1. Product Overview
(±)-Abscisic Acid (CAS 14375-45-2), also known as (2Z,4E)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl)-3-methylpenta-2,4-dienoic acid, is a sesquiterpenoid plant hormone (phytohormone) with the molecular formula C₁₅H₂₀O₄ and a molecular weight of 264.32 g/mol. It is the racemic mixture of the naturally occurring (−)-ABA enantiomer. Abscisic acid regulates seed dormancy, germination inhibition, stomatal closure, and abiotic stress responses (drought, salinity, cold) in higher plants. This compound is used as a reference standard and bioactive reagent in plant physiology, tissue culture, and stress-signaling pathway studies.
2. Key Features and Benefits
• Phytohormone Standard: Used to investigate ABA-mediated signaling cascades including PYR/PYL/RCAR receptor binding, SnRK2 activation, and downstream gene expression.
• Seed Dormancy & Germination Control: Applied in plant tissue culture to induce dormancy or inhibit precocious germination of somatic embryos.
• Abiotic Stress Model: Exogenously applied to elicit stomatal closure and activate stress-responsive genes (e.g., RD29A, COR) in model plants (Arabidopsis, tobacco, rice).
• Racemic (±)-Form: Economical for general plant physiology research where enantiomeric purity is not critical.
• High Purity: Supplied at ≥95% or ≥98% (HPLC), with CoA including UV-Vis λmax ~260 nm (ε ~15,000 M⁻¹cm⁻¹).
3. Major Applications
• Plant Physiology & Hormone Signaling: Used to study ABA perception via PYR/PYL/RCAR receptors, SnRK2 kinase activation, and ABI (ABA-insensitive) mutant characterization.
• Plant Tissue Culture: Added to regeneration media to suppress premature germination of somatic embryos and promote maturation; typical concentration 0.1–10 μM.
• Abiotic Stress Response Research: Exogenous application to induce drought/salt/cold stress markers and study stomatal aperture regulation in leaf epidermal peels.
• Analytical Reference Standard: HPLC/GC/LC-MS quantification of endogenous ABA in plant tissues, xylem sap, and phloem exudates.
• Agricultural & Horticultural R&D: Investigated in screening of ABA analogs, antagonists (e.g., fluridone as biosynthesis inhibitor control), and stress-tolerant crop development.
4. Technical Specifications
Item Description
Product Name (±)-Abscisic Acid (ABA, racemic)
Synonyms Abscisic Acid; (±)-cis,trans-Abscisic Acid; 2-cis,4-trans-Abscisic Acid (racemate); Dormin (historical)
CAS Number 14375-45-2
Molecular Formula C₁₅H₂₀O₄
Molecular Weight 264.32 g/mol
MDL Number MFCD00075619
PubChem CID 49758
Assay (Purity) ≥95% / ≥98% (HPLC)
Appearance White to pale yellow crystalline powder
Melting Point 183–188 °C (decomposes, Literature)
Boiling Point ~458.7 °C (Predicted)
Density ~1.19 g/cm³
pKa (Predicted) ~4.87 ± 0.33 (carboxylic acid)
Calculated LogP ~2.2–2.5
Polar Surface Area (PSA) ~74.6 Ų
Hydrogen Bond Donors 2 (COOH + OH)
Hydrogen Bond Acceptors 4 (C=O ×2, OH, COO⁻)
Rotatable Bonds 5
Solubility Soluble: DMSO (>50 mg/mL, sonication), Methanol, Ethanol, Acetone, Ethyl acetate, CHCl₃ (slight warming), NaHCO₃ aq (as sodium salt).
Slightly Soluble:Water (~0.1–0.5 mg/mL at pH 7; more soluble as Na⁺ or K⁺ salt at pH > pKa).
Insoluble:Hexane, Petroleum ether.
Spectral Data (Literature) ¹H NMR (CD₃OD, 400 MHz): δ 1.00 (s, 6H, gem-dimethyl), 1.85 (s, 3H, vinyl CH₃), 2.30 (d, J≈16 Hz, 1H, cyclohexenone CH₂), 2.55 (d, J≈16 Hz, 1H, cyclohexenone CH₂), 4.05 (br s, 1H, CH-OH), 5.70–6.40 (m, 3H, conjugated diene), 7.80 (d, J≈16 Hz, 1H, α,β-unsat. CH=CH-COOH).
UV-Vis (MeOH):λmax ≈ 260–262 nm (ε ~14,000–16,000 M⁻¹cm⁻¹).
SMILES CC1=CC(=O)CC(C1(C=CC(=CC(=O)O)C)O)(C)C
InChI Key JLIDBLDQVAYHNE-LXGGSRJLSA-N
Storage (Powder) -20 °C, sealed, under inert atmosphere (Ar/N₂), protected from light & moisture; stable ≥12–18 months
Sensitivity Light-sensitive (photoisomerizes to trans-ABA, inactive form); thermally labile above mp; store dark, cold, dry
HS Code 2932.99.90 / 3822.90.00 (Plant Hormone Standard)
5. Storage and Handling
• Storage: Store sealed vial at -20 °C, under inert atmosphere (Ar/N₂ preferred), protected from light in a desiccator. ABA is highly light-sensitive—photoisomerizes to the trans-inactive form within hours under UV/visible light. Stable for ≥12–18 months from date of manufacture under proper dark/cold storage.
• Stock Solution: Dissolve in anhydrous MeOH, EtOH, or DMSO (1–10 mM). Prepare fresh or store aliquots at -20 °C protected from light. For aqueous work, dissolve in minimal 0.1 M NaHCO₃ then dilute into buffer (final pH 5.5–7.0, use within 24 h).
• Working Concentration: Typical range 0.1–10 μM in plant tissue culture or hydroponic systems. Higher concentrations may induce necrosis in sensitive cultivars.
• Light Protection: All weighing, dissolution, and pipetting should be done under dim yellow/red safe-light. Discard any yellowed/brownened solution (indicates photo-degradation).
• Freeze-Thaw: Aliquot stocks; avoid repeated freeze-thaw cycles.
6. Safety Summary (SDS Highlights)
• GHS Classification: GHS07 – Warning (or unclassified at research concentrations; some suppliers label GHS09 for environmental hazard)
• Signal Word: Warning
• Hazard Statements: H315 (Causes skin irritation), H319 (Causes serious eye irritation), H335 (May cause respiratory irritation), H410 (Very toxic to aquatic life with long lasting effects — common for plant hormones)
• Precautionary Statements: P261, P264, P273 (avoid release to environment), P280, P301+P312, P302+P352, P304+P340, P305+P351+P338, P330, P337+P313, P391, P403+P233, P501
• First Aid / Fire / Spill: Standard organic irritant protocol — water spray/CO₂ extinguisher; sweep up; rinse eyes/skin; do not induce vomiting. Avoid environmental release (aquatic toxicity). Decomposes to CO, CO₂, NOₓ.
• Intended Use: For laboratory research and development ONLY. Not for human or veterinary therapeutic, diagnostic, food, or agricultural field application without appropriate regulatory approval.
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