Title: Erythromycin
CAS Registry Number: 114-07-8
Additional Names: E-Base; E-Mycin; Erythromycin A
Trademarks: Aknemycin (Hermal); Aknin (Lichtenstein); Emgel (GSK); Ery-Derm (Abbott); Erymax (Merz); Ery-Tab (Abbott); Erythromid (Abbott); ERYC (Warner-Chilcott); Erycen (APS); Erycin (Nycomed); Erycinum (Cytochemia); Ermysin (Orion); Gallimycin (Bimeda); Ilotycin (Lilly); Inderm (Dermapharm); PCE (Abbott); Retcin (DDSA); Staticin (Westwood); Stiemycin (Stiefel)
Molecular Formula: C37H67NO13
Molecular Weight: 733.93
Percent Composition: C 60.55%, H 9.20%, N 1.91%, O 28.34%
Literature References: Antibiotic substance produced by a strain of Streptomyces erythreus (Waksman) Waksman & Henrici, found in a soil sample from the Philippine Archipelago. Isoln: McGuire et al., Antibiot. Chemother. 2, 281 (1952); Bunch, McGuire, US 2653899 (1953 to Lilly); Clark, Jr., US 2823203 (1958 to Abbott). Properties: Flynn et al., J. Am. Chem. Soc. 76, 3121 (1954). Solubility data: Weiss et al., Antibiot. Chemother. 7, 374 (1957). Structure: Wiley et al., J. Am. Chem. Soc. 79, 6062 (1957). Configuration: Hofheinz, Grisebach, Ber. 96, 2867 (1963); Harris et al., Tetrahedron Lett. 1965, 679. There are three erythromycins produced during fermentation, designated A, B, and C; A is the major and most important component. Erythromycins A and B contain the same sugar moieties, desosamine, q.v., and cladinose (3-O-methylmycarose). They differ in position 12 of the aglycone, erythronolide, A having an hydroxyl substituent. Component C contains desosamine and the same aglycone present in A but differs by the presence of mycarose, q.v., instead of cladinose. Structure of B: P. F. Wiley et al., J. Am. Chem. Soc. 79, 6070 (1957); of C: eidem, ibid. 6074. Synthesis of the aglycone, erythronolide B: E. J. Corey et al., ibid. 100, 4618, 4620 (1978); of erythronolide A: eidem, ibid. 101, 7131 (1979). Asymmetric total synthesis of erythromycin A: R. B. Woodward et al., ibid. 103, 3215 (1981). NMR spectrum of A: D. J. Ager, C. K. Sood, Magn. Reson. Chem. 25, 948 (1987). HPLC determn in plasma: W. Xiao et al., J. Chromatogr. B 817, 153 (2005). Biosynthesis: Martin, Goldstein, Prog. Antimicrob. Anticancer Chemother., Proc. 6th Int. Congr. Chemother. II, 1112 (1970); Martin et al., Tetrahedron 31, 1985 (1975). Cloning and expression of clustered biosynthetic genes: R. Stanzak et al., Biotechnology 4, 229 (1986). Reviews: T. J. Perun in Drug Action and Drug Resistance in Bacteria 1, S. Mitsuhashi, Ed. (University Park Press, Baltimore, 1977) pp 123-152; Oleinick in Antibiotics vol. 3, J. W. Corcoran, F. E. Hahn, Eds. (Springer-Verlag, New York, 1975) pp 396-419; Infection 10, Suppl. 2, S61-S118 (1982). Comprehensive description: W. L. Koch, Anal. Profiles Drug Subs. 8, 159-177 (1979).
Properties: Hydrated crystals from water, mp 135-140°, resolidifies with second mp 190-193°. Melting point taken after drying at 56° and 8 mm. [a]D25 -78° (c = 1.99 in ethanol). uv max (pH 6.3): 280 nm (e 50). pKa1 8.8. Basic reaction. Readily forms salts with acids. Soly in water: ~2 mg/ml. Freely sol in alcohols, acetone, chloroform, acetonitrile, ethyl acetate. Moderately sol in ether, ethylene dichloride, amyl acetate.
Melting point: mp 135-140°, resolidifies with second mp 190-193°
pKa: pKa1 8.8
Optical Rotation: [a]D25 -78° (c = 1.99 in ethanol)
Absorption maximum: uv max (pH 6.3): 280 nm (e 50)
Derivative Type: Ethylsuccinate
CAS Registry Number: 41342-53-4
Trademarks: Anamycin (Chephasaar); Arpimycin (Rosemont); E.E.S. (Abbott); Eritrocina (Abbott); Eryliquid (Linden); Eryped (Abbott); Erythroped (Abbott); Esinol (Toyama); Monomycin (Grenthal); Paediathrocin (Abbott); Pediamycin (Abbott); Refkas (Maruko)
Molecular Formula: C43H75NO16
Molecular Weight: 862.05
Percent Composition: C 59.91%, H 8.77%, N 1.62%, O 29.70%
Literature References: Prepn: GB 830846; R. K. Clark, US 2967129 (1960, 1961 both to Abbott).
Properties: Hydrated crystals from acetone + water, mp 109-110°. [a]D -42.5°.
Melting point: mp 109-110°
Optical Rotation: [a]D -42.5°
Therap-Cat: Antibacterial.
Therap-Cat-Vet: Antibacterial.
Keywords: Antibacterial (Antibiotics); Macrolides.
Erythromycin Acistrate Erythromycin Estolate Erythromycin Glucoheptonate Erythromycin Lactobionate Erythromycin Propionate

Erythromycin A.svg
Erythromycin 3d structure.png
Systematic (IUPAC) name
Clinical data
Trade names E-mycin, Erythrocin
AHFS/ monograph
MedlinePlus a682381
Pregnancy cat. A (AU) B (US)
Legal status Prescription Only (S4) (AU) POM (UK) -only (US)
Routes oral, iv, im, topical, ophthalmic eye drops
Pharmacokinetic data
Bioavailability Depends on the ester type between 30% - 65%
Protein binding 90%
Metabolism liver (under 5% excreted unchanged)
Half-life 1.5 hours
Excretion bile
CAS number 114-07-8 YesY
ATC code D10AF02 J01FA01 S01AA17 QJ51FA01
PubChem CID 3255
IUPHAR ligand 1456
DrugBank DB00199
ChemSpider 12041 YesY
UNII 63937KV33D YesY
KEGG D00140 YesY
ChEBI CHEBI:42355 YesY
Chemical data
Formula C37H67NO13 
Mol. mass 733.93 g/mol
 YesY (what is this?)  (verify)

Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often prescribed for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including Mycoplasma and legionellosis. It was first marketed by Eli Lilly and Company, and it is today commonly known as EES (erythromycin ethylsuccinate, an ester prodrug that is commonly administered). It is also occasionally used as a prokinetic agent.

In structure, this macrocyclic compound contains a 14-membered lactone ring with ten asymmetric centers and two sugars (L-cladinose and D-desosamine), making it a compound very difficult to produce via synthetic methods.

Erythromycin is produced from a strain of the actinomycete Saccharopolyspora erythraea.