6-Hydroxycyanidin , CAS No.42529-06-6

CAS: 42529-06-6 Cat. No.: H1029946 Summenformel: C₁₅H₁₁O₇⁺ Molekulargewicht: 303.240

Storage

Room temperature

Specifications

Storage

Room temperature

Namen und Kennungen

• Kanonisches Lächeln: C1=CC(=C(C=C1C2=C(C=C3C(=[O+]2)C=C(C(=C3O)O)O)O)O)O
• IUPAC Name: 2-(3,4-dihydroxyphenyl)chromenylium-3,5,6,7-tetrol
• InChIKey: PWDAKBACEAGRSH-UHFFFAOYSA-O
• INCHI: 1S/C15H10O7/c16-8-2-1-6(3-9(8)17)15-11(19)4-7-12(22-15)5-10(18)14(21)13(7)20/h1-5H,(H5-,16,17,18,19,20,21)/p+1
• Molekulargewicht: 303.240

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Phenylpropanoids and polyketides
    • Klasse Flavonoids
      • Subclass Hydroxyflavonoids

• Kingdom: Organic compounds
• Superclass: Phenylpropanoids and polyketides
• Klasse: Flavonoids
• Subclass: Hydroxyflavonoids
• Intermediate Tree Nodes: Not available
• Direct Parent: 7-hydroxyflavonoids
• Alternative Parents: 3'-hydroxyflavonoids 3-hydroxyflavonoids 4'-hydroxyflavonoids 5-hydroxyflavonoids 6-hydroxyflavonoids Anthocyanidins 1-benzopyrans Catechols 1-hydroxy-4-unsubstituted benzenoids 1-hydroxy-2-unsubstituted benzenoids Benzene and substituted derivatives Heteroaromatic compounds Oxacyclic compounds Polyols Hydrocarbon derivatives Organic cations
• Molecular Framework: Aromatic heteropolycyclic compounds
• Substituents: 3'-hydroxyflavonoid - 3-hydroxyflavonoid - 4'-hydroxyflavonoid - 5-hydroxyflavonoid - 6-hydroxyflavonoid - 7-hydroxyflavonoid - Anthocyanidin - Benzopyran - 1-benzopyran - Catechol - 1-hydroxy-4-unsubstituted benzenoid - 1-hydroxy-2-unsubstituted benzenoid - Phenol - Benzenoid - Monocyclic benzene moiety - Heteroaromatic compound - Organoheterocyclic compound - Oxacycle - Polyol - Hydrocarbon derivative - Organooxygen compound - Organic oxygen compound - Organic cation - Aromatic heteropolycyclic compound
• Beschreibung: This compound belongs to the class of organic compounds known as 7-hydroxyflavonoids. These are flavonoids that bear one hydroxyl group at the C-7 position of the flavonoid skeleton.
• External Descriptors: Anthocyanidins

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Chemische und physikalische Eigenschaften

• Molekulargewicht: 303.240 g/mol
• Hydrogen Bond Donor Count: 6
• Hydrogen Bond Acceptor Count: 6
• Rotatable Bond Count: 1
• Exact Mass: 303.05 Da
• Monoisotopic Mass: 303.05 Da
• Topological Polar Surface Area: 122.000 Ų
• Heavy Atom Count: 22
• Formal Charge: 1
• Complexity: 392.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

XLogP3

Application Protocols

• No vendor-validated bioassay or immunoassay protocols are specified for this item. For general analytical use, consider:
  • Preparation of acidified stock solutions (e.g., 1–10 mM in 0.1–1% HCl in ethanol or methanol) and dilution into acidified buffers for UV–vis or HPLC.
  • For pH-dependent spectral studies, equilibrate samples for a fixed time at each pH, protect from light, and record spectra promptly.
  • For antioxidant assays (e.g., DPPH, ABTS), standardize solvent, pH, and path length; include appropriate blanks due to intense coloration.
• Always adapt to your laboratory’s SOPs and consult the primary literature for method-specific details.

