Pharmaceutical impurity

Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines)

Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines) is listed in the pharmaceutical impurity collection under CAS 94659-47-9. Its represented structure has formula C16H19N3O5S and a calculated molecular weight of 365.41 g/mol.

2D chemical structure

Chemical identity

Catalog name: Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines)
Common name: Amoxicillin Trihydrate Imp. C (EP)
Chemical name: (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines)
CAS: 94659-47-9
SMILES: CC1(C)SC(C2NC(=O)C(c3ccc(O)cc3)NC2=O)N[C@H]1C(=O)O
InChI: InChI=1S/C16H19N3O5S/c1-16(2)11(15(23)24)19-14(25-16)10-13(22)17-9(12(21)18-10)7-3-5-8(20)6-4-7/h3-6,9-11,14,19-20H,1-2H3,(H,17,22)(H,18,21)(H,23,24)/t9?,10?,11-,14?/m0/s1
InChIKey: IIZCCQJEPBWGJU-DGVZPSOQSA-N
Associated API: Amoxicillin Trihydrate

Record ID: A7d21ae2f981a

Computed properties

C16H19N3O5S Molecular formula

365.411 g/molMolecular weight

365.1045 DaMonoisotopic exact mass

127.76 Å²Topological polar surface area

-0.0578 Calculated LogP (Wildman–Crippen)

90.9387 cm³/molMolar refractivity (Wildman–Crippen)

6 countHydrogen-bond acceptors

5 countHydrogen-bond donors

Descriptors are calculated from the displayed SMILES. Calculated LogP is not a measured partition coefficient or a pH-specific LogD. 3 potential atom stereocenters have unspecified configuration.

Molecular descriptor profile

Descriptor radar

Structural feature counts

Element composition

Radar scale: 0–100 percentile within 25,771 distinct represented structures in this release, using the midpoint rank for ties. Larger values indicate a higher descriptor rank, not greater safety or toxicity. Element counts include hydrogen and combine isotopes under each element.

Radar values and percentile reference

Descriptor	Value	Percentile
Molecular weight	365.411	61.49
Calculated LogP (Wildman–Crippen)	-0.0578	13.55
Topological polar surface area	127.76	84.18
Hydrogen-bond acceptors	6	75.83
Hydrogen-bond donors	5	94.13
Rotatable bonds (strict)	3	37.08

Complete molecular descriptors

Property	Calculated value	Unit / type
Molecular formula	C16H19N3O5S	dimensionless
Molecular weight	365.411	g/mol
Monoisotopic exact mass	365.1045	Da
Topological polar surface area	127.76	Å²
Calculated LogP (Wildman–Crippen)	-0.0578	dimensionless
Molar refractivity (Wildman–Crippen)	90.9387	cm³/mol
Hydrogen-bond acceptors	6	count
Hydrogen-bond donors	5	count
Rotatable bonds (strict)	3	count
Heavy atoms	25	count
Heteroatoms	9	count
Rings	3	count
Aromatic rings	1	count
Aliphatic rings	2	count
Saturated rings	2	count
Aromatic heterocycles	0	count
Aliphatic heterocycles	2	count
Saturated heterocycles	2	count
Aromatic carbocycles	1	count
Aliphatic carbocycles	0	count
Fraction of sp³ carbon atoms	0.4375	fraction
Formal charge	0	e
Disconnected components	1	count
Isotopically specified atoms	0	count
Potential atom stereocenters	4	count
Unspecified atom stereocenters	3	count
Spiro atoms	0	count
Bridgehead atoms	0	count
Labute approximate surface area	147.9149	Å²
Valence electrons	134	count
Radical electrons	0	count
Bertz complexity	720.9853	index
Balaban J	1.7492	index

Ring categories overlap and should not be summed. No toxicity result, PDE, HBEL or acceptable intake is inferred from these descriptors.

Toxicological services and resources for Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines)

Qualification and safety assessment of Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines)

Explore toxicological qualification of Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines) and ICH M7 mutagenic impurity assessment of Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines) for evaluation of this impurity in its pharmaceutical context.

Where data gaps need to be addressed, resources include read-across assessment for Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines) and acceptable intake and limit justification for Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines). The relevant approach depends on the available evidence, exposure and duration of use.

Related Altox services and technical resources

Other catalogue designations with the same represented structure

These are separate catalogue entries; shared structure does not establish interchangeable pharmacopoeial designations.

Identity sources and calculation method

Identifiers originate from the source catalogues and available public identity records. InChI and InChIKey on this page are generated from the displayed SMILES. RDKit validation checks the molecular representation; it does not independently verify every catalogue assignment.

Discuss an assessment for Amoxicillin Trihydrate Imp. C (EP): (4S)-2-[5-(4-Hydroxyphenyl)- 3,6-dioxopiperazin-2-yl]-5,5-dimethyl- thiazolidine-4-carboxylic Acid (Amoxicillin Diketopiperazines)

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