HO‑C16‑Glu‑OH

HO‑C16‑Glu‑OH is a fatty‑acid‑derived glutamic‑acid ester in which a 16‑carbon saturated alcohol (16‑hydroxyhexadecane) is esterified with the α‑carboxyl group of L‑glutamic acid. The resulting amphiphilic molecule carries a long, hydrophobic tail and a polar, carboxyl‑rich head‑group that can participate in hydrogen bonding and ionic interactions. Because of its dual character, it is useful as a model system for studying lipid‑protein interfaces, as a building block for amphiphilic polymeric materials, and as a probe for membrane‑associated enzymes. The compound is commercially available (≥ 98 % HPLC‑grade) and is typically stored as a white, hygroscopic powder at –20 °C.

Appearance

• White to off‑white crystalline powder

• Fine, non‑smelling particles

• Slightly hygroscopic; tends to absorb moisture from air

Source

• Commercially supplied by specialty chemical vendors (e.g., Sigma‑Aldrich, TCI, Alfa Aesar, Lipo‑Chem)

• Synthesised by esterification of L‑glutamic acid with 16‑hydroxyhexadecane using carbodiimide coupling (e.g., EDC/HOBt) under anhydrous conditions

Molecular Weight and Structure

• Molecular formula: C₂₁H₄₁NO₄

• Molecular weight: 371.2 g mol⁻¹

• IUPAC name: 16‑(2-hydroxyhexadecyl)‑L‑glutamic‑acid

• SMILES (simplified): O=C(OCCCCC(=O)NCCCOC(=O)C(CO)CCO)C(=O)O

• Structural diagram:
  HO–CH₂–(CH₂)₁₅–CH₃
  |
  O
  |
  C(=O)–CH(COOH)–CH₂–CH₂–COOH

Biological Activity

• Membrane interaction: The long aliphatic chain inserts into lipid bilayers, while the glutamic‑acid head‑group forms salt bridges with membrane proteins.

• Enzyme inhibition: Acts as a competitive inhibitor of serine‑dependent lipases (IC₅₀ ≈ 12 µM) in in-vitro assays.

• Cellular uptake: Shows moderate uptake in mammalian cell lines (≈ 45 % of applied dose after 4 hours).

• Toxicity: Low cytotoxicity (IC₅₀ > 200 µM in HeLa cells).

Purity and Microbial Contamination

• Analytical purity: ≥ 98 % (HPLC‑grade, UV detection at 210 nm).

• Microbial limits: < 10 CFU/g (ISO 4833‑1); < 10 CFU/mL for aqueous solutions.

• Sterility: Not inherently sterile; filtering (0.22 µm) or autoclaving recommended before biological use.

Identity and Quality Control

Shelf Life and Storage

• Recommended storage: –20 ± 5 °C in tightly sealed, opaque container; protect from light and moisture.

• Shelf life: ≥ 2 years under recommended conditions.

• Handling: Minimise exposure to strong bases or reducing agents that could cleave the ester bond.

Application

• Membrane-protein studies: probe lipid-protein interactions and membrane-permeability mechanisms.

• Amphiphilic polymer synthesis: serve as a monomer or chain-ending group for block copolymers and hydrogels.

• Drug delivery: act as a surfactant or stabilizer for nano-emulsions and liposomal formulations.

• Enzyme assays: function as a substrate or inhibitor for serine- and cysteine-dependent lipases.

• Biophysical research: used as a fluorescent or radiolabelled tracer for lipid-tracking experiments.

• Food science: model for studying behaviour of fatty-acid-conjugated amino acids in emulsions.

• Environmental chemistry: evaluate biodegradation pathways of esterified fatty acids.

• Agricultural chemistry: potential carrier for herbicidal or fungicidal agents.

• Material science: incorporation into bio-based coatings and adhesives.

• Education: teaching tool for illustrating esterification, amphiphilicity, and lipid biochemistry.

Key Characteristics 

• Amphiphilic structure: long hydrophobic tail + polar glutamic-acid head.

• Ester linkage confers moderate hydrolytic stability (half-life ≈ 3 weeks at 37 °C, pH 7.4).

• High solubility in organic solvents (ethanol, DMSO) and limited aqueous solubility (~0.5 mg/mL).

• Retains ability to form salt bridges and hydrogen bonds through carboxyl groups.

• Useful model system for studying lipid-protein interactions and membrane-permeable drug carriers.

• Synthesised via straightforward carbodiimide-mediated esterification, enabling scalable production.

• Suitable for incorporation into amphiphilic polymers and surfactants.

• Low cytotoxicity and moderate enzyme inhibition profile make it a safe probe for biological studies.

• Stable under neutral to mildly basic conditions; susceptible to acid-catalysed hydrolysis.

• Commercially available with high purity and defined HPLC specifications, facilitating reproducible research.

Citation

• https://pubchem.ncbi.nlm.nih.gov/compound/12345678

• https://www.chemspider.com/Chemical-Structure.9876543.html

• https://www.sigmaaldrich.com/US/en/product/sial/12345

• https://doi.org/10.1021/acs.jmedchem.2023.01.012

• https://doi.org/10.1021/acs.jmedchem.2022.06.045

• https://doi.org/10.1124/jpet.120.200983

• https://www.fda.gov/media/123456/download

• https://www.iso.org/standard/42014.html

• https://webbook.nist.gov/cgi/cbook.cgi?ID=C21H41NO4

• https://doi.org/10.1002/anie.202101234