Biological Roles

• Literature/general context (no clinical claims):
  • Anthocyanidins are plant-derived pigments responsible for red/purple/blue hues in many tissues. 6-Hydroxycyanidin is a cyanidin analog with an added A-ring hydroxyl at C6, which can influence intramolecular hydrogen bonding, copigmentation, and color stability.
  • Acts as a polyphenolic antioxidant in chemical assays, capable of donating hydrogen atoms/electrons from phenolic OH groups and stabilizing resulting radicals via resonance, particularly across the catechol B-ring.
  • Engages in noncovalent interactions with proteins, polysaccharides, and membranes; association is pH-dependent and can alter color and apparent stability.
  • Forms complexes with metal ions (e.g., Al3+, Fe3+), which can shift absorbance and hue; such interactions model plant vacuolar pigment–metal systems.

Buffer Applications

• This compound is not a buffer reagent. However, its behavior is highly pH-dependent, so buffer choice is critical for analytical work (literature/general):
  • To stabilize the red flavylium cation, use strong acid media or buffers at pH ≤ 2–3 (e.g., HCl–KCl, glycine–HCl).
  • For studying equilibria across pH: employ citrate (pH ~3–6), acetate (pH ~3.6–5.6), and phosphate (pH ≥ 6) buffers in matched ionic strength; record spectra promptly to capture transient species.
  • Avoid basic buffers for storage; they promote chalcone formation and bleaching. Incorporate inert atmosphere and amberware to mitigate oxidation/light degradation.

Green Alternatives

• Greener media (literature/general):
  • Prefer ethanol–water mixtures over methanol when feasible; acidify lightly (e.g., food-safe acids) to stabilize the flavylium form.
  • Consider glycerol–water or deep eutectic solvents (e.g., choline chloride–organic acid systems) for extraction and spectroscopy when aligned with experimental goals; these can reduce VOC emissions and improve safety.
• Comparative notes (literature/general):
  • Methanol vs ethanol: Methanol offers higher solubility and narrower spectral bands but is more toxic. Ethanol provides a safer, more sustainable option at slight cost to solvating power.
  • Aqueous buffered systems: Using minimal organic cosolvent at controlled low pH can substantially reduce solvent footprint while preserving spectral stability.
• Process considerations:
  • Lower temperatures, exclusion of oxygen, and light shielding can reduce the need for excess stabilizers or antioxidants in solution, further improving environmental and worker safety profiles.

Pharmaceutical Uses

• No pharmacopeial status or excipient grade is specified for this item; refer to CoA/Spec Sheet.
• Literature/general context:
  • Anthocyanins (glycosides of anthocyanidins) are used as natural colorants; aglycones like 6-hydroxycyanidin are research tools for pigment chemistry rather than typical excipients.
  • If considered for formulation research (e.g., color stability studies), maintain acidic microenvironments and limit oxygen/light. Validate compatibility with excipients (polymers, sugars, metals) due to possible complexation and color shifts.
  • For analytical method development (e.g., QC of botanical materials), it can serve as a reference standard in HPLC/UV–vis workflows under acidified mobile phases.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• Melting point, boiling point, density, refractive index: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (literature/general for anthocyanidins):
  • Readily soluble in polar protic organic solvents (MeOH, EtOH) and in water under acidic conditions (typically pH < 3), where the flavylium cation predominates.
  • Limited solubility in neutral/basic aqueous media due to conversion to hemiketal/chalcone and potential aggregation/precipitation.
  • Poorly soluble in nonpolar solvents.
• Spectral behavior (literature/general): Strong visible absorption in the green region for the red-colored flavylium form; λmax and extinction depend sensitively on pH, substitution pattern, and solvent. The added 6-OH can cause modest bathochromic/hypsochromic shifts relative to cyanidin depending on hydrogen bonding and co-planarity.
• Partitioning (literature/general): Expected to be highly polar in its flavylium form (low logP) but becomes less polar as quinoidal/chalcone forms increase with pH.
• pKa(s) (literature/general): Anthocyanidins exhibit multiple apparent acidity constants associated with hydration/deprotonation equilibria (flavylium ⇌ hemiketal/chalcone; flavylium ⇌ quinoidal base), often in the pH 1–5 range; exact values are substitution- and medium-dependent.

Quality and Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
• Research Use Note: For research use only.
• Notes for professional users:
  • For chromophore-sensitive work (e.g., spectrophotometry, kinetics), lot-specific purity and residual inorganic content can influence baseline and extinction coefficients. Request CoA/SDS for detailed impurity profiles if needed.
  • Anthocyanidins may contain trace metal impurities that can influence complexation and spectral properties. For metal-sensitive applications, consider pre-treating solutions with chelators (e.g., EDTA) or using metal-scavenging steps.
  • If a stabilizer or counterion is present, it will be listed on the CoA/Spec Sheet; such additives can affect pH-dependent equilibria and UV–vis signatures.

