Database / API & reference standards
API & reference standardsPhenolphthalein
Phenolphthalein is listed in the API and reference-standard collection under CAS 77-09-8. Its represented structure has formula C20H14O4 and a calculated molecular weight of 318.33 g/mol.
2D chemical structure
Chemical identity
- Catalog name
- Phenolphthalein
- Common name
- Phenolphthalein
- Chemical name
- 3,3-bis(4-hydroxyphenyl)-2-benzofuran-1-one
- CAS
- 77-09-8
- SMILES
- O=C1OC(c2ccc(O)cc2)(c2ccc(O)cc2)c2ccccc21
- InChI
- InChI=1S/C20H14O4/c21-15-9-5-13(6-10-15)20(14-7-11-16(22)12-8-14)18-4-2-1-3-17(18)19(23)24-20/h1-12,21-22H
- InChIKey
- KJFMBFZCATUALV-UHFFFAOYSA-N
- Associated API
- Phenolphthalein
Record ID: Ae04ff1a9b3d5
Computed properties
C20H14O4 Molecular formula
318.328 g/molMolecular weight
318.0892 DaMonoisotopic exact mass
66.76 ŲTopological polar surface area
3.5601 Calculated LogP (Wildman–Crippen)
87.9531 cm³/molMolar refractivity (Wildman–Crippen)
4 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
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 | 318.328 | 49.69 |
| Calculated LogP (Wildman–Crippen) | 3.5601 | 71.79 |
| Topological polar surface area | 66.76 | 47.12 |
| Hydrogen-bond acceptors | 4 | 50.68 |
| Hydrogen-bond donors | 2 | 64.87 |
| Rotatable bonds (strict) | 2 | 24.16 |
Complete molecular descriptors
| Property | Calculated value | Unit / type |
|---|---|---|
| Molecular formula | C20H14O4 | dimensionless |
| Molecular weight | 318.328 | g/mol |
| Monoisotopic exact mass | 318.0892 | Da |
| Topological polar surface area | 66.76 | Ų |
| Calculated LogP (Wildman–Crippen) | 3.5601 | dimensionless |
| Molar refractivity (Wildman–Crippen) | 87.9531 | cm³/mol |
| Hydrogen-bond acceptors | 4 | count |
| Hydrogen-bond donors | 2 | count |
| Rotatable bonds (strict) | 2 | count |
| Heavy atoms | 24 | count |
| Heteroatoms | 4 | count |
| Rings | 4 | count |
| Aromatic rings | 3 | count |
| Aliphatic rings | 1 | count |
| Saturated rings | 0 | count |
| Aromatic heterocycles | 0 | count |
| Aliphatic heterocycles | 1 | count |
| Saturated heterocycles | 0 | count |
| Aromatic carbocycles | 3 | count |
| Aliphatic carbocycles | 0 | count |
| Fraction of sp³ carbon atoms | 0.05 | fraction |
| Formal charge | 0 | e |
| Disconnected components | 1 | count |
| Isotopically specified atoms | 0 | count |
| Potential atom stereocenters | 0 | count |
| Unspecified atom stereocenters | 0 | count |
| Spiro atoms | 0 | count |
| Bridgehead atoms | 0 | count |
| Labute approximate surface area | 138.1332 | Ų |
| Valence electrons | 118 | count |
| Radical electrons | 0 | count |
| Bertz complexity | 865.6287 | index |
| Balaban J | 2.0303 | 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 Phenolphthalein
PDE, HBEL and impurity assessment for Phenolphthalein
For a substance-specific assessment, request a PDE report for Phenolphthalein or explore HBEL derivation for Phenolphthalein. These services address exposure limits using toxicological evidence and the intended use of the substance.
For pharmaceutical development, explore prediction of degradation products of Phenolphthalein and qualification of impurities related to Phenolphthalein.
Related Altox services and technical resources
- PDE calculation
- PDE report
- PDE assessment
- PDE derivation
- Permitted daily exposure
- HBEL value
- ADE value
- Prediction of degradation products and degradation pathways
- Ames prediction and ICH M7 assessment
- Genotoxic impurity assessment
- Mutagenic impurity assessment
- QSAR mutagenicity
- Non-mutagenic impurities assessment
- Qualification of impurities and degradation products
- Read-across
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.
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