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N1-Acetyl-5-methoxykynuramine
''N''1-Acetyl-5-methoxykynuramine (AMK) is a metabolite of melatonin that could improve memory by acting on the melatonin receptors. AMK is produced from the metabolization of melatonin by the kynuramine pathway in the brain. It significantly increased the phosphorylation of both ERK and CREB in the hippocampus. It also helps scavenge free radicals. AMK is highly reactive towards dioxygen (O2) radicals because of AMK's ''N''2-amino group. Anti-inflammatory activity Studies have shown that melatonin, along with its metabolites N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5-methoxykynuramine (AMK), can suppress the activation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase(iNOS). This leads to reduced production of prostaglandin E₂ (PGE₂) and nitric oxide, respectively. COX-2 is a key enzyme involved in inflammation and its activation is triggered by lipopolysaccharide (LPS) in macrophages. Elevated levels of COX-2 expression have been link ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin
Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cows that could induce skin lightening in common frogs. This compound was later identified as a hormone secreted in the brain during the night, playing a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm, in vertebrates. In vertebrates, melatonin's functions extend to Entrainment (chronobiology), synchronizing sleep-wake cycles, encompassing sleep-wake timing and blood pressure regulation, as well as controlling seasonal rhythmicity (circannual cycle), which includes reproduction, fattening, molting, and hibernation. Its effects are mediated through the activation of melatonin receptors and its role as an antioxidant. In plants and bacteria, melatonin primarily serves as a defense mechanism against oxidative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, catalytic activity of their own (usually as a cofactor to an enzyme), defense, and interactions with other organisms (e.g. pigments, odorants, and pheromones). A primary metabolite is directly involved in normal "growth", development, and reproduction. Ethylene exemplifies a primary metabolite produced large-scale by industrial microbiology. A secondary metabolite is not directly involved in those processes, but usually has an important ecological function. Examples include antibiotics and pigments such as resins and terpenes etc. Some antibiotics use primary metabolites as precursors, such as actinomycin, which is created from the primary metabolite tryptophan. Some sugars are metabolites, such as fructose or glucose, which ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methoxy Compounds
In organic chemistry, a methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula . On a benzene ring, the Hammett equation classifies a methoxy substituent at the ''para'' position as an electron-donating group, but as an electron-withdrawing group if at the ''meta'' position. At the ''ortho'' position, steric effects are likely to cause a significant alteration in the Hammett equation prediction, which otherwise follows the same trend as that of the ''para'' position. Occurrence The simplest of methoxy compounds are methanol and dimethyl ether. Other methoxy ethers include anisole and vanillin. Many metal alkoxides contain methoxy groups, such as tetramethyl orthosilicate and titanium methoxide. Esters with a methoxy group can be referred to as methyl esters, and the —COOCH3 substituent is called a methoxycarbonyl. Biosynthesis In nature, methoxy groups are found on nucleosides subjected to 2′-''O''-methyla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is from the Greek ''tyrós'', meaning ''cheese'', as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese. It is called tyrosyl when referred to as a functional group or side chain. While tyrosine is generally classified as a hydrophobic amino acid, it is more hydrophilic than phenylalanine. It is encoded by the codons UAC and UAU in messenger RNA. The one-letter symbol Y was assigned to tyrosine for being alphabetically nearest of those letters available. Note that T was assigned to the structurally simpler threonine, U was avoided for its similarity with V for valine, W was assigned to tryptophan, while X was reserved for undetermined or atypical amino acids. The mnemonic t''Y''rosine was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanoma
Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare cases melanoma can also happen in the lung which is known as primary pulmonary melanoma and only happens in 0.01% of primary lung tumors. In women, melanomas most commonly occur on the legs; while in men, on the back. Melanoma is frequently referred to as malignant melanoma. However, the medical community stresses that there is no such thing as a 'benign melanoma' and recommends that the term 'malignant melanoma' should be avoided as redundant. About 25% of melanomas develop from nevus, moles. Changes in a mole that can indicate melanoma include increaseespecially rapid increasein size, irregular edges, change in color, itchiness, or nevus#Classification, skin breakdown. The primary cause of melanoma is ultraviolet light (UV) exposure in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratinocyte
Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Basal cells in the basal layer (''stratum basale'') of the skin are sometimes referred to as basal keratinocytes. Keratinocytes form a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses. A number of structural proteins, enzymes, lipids, and antimicrobial peptides contribute to maintain the important barrier function of the skin. Keratinocytes differentiate from epidermal stem cells in the lower part of the epidermis and migrate towards the surface, finally becoming corneocytes and eventually being shed, which happens every 40 to 56 days in humans. Function The primary function of keratinocytes is the formation of a barrier against environmental damage by heat, UV radiation, dehydration, pathogenic bacteria, fungi, parasites, and viruses. Pathoge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanin
Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are five basic types of melanin: eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization. Pheomelanin is a cysteinated form containing poly benzothiazine portions that are largely responsible for the red or yellow tint given to some skin or hair colors. Neuromelanin is found in the brain. Research has been undertaken to investigate its efficacy in treating neurodegenerative disorders such as Parkinson's. Allomelanin and pyomelanin are two types of nitrogen-free melanin. The phenotypic color variation observed in the epidermis and hair of mammals is primarily determi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (; abbreviated MPhi, φ, MΦ or MP) are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. This self-protection method can be contrasted with that employed by Natural killer cell, Natural Killer cells. This process of engulfment and digestion is called phagocytosis; it acts to defend the host against infection and injury. Macrophages are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adapti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin E2
Prostaglandin E2 (PGE2), also known as dinoprostone, is a naturally occurring prostaglandin with oxytocic properties that is used as a medication. Dinoprostone is used in labor induction, bleeding after delivery, termination of pregnancy, and in newborn babies to keep the ductus arteriosus open. In babies it is used in those with congenital heart defects until surgery can be carried out. It is also used to manage gestational trophoblastic disease. It may be used within the vagina or by injection into a vein. PGE2 synthesis within the body begins with the activation of arachidonic acid (AA) by the enzyme phospholipase A2. Once activated, AA is oxygenated by cyclooxygenase (COX) enzymes to form prostaglandin endoperoxides. Specifically, prostaglandin G2 (PGG2) is modified by the peroxidase moiety of the COX enzyme to produce prostaglandin H2 (PGH2) which is then converted to PGE2. Common side effects of PGE2 include nausea, vomiting, diarrhea, fever, and excessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipopolysaccharide
Lipopolysaccharide (LPS), now more commonly known as endotoxin, is a collective term for components of the outermost membrane of the cell envelope of gram-negative bacteria, such as '' E. coli'' and ''Salmonella'' with a common structural architecture. Lipopolysaccharides are large molecules consisting of three parts: an outer core polysaccharide termed the O-antigen, an inner core oligosaccharide and Lipid A (from which toxicity is largely derived), all covalently linked. In current terminology, the term endotoxin is often used synonymously with LPS, although there are a few endotoxins (in the original sense of toxins that are inside the bacterial cell that are released when the cell disintegrates) that are not related to LPS, such as the so-called delta endotoxin proteins produced by '' Bacillus thuringiensis''. Lipopolysaccharides can have substantial impacts on human health, primarily through interactions with the immune system. LPS is a potent activator of the immune syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
