Cetyl Phosphate - ≥98% , CAS No.3539-43-3

CAS: 3539-43-3 Cat. No.: C1072986 Formula: C₁₆H₃₅O₄P Molecular Weight: 322.420 EC Number: 222-581-1

GRADE & PURITY ≥98%

Storage

Room temperature

Specifications

Specifications & Purity

≥98%

Storage

Room temperature

Purity

≥98%

Names and Identifiers

• Canonical Smiles: CCCCCCCCCCCCCCCCOP(=O)(O)O
• IUPAC Name: hexadecyl dihydrogen phosphate
• InChIKey: ZUVCYFMOHFTGDM-UHFFFAOYSA-N
• INCHI: 1S/C16H35O4P/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-20-21(17,18)19/h2-16H2,1H3,(H2,17,18,19)
• Molecular Weight: 322.420

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organic acids and derivatives
    • Class Organic phosphoric acids and derivatives
      • Subclass Phosphate esters
        • Level5 Alkyl phosphates
          • Level6 Monoalkyl phosphates

• Kingdom: Organic compounds
• Superclass: Organic acids and derivatives
• Class: Organic phosphoric acids and derivatives
• Subclass: Phosphate esters
• Intermediate Tree Nodes: Alkyl phosphates
• Direct Parent: Monoalkyl phosphates
• Alternative Parents: Organooxygen compounds Organic oxides Hydrocarbon derivatives
• Molecular Framework: Aliphatic acyclic compounds
• Substituents: Monoalkyl phosphate - Organic oxygen compound - Organic oxide - Hydrocarbon derivative - Organooxygen compound - Aliphatic acyclic compound
• Description: This compound belongs to the class of organic compounds known as monoalkyl phosphates. These are organic compounds containing a phosphate group that is linked to exactly one alkyl chain.
• External Descriptors: Not available

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: 322.420 g/mol
• XLogP3: 6.200
• Hydrogen Bond Donor Count: 2
• Hydrogen Bond Acceptor Count: 4
• Rotatable Bond Count: 16
• Exact Mass: 322.227 Da
• Monoisotopic Mass: 322.227 Da
• Topological Polar Surface Area: 66.800 Ų
• Heavy Atom Count: 21
• Formal Charge: 0
• Complexity: 253.000
• 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 tested bioassay protocols (e.g., WB, IHC, IF, FC) are associated with this small molecule. For formulation or colloid studies, general guidance is as follows (literature-based):

• Stock preparation: dissolve the free acid in ethanol or isopropanol to 10–100 mg/mL. For aqueous use, neutralize with KOH/NaOH while diluting into water under vigorous stirring.
• Emulsion screening: prepare 1–5% w/w cetyl phosphate (as K+ salt) in oil-in-water emulsions; homogenize and evaluate droplet size/zeta potential over time.

For any application-specific protocol, optimize concentrations, pH, counterion, and temperature empirically for your system.

Biological Roles

Cetyl phosphate is not a natural metabolite; it is a synthetic phosphate monoester of a long-chain fatty alcohol. The following points frame its relevance to biochemical research (literature/general):

• Membrane mimetic: the phosphate monoester headgroup provides a negatively charged interface reminiscent of phosphomonoester functionalities found in biological phospholipids, though true phospholipids typically bear diesters and glycerol backbones. Cetyl phosphate can be used to modulate surface charge in mixed assemblies with neutral/zwitterionic lipids.
• Self-assembly: upon neutralization (e.g., K+ salt), forms micelles and can participate in mixed micelles with bile salts or zwitterionic detergents; used to study protein–surfactant interactions and enzyme inactivation/activation by anionic interfaces (literature).
• Surface binding to minerals: phosphate groups exhibit strong affinity to calcium and iron oxides; this can model biomineralization interfaces or adsorption of phosphorylated ligands.
• Enzymatic relevance: although many phosphatases act on phosphate monoesters, long-chain alkyl phosphates like cetyl phosphate are poor enzyme substrates in aqueous media due to aggregation/hydrophobicity; they can, however, serve as test substrates in nontraditional media or emulsified systems (reported case-dependent, literature).

