Aesculin
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Names | |
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IUPAC name
7-hydroxy-6-{[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy- 6-(hydroxymethyl)-2-tetrahydropyranyl]oxy}-2-chromenone | |
Other names
Esculetin 6-β-D-glucoside 6,7-dihydroxycoumarin 6-β-D-glucoside 6,7-dihydroxychromen-2-one 6-β-D-glucoside | |
Identifiers | |
531-75-9 ![]() | |
3D model (Jmol) | Interactive image |
ChEMBL | ChEMBL482581 ![]() |
ChemSpider | 4444765 ![]() |
ECHA InfoCard | 100.007.744 |
PubChem | 5281417 |
UNII | 1Y1L18LQAF ![]() |
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Properties | |
C15H16O9 | |
Molar mass | 340.282 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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Infobox references | |
Aesculin, also rendered Æsculin or Esculin, is a coumarin glucoside that naturally occurs in the horse chestnut (Aesculus hippocastanum),[1] California buckeye (Aesculus californica),[2] Prickly Box (Bursaria spinosa) and in daphnin (the dark green resin of Daphne mezereum). It is also found in dandelion coffee.
Medical uses
As medication, aesculin is sometimes used as a vasoprotective agent.[3]
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 æsculin in 40% bile.
Aesculin hydrolysis test
Aesculin is incorporated into agar with ferric citrate and bile salts (bile aesculin agar).[4] Hydrolysis of the aesculin forms aesculetin (6,7-dihydroxycoumarin) and glucose. The aesculetin forms dark brown or black complexes with ferric citrate, allowing the test to be read.
The bile aesculin agar is streaked and incubated at 37 °C for 24 hours. The presence of a dark brown or black halo indicates that the test is positive. A positive test can occur with Enterococcus, Aerococcus and Leuconostoc. Aesculin will fluoresce under long wave ultraviolet light (360 nm): hydrolysis of aesculin results in loss of this fluorescence.
Enterococcus will often flag positive within four hours of the agar being inoculated.
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Warnings
Aesculin ingestion can produce stomachache, spasms, diarrhea, disorientation and even death at high doses.
Notes
References
- Plant poisons: Aesculin
- National Standard Methods MSOP 48 (Bile aesculin agar) and BSOPTP 2 (Aesculin hydrolysis test (UK)).
- C. Michael Hogan (2008) California Buckeye: Aesculus californica, GlobalTwitcher.com, N. Stromberg ed.