Rivularin (flavone) - ≥98% , CAS No.70028-59-0

CAS: 70028-59-0 Cat. No.: R994614 PubChem CID: 13889022

GRADE & PURITY ≥98%

Storage

Room temperature

Specifications

Specifications & Purity

≥98%

Storage

Room temperature

Purity

≥98%

Names and Identifiers

Canonical Smiles

COC1=CC=CC(=C1C2=CC(=O)C3=C(O2)C(=C(C=C3O)OC)OC)O

IUPAC Name

5-hydroxy-2-(2-hydroxy-6-methoxyphenyl)-7,8-dimethoxychromen-4-one

InChIKey

IYMNRCWUEDWTPE-UHFFFAOYSA-N

INCHI

1S/C18H16O7/c1-22-12-6-4-5-9(19)16(12)13-7-10(20)15-11(21)8-14(23-2)17(24-3)18(15)25-13/h4-8,19,21H,1-3H3

Isomeric SMILES

COC1=CC=CC(=C1C2=CC(=O)C3=C(O2)C(=C(C=C3O)OC)OC)O

PubChem CID

13889022

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Phenylpropanoids and polyketides
    • Class Flavonoids
      • Subclass O-methylated flavonoids

• Kingdom: Organic compounds
• Superclass: Phenylpropanoids and polyketides
• Class: Flavonoids
• Subclass: O-methylated flavonoids
• Intermediate Tree Nodes: Not available
• Direct Parent: 8-O-methylated flavonoids
• Alternative Parents: 2'-O-methylated flavonoids 7-O-methylated flavonoids 5-hydroxyflavonoids Flavones Chromones Methoxyphenols Phenoxy compounds Methoxybenzenes Anisoles 1-hydroxy-2-unsubstituted benzenoids Pyranones and derivatives 1-hydroxy-4-unsubstituted benzenoids Alkyl aryl ethers Vinylogous acids Heteroaromatic compounds Oxacyclic compounds Organic oxides Hydrocarbon derivatives
• Molecular Framework: Aromatic heteropolycyclic compounds
• Substituents: 2p-methoxyflavonoid-skeleton - 7-methoxyflavonoid-skeleton - 8-methoxyflavonoid-skeleton - 5-hydroxyflavonoid - Flavone - Hydroxyflavonoid - Chromone - Benzopyran - Methoxyphenol - 1-benzopyran - Phenoxy compound - Anisole - Methoxybenzene - Phenol ether - 1-hydroxy-4-unsubstituted benzenoid - 1-hydroxy-2-unsubstituted benzenoid - Alkyl aryl ether - Phenol - Pyranone - Monocyclic benzene moiety - Benzenoid - Pyran - Vinylogous acid - Heteroaromatic compound - Organoheterocyclic compound - Ether - Oxacycle - Hydrocarbon derivative - Organooxygen compound - Organic oxide - Organic oxygen compound - Aromatic heteropolycyclic compound
• Description: This compound belongs to the class of organic compounds known as 8-o-methylated flavonoids. These are flavonoids with methoxy groups attached to the C8 atom of the flavonoid backbone.
• External Descriptors: Flavones and Flavonols

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

Chemical and Physical Properties

• Molecular Weight: 344.300 g/mol
• XLogP3: 2.900
• Hydrogen Bond Donor Count: 2
• Hydrogen Bond Acceptor Count: 7
• Rotatable Bond Count: 4
• Exact Mass: 344.09 Da
• Monoisotopic Mass: 344.09 Da
• Topological Polar Surface Area: 94.500 Ų
• Heavy Atom Count: 25
• Formal Charge: 0
• Complexity: 520.000
• 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

Application Protocols

No validated biological assay protocols are provided for this item. The compound is offered for research use as a small-molecule standard.

• General handling protocols (research-use, not item-specific)

  • Stock preparation: dissolve in anhydrous DMSO or methanol to a convenient concentration (e.g., 10–50 mM), vortex/sonicate if needed, and filter (0.2 µm PTFE) to remove particulates.
  • Working solutions: dilute into assay buffer or mobile phase keeping organic co-solvent ≤1–2% v/v to prevent precipitation; verify solubility visually and by test injection (for HPLC).
  • Stability check: confirm integrity by LC–MS/HPLC after 24–48 h in your assay medium; protect solutions from light.

• Analytical example (illustrative, literature-based)

  • HPLC-UV quantitation: C18, gradient 30→80% ACN in water (0.1% FA) over 10–15 min, detection 254 and 340 nm; prepare calibration curve from serial dilutions of the stock.

Refer to your internal SOPs for detailed protocols and acceptance criteria.