Note: No medical, diagnostic, or therapeutic roles are implied. Use is limited to research and laboratory investigations.

Buffer Applications

Cetyl phosphate is not a conventional buffering agent. While the phosphate monoester possesses two acidic protons (literature pKa1 ~1–2; pKa2 ~6–7), its poor aqueous solubility in the free-acid form and surfactant behavior upon neutralization make it unsuitable for preparing standard laboratory buffers.

• Recommendation: use established inorganic/organic phosphate buffers (e.g., Na2HPO4/NaH2PO4) for pH control, and refer to cetyl phosphate primarily as a surfactant/emulsifier component when relevant.
• If included in aqueous systems, adjust pH independently with conventional buffers; do not rely on cetyl phosphate for buffering capacity.

Green Alternatives

Selection of surfactant headgroups and counterions affects environmental footprint. For research involving anionic surfactants/emulsifiers, consider the following (literature/general guidance):

Comparison (illustrative):

• Cetyl phosphate (free acid or alkali salts)
  • Pros: strong binding to mineral surfaces; phosphate headgroup offers buffering/charge control; good performance in O/W emulsions when neutralized.
  • Cons: phosphate discharge may contribute to eutrophication; free acid has poor water solubility.
• Cetyl sulfate (e.g., sodium cetyl sulfate)
  • Pros: effective anionic surfactant; sulfate is more biodegradable in some contexts; high aqueous solubility of salts.
  • Cons: sulfate headgroup binds less strongly to metal oxides; can be more irritating; oxidative synthesis routes may have harsher reagents.
• Bio-based anionic surfactants (e.g., alkyl polyglucosides with carboxylate/phosphate modifications)
  • Pros: renewable feedstocks, favorable biodegradability; lower aquatic toxicity profiles reported (literature varies).
  • Cons: different CMC and HLB; may not match interfacial behavior or salt tolerance of phosphate headgroups.

Greener practices with cetyl phosphate:

• Use aqueous/ethanolic systems instead of chlorinated solvents when preparing solutions.
• Generate alkali salts in situ to avoid separate isolation steps and reduce solvent use.
• Optimize surfactant loading to the minimum effective concentration; recover and recycle aqueous phases when feasible.
• Consider benign counterions (e.g., K+ vs quaternary ammonium) for improved environmental compatibility.

Pharmaceutical Uses

No pharmacopeial grade or excipient designation is specified for this item; refer to the CoA/Spec Sheet. The following are research/formulation-context notes (no therapeutic claims):

• Emulsification aid (research): alkali salts of cetyl phosphate (e.g., potassium cetyl phosphate) are used as anionic emulsifiers in topical formulations and can be evaluated in pre-formulation studies for oil-in-water systems. The free acid can be neutralized in situ to achieve target pH and HLB.
• Particle stabilization: serves as a surface-active agent to stabilize dispersions of hydrophobic actives or excipient nanoparticles during screening studies.
• Counterion screening: enables investigation of counterion effects (Na+, K+, NH4+, organic ammonium) on viscosity, CMC, and zeta potential in semisolid prototypes.
• Compatibility: generally compatible with fatty alcohols, esters, and many nonionic surfactants; may be incompatible with high levels of cationic polymers/surfactants due to ionic complexation (formulation-dependent; evaluate experimentally).

Regulatory note: This product is for research use only. It is not intended for use in humans or for manufacturing of finished dosage forms without appropriate qualification and regulatory assessment.

