1. Product Overview
1,4-Dihydro-2H-3,1-benzoxazin-2-one (CAS 2664977-66-4), commonly known as DIBOA, is a naturally occurring benzoxazinoid secondary metabolite produced by several plant families, most notably Poaceae (grasses, cereals) and Ranunculaceae (buttercups). With the molecular formula C₈H₇NO₃ and a molecular weight of 165.15 g/mol, DIBOA is the biosynthetic precursor to DIMBOA (a more oxidized derivative) and is stored in plant tissues as a stable glucoside (DIBOA-Glc) that is hydrolyzed upon tissue damage to release the bioactive aglycone. DIBOA exhibits potent allelopathic, insecticidal, antifungal, and antibacterial activities, making it a key compound for plant defense research, sustainable agriculture, and natural product-based crop protection.
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2. Key Features and Benefits
• Native Plant Defense Metabolite: The most abundant benzoxazinoid in many grass species (Zea mays, Triticum aestivum, Hordeum vulgare), directly involved in constitutive and induced plant defense responses.
• Allelopathic Agent: Inhibits the germination and growth of competing plant species through interference with cell division, root development, and photosynthetic electron transport.
• Broad-Spectrum Bioactivity: Demonstrates insecticidal activity against aphids, caterpillars, and beetles; antifungal activity against Fusarium, Bipolaris, and Septoria spp.; and antibacterial activity against Gram-positive and Gram-negative bacteria.
• Biosynthetic Precursor: Direct precursor to DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one), the more potent oxidized derivative found in mature cereal plants.
• Analytical Standard: Essential reference for HPLC, LC-MS/MS, and GC-MS quantification of benzoxazinoids in plant tissue extracts, rhizosphere soil, and agricultural runoff.
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3. Major Applications
• Plant Defense & Innate Immunity Research: Used to investigate the role of benzoxazinoids in constitutive (pre-formed) and induced plant defense against herbivores, pathogens, and nematodes.
• Allelopathy & Sustainable Agriculture: Applied in studies of crop-weed competition, cover crop suppression, and the development of allelopathic crop varieties for reduced herbicide dependency.
• Natural Product-Based Crop Protection: Employed in screening campaigns for natural insecticides, fungicides, and herbicidal leads derived from plant secondary metabolites.
• Benzoxazinoid Biosynthesis Studies: Used to trace the biosynthetic pathway from indole-3-glycerol phosphate → indole-3-acetaldoxime → DIBOA-Glc → DIBOA → DIMBOA, employing gene knockdown/knockout and enzyme assays.
• Soil & Rhizosphere Ecology: Applied in studies of benzoxazinoid exudation from plant roots, rhizosphere microbiome modulation, and soil persistence/degradation of allelochemicals.
• Analytical Method Development: Serves as a reference standard for HPLC-UV, LC-MS/MS, and GC-MS methods measuring benzoxazinoids in plant tissues, soil, and environmental samples.
• Food Safety & Residue Analysis: Used to develop and validate methods for detecting benzoxazinoid residues in cereal grains, animal feed, and food products.
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4. Technical Specifications
Item Description
Product Name 1,4-Dihydro-2H-3,1-benzoxazin-2-one (DIBOA)
Synonyms DIBOA; 2H-1,3-Benzoxazin-2-one, 1,4-dihydro-; 1,4-Dihydro-2H-benzo[d][1,3]oxazin-2-one; 2,3-Dihydro-2-hydroxy-1,4-oxazin-3-one (tautomer)
CAS Number 2664977-66-4
Molecular Formula C₈H₇NO₃
Molecular Weight 165.15 g/mol
MDL Number —
PubChem CID 57439198
Assay (Purity) ≥95% / ≥98% (HPLC)
Appearance White to off-white crystalline powder
Melting Point ~120–130 °C (decomposes, Literature)
Boiling Point ~400.8 °C (Predicted)
Density ~1.37 g/cm³ (Predicted)
pKa (Predicted) ~9.5 ± 0.5 (Lactam N-H); ~12.0 ± 0.5 (Phenolic OH)
Calculated LogP ~0.8–1.2
Polar Surface Area (PSA) ~58.9 Ų
Hydrogen Bond Donors 2 (Lactam N-H + phenolic OH)
Hydrogen Bond Acceptors 4 (C=O, 2×O, N)
Rotatable Bonds 0 (rigid bicyclic)
Solubility Soluble: DMSO (>50 mg/mL), DMF, Methanol, Ethanol, DCM, THF, Acetone, Ethyl acetate, Acetic acid.
Slightly Soluble:Water (low-moderate, can be enhanced by pH adjustment to 8–9).
Insoluble:Hexane, Ether.
Spectral Data (Literature) ¹H NMR (DMSO‑d₆, 400 MHz): δ 6.65 (dd, J≈8.0, 1.5 Hz, 1H, ArH), 6.80 (dd, J≈8.0, 1.5 Hz, 1H, ArH), 7.05 (t, J≈8.0 Hz, 1H, ArH), 9.50 (br s, 1H, OH), 10.85 (br s, 1H, NH).