Biological Roles

• General context (literature; not item-specific claims)

  • Flavones are polyphenolic secondary metabolites widely distributed in plants and also reported in certain cyanobacteria. They contribute to pigmentation, UV protection, and defense against herbivores/microbes.
  • Their conjugated systems enable interactions with proteins and membranes; phenolic groups (if present) can engage in hydrogen bonding and metal chelation.

• Biochemical behavior

  • Antioxidant/redox: phenolic flavones can undergo radical scavenging and redox cycling; the 4-oxo and C2=C3 enone contribute to electron delocalization (literature mechanistic insight).
  • Metabolism (general mammalian systems): typical phase II conjugation (glucuronidation/sulfation) of phenolic OH groups; O-demethylation (CYP-mediated) if methoxy substituents are present.
  • Binding motifs: common to see interactions with ATP- or NAD(P)H-dependent enzymes in vitro due to planar, H-bonding-capable scaffolds; specificity is highly dependent on substitution patterns.

• Experimental use

  • Employed as a reference standard in metabolomics and natural product libraries to profile polyphenol pathways and uptake/transport in cell-free systems or lysates.
  • Spectroscopic probe: UV–Vis and fluorescence characteristics facilitate tracking in biochemical mixtures without derivatization.

• Important caveats

  • Biological activity reported for flavones in literature varies widely and is context-/substitution-dependent; no biological performance is claimed for this specific product.
  • For any cellular work, maintain co-solvent below cytotoxic thresholds and verify compound integrity in assay media (e.g., LC–MS stability checks).

Buffer Applications

This product is a neutral, hydrophobic small molecule and is not a buffering agent. It is not typically used to prepare or adjust pH buffers.

• Practical note
  • If introducing rivularin into aqueous buffers for assays, dissolve first in a water-miscible organic co-solvent (e.g., DMSO or ethanol) and add slowly to the buffer with vigorous mixing to avoid precipitation (general practice).
  • Consider using cyclodextrins, mild surfactants (e.g., 0.01–0.1% Tween 80), or protein carriers (e.g., BSA) if higher apparent aqueous solubility is required for in vitro work.

Green Alternatives

While rivularin itself is the analyte/reagent, greener choices mainly concern solvent selection and process conditions when using or synthesizing flavones.

• Greener solvent choices (literature, general)

  • Replace chlorinated solvents (DCM/CHCl3) with ethyl acetate or 2-MeTHF for extractions and chromatography where feasible.
  • Prefer ethanol or isopropanol over methanol when solubility permits, due to lower toxicity and improved EHS profile.
  • For hydrogenations or reductions, use ethanol or water/ethanol biphasic systems with supported catalysts instead of DMF/THF when chemistry tolerates.

• Energy and process intensity

  • Microwave-assisted cyclizations (e.g., Baker–Venkataraman to flavones) can shorten reaction times and reduce solvent volumes.
  • Flow photochemistry or electrochemical oxidations may replace stoichiometric oxidants in certain flavone syntheses (literature).

• Mini-comparison (general)

  • DCM vs EtOAc: EtOAc offers biodegradability and lower toxicity; polarity similar for normal-phase separations, though EtOAc is more polar and may change selectivity.
  • MeOH vs EtOH: EtOH is less toxic and often an adequate replacement; modest changes in elution strength/selectivity need optimization.
  • THF vs 2-MeTHF: 2-MeTHF derived from renewable sources, lower peroxide formation tendency than THF, and suitable for many extractions/reactions.

• Waste minimization

  • Use higher-loading cartridges/columns or preparative RP methods to reduce solvent volume.
  • Apply “analyse-then-scale” to avoid excess synthesis or purification when preparing rivularin analogs.

Note: Choose alternatives consistent with target analytical performance and compound stability.

Pharmaceutical Uses

No pharmacopeial or excipient role is specified for this item.

• Item-specific status

  • Grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
  • Regulatory/compendial listings: Not specified for this item.

• General context (literature; not product-specific)

  • Flavones are occasionally employed as analytical reference materials during pharmaceutical natural products research or as scaffolds in medicinal chemistry campaigns. In such contexts, they serve as screening library members rather than as approved excipients or actives.
  • For formulation research, solubility enhancement strategies (co-solvents, cyclodextrin inclusion, amorphous dispersions) are often evaluated; however, no formulation guidance is provided or implied for this product.

• Compliance and use limitations

  • For research use only. Not for human or veterinary use, diagnostic procedures, or clinical applications.
  • If used in GMP-analogous analytical settings, establish full method validation and reference standard qualification per ICH guidance using your in-house procedures.

