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Aesculin

Names
IUPAC name 6-(β-D-Glucopyranosyloxy)-7-hydroxy-2H-1-benzopyran-2-one
Systematic IUPAC name 7-Hydroxy-6-{oxy}-2H-1-benzopyran-2-one
Other names Æsculin Esculin Esculetin 6-β-D-glucoside 6,7-Dihydroxycoumarin 6-β-D-glucoside 6,7-Dihydroxychromen-2-one 6-β-D-glucoside
Identifiers
CAS Number	531-75-9
3D model (JSmol)	Interactive image
ChEBI	CHEBI:4853
ChEMBL	ChEMBL482581
ChemSpider	4444765
DrugBank	DB13155
ECHA InfoCard	100.007.744
EC Number	208-517-5
KEGG	C09264
PubChem CID	5281417
UNII	1Y1L18LQAF
CompTox Dashboard (EPA)	DTXSID7045318
InChI InChI=1S/C15H16O9/c16-5-10-12(19)13(20)14(21)15(24-10)23-9-3-6-1-2-11(18)22-8(6)4-7(9)17/h1-4,10,12-17,19-21H,5H2/t10-,12-,13+,14-,15-/m1/s1Key: XHCADAYNFIFUHF-TVKJYDDYSA-N InChI=1/C15H16O9/c16-5-10-12(19)13(20)14(21)15(24-10)23-9-3-6-1-2-11(18)22-8(6)4-7(9)17/h1-4,10,12-17,19-21H,5H2/t10-,12-,13+,14-,15-/m1/s1Key: XHCADAYNFIFUHF-TVKJYDDYBL
SMILES O=C/3Oc2c(cc(O1O((O)(O)1O)CO)c(O)c2)\C=C\3
Properties
Chemical formula	C15H16O9
Molar mass	340.282 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Y verify (what is  ?) Infobox references

Aesculin, also called æsculin or esculin, is a coumarin glucoside that naturally occurs in the trees horse chestnut (Aesculus hippocastanum), California buckeye (Aesculus californica), prickly box (Bursaria spinosa), and daphnin (the dark green resin of Daphne mezereum). It is also found in dandelion coffee and olive bark. It is reported to present in olive bark, not in olive leaf, therefore, identification of aesculin (coumarin derivative) in abundance in an 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 æsculin in 40% bile.

Aesculin hydrolysis test

Aesculin is incorporated into agar with ferric citrate and bile salts (bile aesculin agar). Hydrolysis of aesculin forms aesculetin (6,7-dihydroxycoumarin) and glucose. 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 (99 °F) 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) and hydrolysis of aesculin results in loss of this fluorescence.

Enterococcus will often flag positive within four hours of the agar being inoculated.

References

1. "Plant poisons: Aesculin". University of Bristol. Retrieved July 17, 2018.
2. C. Michael Hogan (2008) California Buckeye: Aesculus californica, GlobalTwitcher.com, N. Stromberg ed.
3. ^ Lo Giudice, V.; Faraone, I.; Bruno, M. R.; Ponticelli, M.; Labanca, F.; Bisaccia, D.; Massarelli, C.; Milella, L.; Todaro, L. (2021). "Olive Trees By-Products as Sources of Bioactive and Other Industrially Useful Compounds: A Systematic Review". Molecules (Basel, Switzerland). 26 (16): 5081. doi:10.3390/molecules26165081. PMC 8399450. PMID 34443669.
4. Hussain Qadri, S. M.; Smith, Janet C.; Zubairi, Sabiha; Desilva, M. I. (1981). "Esculin hydrolysis by gram positive bacteria". Medical Microbiology and Immunology. 169 (2): 67–74. doi:10.1007/BF02171773. PMID 6783825. S2CID 21361418.
5. National Standard Methods MSOP 48 (Bile aesculin agar) and BSOPTP 2 (Aesculin hydrolysis test (UK))

• Coumarin glycosides
• Microbiological media ingredients