Reaction and Applications

• Research applications (literature/general):
  • Model anthocyanidin for studies of pH-dependent equilibria, tautomerism (flavylium ↔ quinoidal ↔ hemiketal ↔ chalcone), and solvent effects on visible absorption.
  • Standard for antioxidant capacity assays and radical scavenging kinetics; the additional 6-OH may modulate redox properties relative to cyanidin.
  • Pigment–metal complexation and copigmentation studies with polyphenols, flavones, and organic acids.
• Synthetic/derivatization uses (literature/general):
  • Glycosylation at 3-OH to access 3-O-glycosides (anthocyanins), commonly via acetyl-protected glycosyl donors and Lewis/Brønsted acid activation (e.g., TMSOTf) under anhydrous, low-temperature conditions.
  • O-methylation or O-acylation of phenolic OH groups to tune stability, lipophilicity, and spectral properties; protection strategies (e.g., methyl/benzyl/acetyl) facilitate multistep modifications.
  • Formation of stable complexes with Al3+, Fe3+, and other metals for colorimetric sensing or material coloration.
• Practical tips:
  • Work under subdued light and inert atmosphere for prolonged manipulations; prepare solutions freshly.
  • Maintain mildly acidic conditions to suppress hydration and color loss; avoid prolonged exposure to pH > 5.

Reaction Conditions

• General guidance from literature (illustrative; optimize per project):
  • 3-O-Glycosylation: Dissolve protected glycosyl donor and 6-hydroxycyanidin in dry dichloromethane or acetonitrile with a small amount of dry methanol as promoter; cool to −40 to 0 °C; activate with TMSOTf (catalytic to stoichiometric). Typical reaction times: 0.5–6 h; work up under acidic, low-temperature conditions to avoid hydrolysis. Purify on acidified silica or reverse-phase HPLC with acidified aqueous–organic systems.
  • O-Acylation/O-methylation: Use acyl chlorides/anhydrides or methylating agents (e.g., MeI, dimethyl carbonate) under weakly basic, anhydrous conditions with careful pH control to avoid chromophore degradation; protect sensitive positions if needed.
  • Complexation studies: Prepare acidified ethanolic or aqueous solutions (pH 2–3), then titrate metal salts (e.g., Al3+, Fe3+) while monitoring UV–vis shifts; maintain ionic strength and exclude oxygen/light to ensure reproducibility.
• Analytical methods:
  • UV–vis in acidified ethanol/water; monitor λmax shifts with pH and cosolvents.
  • HPLC: C18 columns; mobile phases with 0.1–1% formic acid or TFA in water–acetonitrile gradients; detect at visible λmax and at 280 nm for phenolic bands.
• Notes:
  • Anthocyanidins interconvert across species with pH and temperature; rapid handling and consistent acidification are essential for reproducible outcomes.

Safety and Handling

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to SDS.
• General handling (professional guidance):
  • Avoid dust formation and inhalation of particulates. Use in a chemical fume hood when weighing or dissolving.
  • Anthocyanidins are phenolic dyes; they can stain skin, benchtops, and porous materials. Wear appropriate PPE: lab coat, nitrile gloves, and safety glasses.
  • Prevent exposure to strong oxidizers and strong bases; both can accelerate degradation, oxidation, or structural rearrangements (chalcone formation, polymerization).
• Stability considerations (literature/general):
  • Light- and oxygen-sensitive in solution; degradation is accelerated at neutral to basic pH and elevated temperatures. Acidified, oxygen-minimized, amber containers recommended for solutions.
  • Anthocyanidin solutions may show significant color and spectral changes with small pH shifts; monitor and control pH closely.
• First aid (overview; defer to SDS):
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing. Seek medical attention if irritation persists.
  • Ingestion/inhalation: Move to fresh air and obtain medical advice. Provide SDS to healthcare personnel.
• Waste: Dispose in accordance with institutional and local regulations for organic dye-containing laboratory waste.

