Santin (22-10-6) Physical and Chemical Properties
Santin
O‑methylated flavone supplied as a crystalline research-grade material used in analytical development, natural‑products R&D and QC workflows.
| CAS Number | 22-10-6 |
| Family | Flavonoids (flavone) |
| Typical Form | Powder or crystalline solid |
| Common Grades | EP |
Santin is a polyphenolic flavone belonging to the flavonoid structural class; specifically it is a trimethoxy‑ and dihydroxy‑substituted 2‑phenylchromen‑4‑one. The molecule features a conjugated chromenone (flavone) core bearing hydroxy substituents at the 5 and 7 positions and methoxy substituents at the 3, 6 and 4' positions, giving the IUPAC description 5,7-dihydroxy-3,6-dimethoxy-2-(4-methoxyphenyl)chromen-4-one. The conjugated π system across the benzopyranone and the pendant phenyl ring imparts planarity to the scaffold and contributes to characteristic UV/visible absorbance and redox behavior typical of flavones.
Electronically, the aromatic and carbonyl conjugation together with phenolic OH groups produce localized sites for hydrogen bonding and metal coordination; the 5‑OH is typically involved in intramolecular hydrogen bonding to the 4‑carbonyl in flavones, which modulates acidity and reduces the free phenolic reactivity relative to non‑conjugated phenols. The multiple methoxy substituents increase electron density on the ring system and raise lipophilicity relative to unsubstituted or hydroxylated analogs, while the remaining polar functionalities (two OH groups and multiple ether oxygens) create moderate overall polarity and hydrogen‑bonding capacity.
In practical terms, Santin behaves as a moderately lipophilic natural product: it is expected to have limited water solubility, appreciable solubility in polar organic solvents (methanol, ethanol, acetone, dimethyl sulfoxide), and moderate membrane affinity. The phenolic hydroxyls confer weak acidity and make the molecule susceptible to phase II biotransformations (conjugation, O‑methylation/demethylation) and to oxidative metabolism; chemical hydrolysis under strongly basic or nucleophilic conditions can lead to ring opening or dealkylation of aryl methyl ethers but the flavone core is generally stable to neutral aqueous media. Santin is encountered primarily as a plant metabolite and is of interest in phytochemical, natural‑product and bioactivity screening contexts.
Common commercial grades reported for this substance include: EP.
Basic Physical Properties
Density
No experimentally established value for this property is available in the current data context.
Melting Point
No experimentally established value for this property is available in the current data context.
Boiling Point
No experimentally established value for this property is available in the current data context.
Vapor Pressure
No experimentally established value for this property is available in the current data context.
Flash Point
No experimentally established value for this property is available in the current data context.
Chemical Properties
Solubility and Phase Behavior
Computed and structural descriptors indicate moderate lipophilicity (XLogP3 = 3.1) combined with a substantial polar surface (topological polar surface area = 94.5 \(\text{Å}^2\)) and two hydrogen‑bond donors plus seven acceptors. This balance predicts poor to low aqueous solubility and reasonable solubility in polar organic solvents such as methanol, ethanol and dimethyl sulfoxide. The molecule’s planarity and aromatic surface area favor π–π interactions and may promote aggregation or strong adsorption to hydrophobic surfaces in mixed solvent systems. Phase behavior in formulations will therefore depend strongly on solvent polarity, pH (affecting phenolic dissociation), and presence of solubilizing excipients.
Reactivity and Stability
Santin’s chemical reactivity is dominated by the conjugated flavone core and the two phenolic hydroxyl groups. The 5‑OH commonly forms an intramolecular hydrogen bond with the 4‑carbonyl, lowering its effective acidity and reducing its nucleophilicity relative to free phenols. O‑Demethylation (cleavage of aryl methyl ethers) and oxidative transformations are plausible under strongly oxidative, enzymatic or demethylating conditions; the methoxy groups provide some steric shielding that can reduce facile electrophilic substitution. Under mild, neutral aqueous conditions the chromenone framework is comparatively stable; however, strong bases, nucleophiles or prolonged exposure to oxidants or light can induce degradation pathways (dealkylation, ring cleavage, oxidation). For synthetic handling, standard precautions for phenolic and aromatic ether compounds apply.
Thermodynamic Data
Standard Enthalpies and Heat Capacity
No experimentally established value for this property is available in the current data context.