Physical Properties

• Item-specific specifications

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
  • Melting point: Not specified for this item; refer to CoA/Spec Sheet.
  • Boiling point: Not specified for this item; refer to CoA/Spec Sheet.
  • Density, refractive index, UV cut-off, elemental/impurity limits: Not specified for this item; refer to CoA/Spec Sheet.

• General/literature guidance for flavones (not item-specific)

  • Physical state: typically crystalline solids with yellowish hue due to extended conjugation.
  • Solubility: poor in water; soluble in polar aprotic and protic organic solvents (DMSO, DMF, acetone, acetonitrile, methanol, ethanol); increased solubility upon deprotonation of phenolic OH in basic media.
  • UV–Vis: strong π→π* bands around 240–280 nm and 330–380 nm (Band II and Band I, respectively; literature for flavones), useful for quantitative HPLC-UV detection.
  • LogP: often moderate (c. 2–4 for methoxy/phenolic flavones; literature), reflecting limited aqueous solubility and good membrane affinity.
  • pKa: phenolic OH (if present) typically pKa ~6–10 depending on substitution; non-chelating phenols higher, 5,7-dihydroxy systems lower for the 7-OH (literature).

• Practical notes

  • For analytical work, prepare stock solutions in dry DMSO or MeOH and dilute into assay buffers with co-solvent ≤1–2% v/v to avoid precipitation (general practice).
  • Determine exact solubility/MP for this lot from the CoA prior to preparative or analytical use.

Quality & Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

• Interpreting grades (general guidance)

  • Analytical/reference standard grade: emphasizes identity confirmation (NMR, MS, HPLC purity), and low levels of non-UV-absorbing impurities for quantitative assays.
  • Research grade: suitable for discovery biology/chemistry where ultra-trace impurities are less critical; verify purity for sensitive analytical or photophysical studies.
  • HPLC grade solvents vs. compound purity: “HPLC grade” refers to solvent quality, not solid reagents; for flavone analytes, low UV-absorbing impurities are desirable to reduce baseline noise in chromatographic detection.

• Recommended verifications on receipt (best practice)

  • Confirm identity by 1H NMR/HRMS against literature spectra for rivularin; optional 13C NMR for substitution pattern.
  • Check purity by HPLC-UV/ELSD at two wavelengths (e.g., 254/340 nm) due to flavone chromophores.
  • Record water content by KF if hygroscopic behavior is suspected (literature: most flavones are not strongly hygroscopic, but hydrate formation is occasionally observed).

• Stabilizers/additives

  • Not specified for this item; refer to CoA/Spec Sheet. If none, store tightly closed, desiccated, and protected from light to preserve assay-grade integrity.

Reaction & Applications

• Research applications (general for flavone natural products; no medical claims)

  • Analytical reference: calibration standard in phytochemical profiling, dereplication, and LC–MS method development targeting flavonoid-like metabolites.
  • Photophysics: probe molecule for studying conjugation-dependent UV–Vis absorption and fluorescence quenching in supramolecular systems (literature).
  • Binding/assay studies: structure–affinity explorations against purified enzymes/receptors in biochemical assays as part of SAR panels (research use only).

• Chemical transformations (synthetic handling of flavones; literature)

  • O-demethylation (if methoxy present): BBr3 or AlCl3/thiophenol to reveal phenols.
  • Electrophilic substitution: nitration/sulfonation typically deactivated by the 4-oxo; directed metalation can be used on electron-rich rings.
  • Hydrogenation: selective C2–C3 double bond reduction to flavanone under catalytic hydrogenation; further hydrogenolysis possible.
  • Cycloaddition/annulation: 2′-hydroxychalcone precursors undergo oxidative cyclization to the flavone (Algar–Flynn–Oyamada), useful for analog generation.

• Practical tips

  • Light sensitivity: store and conduct extended reactions under subdued light to reduce photo-oxidation.
  • Purification: RP flash or silica gel with EtOAc/hexane or DCM/MeOH works well; phenolic forms may tail—add 0.1% TEA to mobile phase (silica) or use end-capped C18 for HPLC.
  • Characterization: strong UV at 254/340 nm, diagnostic HMBC/HMQC correlations around the C4 carbonyl and C2–C3 enone system.

Note: No manufacturer-specific application notes were provided for this item; the above represents general practices for flavone standards.

Reaction Conditions

The following are literature-general conditions for preparing and transforming flavones; adapt to rivularin once its exact substitution is verified from CoA/literature.

