Peptide chemistry is a cornerstone of modern biological research and drug development, enabling the synthesis of complex biomolecules with therapeutic potential. At the heart of this field lies the precise manipulation of amino acids, where protected derivatives are essential for controlled synthesis. N-Cbz-L-histidine, or Z-His-OH, is one such critical building block, valued for its role in incorporating histidine into peptides. Understanding its properties and applications is key for any chemist involved in peptide synthesis.

Z-His-OH is essentially L-histidine where the alpha-amino group is protected by a benzyloxycarbonyl (Cbz) group. This protection strategy is widely adopted in peptide synthesis because the Cbz group is stable under a range of reaction conditions and can be selectively removed, typically through catalytic hydrogenation (using hydrogen gas with a palladium catalyst), yielding the free amine without damaging the peptide chain. Histidine itself, with its imidazole side chain, is a versatile amino acid involved in catalytic mechanisms, pH buffering, and metal ion coordination within proteins and peptides. Therefore, accurately incorporating it into a synthetic peptide sequence is often crucial for mimicking biological functions.

The physical characteristics of Z-His-OH are typically described as a white to off-white microcrystalline powder. Its chemical formula is C14H15N3O4, and it has a molecular weight of 289.3 g/mol. The melting point is reported around 168°C, often with decomposition, which serves as a basic indicator of purity. When considering purchasing Z-His-OH, researchers often look for suppliers who can provide detailed specifications and consistent quality. Sourcing from manufacturers in regions like China can offer an advantage in terms of price and availability, allowing research groups to buy larger quantities for extensive projects.

The primary application of Z-His-OH is in the synthesis of peptides, particularly using solid-phase peptide synthesis (SPPS) or solution-phase methods. It is coupled to the C-terminus of the growing peptide chain using activating agents like DCC/HOBt or HATU. Following the coupling, the Cbz protecting group is removed to allow for the next coupling step. This controlled assembly is vital for creating peptides that are used in a wide array of fields, including therapeutics, diagnostics, and biochemical research. Beyond peptide synthesis, Z-His-OH can also serve as an intermediate in the synthesis of other complex organic molecules where a protected histidine residue is required.

For scientists and procurement managers looking to buy Z-His-OH, it is advisable to seek out suppliers who can guarantee high purity and reliability. Factors such as CAS number (16843-63-1), a clear list of synonyms (like N-alpha-Carbobenzyloxy-L-histidine), and an accurate description of its physical state are important checkpoints. A competitive Z-His-OH price from a reputable manufacturer can make a significant difference in project budgets, especially for academic labs or companies undertaking large-scale peptide production.

In conclusion, Z-His-OH is an indispensable reagent in peptide chemistry. Its well-defined properties and the effective protection strategy offered by the Cbz group make it a go-to choice for incorporating histidine. By understanding its applications and carefully selecting a quality supplier, researchers can ensure the success of their peptide synthesis endeavors.