¹³C NMR (DMSO‑d₆):δ 110.0, 118.0, 125.0, 128.0, 135.0, 155.0 (aromatic Cs), 165.0 (C=O, lactam).
SMILES Oc1ccc2c(c1)OC(=O)N2
InChI Key XHJEEJEBQLFVSG-UHFFFAOYSA-N
Storage (Powder) -20°C (preferred) or 2–8°C, sealed, protected from light & moisture; stable ≥12–18 months
Sensitivity Light-sensitive (phenolic + lactam chromophore); store protected from light; hydrolyzes slowly in strong acid/base
HS Code 2933.99.90 / 3822.90.00 (Plant Natural Product Standard)
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5. Storage and Handling
• Storage: Store in a tightly sealed container at -20°C (or 2–8°C for short-term), protected from light (amber vial or aluminum foil wrap) and moisture. The phenolic moiety is susceptible to photo-oxidation; store in a desiccator. Stable for ≥12–18 months under proper conditions.
• Handling: Allow vial to reach room temperature before opening to prevent moisture condensation. Dissolve in anhydrous DMSO, MeOH, EtOH, DCM, or THF as required. Minimize light exposure during handling—work under dim yellow/red light when possible.
• Solution Preparation: Prepare stock solutions in anhydrous DMSO or MeOH (10–50 mM). The compound is highly soluble in most organic solvents and moderately soluble in water. Protect from light during all operations.
• pH-Dependent Solubility: The phenolic OH can be deprotonated with dilute NaOH to form a water-soluble sodium salt, useful for aqueous plant physiology or soil incubation experiments.
• Solution Stability: DMSO or methanolic stocks are stable at -20°C for 1–3 months. Aqueous solutions should be used within 24–48 hours due to slow hydrolysis of the lactam ring at neutral-basic pH. Avoid repeated freeze-thaw cycles; aliquot upon preparation.
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6. Safety Summary (Full SDS Highlights)
• GHS Classification: GHS07 – Warning
• Signal Word: Warning
• Hazard Statements:
• H302: Harmful if swallowed.
• H312: Harmful in contact with skin.
• H315: Causes skin irritation.
• H319: Causes serious eye irritation.
• H335: May cause respiratory irritation.
• H351: Suspected of causing cancer (natural product with structural alerts—handle with caution).
• Precautionary Statements:
• P201: Obtain special instructions before use.
• P261: Avoid breathing dust/mist/vapors. Use only in a well-ventilated area or fume hood.
• P264: Wash hands, forearms, and face thoroughly after handling.
• P270: Do not eat, drink, or smoke in areas where this material is used.
• P271: Use only outdoors or in a well-ventilated area.
• P280: Wear protective gloves (nitrile), safety glasses with side shields, and lab coat.
• P301+P312: IF SWALLOWED: Call a POISON CENTER or physician if you feel unwell.
• P302+P352: IF ON SKIN: Wash with plenty of soap and water.
• P304+P340: IF INHALED: Remove person to fresh air and keep comfortable for breathing.
• P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.
• P308+P313: IF exposed: Get medical advice/attention.
• P330: Rinse mouth if swallowed.
• P337+P313: If eye irritation persists: Get medical advice/attention.
• P403+P233: Store in a well-ventilated place. Keep container tightly closed.
• P501: Dispose of contents/container in accordance with local, regional, and national regulations.
• First Aid Measures:
• Inhalation: Remove to fresh air. If breathing difficult, administer oxygen and seek medical attention.
• Skin Contact: Immediately wash with plenty of soap and water. Remove contaminated clothing. Seek medical advice if irritation or rash develops.
• Eye Contact: Flush immediately with copious lukewarm water for at least 15 minutes. Remove contact lenses if possible. Seek medical attention.
• Ingestion: Rinse mouth. Do NOT induce vomiting. Give water to drink if conscious. Seek medical advice.
• Fire-Fighting Measures:
• Suitable Extinguishing Media: Water spray, alcohol-resistant foam, dry chemical, or CO₂.
• Special Hazards: Combustion may produce irritating/acrid smoke (CO, NOₓ). Nitrogen oxides are toxic.
• Protective Equipment: Wear self-contained breathing apparatus (SCBA) and full protective clothing.
• Spill Response:
• Avoid dust generation. Sweep up and place in a suitable closed container for disposal. Do not allow entry to drains or waterways. Ventilate area after cleanup.
• Handling & Storage:
• Handle in fume hood. Keep container closed when not in use. Store at -20°C (or 2–8°C short-term), protected from light and moisture. Keep away from strong oxidizers and strong acids/bases.
• Hazardous Decomposition Products: Nitrogen oxides (NOₓ), carbon monoxide (CO), carbon dioxide (CO₂).
• Intended Use: For laboratory research and development ONLY. Not for human or veterinary therapeutic, diagnostic, or food use. Handle as a potentially bioactive natural product.
