Eei-AOAc-OSu

Eei-AOAc-OSu is an amino acid derivative featuring an Eei (amino acid) backbone bearing an acetate (AOAc) functionality and an activated N-hydroxysuccinimide ester (OSu) that converts the carboxylate equivalent into a highly reactive acylating group. The molecule's stereochemistry at the Eei center is preserved for chiral recognition during peptide coupling and for maintaining defined spatial presentation in bioconjugation workflows. The OSu ester is designed to undergo nucleophilic acyl substitution with amines under mild conditions, while the AOAc-associated functionality supports downstream functional group adjustment through controlled deprotection or transformation. As a chiral, activated acyl intermediate, Eei-AOAc-OSu can serve as a bridge between protected amino acid chemistry and amide-bond formation, enabling both synthetic peptide construction and targeted derivatization of biomolecules or polymeric substrates.

1. Peptide Coupling Building Block

Eei-AOAc-OSu is applied in peptide synthesis workflows where rapid amide bond formation is required for constructing Eei-containing sequences. The OSu ester provides a carboxyl-activated handle that reacts with amino components to form an amide linkage without relying on harsher coupling reagents, while the retained stereocenter supports stereochemically defined peptide assembly. The AOAc functionality can be used as a protected or masked motif that may be carried through coupling steps and later adjusted to match the desired side-chain or terminal functionality. Downstream, the resulting amide products can be carried into further elongation, cyclization, or side-chain functional elaboration consistent with protected amino acid derivative strategies.

2. Bioconjugation Chemistry

Eei-AOAc-OSu is suitable for chemical biology and bioconjugation applications that require controlled acylation of primary amines on proteins, peptides, or carrier scaffolds. The activated OSu ester reacts with lysine side chains, N-terminal amines, or engineered amine tags to generate stable amide bonds, enabling site-specific labeling strategies when combined with appropriate targeting chemistry. The chiral Eei backbone can influence local conformational preferences and may improve the fidelity of amino acid-based motifs presented on biomolecular conjugates. The AOAc-associated functionality can then be leveraged for subsequent derivatization steps, including conversion to alternative functional groups for linking, immobilization, or analytical characterization.

3. Chiral Amino Acid Derivatization

Eei-AOAc-OSu is employed as a chiral acylating intermediate in amino acid derivatization and fine chemical synthesis where stereochemical integrity must be maintained. The OSu ester allows selective transformation of the carboxylate equivalent into amide derivatives with chosen nucleophiles, supporting the preparation of chiral amide libraries for structure-activity relationship studies and molecular design efforts. The Eei stereocenter provides defined 3D information that can be reflected in downstream binding or recognition assays, while the AOAc functionality can serve as a handle for later functional group tuning. The product's activated ester form also supports streamlined intermediate preparation for subsequent protection-group management in multi-step synthetic sequences.

4. Pharmaceutical Intermediate Preparation

Eei-AOAc-OSu is applicable to pharmaceutical intermediate preparation and process chemistry routes that require controlled activation of an amino acid-derived carboxyl equivalent for amide formation. The OSu ester format can be integrated into synthetic planning for generating amide-linked fragments used in peptidomimetic scaffolds, solubilizing motifs, or intermediate precursors for larger drug-like molecules. The presence of a chiral Eei center supports stereodefined intermediate manufacture, while the AOAc-related functionality can be managed through protecting-group strategies to align with downstream coupling, deprotection, or functional group interconversion steps. The resulting amide intermediates can be carried into further synthesis toward complex heteroatom-containing or aromatic-containing structures commonly encountered in industrial fine chemical production.

5. Analytical Standards And SAR Studies

Eei-AOAc-OSu is used to generate defined amino acid derivatives and acylated standards for analytical research and structure-activity relationship studies. The OSu ester enables reproducible formation of amide products with selected amine partners, supporting the preparation of reference materials for LC-MS, HPLC method development, and identity confirmation of Eei-containing compounds. The chiral integrity of the Eei backbone can be reflected in chromatographic behavior and fragment ion patterns, aiding stereospecific analysis and impurity profiling. AOAc-associated functionality provides an additional structural element that can be monitored during derivatization and used to track transformations across synthetic sequences, supporting robust SAR workflows in medicinal chemistry and chemical biology.

1. An Open-label, Single-center, Safety and Efficacy Study of Eyelash Polygrowth Factor Serum

2. Application of human liver organoids as a patient-derived primary model for HBV infection and related hepatocellular carcinoma

3. Immune-awakening Saccharomyces-inspired nanocarrier for oral target delivery to lymph and tumors

4. Crystal Structure of BamB from Pseudomonas aeruginosa and Functional Evaluation of Its Conserved Structural Features

5. An Isolated TCR αβ Restricted by HLA-A* 02: 01/CT37 Peptide Redirecting CD8+ T Cells to Kill and Secrete IFN-γ in Response to Lung Adenocarcinoma Cell Lines