• Synthesis to flavone core

  • Baker–Venkataraman route: acylate 2-hydroxyacetophenone, then base-promoted rearrangement (K2CO3 or KOtBu, 60–90°C, polar aprotic solvent), cyclodehydrate with acid (AcOH/H2SO4 or POCl3) to afford flavone; typical yields 40–75% over steps (literature).
  • Algar–Flynn–Oyamada: oxidize 2′-hydroxychalcone with H2O2 in alkaline ethanol or t-BuOOH/NaOH; 0–25°C to reflux; yields 30–70% depending on substitution.

• Transformations of flavones

  • Hydrogenation to flavanone: Pd/C (5–10 wt%), H2 (1–3 atm), EtOH, rt–50°C, 2–8 h; monitor by TLC/HPLC.
  • O-Demethylation: BBr3 (1–3 eq per OMe) in DCM, −78 to 0°C, then warm to rt; quench cautiously; yields 60–90% with appropriate workup.
  • Electrophilic halogenation: NBS (1.0–1.2 eq) in DMF/AcOH, 0–25°C, 1–3 h, followed by purification.

• Analytical conditions

  • RP-HPLC assay: C18, 30–60% ACN in water (0.1% FA), 1 mL/min, 254/340 nm detection; retention varies with substitution.
  • LC–MS: ESI(−) often favorable for phenolic flavones; ESI(+) for methoxy-rich analogs.

• Stability considerations

  • Avoid prolonged strong base/heat to limit ring opening/polymerization.
  • Protect from light/oxygen during extended reactions and storage in solution.

These conditions are provided as general guidance; optimize for your substrate and scale.

Safety & Handling

• GHS and hazard statements (item-specific)

  • Signal word: Not specified for this item; refer to SDS.
  • H-statements: Not specified for this item; refer to SDS.
  • GHS classification/pictograms: Not specified for this item; refer to SDS.

• General safety guidance for flavone research standards (not item-specific)

  • Expected hazards: many flavones are of low acute toxicity but may cause irritation to eyes/skin/respiratory tract. Avoid dust formation and inhalation.
  • PPE: lab coat, nitrile gloves, safety glasses; use a fume hood when weighing or dissolving.
  • Hygiene: wash hands after handling; do not eat/drink/smoke in lab areas.
  • First aid (general): if on skin/eyes, rinse with water for several minutes; if inhaled, move to fresh air; if ingested, rinse mouth and seek medical attention. Always follow SDS-specific instructions.

• Handling and incompatibilities

  • Avoid strong oxidizers; phenolic/methoxy aromatics can undergo oxidative degradation.
  • Protect from prolonged light exposure to minimize photo-oxidation and color changes (common for conjugated aromatics).
  • Minimize moisture if forming basic solutions; strong bases deprotonate phenols and may promote degradation under heat/air.

• Fire safety

  • Most organic solids are combustible; keep away from ignition sources. Use CO2, dry chemical, or foam for small fires. Thermal decomposition may release CO/CO2 and irritating fumes.

• Definitive information

  • Consult the product-specific SDS for authoritative classification, exposure limits, and spill/accident response.

Solvent Selection

Rivularin, as a flavone, is expected to be non-ionic and moderately lipophilic with poor aqueous solubility (literature). Choose solvents accordingly for stock solutions, reactions, and analyses.

• Polarity and miscibility (general for flavones)

  • Preferred solvents: DMSO, DMF, acetone, acetonitrile, methanol, ethanol, ethyl acetate; limited solubility in hexanes/heptane.
  • Aqueous media: typically insoluble; co-solvent strategies (≤1–2% DMSO/MeOH) or use of surfactants/cyclodextrins may be needed for bioassays (literature practice).

• Analytical chromatography

  • RP-HPLC: water (0.1% formic acid or ammonium acetate) with acetonitrile or methanol. Flavones often elute at moderate organic content (40–80% B), with UV detection ~254–360 nm.
  • Normal-phase TLC/HPLC: hexane/EtOAc or DCM/MeOH gradients separate O-methylated vs. phenolic congeners.

• Sample preparation tips

  • Prepare concentrated stocks (e.g., 10–50 mM) in dry DMSO or MeOH to minimize repeated dissolution. Filter through 0.2 µm PTFE if particulate forms.
  • Avoid basic aqueous media unless deprotonation is desired; base can accelerate degradation upon heating/air exposure.

• Comparison (general, literature)

  • DMSO vs MeOH: DMSO provides highest solubility and stability but may complicate bioassays at >1% v/v; MeOH is more volatile/easily removed but may participate in acyl migration/transesterification in some systems (less relevant for flavones).
  • ACN vs MeOH in HPLC: ACN often yields sharper peaks and lower backpressure; MeOH provides different selectivity for positional isomers.

