Description

Z-Leu-Onp (CAS NO 1738-87-0) is a protected amino acid derivative, specifically the p-nitrophenyl ester of N-benzyloxycarbonyl-L-leucine, widely used as a key building block in peptide synthesis. Its primary value lies in its role as an activated ester, facilitating efficient and selective amide bond formation under mild conditions, which is critical for constructing complex peptides and peptidomimetics. This high-purity intermediate is essential for researchers and manufacturers in the pharmaceutical, biotechnology, and life science sectors engaged in the development of therapeutic peptides, diagnostic agents, and biochemical tools.

Application

• Solid-Phase Peptide Synthesis (SPPS): Employed as an activated amino acid derivative for the sequential coupling of leucine residues, enabling the automated production of custom peptides.
• Solution-Phase Peptide Synthesis: Used in classical solution-phase methodologies for the synthesis of short to medium-length peptide sequences and peptide fragments.
• Pharmaceutical Intermediate: Serves as a critical precursor in the research and development of peptide-based active pharmaceutical ingredients (APIs) and prodrugs.
• Bioconjugation: Facilitates the site-specific labeling of proteins, antibodies, or other biomolecules with leucine-containing tags or probes for diagnostic and research applications.
• Combinatorial Chemistry: Utilized in the generation of diverse peptide libraries for high-throughput screening in drug discovery programs.
• Biochemical Research: Acts as a substrate or inhibitor in enzymatic studies, particularly those involving proteases or peptidases.

Basic Information

Product Name	Z-Leu-Onp
CAS No.	1738-87-0
Molecular Formula	C₂₀H₂₂N₂O₆
Molecular Weight	386.40 g/mol
Synonyms	N-Carbobenzoxy-L-leucine p-nitrophenyl ester; N-Cbz-L-leucine 4-nitrophenyl ester; Z-L-Leucine p-nitrophenyl ester; (S)-2-(((Benzyloxy)carbonyl)amino)-4-methylpentanoic acid 4-nitrophenyl ester; Cbz-Leu-ONp; Benzyl N-[(2S)-1-[(4-nitrophenoxy)-oxomethyl]-4-methyl-pentyl]carbamate; Nα-Carbobenzyloxy-L-leucine p-nitrophenyl ester
EINECS	217-099-1

Quality Control

Our Z-Leu-Onp is manufactured under strict quality management systems to ensure batch-to-batch consistency and high chemical purity suitable for research and synthesis applications. Each lot undergoes comprehensive analytical testing, including HPLC for purity assessment, chiral analysis to confirm enantiomeric purity, and identity confirmation via IR and NMR spectroscopy. A detailed Certificate of Analysis (COA) is provided with every shipment, documenting all critical quality attributes.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 15-25°C. This product is hygroscopic (moisture-sensitive) and should be handled in a dry environment to prevent hydrolysis of the active ester moiety. For long-term storage, consider desiccation.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Identification (NMR)	Conforms to structure
Assay (HPLC)	≥ 98.0%
Enantiomeric Purity (Chiral HPLC)	≥ 99.0% (L-isomer)
Melting Point	88 - 92 °C
Specific Rotation [α]²⁰D	-15° to -18° (c=1 in DMF)
Loss on Drying	≤ 0.5%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.