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Microalgae for Pigments and Cosmetics
Published in Sanjeet Mehariya, Shashi Kant Bhatia, Obulisamy Parthiba Karthikeyan, Algal Biorefineries and the Circular Bioeconomy, 2022
Nídia S. Caetano, Priscila S. Corrêa, Wilson G. de Morais Júnior, Gisela M. Oliveira, António A.A. Martins, Teresa M. Mata, Monique Branco-Vieira
Carotenoids are yellow to red pigments, formed by isoprenoid molecules that occur as isomers with 5-, 9-, 13-, and 15-cis, and all trans forms, commonly found in chloroplasts, endoplasmic reticulum, or in the mitochondria of microalgae (Kaur et al., 2009). Carotenoids are a group of lipophilic compounds characterized by molecules with a tetraterpene carbon structure: a long chain of forty C atoms having several conjugated double C=C bonds, which creates chromophores where visible light may excite the double bond electrons to high energy levels. The antioxidant effect of carotenoids is due to reactive electrons suitable for scavenging reactive oxygen species (ROS) and free radicals that are made relatively available due to the long chains of conjugated double carbon bonds. The antioxidant properties of carotenoids play an important role in the mitigation of oxidative reactions as they induce the release of reactive oxygen species in the metabolic activity (Santos-Sánchez et al., 2019) and photoprotection against light damage of different biological systems (Galasso et al., 2019).
Long-Time Recording of Single-Molecule Dynamics in Solution by Anti-Brownian Trapping
Published in Shuo Huang, Single-Molecule Tools for Bioanalysis, 2022
Quan Wang, Elif Karasu, Hugh Wilson
In cyanobacteria, APC plays an important role in light-harvesting, energy transfer, and photoprotection. Each monomer of APC covalently binds two (referred to as α and β) phycocyanobilin pigments in similar but distinct protein environments. Monomers self-assemble to form trimers (Figure 6.10a). During the self-assembly process, the absorption spectrum of the protein redshifts is ~30 nm. Due to the functional importance of this red shift, we set out to characterize the optical properties of individual pigments on the protein in both the monomer and trimer using the ABEL trap. To maximize the amount of spectroscopic information, we measured multiple fluorescence parameters including brightness, excited-state lifetime, fluorescence polarization, emission spectrum, and photon antibunching. Some of these parameters were measured simultaneously.
Plant-Based Compounds as Alternative Adjuvant Therapy for Multidrug-Resistant Cancer
Published in Parimelazhagan Thangaraj, Phytomedicine, 2020
E. C. Aniogo, Blassan P. George, Heidi Abrahamse
They are lipid-soluble compounds that play an important role together with chlorophylls in photosynthesis and photoprotection (Kapinova et al. 2018). This molecule has a long conjugated double bond series in its center, which gives them their sharp, chemical reactivity and light-absorbing properties. Carotenoids inhibit the oxidative effects of reactive and singlet oxygen species that are produced from a plant’s exposure to light and air. They react with radical molecules and delocalize the unpaired electron, thus inhibiting the oxidative effects of the radicals. This antioxidant activity makes them an excellent free radical scavenger (Ramel et al. 2012). Carotenoids are widely found in nature and can be used to prevent lipid oxidation and other related oxidative stress. Fruits including carrots, watermelons, apricots, pink guavas, tomatoes, pumpkin, mango, and sweet potatoes are rich sources of carotenoids (Jaswir et al. 2011). Generally, carotenoids are classified into α-carotene, β-carotene, β-cryptoxanthin, lutin, and lycopene (Liu 2004). Many epidemiological studies have found beneficial effects of carotenoid-rich foods in the reduction of cancer progression. As a chemoprevention strategy against certain human cancers, carotenoids and other antioxidants could be used, although there appears to be a detrimental interaction between β-carotene, smoke, and alcohol (Tanaka et al. 2012).
Bioactivities and phenolic composition of Limonium boitardii Maire and L. cercinense Brullo & Erben (Plumbaginaceae): two Tunisian strict endemic plants
Published in International Journal of Environmental Health Research, 2022
Ons Sefi, Soumaya Bourgou, Wided Megdiche-Ksouri, Mohamed Libiad, Abdelmajid Khabbach, Mohamed El Haissoufi, Fatima Lamchouri, Nikos Krigas, Zeineb Ghrabi-Gammar
Melanins, the main pigments primarily responsible in the skin and hair pigmentation, are produced by melanocytes through melanogenesis. Melanogenesis and skin pigmentation are the most important photoprotective factors in response to the damaging solar ultraviolet radiation inducing skin photocarcinogenesis. The increased melanin synthesis of these pigments occurs in many types of skin disorders, including Acanthosis nigricans, Cervical Poikiloderma, melasma, Periorbital hyperpigmentation, Lentigines and increased skin cancer risk. Tyrosinase enzyme possesses an essential role in the melanogenesis process since it catalyzes the hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) and the oxidation of L-DOPA to dopaquinone. These reactions are considered rate-limiting steps for the melanin biosynthesis pathway, and therefore, for the production of skin pigments in melanocytes. Consequently, controlling the activity of this enzyme by tyrosinase inhibitors is an essential endeavor for treating pigmentary disorders in mammals. The mushroom tyrosinase inhibition biological assay is commonly used to investigate the whitening potential of natural extracts (Promden et al. 2018).
Caffeine analysis and extraction from a topical cream intended for UV-skin protection
Published in Journal of Dispersion Science and Technology, 2022
Ana Melero, Antonio Guillot, Carlos Carneiro, Hugo Nuñez-Sanchez, Laura Rodríguez-Martí, Bruna Galdorfini Chiari-Andréo, Joana Marto, Helena Ribeiro, Teresa Garrigues, Vera Isaac
Sunscreens rank among the best photoprotective measures and their use is considered the first line of defense against the harmful effects from UV-R.[5] They contain molecules or molecular complexes, known as filters, with the capacity of UV-R absorption, reflection or scattering. They may be composed of various types of UV filters, including inorganic and organic compounds.[6] Additionally, it has been suggested that supplementing sunscreens with active natural compounds can help to increase their photoprotective potential for patients. In this context, novel substances with this potential, such as caffeine, present in coffee oil, has been investigated.[7]