ALMECILLIN

US Previously Marketed

First approved in 1950

Details

Stereochemistry	ABSOLUTE
Molecular Formula	C13H18N2O4S2
Molecular Weight	330.423
Optical Activity	UNSPECIFIED
Defined Stereocenters	3 / 3
E/Z Centers	0
Charge	0

SHOW SMILES / InChI

Structure Search

SMILES

CC1(C)S[C@@H]2[C@H](NC(=O)CSCC=C)C(=O)N2[C@H]1C(O)=O

InChI

InChIKey=QULKGELYPOJSLP-WCABBAIRSA-N

InChI=1S/C13H18N2O4S2/c1-4-5-20-6-7(16)14-8-10(17)15-9(12(18)19)13(2,3)21-11(8)15/h4,8-9,11H,1,5-6H2,2-3H3,(H,14,16)(H,18,19)/t8-,9+,11-/m1/s1

HIDE SMILES / InChI

Molecular Formula	C13H18N2O4S2
Molecular Weight	330.423
Charge	0
Count

Stereochemistry	ABSOLUTE
Additional Stereochemistry	No
Defined Stereocenters	3 / 3
E/Z Centers	0
Optical Activity	UNSPECIFIED

Description
Sources: https://www.ncbi.nlm.nih.gov/pubmed/14856987 | https://www.ncbi.nlm.nih.gov/pubmed/15421819

ALMECILLIN (also known as penicillin O) is an antibiotic that can be safely substituted for penicillin G in instances of hypersensitivity reactions to the latter.

Approval Year

Conditions

Condition	Modality	Targets	Highest Phase	Product
Bacterial infection 6 Sources: https://www.ncbi.nlm.nih.gov/pubmed/15421819 https://www.ncbi.nlm.nih.gov/pubmed/14856987	Curative		Not Provided 511	Unknown Approved Use Unknown

Doses

Dose	Population	Adverse events
1000000 unit 1 times / day multiple, intramuscular Highest studied dose Dose: 1000000 unit, 1 times / day Route: intramuscular Route: multiple Dose: 1000000 unit, 1 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	unhealthy, 23 years Health Status: unhealthy Age Group: 23 years Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	Other AEs: Nausea, Increased salivation... Other AEs: Nausea (mild) Increased salivation Sources: https://pubmed.ncbi.nlm.nih.gov/13182618
600000 unit single, intramuscular Dose: 600000 unit Route: intramuscular Route: single Dose: 600000 unit Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	unhealthy, 23 years Health Status: unhealthy Age Group: 23 years Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	Disc. AE: Anaphylactic shock... AEs leading to discontinuation/dose reduction: Anaphylactic shock (severe) Sources: https://pubmed.ncbi.nlm.nih.gov/13182618

AEs

AE	Significance	Dose	Population
Increased salivation		1000000 unit 1 times / day multiple, intramuscular Highest studied dose Dose: 1000000 unit, 1 times / day Route: intramuscular Route: multiple Dose: 1000000 unit, 1 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	unhealthy, 23 years Health Status: unhealthy Age Group: 23 years Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/13182618
Nausea	mild	1000000 unit 1 times / day multiple, intramuscular Highest studied dose Dose: 1000000 unit, 1 times / day Route: intramuscular Route: multiple Dose: 1000000 unit, 1 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	unhealthy, 23 years Health Status: unhealthy Age Group: 23 years Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/13182618
Anaphylactic shock	severe Disc. AE	600000 unit single, intramuscular Dose: 600000 unit Route: intramuscular Route: single Dose: 600000 unit Sources: https://pubmed.ncbi.nlm.nih.gov/13182618	unhealthy, 23 years Health Status: unhealthy Age Group: 23 years Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/13182618

Sourcing

Vendor/Aggregator	ID	URL
ABI Chem	AC1L2G0T
Alfa Chemistry	87-09-2	https://www.alfa-chemistry.com/cas_87-09-2.htm
ChemMol	99171458	http://www.chemmol.com/chemmol/99171458.html
ChemTik	CTK3E8703
Compound Cloud	71365
eMolecules	260188440
NovoSeek	71365
ZINC	ZINC000004214768	http://zinc15.docking.org/substances/ZINC000004214768

PubMed

Title	Date	PubMed
Studies on the mechanism of the formation of the penicillin antigen. I. Delayed allergic cross-reactions among penicillin G and its degradation products.	1960-12-01	13761469
Some immunochemical properties of penicillenic acid. An antigenic determinant derived from penicillin.	1960-12-01	13720937
Clinical and pharmacologic studies with allylmercaptomethyl penicillin (penicillin O).	1951-08	14856987
Use of penicillin O in patients hypersensitive to pencilling G.	1950-07-01	15421819

Patents

Substance Class	Chemical Created by `admin` on `Mon Mar 31 18:07:36 GMT 2025` Edited by `admin` on `Mon Mar 31 18:07:36 GMT 2025`
Record UNII	6246WH0S1O
Record Status	`Validated (UNII)`
Record Version

Download

Name

Type

Language

ALMECILLIN

Official Name

English

PENICILLIN O

Preferred Name

English

ALLYLMERCAPTOMETHYLPENICILLIN

Common Name

English

((ALLYLTHIO)METHYL) PENICILLIN

Common Name

English

ALLYLMERCAPTOMETHYLPENICILLINIC ACID

Common Name

English

almecillin [INN]

Common Name

English

PENICILLIN AT

Common Name

English

3,3-DIMETHYL-7-OXO-6-(((2-PROPENYLTHIO)ACETYL)AMINO)-4-THIA-1-AZABICYCLO(3.2.0)HEPTANE-2-CARBOXYLIC ACID

Systematic Name

English

PENICILLIN O [MI]

Common Name

English

(2S,5R,6R)-3,3-DIMETHYL-7-OXO-6-(((2-PROPENYLTHIO)ACETYL)AMINO)-4-THIA-1-AZABICYCLO(3.2.0)HEPTANE-2-CARBOXYLIC ACID

Systematic Name

English

Classification Tree Code System Code

NCI_THESAURUS

C1500