(S)-2-(16-(tert-butoxy)-16-oxohexadecanamido)-5-((2,5-dioxopyrrolidin-1-yl)oxy)-5-oxopentanoic acid [L-tBuO-Pal-Glu(OSu)-OH]

(S)-2-(16-(tert-butoxy)-16-oxohexadecanamido)-5-((2,5-dioxopyrrolidin-1-yl)oxy)-5-oxopentanoic acid, abbreviated as L-tBuO-Pal-Glu(OSu)-OH, is a synthetically derived building block used for lipidating peptides, proteins, or other molecules. It features tert-butyl protected palmitic acid, glutamic acid, and an N-hydroxysuccinimide (NHS) ester (OSu). The tert-butyl ester on palmitic acid provides potential advantages in controlled release and self-assembly. The compound’s long alkyl chain affords lipophilicity for membrane insertion, while the NHS ester enables conjugation to primary amines on target molecules. Applications include membrane-anchored peptide synthesis, liposomal formulations, and protein modification. The tert-butyl ester can be selectively removed under acidic conditions for further lipid modification.

Appearance

• White to off-white solid, possibly waxy due to palmitic chain.

Source

• Chemically synthesized; not naturally occurring.

• Supplied by specialized chemical and bioconjugation vendors.

Molecular Weight and Structure

• Approximate molecular weight: 622.8 g/mol (C33H58N2O9).

• Structure includes palmitic acid with tert-butyl ester, glutamic acid core, and NHS ester on glutamic acid side chain.

Biological Activity

• Generally biologically inactive alone.

• Activity depends on conjugated molecules.

• Alkyl chain enables membrane insertion; NHS ester supports biomolecule conjugation.

Purity and Microbial Contamination

• Purity: ≥ 95% (HPLC).

• Minimal microbial contamination; suppliers provide COAs.

• Tested by LAL assay and sterility testing.

Identity and Quality Control

• Confirmed by mass spectrometry (MS), NMR spectroscopy (¹H & ¹³C), and IR spectroscopy.

• Purity assessed by HPLC.

• Amine quantification confirms NHS ester reactivity.

Shelf Life and Storage

Application

• Lipopeptide synthesis for membrane anchorage.

• Protein lipidation.

• Liposomal drug formulation.

• Surface hydrophobic modification.

• Bioconjugation targeting primary amines.

Key Characteristics

• Lipophilic due to palmitic acid tert-butyl ester.

• NHS ester reactive toward primary amines.

• tert-Butyl ester allows selective deprotection.

• Versatile in chemical coupling.

• Soluble in chloroform, DCM, DMSO.

Citation

• NHS ester-mediated lipid conjugation chemistry:
  https://pubmed.ncbi.nlm.nih.gov/30613757/

• Palmitoylation and lipid modification of peptides and proteins:
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6653962/

• Lipidated peptides in drug delivery and self-assembly:
  https://www.sciencedirect.com/science/article/pii/S0142961219304954

• Use of tert-butyl esters in lipid and peptide synthesis:
  https://doi.org/10.1016/j.tet.2014.11.058

• Applications of NHS esters in protein bioconjugation:
  https://pubmed.ncbi.nlm.nih.gov/20420327/

• Liposomal formulations incorporating NHS ester lipids:
  https://pubmed.ncbi.nlm.nih.gov/30817167/

• Self-assembling lipids and peptides with functional modifications:
  https://pubmed.ncbi.nlm.nih.gov/29395641/

• Patents on lipid-NHS ester compounds for drug delivery:
  https://patents.google.com/patent/US20170268536A1/en

• Chemical databases for palmitoylated and tert-butyl protected glutamic acid derivatives:
  https://pubchem.ncbi.nlm.nih.gov/compound/5386443

• Studies on fatty acid conjugation and membrane interactions:
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5357263/