Physical Properties

Item-specific specifications were not provided. The following are literature/general values for the free acid (monoester) and should be used as guidance only; verify with the CoA/SDS for this item.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (Literature: waxy solid or paste for long-chain phosphate monoesters.)
• Molecular weight (literature): ~322.43 g/mol (C16H35O4P)
• Acid–base properties (literature): phosphate monoester pKa1 ~1–2; pKa2 ~6–7 (partial ionization near neutral pH).
• Solubility (literature):
  • Water: low for the free acid due to the long hydrophobic chain; markedly increases upon neutralization to alkali salts (e.g., Na+/K+ cetyl phosphate).
  • Organic solvents: soluble in polar organics such as alcohols (EtOH, i-PrOH), glycols, acetone, and aprotic polar solvents (DMF, DMSO); limited solubility in alkanes.
• Partitioning (literature): amphiphilic; high apparent hydrophobicity in protonated form; becomes anionic surfactant upon neutralization.
• Density, mp/bp, refractive index, UV cut‑off: Not specified for this item; refer to CoA/Spec Sheet.

Practical notes (general):

• Forms micelles/aggregates in water when partially or fully neutralized; critical micelle concentration depends strongly on counterion and ionic strength (literature, varies by formulation).
• Hygroscopicity can be modest due to acidic headgroup; keep container tightly closed to minimize moisture uptake.

Quality & Grades

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

Guidance on grades and implications (general):

• Research-grade alkyl phosphate monoesters are typically assessed for identity (NMR/IR), acid number (neutralization value), residual solvents, inorganic content (ash), and moisture. Low inorganic residue is important when preparing defined counterion salts.
• If provided as free acid, absence of pre‑neutralized salts (Na+, K+, NH4+) is important for reproducible titrations and self-assembly behavior. If inhibitors/stabilizers are used (rare for phosphate monoesters), these should be declared on the CoA.
• For chromatography- or HPLC-oriented uses (less common here), low UV background and minimal peroxide/aldehyde impurities are desirable; however, such specifications are not typical for this class.
• Batch-to-batch considerations: chain length distribution (must be C16-specific, minimal C14/C18), degree of phosphorylation (monoester vs diester/pyrophosphate byproducts), and water content can influence CMC and emulsification performance. Verify by 31P NMR and acid/base titration if critical.

What is specific to this item: only the storage condition is specified as room temperature; all other quality details should be confirmed on the CoA/Spec Sheet for SKU C1072986.

Reaction & Applications

Applications (research/manufacturing context):

• Anionic surfactant precursor: neutralization with alkali to give Na+/K+ cetyl phosphate, a robust O/W emulsifier and dispersant for colloids and nanoparticle suspensions (literature). Useful for studying interfacial phenomena, micellization, and vesicle formation.
• Model membrane component: mimics a phospho-headgroup attached to a single alkyl chain; used in monolayers (Langmuir trough), supported films, and mixed micelles to probe charge/pH effects (literature).
• Surface modification: adsorption onto metal oxides (e.g., TiO2, Al2O3) via phosphate binding can tailor wettability and zeta potential in materials studies (literature).
• Precursor chemistry: convertible to specific counterion salts (e.g., tetraalkylammonium) to tune solubility in organic media and enable organocatalysis in biphasic systems.

Synthesis/derivatization notes (general):

• Prepared by phosphorylation of cetyl alcohol using POCl3, P2O5, or phosphoramidite routes; control of mono- vs diester formation requires stoichiometry and temperature control (literature).
• Hydrolytic stability: phosphate monoesters are generally robust at neutral pH; acid/base extremes accelerate cleavage to phosphoric acid and cetyl alcohol.

Practical tips:

• For aqueous applications, titrate to desired pH with KOH/NaOH while monitoring conductivity; allow time for micelle equilibration before measurements.
• To minimize foaming during neutralization, add base slowly under cooling and vigorous stirring.
• Verify degree of neutralization and purity by 31P NMR (monoester resonance typically around 0 to +2 ppm vs external 85% H3PO4; literature, solvent-dependent).

