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Kojic Acid
Kojic acid is an organic compound with the formula . It is a derivative of 4-Pyrone, 4-pyrone that functions in nature as a chelation agent produced by several species of fungus, especially ''Aspergillus oryzae'', which has the Japanese common name ''koji''. Kojic acid is a by-product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine. It is a mild inhibitor of the formation of pigment in plant and animal tissues, and is used in food and cosmetics to preserve or change colors of substances. It forms a bright red complex with ferric ions. Biosynthesis 13C-Labeling studies have revealed at least two pathways to kojic acid. In the usual route, dehydratase enzymes convert glucose to kojic acid. Pentoses are also viable precursors in which case dihydroxyacetone is invoked as an intermediate. Applications Kojic acid may be used on cut fruits to prevent redox, oxidative browning, in seafood to preserve pink and red colors, and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Alcohols
A primary alcohol is an Alcohol (chemistry), alcohol in which the hydroxy group is bonded to a primary carbon atom. It can also be defined as a molecule containing a “–CH2OH” group. In contrast, a secondary alcohol has a formula “–CHROH” and a tertiary alcohol has a formula “–CR2OH”, where “R” indicates a carbon-containing group. Examples of primary alcohols include ethanol, 1-propanol, and n-Butanol, 1-butanol. Methanol is also generally regarded as a primary alcohol, including by the 1911 edition of the Encyclopædia Britannica. See also * Alcohol (chemistry), Alcohol (especially Nomenclature section for discussion on Secondary and Tertiary alcohols.) * Oxidation of primary alcohols to carboxylic acids References Primary alcohols, {{organic-chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Additives
Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke (smoking) and sugar (crystallization), have been used for centuries to preserve food. This allows for longer-lasting foods, such as bacon, sweets, and wines. With the advent of ultra-processed foods in the late 20th century, many additives having both natural and artificial origin were introduced. Food additives also include substances that may be introduced to food indirectly (called "indirect additives") in the manufacturing process through packaging, storage or transport. In Europe and internationally, many additives are designated with E numbers, while in the United States, additives in amounts deemed safe for human consumption are designated as GRAS. Identification To regulate these additives and inform consumers each additive is assigned a unique number called an "E number", which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ResearchGate (website)
ResearchGate is a German commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a 2014 study by ''Nature'' and a 2016 article in ''Times Higher Education'', it is the largest academic social network in terms of active users, although other services have more registered users, and a 2015–2016 survey suggests that almost as many academics have Google Scholar profiles. While reading articles does not require registration, people who wish to become site members need to have an email address at a recognized institution or to be manually confirmed as a published researcher in order to sign up for an account. Articles are free to read by visitors, however additional features (such as job postings or advertisements) are accessible only as a paid subscription. Members of the site each have a user profile and can upload research output including papers, data, chapters, negative results, patents, resea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinogenic
A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and Biological agent, biologic agents such as viruses and carcinogenic bacteria, bacteria. Most carcinogens act by creating mutations in DNA that disrupt a cell's normal processes for regulating growth, leading to uncontrolled cellular proliferation. This occurs when the cell's DNA repair processes fail to identify DNA damage allowing the defect to be passed down to daughter cells. The damage accumulates over time. This is typically a multi-step process during which the regulatory mechanisms within the cell are gradually dismantled allowing for unchecked Cell division, cellular division. The specific mechanisms for carcinogenic activity is unique to each agent and cell type. Carcinogens can be broadly categorized, however, as activation-dependent and activation-independent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thionyl Chloride
Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately Volatility (chemistry), volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a Halogenation, chlorinating reagent, with approximately per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also List of Schedule 3 substances (CWC), listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons. Thionyl chloride is sometimes confused with sulfuryl chloride, , but the properties of these compounds differ significantly. Sulfuryl chloride is a source of chlorine whereas thionyl chloride is a source of chloride ions. Production The major industrial synthesis involves the reaction of sulfur trioxide and sulfur dichloride. This synthesis can be adapted to the laboratory by heating oleum to slowly distill the sulfur trioxide into a cooled fla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxymethyl Group
The hydroxymethyl group is a substituent with the structural formula . It consists of a methylene bridge ( unit) bonded to a hydroxyl group (). This makes the hydroxymethyl group an alcohol. It has the identical chemical formula with the methoxy group () that differs only in the attachment site and orientation to the rest of the molecule. However, their chemical properties are different. Hydroxymethyl is the side chain of encoded amino acid serine Serine (symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α- amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − .... References External links {{Organic-compound-stub Functional groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melasma
Melasma (also known as chloasma faciei,James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . or the mask of pregnancy when present in pregnant women) is a tan or dark skin discoloration. Melasma is thought to be caused by sun exposure, genetic predisposition, hormone changes, and skin irritation. Although it can affect anyone, it is particularly common in women, especially pregnant women and those who are taking oral or patch contraceptives or hormone replacement therapy medications. Signs and symptoms The symptoms of melasma are dark, irregular, well-demarcated, hyperpigmented macules to patches. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration. Patches can vary in size from to larger than depending on the person. Its location can be categorized as centrofacial, malar, or mandibular. The most common is centrofacial, in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-Pyrone
4-Pyrone (γ-pyrone or pyran-4-one) is an unsaturated cyclic chemical compound with the molecular formula C5H4O2.It is isomeric with 2-pyrone. Preparation 4-Pyrone is prepared via the thermal decarboxylation of chelidonic acid. Reactions 4-Pyrone and its derivatives react with amines in protic solvents to form 4-Pyridones. Derivatives 4-Pyrone forms the central core of several natural chemical compounds, including maltol, meconic acid, kojic acid, and of the important class of the Flavones. : See also * Pyrone Pyrones or pyranones are a class of heterocyclic chemical compounds. They contain an unsaturated six-membered ring, which has one oxygen atom and a carbonyl functional group. There are two isomers, denoted as 2-pyrone and 4-pyrone. The 2-pyrone ... * 4-Pyridone * Dehydroacetic acid References {{DEFAULTSORT:Pyrone, 4- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seafood
Seafood is any form of Marine life, sea life regarded as food by humans, prominently including Fish as food, fish and shellfish. Shellfish include various species of Mollusca, molluscs (e.g., bivalve molluscs such as clams, oysters, and mussels, and cephalopods such as octopus and squid), crustaceans (e.g. shrimp, crabs, and lobster), and echinoderms (e.g. sea cucumbers and sea urchins). Historically, marine mammals such as cetaceans (whales and dolphins) as well as Pinniped, seals have been eaten as food, though that happens to a lesser extent in modern times. Edible sea plants such as some Edible seaweed, seaweeds and microalgae are widely eaten as :edible seaweeds, sea vegetables around the world, especially in Asia. Seafood is an important source of (animal) protein in many Diet (nutrition), diets around the world, especially in coastal areas. Semi-vegetarianism, Semi-vegetarians who consume seafood as the only source of meat are said to adhere to pescetarianism. The harv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
