Aesculin Identifiers CAS number PubChem ChemSpider UNII ChEMBL Jmol-3D images Image 1 Properties Molecular formula C15H16O9 Molar mass 340.282 g/mol Exact mass 340.079432 (what is: /?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Aesculin, also rendered Æsculin or Esculin, is a glucoside that naturally occurs in the horse chestnut (Aesculus hippocastanum), California Buckeye (Aesculus californica) and in daphnin (the dark green resin of Daphne mezereum).
Aesculin is 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). 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.
- 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.
Bond Geometry Glycone Aglycone Aglycones glycosidesAesculin | Skimmin (7-O-β-D-glucopyranosylumbelliferone) | Scopolin Furan derivatives Monoterpene coumarin ether Synthetic or drugs
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