Molecular Parameters
Molecular Weight and Formula
- Molecular formula: C18H16O7
- Molecular weight: 344.3 \(\mathrm{g}\,\mathrm{mol}^{-1}\)
- Exact mass: 344.08960285
- Monoisotopic mass: 344.08960285
These values reflect a polyoxygenated aromatic scaffold with 25 heavy atoms and a formal charge of 0; the structural complexity is substantial for a small natural product (computed complexity = 524).
LogP and Polarity
- XLogP3 (computed): 3.1
- Topological polar surface area (TPSA): 94.5 \(\text{Å}^2\)
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 7
- Rotatable bond count: 4
The computed XLogP3 of 3.1 indicates moderate lipophilicity consistent with limited aqueous solubility; the TPSA and hydrogen‑bonding counts indicate sufficient polarity and H‑bond capability to affect absorption, solvation and formulation behaviour.
Structural Features
Santin is a flavone (2‑phenylchromen‑4‑one) with substitution pattern 5,7‑dihydroxy‑3,6,4'‑trimethoxy. The planar conjugated chromenone ring system and the attached para‑methoxy phenyl ring provide an extended π system responsible for characteristic UV absorbance and redox properties. Intramolecular hydrogen bonding (notably between the 5‑OH and the 4‑carbonyl) is structurally important and influences acidity and solvation. The methoxy substituents increase steric bulk and electron density on the aromatic rings, reducing the propensity for electrophilic attack at those positions and modifying metabolic O‑demethylation pathways in biological systems. The limited number of rotatable bonds (4) implies constrained conformational flexibility relative to aliphatic molecules.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS: 22-10-6
- InChIKey: DWZAJFZEYZIHPO-UHFFFAOYSA-N
- InChI: InChI=1S/C18H16O7/c1-22-10-6-4-9(5-7-10)16-18(24-3)15(21)13-12(25-16)8-11(19)17(23-2)14(13)20/h4-8,19-20H,1-3H3
- SMILES: COC1=CC=C(C=C1)C2=C(C(=O)C3=C(O2)C=C(C(=C3O)OC)O)OC
- CID: 5281695
- UNII: 5785Y952EH
- ChEBI: CHEBI:9024
- ChEMBL: CHEMBL161957
- KEGG: C10180
- DSSTox: DTXSID10182109
- LipidMaps ID: LMPK12112861
- Metabolomics Workbench ID: 25944
Synonyms and Structural Names
Common synonyms and systematic names reported for this structure include: Santin; 5,7-dihydroxy-3,6,4'-trimethoxyflavone; 5,7-dihydroxy-3,6-dimethoxy-2-(4-methoxyphenyl)chromen-4-one; 5,7-dihydroxy-3,6-dimethoxy-2-(4-methoxy-phenyl)-4H-1-benzopyran-4-one; CENTAURIDIN; 3‑METHYLBETULETOL. The IUPAC/systematic names above reflect the same substitution pattern on the flavone scaffold.
Industrial and Commercial Applications
Representative Uses and Industry Sectors
Santin is primarily encountered as a plant metabolite and phytochemical constituent reported from species such as Artemisia and Tanacetum. Its principal relevance is in natural‑product chemistry, phytochemistry, metabolomics and screening for biological activity. There is no concise industrial commodity use listed in the current data context; in practice, this substance is most often handled as a research chemical or analytical reference standard due to its occurrence in botanical extracts and interest in flavonoid bioactivity.
Role in Synthesis or Formulations
No concise application summary is available in the current data context; in practice flavones such as Santin are selected as lead compounds, reference materials, or starting scaffolds in medicinal chemistry and natural‑product studies. Their use in formulations is typically limited to research and development contexts rather than large‑scale commodity applications.
Safety and Handling Overview
Acute and Occupational Toxicity
No quantitative toxicity endpoints (LD50, chronic toxicity values) are available in the current data context. As a polyphenolic aromatic compound, Santin should be handled under standard laboratory safety precautions: avoid inhalation of dust or aerosols, prevent skin and eye contact, and use appropriate personal protective equipment (gloves, eye protection, lab coat). Phenolic compounds can cause skin or eye irritation in some individuals and may be bioactive; workplace exposures should be controlled by engineering measures and good laboratory practices.
Storage and Handling Considerations
Store in a cool, dry, well‑ventilated area, in a tightly closed container protected from light to limit photodegradation. Avoid exposure to strong oxidizing agents and strong bases that can promote demethylation or decomposition. For transport, disposal and regulatory compliance, consult the product‑specific Safety Data Sheet (SDS) and applicable local legislation for hazard classification, packaging and handling requirements.