Storage & Reconstitution

• Storage (item-specific)

  • Storage conditions: Room temperature (from Product Data). Keep container tightly closed, in a dry place, and protected from light for maximum stability.
  • Shipped in: Not specified for this item; refer to CoA/Spec Sheet.

• Reconstitution (general guidance; not item-specific)

  • Solvents: Use anhydrous DMSO or methanol to prepare concentrated stock solutions. If required, ethanol or acetonitrile may also be used depending on solubility.
  • Concentration: Prepare 10–50 mM stocks to minimize repeated freeze–thaw cycles; filter through 0.2 µm PTFE if particulates are present.
  • Aqueous use: Add stock slowly to vigorously stirred buffer to a final co-solvent content ≤1–2% v/v. If precipitation occurs, increase co-solvent slightly or warm gently to 30–37°C while mixing.

• In-use stability (general)

  • Protect solutions from light and air; store aliquots in amber vials. DMSO stocks are often stable for weeks at −20°C; verify by HPLC prior to critical assays.
  • Avoid strong bases and oxidants which can degrade flavone scaffolds.

• Spec sheet/SDS precedence

  • Where available, follow the product’s CoA/SDS for definitive storage limits, solution stability, and handling instructions.

• Research Use Note

  • For research use only.

Structure & Identity

Rivularin (flavone) is cataloged as a member of the flavone class (2-phenyl-4H-1-benzopyran-4-one core), typically bearing phenolic and/or methoxy substituents on the A- and B-rings.

• Item-specific identifiers (from Product Data)

  • CAS: 70028-59-0
  • PubChem CID: 13889022
  • InChIKey: 153790 (as provided; note this is not in standard InChIKey format; consult CoA/SDS for confirmation)
  • 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 features (general flavone framework; literature)

  • Core scaffold: 2-phenylchromen-4-one (flavone) with a conjugated 4-oxo chromen system.
  • Functional groups: aromatic rings, an enone (C=O conjugated with C=C), possible phenolic –OH and/or –OCH3 substituents depending on exact substitution pattern reported for rivularin in the literature.
  • 2D description: a fused benzopyran (A- and C-rings) featuring a carbonyl at C4, and a pendant phenyl B-ring at C2; substituents (if present) lie ortho/meta/para on A/B rings typical of natural-product flavones.

• Notes

  • Rivularin has been reported as a naturally occurring flavone in certain cyanobacterial/blue-green algal sources (literature). Exact substitution pattern should be verified against the specific batch documentation.
  • For definitive structure, stereochemistry (flavones are typically achiral), and identifiers, consult the item’s CoA/SDS.

Synthetic Utility

As a substituted flavone, rivularin represents a versatile aromatic enone scaffold valuable for synthesis, derivatization, and SAR exploration.

• Functional group reactivity (literature, general)

  • Conjugated enone (C2=C3–C4=O): supports Michael additions (usually at C3 in activated systems) and selective reductions to flavanones.
  • Phenolic groups (if present): amenable to O-alkylation, O-acylation, carbonate/urethane formation; can direct metalation and chelation.
  • Methoxy groups (if present): serve as protected phenols; can be demethylated (BBr3) or undergo cross-coupling after conversion to aryl triflates.

• Named reactions and routes to analogs

  • Baker–Venkataraman rearrangement from 2-acylated O-acylated hydroxyacetophenones to 1,3-diketones followed by cyclodehydration to flavones.
  • Algar–Flynn–Oyamada oxidative cyclization from 2′-hydroxychalcones to flavones (H2O2/alkali or catalytic oxidants).
  • Allan–Robinson condensation using o-hydroxyaryl anhydrides and phenolic substrates for selected substitution patterns.

• Diversification strategies

  • Late-stage C–H functionalization on electron-rich rings (e.g., Ir-catalyzed borylation) followed by Suzuki/Sonogashira couplings to access B-ring variants.
  • Electrophilic halogenation (NBS/NCS) at activated positions enabling subsequent cross-couplings.

• Analytical/characterization

  • Diagnostic NMR: downfield C2–H/C3–H (if present) and carbonyl signal at ~175–180 ppm (13C); UV maxima near 270–280 and 330–360 nm aid purity checks.

Note: Exact substituent behavior should be matched to the confirmed rivularin substitution pattern per CoA/literature.

Target Specificity

Not applicable to this product category. Rivularin is a small-molecule flavone standard, not a biological targeting reagent or antibody.

• Item-specific data such as antigen, epitope, species reactivity, clone, and isotype are not relevant and are not provided for this item.