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Plant Source Foods
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
The main plant pigments in leaves, flowers, fruits, and vegetables include chlorophylls, carotenoids, flavonoids, anthocyanins, and betalains (20, 22). All biological pigments selectively absorb certain wavelengths of sunlight while reflecting others, giving different colors to different parts of plants (22). The principal colors of these pigments are green, orange, yellow, red, blue, and violet, though brown and black are also present in some fruits, seeds, and leaves. However, in fruits and vegetables, colors derived from these natural pigments can change as the plant proceeds through maturation and ripening.
Lasers in Medicine: Healing with Light
Published in Suzanne Amador Kane, Boris A. Gelman, Introduction to Physics in Modern Medicine, 2020
Suzanne Amador Kane, Boris A. Gelman
In some molecules, the new splitting between energy levels will still be small, in some cases, small enough to permit transitions that still absorb or emit visible light. This often occurs with heavy metals such as iron and lead, and in certain organic pigments where the electrons are loosely held. Artists’ paints utilize the rich colors generated by heavy metal compounds; paint pigments consequently go by names such as cadmium red, chrome yellow, and cobalt blue. Many biological pigments have evolved chemical mechanisms to absorb light in the visible range, where the sun's light is most intense. Examples include the incorporation of metals such as iron in the oxygen-carrying hemoglobin found in blood, and magnesium in the photosynthetic pigment chlorophyll in plants, and complexes containing loosely bound electrons such as in carotene, a form of vitamin A, or in retinol, a visual pigment found in the retina.
A promising and effective platform for delivering hydrophilic depigmenting agents in the treatment of cutaneous hyperpigmentation: kojic acid nanostructured lipid carrier
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Khadijeh Khezri, Majid Saeedi, Katayoun Morteza-Semnani, Jafar Akbari, Akbar Hedayatizadeh-Omran
Skin melanin is a biological pigment, which is produced by melanocytes. Melanin is a main factor in determining skin colour which protects human skin from the hazardous effects of ultraviolet (UV) sun radiation. Over synthesis of melanin is called hyperpigmentation [1]. Treatment of hyperpigmentation has always been challenging and discouraging for most people, especially women [2]. Kojic acid (KA) is a natural bleaching agent and a well-known tyrosinase inhibitor with hydrophilic character which is used to treat hyperpigmentation. KA inactivates the tyrosinase enzyme and suppresses the tautomerization of dopachrome by chelating copper atoms. It is synthesized by several fungal species such as the Aspergillus and Penicillum [3]. Despite the unique properties of KA and its derivatives, their use is very limited in the cosmetic industries. KA is a hydrophilic ingredient due to the presence of two hydroxyl functional groups in its chemical structure and because of its hydrophilic nature. It has inadequate absorption from the skin [4].
Proteomes of the past: the pursuit of proteins in paleontology
Published in Expert Review of Proteomics, 2019
A third trend that Table 1 reveals is that of an increased interest in, and investigation of, original biochemistry fossils in recent years. What accounts for the increase in published papers on this topic? A 2005 Science paper showed full-color, clear photographs of blood red tissue and still-red erythrocyte-like elements inside blood vessels extracted from the sectioned femur of ‘B rex’ (MOR 1125), a T. rex named after discoverer and dig volunteer Bob Harmon [81]. That paper, plus three follow-up reports published in a 2007 issue of Science [96,114,115], invigorated fascination in those investigating dinosaur phylogenies as well as controversy in those familiar with the lability of biochemicals. The recent increase in publications shown in Figure 4 appears to have stimulated some negative reactions [9,116] while also sparking paleoproteomics research. Researchers have investigated proteins and other biochemistry such as lipids [25], nucleic acids [82], and biological pigments such as melanin [117] and protoporphyrin [118] in fossils.
An emerging technology in lipid research for targeting hydrophilic drugs to the skin in the treatment of hyperpigmentation disorders: kojic acid-solid lipid nanoparticles
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Khadijeh Khezri, Majid Saeedi, Katayoun Morteza-Semnani, Jafar Akbari, Seyyed Sohrab Rostamkalaei
Cutaneous melanin (an irregular light-absorbing polymer) is a ubiquitous class of biological pigments [1]. The step of melanin synthesis in melanocytes is carried out through the complex chemical process by several enzymes. Tyrosinase (monophenol or o-diphenol oxygen oxidoreductase) is an essential enzyme for melanin synthesis that is a copper-containing enzyme. In addition, it has been introduced as polyphenol oxidase, phenolase, catecholase and cresolase [2,3].