Reaction Conditions

General conditions relevant to handling and transforming cetyl phosphate (literature-based guidance; adjust to your system):

• Neutralization to alkali salts:
  • Solvent: water or water/ethanol (1:1 to 4:1 v/v).
  • Base: KOH or NaOH (0.1–1.0 M aqueous), added dropwise at 0–25°C with vigorous stirring.
  • Endpoint: target pH 6.5–7.5 for full or near-full neutralization; monitor conductivity and pH. Allow 30–60 min for equilibration.
• Formation of tetraalkylammonium salts (for organic solubility):
  • Solvent: ethanol or isopropanol; or biphasic H2O/CH2Cl2 with phase-transfer.
  • Base/counterion: Et3N or quaternary ammonium hydroxides; keep temperature ≤25°C to limit hydrolysis.
• Self-assembly studies (micelles/monolayers):
  • Aqueous media at ionic strength 10–100 mM (NaCl) and pH 6–8 (for alkali salts).
  • Equilibrate samples ≥1 h before DLS/zeta/CMC measurements.
• Hydrolysis stress tests:
  • Acid: 0.1–1 M HCl, 40–60°C; Base: 0.1–1 M NaOH, 25–50°C; monitor by 31P NMR/LC to assess stability (rates depend on medium and ionization).

Notes:

• Avoid strong dehydrating agents or elevated temperatures during neutralization to prevent side reactions.
• Expected yields for simple neutralizations/salt exchanges are typically high (>90%, literature), limited mainly by workup and drying losses.

Safety & Handling

Item-specific GHS details were not provided; consult the SDS for authoritative information. The following are general handling considerations for alkyl phosphate monoesters.

• GHS classification, signal word, pictograms, H‑statements: Not specified for this item; refer to SDS.
• Likely hazards (general): may cause eye/skin irritation; acidic phosphate can be irritating; dusts or aerosols may irritate respiratory tract.
• PPE: wear lab coat, safety glasses or face shield for splashes, and appropriate chemical-resistant gloves (e.g., nitrile). Use in a fume hood when handling powders, solutions at low/high pH, or during neutralization steps.
• Handling: avoid inhalation of dust; prevent contact with eyes/skin. When preparing salts (neutralization with NaOH/KOH), add base slowly with cooling and stirring to control exotherm and foaming.
• Storage incompatibilities: avoid strong oxidizers and strong bases/acids that could lead to degradation/hydrolysis. Avoid reactive acylating/chlorinating agents.
• Spill/cleanup: absorb small liquid spills with inert material; for solids, gently sweep/HEPA vacuum to minimize dust; wash area with water/detergent. Prevent entry into drains until neutralized/contained.
• First aid (overview):
  • Skin: wash with soap and water; remove contaminated clothing.
  • Eyes: rinse cautiously with water for several minutes; remove contact lenses; seek medical attention if irritation persists.
  • Inhalation: move to fresh air; seek medical attention if symptoms occur.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical advice.
• Defer to SDS for disposal and transport classifications.

Solvent Selection

Cetyl phosphate (free acid) is amphiphilic but overall hydrophobic; its solubility and behavior depend strongly on ionization state and counterion.

• Polarity/miscibility (literature):
  • Water: poor solubility as free acid; forms dispersions or aggregates. Solubility increases significantly upon neutralization (e.g., Na+, K+ salts) or with co‑surfactants/cosolvents.
  • Alcohols (MeOH, EtOH, i‑PrOH), glycols (PG), and aprotic polar solvents (DMF, DMSO): good solubility for stock solutions.
  • Nonpolar solvents (hexanes, toluene): limited solubility due to polar headgroup.
• Typical use scenarios:
  • Prepare concentrated stocks in EtOH/i‑PrOH, then dilute into aqueous media while stirring; adjust pH with base to achieve desired ionization/clarity.
  • For fully aqueous systems, pre‑neutralize to the potassium/sodium salt to obtain true solutions and controlled CMC.
• Comparison (general, literature):
  • Free acid vs potassium salt: the potassium salt shows higher water solubility and better emulsifying power at neutral pH; the free acid is preferred when precise counterion control or subsequent salt metathesis is required.

Small selection guide:

• Need aqueous clarity at pH 6–8: use pre‑neutralization (KOH/NaOH) or prepare the corresponding alkali salt in situ.
• Need organic stock: use EtOH or DMSO; filter through 0.2 µm if aggregates persist.
• Avoid strong acid/base extremes during dissolution to minimize hydrolysis.

