantages attributed lycopene. When ingested through food or supplements, beta-carotene manage prevent number diseases, metabolic, inflammatory, cardiovascular, hepatic, ophthalmic, skeletal, infertility disorders. main point toxicity uncommon, these generally accepted be safe at different doses. Including nutrients your diet can improve general provide illness prevention.

Язык: Английский

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Innovative Nano Delivery Systems for Astaxanthin: Enhancing Stability, Bioavailability, and Targeted Therapeutic Applications

Journal of Agricultural and Food Chemistry, Год журнала: 2025, Номер 73(6), С. 3286 - 3304

Опубликована: Янв. 31, 2025

Astaxanthin (AST), as a natural antioxidant, has broad application prospects in medicine and health products. However, its highly unsaturated structure significant lipophilic characteristics limit dispersibility bioavailability, thereby restricting food, medicines, nutraceuticals. To overcome these limitations, researchers have proposed the use of nano delivery systems. This review summarizes various nanocarriers, including liposomes, nanostructured lipid carriers, nanoparticles, others, analyzes their advantages enhancing solubility, stability, bioavailability AST. Furthermore, study focuses on targeted systems achieved through biomolecular modifications, which enable precise AST to specific cells or tissues, therapeutic effects. Additionally, smart-responsive systems, such pH-responsive light-sensitive are also discussed, showing immense potential release therapy. These findings provide new perspectives for nutrition clinical applications Future research should further optimize design nanocarriers broader applications.

Язык: Английский

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Astaxanthin alleviates high-fat diet-induced obesity by promoting adipose thermogenesis: Insights from microbiome-metabolomics

Food Bioscience, Год журнала: 2025, Номер unknown, С. 106097 - 106097

Опубликована: Фев. 1, 2025

Язык: Английский

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Z‐Astaxanthin exhibits superior anti‐obesity effects in Caenorhabditis elegans: insights from geometric isomers and signaling pathways

Journal of the Science of Food and Agriculture, Год журнала: 2025, Номер unknown

Опубликована: Март 9, 2025

Abstract Background Astaxanthin (AST) exists as an ‘all‐ E ’ isomer and various ‘ Z isomers due to its multiple conjugated double bonds. The configuration has been reported exhibit stronger antioxidant activity, raising interest in potential health benefits. All‐ AST is a potent chemopreventive agent for weight loss but the anti‐obesity efficacy of remains unclear. This study therefore explored role geometric (all‐ , 9‐ 13‐ ) on alleviation obesity using Caenorhabditis elegans well established model organism. Results reduced high‐fat worms substantially. Triglyceride (TG) decreased by 18.84%, with all‐ AST, 41.18%, 35.94% ( P < 0.05), indicating that displayed superior effect. Interestingly, particularly ‐isomers, large lipid droplets (LDs) oleic acid/stearic acid (C18:1Δ9/C18:0) significantly; these contribute accumulation. also minimized food intake boosted energy consumption, ‐isomers outperformed enhancing mobility. Using quantitative polymerase chain reaction (qPCR), green fluorescent protein binding, gene‐deficient nematodes, findings current indicated especially isomers, suppressed key gene expression sbp‐1 / mdt‐15 insulin/insulin‐like growth factor signaling (IIS) pathways, which are responsible regulating fatty composition balance, subsequently co‐downregulated essential genes fat‐6 fat‐7 involved C18:1 Δ 9 synthesis. Conclusion provides important insights into association between effects carotenoids, guiding their application field. © 2025 Society Chemical Industry.

Язык: Английский

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Thermal isomerization of astaxanthin esters in the green alga Haematococcus lacustris without any chemicals

Food Bioscience, Год журнала: 2024, Номер 61, С. 104645 - 104645

Опубликована: Июнь 27, 2024

Язык: Английский

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Cluster of Differentiation 36 (CD36) Preferentially Mediates Intestinal Absorption of Dietary Z-Astaxanthin and Especially 9-Z-Isomer via Higher Binding Affinity

Journal of Agricultural and Food Chemistry, Год журнала: 2024, Номер 72(29), С. 16287 - 16297

Опубликована: Июль 10, 2024

Variances in the biological functions of astaxanthin geometric isomers (i.e., all-

Язык: Английский

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Development of a simple and economical analytical method for investigating the distribution of astaxanthin E/Z-isomers in foods and cosmetics

Journal of Food Composition and Analysis, Год журнала: 2024, Номер 137, С. 106932 - 106932

Опубликована: Ноя. 6, 2024

Язык: Английский

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The Effects of Astaxanthin on Metabolic Syndrome: A Comprehensive Review

Marine Drugs, Год журнала: 2024, Номер 23(1), С. 9 - 9

Опубликована: Дек. 27, 2024

Metabolic syndrome (MS) represents a complex cluster of metabolic disorders primarily characterized by obesity, insulin resistance, hyperglycemia, dyslipidemia, hypertension, and hyperuricemia. Diet functional ingredients play pivotal role in seeking non-pharmacological strategies to prevent ameliorate MS. Astaxanthin (AST), carotenoid found various marine organisms, exhibits exceptional antioxidant properties holds great promise as natural compound that improves This article introduces the basic AST, including its absorptance pathways, along with isomers. Most importantly, we comprehensively review effects mechanisms AST on improving primary components These involve regulating signal transduction, transport, or pathways within body, well influencing intestinal microbiota metabolites, thereby exerting positive metabolism inhibiting occurrence emphasizes potential efficacy managing However, more studies are needed confirm clinical effect MS reveal molecular mechanisms.

Язык: Английский

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Complex formation and stabilization of Z‐isomer‐enriched astaxanthin esters derived from Haematococcus lacustris with water‐soluble carriers via spray drying

European Journal of Lipid Science and Technology, Год журнала: 2024, Номер unknown

Опубликована: Сен. 8, 2024

Abstract To enhance the water solubility and bioavailability of astaxanthin esters, inclusion complexes Z ‐isomer‐enriched esters with water‐soluble carriers were prepared using a spray drying technique. A food‐grade Haematococcus alga extract was used as source ‐isomerization performed via direct heating extract. Polyvinylpyrrolidone (PVP) hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) carriers. The effects conditions on encapsulation efficiency in total ‐isomer ratio encapsulated investigated, physical properties storage stability resulting composites evaluated. Under optimum conditions, efficient production highly ‐isomer‐rich achieved both carriers: >95% >55% ratio. properties, such surface morphology particle size distributions, particles differed significantly between PVP HP‐β‐CD. Storage tests demonstrated that formulated stable. Our findings will contribute to practical applications materials. Practical Applications : formulation technology developed this study has potential address industrial challenges astaxanthin, is, low bioavailability. Furthermore, ‐isomers, which hinders their use, can be solved simultaneously. powders are expected wide range applications, including nutraceuticals, cosmetics, animal feeds.

Язык: Английский

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