Erythromycin
Also called Robimycin, Ilotycin, Erythra-Derm and Emgel.
A macrolide antibiotic from a soil bacterium, the standard alternative for people allergic to penicillin.
Sources and notes
- The introductionfrom sourceMoleculeFinder curated
- Other namesfrom sourceWikidataIts English label and aliases on Wikidata.
- Formula and weightcomputedPubChem
- 2D drawingcomputedPubChem structure, drawn by RDKit
Where you encounter it
Dispensed on prescription, not sold on a shelf.
Sources and notes
- The line abovefrom sourceMoleculeFinder curatedFrom the group the molecule belongs to.
Explore its structure
Choose a part to light it up.
An ester closed into a ring: the C=O carbon and the oxygen beside it are both ring atoms. Like any ester, it can be split by water, which opens the ring.
From: standard chemistry.
A C=O with a carbon on each side. Its oxygen accepts hydrogen bonds but has no hydrogen to give, and it resists oxidation better than an aldehyde.
From: standard chemistry.
A nitrogen bonded to three carbons, with no hydrogen of its own. Its spare pair of electrons can still pick up a hydrogen ion, so a tertiary amine is a base.
From: standard chemistry.
Sources and notes
- The drawingcomputedPubChem structure, drawn by RDKitThe page's one shipped drawing, with the chosen part lit in amber under it.
- The partscomputedFound by ruleEach part is found by a chemical pattern, never picked by hand atom by atom; its words say where they come from.
Properties and sources
Calculated by PubChem
- Molecular formula
- C37H67NO13
- Molecular weight
- 733.9 g/mol
- XLogP3octanol/water, log units
- 2.7
- Polar surface areatopological
- 194 Ų
- H-bond donors
- 5
- H-bond acceptors
- 14
- Rotatable bonds
- 7
- Complexity
- 1180
Measured LD50, HSDB via PubChem
9,272 mg/kg pure erythromycin, rat, oral
An LD50 is an animal study measurement, not a dose for a person.
Reported Hazard label (GHS), ECHA via PubChem
Danger Irritant pictogram (GHS07), Health hazard pictogram (GHS08) and Environmental pictogram (GHS09); hazard statements H317, H319, H334, H400, H410
Reported Licence
The US Food and Drug Administration licenses Erythromycin for human use (NDA 050536, authorized January 26, 1981). Drugs@FDA
Groups it belongs to
- Category
- Prescription medicine
- Family
- Antibiotics
- Elements
- Nitrogen
- Hazard classes
- Irritant, Health hazard, Environmental hazard, GHS Danger
CC[C@@H]1[C@@]([C@@H]([C@H](C(=O)[C@@H](C[C@@]([…180 charactersPubChem CID 12560 · Wikidata Q213511 · InChIKey ULGZDMOVFRHVEP-RWJQBGPGSA-N · Data refreshed
Questions
- What is Erythromycin?
- A macrolide antibiotic from a soil bacterium, the standard alternative for people allergic to penicillin.
- How toxic is Erythromycin?
- The reported LD50 of Erythromycin is 9,272 mg/kg (rat, oral). An LD50 is an animal study measurement, not a dose for a person. Its GHS hazard label carries the signal word Danger and the hazard pictograms Irritant, Health hazard and Environmental. from sourcefrom source
- What kind of molecule is Erythromycin?
- Erythromycin has the formula C37H67NO13 and a molecular weight of 733.9 g/mol. MoleculeFinder files it under antibiotics, in the prescription medicine group. from sourcefrom sourcefrom sourcefrom source
- What else is Erythromycin called?
- Erythromycin is also called Robimycin, Ilotycin, Erythra-Derm and Emgel. from source
- Who licenses Erythromycin as a medicine?
- The US Food and Drug Administration licenses Erythromycin for human use (NDA 050536, authorized January 26, 1981). from source
Sources and notes
- Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
- LD50from sourceHSDB via PubChemOther values the sources report: mouse, another route, 426 mg/kg; mouse, another route, 463 mg/kg; mouse, another route, 1,800 mg/kg. The page shows the one LD50 the site uses everywhere.
- Hazard labelfrom sourceECHA via PubChemThe label combines these classifications.
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Licencefrom sourceDrugs@FDARead 2026-10-21.
- Data refreshedfrom sourceMoleculeFinder2026-11-09
Keep exploring
Sources and notes
- The same kind of moleculefrom sourceMoleculeFinder curated groupsA structural neighbour in the same family or type group; the line names the group in its own words.
- The drawingscomputedPubChem structures, drawn by RDKit