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Aesculin
Aesculin, also called æsculin or esculin, is a coumarin glucoside that naturally occurs in the trees horse chestnut (''Aesculus hippocastanum''), California buckeye (''Aesculus californica''), and prickly box (''Bursaria spinosa''). It is also found in daphnin (the dark green resin of '' Daphne mezereum''), dandelion coffee, and olive bark. It is reported to be present in olive bark, but not in olive leaf; therefore, identification of aesculin in abundance in an olive extract indicates that the extract has been derived from olive bark. Uses Aesculin is also used in a microbiology laboratory to aid in the identification of bacterial species (especially ''Enterococci'' and Listeria). In fact, all strains of Group D Streptococci hydrolyze aesculin in 40% bile. Aesculin hydrolysis test Aesculin is incorporated into agar with ferric citrate and bile salts ( bile aesculin agar). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Aesculetin
Aesculetin (also known as esculetin, 6,7-dihydroxycoumarin and cichorigenin) is a derivative of coumarin. It is a natural lactone that derives from the intramolecular cyclization of a cinnamic acid derivative. It is present in chicory and in many toxic plant, toxic and medicinal plants, in form of glycosides and caffeic acid conjugates. This compound is used in some sunscreens, but there is evidence that it acts as a photosensitizer for DNA damage. The sodium salt of its methyl-derivative is used in dermatology for the treatment of varicose veins. It is a blue fluorescence compound found in plants. Aesculin, the glucoside of aesculetin, will fluorescence, fluoresce under long wave ultraviolet light (360 nanometre, nm). The hydrolysis of aesculin results in loss of this fluorescence. Aesculetin has the ability to quench the inner fluorescence of bovine serum albumin. Aesculetin can be transformed into scopoletin (7-hydroxy-6-methoxycoumarin) and isoscopoletin (6-hydroxy-7-me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bile Aesculin Agar
Bile Esculin Agar (BEA) is a selective differential agar used to isolate and identify members of the genus ''Enterococcus'', formerly part of the "group D streptococci" (enterococci were reclassified in their own genus in 1984). Composition and process Bile salts are the selective ingredient, while esculin is the differential component. ''Enterococcus'' hydrolyze esculin to products that react with ferric citrate in the medium to produce insoluble iron salts, resulting in the blackening of the medium. Test results must be interpreted in conjunction with gram stain morphology. Uses Bile Esculin Agar is used primarily to differentiate ''Enterococcus'' from ''Streptococcus''. Members of the genus ''Enterococcus'' are capable of growing in the presence of 40% bile (oxgall) and hydrolyzing esculin to glucose and esculetin. Esculetin combines with ferric ions to produce a black complex. For some purposes, certain bacteria are able to hydrolyze aesculin Aesculin, also called æ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Aescin
Aescin or escin is a mixture of saponins with anti-inflammatory, vasoconstrictor and vasoprotective effects found in ''Aesculus hippocastanum'' (the horse chestnut). Aescin is the main active component in horse chestnut, and is responsible for most of its medicinal properties. The main active compound of aescin is β-aescin, although the mixture also contains various other components including α-aescin, protoescigenin, barringtogenol, cryptoescin and benzopyrones. Evidence suggests that aescin, especially pure β-aescin, is a safe and effective treatment for short-term treatment of chronic venous insufficiency; however, more high quality randomized controlled trials are required to confirm the effectiveness. Horse chestnut extract may be as effective and well tolerated as the use of compression stockings. Mechanism of action Aescin appears to produce effects through a wide range of mechanisms. It induces endothelial nitric oxide synthesis by making endothelial cells more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Horse-chestnut (tree)
The genus ''Aesculus'' ( or ), with notable species including buckeye and horse chestnut, comprises 13–19 species of flowering plants in the family Sapindaceae. They are trees and shrubs native to the temperate Northern Hemisphere, with six species native to North America and seven to 13 species native to Eurasia. Several hybrids occur. ''Aesculus'' exhibits a classical Arcto-Tertiary distribution. Mexican buckeye seedpods resemble the ''Aesculus'' seedpods, but belong to a different genus. Carl Linnaeus named the genus ''Aesculus'' after the Roman name for an edible acorn. Common names for these trees include "buckeye" and "horse chestnut", though they are not in the same order as the true chestnuts, '' Castanea'' in the Fagales The Fagales are an order of flowering plants in the rosid group of dicotyledons, including some of the best-known trees. Well-known members of Fagales include: beeches, chestnuts, oaks, walnut, pecan, hickory, birches, alders, hazels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Prickly Box
