Ceftiofur

Ceftiofur is an antibiotic of the cephalosporin type (third generation), licensed for use in veterinary medicine. It was first described in 1987.^[3] It is marketed by pharmaceutical company Zoetis as Excenel,^[4] Naxcel, and Excede and is also the active ingredient in that company's Spectramast LC (lactating cow formulation) and Spectramast DC (dry cow formulation) product.^{[citation needed]}

Ceftiofur

Clinical data
Trade names	Naxcel
AHFS/Drugs.com	International Drug Names
ATCvet code	QJ01DD90 (WHO) QJ01DD99 (WHO), QJ51DD90 (WHO)
Legal status
Legal status	EU: Rx-only[1][2]
Identifiers
IUPAC name (6R,7R)-7-[ [(2Z)-2-(2-Amino-1,3-thiazol-4-yl)- 2-methoxyiminoacetyl]amino]-3-(furan-2- carbonylsulfanylmethyl)-8-oxo-5-thia-1- azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
CAS Number	80370-57-6 Y
PubChem CID	6328657
ChemSpider	4886668 Y
UNII	83JL932I1C
KEGG	D07657 Y
ChEMBL	ChEMBL222913 Y
CompTox Dashboard (EPA)	DTXSID7046702
Chemical and physical data
Formula	C19H17N5O7S3
Molar mass	523.55 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C2N1/C(=C(\CS[C@@H]1[C@@H]2NC(=O)C(=N\OC)/c3nc(sc3)N)CSC(=O)c4occc4)C(=O)O
InChI InChI=1S/C19H17N5O7S3/c1-30-23-11(9-7-34-19(20)21-9)14(25)22-12-15(26)24-13(17(27)28)8(5-32-16(12)24)6-33-18(29)10-3-2-4-31-10/h2-4,7,12,16H,5-6H2,1H3,(H2,20,21)(H,22,25)(H,27,28)/b23-11-/t12-,16-/m1/s1 Y Key:ZBHXIWJRIFEVQY-IHMPYVIRSA-N Y
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It is resistant to the antibiotic resistance enzyme beta-lactamase, and has activity against both Gram-positive and Gram-negative bacteria. Escherichia coli strains resistant to ceftiofur have been reported.^[5]

The metabolite desfuroylceftiofur also has antibiotic activity.^[6] The two compounds are measured together to measure for antibiotic activity in milk (alongside other antibiotics).^[7]