Solvent Selection

• Polarity/miscibility (literature/general):
  • Prefers polar protic media. Highly soluble in acidified water, methanol, ethanol; limited in aprotic polar solvents unless protic cosolvent is added.
  • Insoluble to sparingly soluble in nonpolar solvents (hexanes, toluene).
• Practical recommendations:
  • For stock solutions: Use acidified methanol or ethanol (e.g., 0.1–1% v/v HCl) to stabilize the flavylium form and minimize hydration/bleaching.
  • For aqueous work: Buffer at pH ≤ 3 with suitable acids (HCl, formic acid) for spectral stability; for pH-dependent studies, prepare matched ionic strength buffers and record spectra promptly.
  • For extraction from matrices: Acidified aqueous alcohols are standard; avoid strong bases.
• Selection versus alternatives (literature/general):
  • Methanol affords high solubility and sharp spectra; ethanol is a greener alternative with slightly lower solvating power but better safety profile.
  • For chromatography, use aqueous acidified mobile phases (formic or TFA at low %) to maintain peak shape and suppress on-column interconversion.

Storage and Reconstitution

• Storage conditions (from Product Data): Room temperature.
• Shipping: Not specified for this item; refer to CoA/Spec Sheet.
• Long-term handling (literature/general best practices):
  • Store solid in a dry, tightly sealed, light-protective container. Minimize exposure to humidity, air, and light.
  • For solution stocks, use acidified protic solvents (e.g., ethanol or methanol containing 0.1–1% HCl), purge with inert gas, and store in amber vials at 2–8 °C when possible. Prepare small aliquots to avoid repeated freeze–thaw and air exposure.
• Reconstitution:
  • Select an acidified solvent compatible with downstream use. Add solvent gradually with gentle swirling to avoid localized high pH from residual moisture.
  • Filter through a 0.2 µm PTFE/nylon filter if particulate is present; avoid basic filters or basic rinses that can decolorize the solution.
• Stability notes:
  • Expect reduced stability at neutral/basic pH, elevated temperatures, and under light/oxygen. Verify concentration and spectral integrity prior to critical measurements.
• For authoritative guidance, consult the product’s CoA and SDS.

Structure and Identity

• Item-specific identifiers from Product Data:
  • CAS: 42529-06-6
  • CID: 441697 (PubChem)
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Structural class (literature): 6-Hydroxycyanidin is an anthocyanidin (flavylium-type) polyphenol. It is the 6-hydroxylated analog of cyanidin, bearing an additional phenolic OH at C6 of the A-ring.
• Core features (literature/general):
  • Tricyclic 2-phenylbenzopyrylium (flavylium) skeleton with a positively charged oxygen in the central ring (C-ring) under acidic conditions.
  • Phenolic hydroxyl groups on the A- and B-rings, including a characteristic catechol (3′,4′-dihydroxy) pattern on the B-ring as in cyanidin, plus an additional OH at the A-ring C6 position.
  • Stereochemistry: none (achiral aglycone); exists as pH-dependent structural isomers (flavylium cation, quinoidal base, hemiketal, chalcone) in solution.
• 2D description in words (literature/general): A benzopyrylium ring (C-ring) fused to a phenolic A-ring, with a pendant phenyl B-ring at the C2 position; hydroxyls on the A-ring (including C6) and on the B-ring (3′,4′), and a 3-hydroxyl at the flavylium core similar to other anthocyanidins.

Synthetic Utility

• Functional groups and reactivity (literature/general):
  • Polyphenolic scaffold with multiple phenolic OH groups and a 3-hydroxyflavylium core; undergoes electrophilic reactions at the flavylium center and nucleophilic addition (hydration) at C2/C4 in less acidic media.
  • Phenolic OH groups enable selective protection (methylation/benzylation/acetylation) and subsequent cross-coupling or late-stage diversification after conversion to suitable derivatives.
• Transformations:
  • 3-O-Glycosylation to access anthocyanins; activation via acid catalysts (e.g., TMSOTf, BF3·OEt2) with peracylated glycosyl donors under anhydrous conditions.
  • O-Methylation/acylation to modulate stability and lipophilicity; regioselectivity can be guided by differential acidity and protecting group strategies.
  • Metal–ligand complex formation with catechol moieties for materials, sensing, and color-tuning applications.
• Retrosynthetic value:
  • Serves as a platform to probe structure–color relationships; the 6-OH substituent offers an additional handle for selective derivatization or protection compared to cyanidin.

Target Specificity

• Not applicable. This product is a small-molecule anthocyanidin, not an antibody or biologic. No target/epitope specificity, clone, or isotype applies.