''Bursaria spinosa'' is a small tree or shrub in the family Pittosporaceae. The species occurs mainly in the eastern and southern half of Australia and not in Western Australia or the Northern Territory. Reaching 10 m (35 ft) high, it bears fragrant white flowers at any time of year but particularly in summer. A common understorey shrub of eucalyptus woodland, it colonises disturbed areas and fallow farmland. It is an important food plant for several species of butterflies and moths, particularly those of the genus ''Paralucia'', and native bees. Description ''Bursaria spinosa'' has a variable habit, and can grow anywhere from 1 to 12 m high. The dark grey bark is furrowed. The smooth branches are sometimes armed with thorns, and the leaves are arranged alternately along the stems or clustered around the nodes and have a pine-like fragrance when bruised. Linear to oval or wedge-shaped (ovate, obovate or cuneate), they are 2–4.3 cm long and 0.3–1.2 cm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nanometre
330px, Different lengths as in respect to the Molecule">molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm), or nanometer (American spelling), is a unit of length in the International System of Units (SI), equal to one billionth ( short scale) or one thousand million (long scale) of a meter (0.000000001 m) and to 1000 picometres. One nanometre can be expressed in scientific notation as 1 × 10−9 m and as m. History The nanometre was formerly known as the "''millimicrometre''" – or, more commonly, the "''millimicron''" for short – since it is of a micrometer. It was often denoted by the symbol ''mμ'' or, more rarely, as ''μμ'' (however, ''μμ'' should refer to a ''millionth'' of a micron). Etymology The name combines the SI prefix '' nano-'' (from the Ancient Greek , ', "dwarf") with the parent unit name ''metre'' (from Greek , ', "unit of measurement"). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Fluorescence
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colored visible light. The color of the light emitted depends on the chemical composition of the substance. Fluorescent materials generally cease to glow nearly immediately when the radiation source stops. This distinguishes them from the other type of light emission, phosphorescence. Phosphorescent materials continue to emit light for some time after the radiation stops. This difference in duration is a result of quantum spin effects. Fluorescence occurs when a photon from incoming radiation is absorbed by a molecule, exciting it to a higher energy level, followed by the emission of light as the molecule returns to a lower energy state. The emitted light may have a longer wavelength and, therefore, a lower photon energy than the absorbed radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Leuconostoc
''Leuconostoc'' is a genus of gram-positive bacteria, placed within the family of Lactobacillaceae. They are generally ovoid cocci often forming chains. ''Leuconostoc'' spp. are intrinsically resistant to vancomycin and are catalase-negative (which distinguishes them from staphylococci). All species within this genus are heterofermentative and are able to produce dextran from sucrose. They are generally slime-forming. The name Leuconostoc comes from Greek adjective ''leukos'' meaning clear; and the word ''nostoc'' gelatinous colonies, Leuconostoc - colorless nostoc. Blamed for causing the 'stink' when creating a sourdough starter, some species are also capable of causing human infection. Because they are an uncommon cause of disease in humans, standard commercial identification kits are often unable to identify the organism. ''Leuconostoc'' spp., along with other lactic acid bacteria such as '' Pediococcus'' and ''Lactobacillus'', are responsible for the fermentation of cabba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Aerococcus
''Aerococcus'' is a genus of bacterium in the phylum Bacillota (Bacteria). The genus was first identified in 1953 from samples of air and dust as a catalase-negative, gram-positive coccus that grew in small clusters. They were subsequently found in hospital environments and meat-curing brines. It has been difficult to identify as it resembles alpha-hemolytic ''Streptococcus'' on blood agar plates and is difficult to identify by biochemical means. Sequencing of 16S rRNA has become the gold standard for identification, but other techniques such as MALDI-TOF have also been useful for identifying both the genus and species. Etymology The name ''Aerococcus'' derives from the Greek ''aer, aeros'' (ἀήρ, ἀέρος), air; Neo-Latin ''coccus'' (from Greek''kokkos'' (κόκκος)), a berry; Neo-Latin ''Aerococcus'', air coccus. The name was given based on its round shape and that it was first discovered in air samples. Species The genus contains these species: * '' A. christensen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
