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Necatorin
Necatorin is a highly mutagenic chemical compound with the molecular formula . It is found in some mushrooms including '' Lactarius necator'' (ugly milk-cap), from which it was first isolated and characterized. It tests positive in the Ames test The Ames test is a widely employed method that uses bacteria to test whether a given chemical can cause mutations in the DNA of the test organism. More formally, it is a bioassay, biological assay to assess the mutagenic potential of chemical com ..., an assay for mutagenicity. Crude extracts of ''L. necator'' are also highly mutagenic in a bacterial test system, and this effect it attributed to necatorin. Necatorin is present in ''L. necator'' at concentrations of 3 to 20 mg/kg, and blanching the mushroom can reduce it to about 25% of its original amount. In boiling water, the chemical compound is stable except under acidic conditions (pH = 5). References {{reflist Mutagens Lactones Alkaloids Heterocyclic compounds with 4 ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactarius Necator
''Lactarius turpis'' (also ''L. plumbeus'' or ''L. necator'') is a Eurasian species of fungus, commonly known as the ugly milk-cap in English. Its messy, dirty appearance is characteristic of the species and gives it its English name and the Latin species epithet, ''turpis''. It seems to collect debris on top and the gills acquire a dirty brownish stain due to discoloured milk. Taxonomy This very variable mushroom demonstrates a common phenomenon in mycology as there is much disagreement over naming. The three main scientific designations: *''Lactarius turpis'' Fr., *''Lactarius necator'' ( Bull.: Fr.) Karsten, and *''Lactarius plumbeus'' ( Bull.: Fr.) S. F. Gray, are usually,Marcel Bon: "The Mushrooms and Toadstools of Britain and North-Western Europe" Hodder & Stoughton . but not always, considered to be synonyms for same species. The epithets ''necator'' and ''plumbeus'' were both coined by Pierre Bulliard as ''Agaricus necator'' (1791) and ''Agaricus plumbeus'' (1793), b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutagenic
In genetics, a mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer in animals, such mutagens can therefore be carcinogens, although not all necessarily are. All mutagens have characteristic mutational signatures with some chemicals becoming mutagenic through cellular processes. The process of DNA becoming modified is called mutagenesis. Not all mutations are caused by mutagens: so-called "spontaneous mutations" occur due to spontaneous hydrolysis, errors in DNA replication, repair and recombination. Discovery The first mutagens to be identified were carcinogens, substances that were shown to be linked to cancer. Tumors were described more than 2,000 years before the discovery of chromosomes and DNA; in 500 B.C., the Greek physician Hippocrates named tumors resembling a crab ''karkinos'' (from which the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ames Test
The Ames test is a widely employed method that uses bacteria to test whether a given chemical can cause mutations in the DNA of the test organism. More formally, it is a bioassay, biological assay to assess the mutagenic potential of chemical compounds. A positive test indicates that the chemical is mutagenic and therefore may act as a carcinogen, because cancer is often linked to mutation. The test serves as a quick and convenient assay to estimate the carcinogenic potential of a compound because standard carcinogen assays on mice and rats are time-consuming (taking two to three years to complete) and expensive. However, false-positives and false-negatives are known. The procedure was described in a series of papers in the early 1970s by Bruce Ames and his group at the University of California, Berkeley. General procedure The Ames test uses several strains of the bacterium ''Salmonella typhimurium'' that carry mutations in genes involved in histidine synthesis. These strains a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blanching (cooking)
Blanching is a process in which a food, usually a vegetable or fruit, is partially cooked by first scalding in boiling water, then removing after a brief timed interval, and finally plunging into iced water or placing under cold running water (known as shocking or refreshing) to halt the cooking process. Blanching foods helps reduce quality loss over time. Blanching is often used as a treatment prior to freezing, dehydrating, or canning vegetables or fruits to deactivate enzymes, modify texture, remove the peel and wilt tissue. The inactivation of enzymes preserves colour, flavour, and nutritional value. The process has three stages: preheating, blanching, and cooling. The most common blanching methods for vegetables/fruits are hot water and steam, while cooling is either done using cold water or cool air. Other benefits of blanching include removing pesticide residues and decreasing microbial load. Drawbacks to the blanching process can include leaching of water-soluble and he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutagens
In genetics, a mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer in animals, such mutagens can therefore be carcinogens, although not all necessarily are. All mutagens have characteristic mutational signatures with some chemicals becoming mutagenic through cellular processes. The process of DNA becoming modified is called mutagenesis. Not all mutations are caused by mutagens: so-called "spontaneous mutations" occur due to spontaneous hydrolysis, errors in DNA replication, repair and recombination. Discovery The first mutagens to be identified were carcinogens, substances that were shown to be linked to cancer. Tumors were described more than 2,000 years before the discovery of chromosomes and DNA; in 500 B.C., the Greek physician Hippocrates named tumors resembling a crab ''karkinos'' (from which the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactones
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresponding hydroxycarboxylic acids. Nomenclature Greek prefixes in alphabetical order indicate ring size. Lactones are usually named according to the precursor acid molecule (''aceto'' = 2 carbon atoms, ''propio'' = 3, ''butyro'' = 4, ''valero'' = 5, ''capro'' = 6, etc.), with a ''-lactone'' suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone. The first carbon atom after the carbon in the -COOH group on the parent compound is labelled α, the second will be labeled β, and so forth. Therefore, the prefixes also indicate the size of the lactone ring: α-lactone = 3-membered ring, β-lactone = 4-membered, γ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaloids
Alkaloids are a broad class of naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large variety of organisms including bacteria, fungi, plants, and animals. They can be purified from crude extracts of these organisms by acid-base extraction, or solvent extractions followed by silica-gel column chromatography. Alkaloids have a wide range of pharmacological activities including antimalarial (e.g. quinine), antiasthma (e.g. ephedrine), anticancer (e.g. homoharringtonine), cholinomimetic (e.g. galantamine), vasodilatory (e.g. vincamine), antiarrhythmic (e.g. quinidine), analgesic (e.g. morphine), antibacterial (e.g. chelerythrine), and antihyperglycemic activities (e.g. berberine). Many have found use in traditional or modern medicine, or as starting points for drug discovery. Other alkaloids possess psychotropic (e.g. psilocin) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compounds With 4 Rings
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of organic heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of organic heterocyclic chemistry focuses especially on organic unsaturated derivatives, and the preponderance of work and applications involves unstrained organic 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
