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Pharmaceutical impurity

Didanosine impurity A,

Didanosine impurity A, is listed in the pharmaceutical impurity collection under CAS 68-94-0. Its represented structure has formula C5H4N4O and a calculated molecular weight of 136.11 g/mol.

2D chemical structure

O H N N N N H

Chemical identity

Catalog name
Didanosine impurity A,
Common name
Didanosine impurity A,
Chemical name
Not available
CAS
68-94-0
SMILES
O=c1[nH]cnc2nc[nH]c12
InChI
InChI=1S/C5H4N4O/c10-5-3-4(7-1-6-3)8-2-9-5/h1-2H,(H2,6,7,8,9,10)
InChIKey
FDGQSTZJBFJUBT-UHFFFAOYSA-N
Associated API
didanosine | Didanosine

Record ID: Ac1b3836276d4

Computed properties

C5H4N4O Molecular formula
136.114 g/molMolecular weight
136.0385 DaMonoisotopic exact mass
74.43 ŲTopological polar surface area
-0.3538 Calculated LogP (Wildman–Crippen)
34.5094 cm³/molMolar refractivity (Wildman–Crippen)
3 countHydrogen-bond acceptors
2 countHydrogen-bond donors

Descriptors are calculated from the displayed SMILES. Calculated LogP is not a measured partition coefficient or a pH-specific LogD.

Molecular descriptor profile

Descriptor radar

Mol. weight LogP TPSA HBA HBD Rotatable 25 50 75 100

Structural feature counts

0 1 2 3 Count H-bond acceptors H-bond donors Rotatable bonds Rings Aromatic rings Stereo centers

Element composition

C H N O 0 2 4 Number of atoms

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
DescriptorValuePercentile
Molecular weight136.1143.78
Calculated LogP (Wildman–Crippen)-0.353811.35
Topological polar surface area74.4353.13
Hydrogen-bond acceptors333.13
Hydrogen-bond donors264.87
Rotatable bonds (strict)03.45

Complete molecular descriptors

PropertyCalculated valueUnit / type
Molecular formulaC5H4N4Odimensionless
Molecular weight136.114g/mol
Monoisotopic exact mass136.0385Da
Topological polar surface area74.43Ų
Calculated LogP (Wildman–Crippen)-0.3538dimensionless
Molar refractivity (Wildman–Crippen)34.5094cm³/mol
Hydrogen-bond acceptors3count
Hydrogen-bond donors2count
Rotatable bonds (strict)0count
Heavy atoms10count
Heteroatoms5count
Rings2count
Aromatic rings2count
Aliphatic rings0count
Saturated rings0count
Aromatic heterocycles2count
Aliphatic heterocycles0count
Saturated heterocycles0count
Aromatic carbocycles0count
Aliphatic carbocycles0count
Fraction of sp³ carbon atoms0fraction
Formal charge0e
Disconnected components1count
Isotopically specified atoms0count
Potential atom stereocenters0count
Unspecified atom stereocenters0count
Spiro atoms0count
Bridgehead atoms0count
Labute approximate surface area55.1427Ų
Valence electrons50count
Radical electrons0count
Bertz complexity400.9402index
Balaban J3.0929index

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 Didanosine impurity A,

Qualification and safety assessment of Didanosine impurity A,

Explore toxicological qualification of Didanosine impurity A, and ICH M7 mutagenic impurity assessment of Didanosine impurity A, for evaluation of this impurity in its pharmaceutical context.

Where data gaps need to be addressed, resources include read-across assessment for Didanosine impurity A, and acceptable intake and limit justification for Didanosine impurity A,. 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 Didanosine impurity A,

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