Storage & Reconstitution

• Storage conditions (as provided): Room temperature.
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.
• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

General guidance:

• Keep tightly closed in a dry, well-ventilated place. Protect from excessive moisture to maintain defined acid content and prevent caking/aggregation.
• If prolonged storage is anticipated, consider desiccation and protecting from strong light/heat.
• Reconstitution/stock solutions:
  • Organic stocks: dissolve in ethanol, isopropanol, or DMSO at 10–100 mg/mL; mix until homogeneous. Filter (0.2 µm) if needed to remove particulates/aggregates.
  • Aqueous use: slowly add the organic stock to water under vigorous stirring, then titrate with KOH/NaOH to desired pH (typically 6.5–7.5) to obtain clear solutions of the alkali salt. Allow equilibration before use.
• Freeze–thaw: not generally required for the solid. For solutions, store at 2–8°C and use within days to weeks depending on pH/medium; avoid repeated freeze–thaw cycles which can change aggregate state.
• Disposal: follow institutional and local regulations; consult SDS for details.

Research use note: For research use only.

Structure & Identity

Cetyl phosphate is the monoester of phosphoric acid with cetyl alcohol (hexadecanol), comprising a phosphate headgroup attached via an O–P bond to a linear C16 alkyl chain.

• SKU: C1072986
• Product name: Cetyl Phosphate
• CAS: 3539-43-3
• PubChem CID: 19059
• InChIKey (as provided): 467073. Note: a standard InChIKey is typically 27 characters; a canonical InChIKey/SMILES is not specified for this item; refer to CoA/Spec Sheet.
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula (literature): C16H35O4P (free acid, monoester)
• Molecular weight (literature): ~322.43 g/mol

Structural features (general description):

• Functional groups: a phosphate monoester (–O–PO3H2) linked to a saturated C16 alkyl chain (CH3–(CH2)15–O–P(=O)(OH)2).
• No rings, no heteroatoms beyond O and P; no stereocenters.
• Amphiphilic architecture: hydrophilic, acidic phosphate headgroup; hydrophobic cetyl tail.
• Expected ionic states (literature): diacid with two acidic protons on phosphate; partial ionization around neutral pH (phosphate monoester pKa1 ~1–2; pKa2 ~6–7, literature).

Synthetic Utility

Cetyl phosphate is a useful functional intermediate combining a reactive phosphate monoester with a hydrophobic C16 tail.

• Transformations (literature/general):
  • Salt formation: neutralization to alkali or tetraalkylammonium salts tunes solubility from water to organic solvents, enabling phase-transfer or interfacial catalysis studies.
  • Activation of phosphate: conversion to phosphorimidazolide or mixed anhydrides can increase reactivity toward nucleophiles for further derivatization of the phosphate moiety (specialized literature methods).
  • Hydrolysis/cleavage: controlled deprotection to cetyl alcohol and phosphoric acid under acidic or basic conditions provides a handle for reversible surface functionalization.
• Materials chemistry: phosphate anchoring to metal oxides (TiO2, ZrO2, Al2O3) creates hydrophobized yet charged surfaces; useful in adhesion promoters and corrosion studies.
• Retrosynthetic value: represents a convenient route to introduce a phosphate headgroup onto hydrophobic scaffolds without constructing a full glycerophospholipid backbone.

Practical notes:

• Verify monoester purity by 31P NMR to avoid diester/pyrophosphate contaminants that can alter reactivity and interfacial properties.
• When forming tetraalkylammonium salts for organic-phase chemistry, exchange counterions via ion-exchange resins or metathesis (e.g., from K+ to NR4+ using halide salts) and thoroughly remove inorganic residues.

Target Specificity

Not applicable. This product is a small-molecule surfactant/intermediate, not an antibody, enzyme, or affinity reagent. No target, epitope, clone, or species reactivity information is associated with cetyl phosphate.