Name: China Factory Supplier High Quality Ethyl N-benzoyl-L-argininate hydrochloride CAS 2645-08-1
Brand: Wuhan Fortuna Chemical Co., Ltd.

Ethyl N-benzoyl-L-argininate hydrochloride is a synthetic, water-soluble ester derivative of the amino acid L-arginine. Its primary use is as a chromogenic substrate in biochemical laboratories to detect, measure, and study the activity of specific enzymes, most notably the serine protease trypsin.

1. Chemical Definition and Structure

Core Structure: It is based on the natural amino acid L-arginine.
Modifications:
N-benzoyl: A benzoyl group (C₆H₅C=O-) is attached to the alpha-amino group (NH₂-) of the arginine. This makes it a specific target for certain enzymes.
Ethyl ester: The carboxylic acid group (-COOH) of the arginine is converted into an ethyl ester (-COOCH₂CH₃). This modification enhances stability and solubility.
Hydrochloride salt: The compound is stabilized as a hydrochloride salt (HCl), which ensures it is crystalline, stable, and highly soluble in water—a crucial property for its use in aqueous lab assays.
Abbreviation: It is often abbreviated as BAEE (Benzoyl-Arginine Ethyl Ester) or Bz-Arg-OEt ∙ HCl in scientific literature and product catalogs.

2. Key Properties and Mechanism of Use

This compound is a classic example of a chromogenic substrate. Its value lies in what happens when a specific enzyme acts on it.

Enzyme Target: It is specifically hydrolyzed (cleaved) by enzymes from the serine protease family, with trypsin being the most important one. Trypsin naturally cleaves peptide bonds next to the amino acids arginine and lysine.
The Reaction: Trypsin cleaves the ester bond of BAEE, releasing ethanol and N-benzoyl-L-arginine.
How it's Measured (The "Chromogenic" Part): The reaction mixture is monitored using a spectrophotometer. The product of the hydrolysis, N-benzoyl-L-arginine, has a different electrical charge than the original substrate. This change in charge can be measured as a steady increase in electrical conductivity of the solution.
Historically, this reaction was one of the first to be followed using pH-stat titration, as the hydrolysis also slowly liberates a proton (H⁺ ion), which changes the pH of the solution.

3. Primary Uses and Applications

Enzyme Activity Assays: Its main application is to quantitatively determine the activity or concentration of trypsin in a sample. By measuring the rate of the reaction (the increase in conductivity per minute), a researcher can calculate how much active enzyme is present.
Enzyme Kinetics: It is used to study the catalytic mechanism of trypsin and other arginine-specific proteases, determining parameters like Michaelis constant (Kₘ) and maximum velocity (Vₘₐₓ).
Inhibitor Screening: It can be used to test for molecules that inhibit trypsin activity. If an inhibitor is present, the rate of the BAEE hydrolysis reaction will decrease.
Quality Control: Used in the production and QC of trypsin preparations to ensure consistent and specific activity.

4. Comparison with Similar Substrates

Substrate	Abbreviation	Key Feature	Typical Use
Ethyl N-benzoyl-L-argininate	BAEE	Measures activity via conductivity/pH change	Classic assay for trypsin activity
Nα-Benzoyl-L-arginine 4-nitroanilide	BAPNA	Releases yellow 4-nitroaniline	Spectrophotometric assay (absorbance at 410 nm)
Tosyl-Gly-Pro-Arg 4-nitroanilide	...	More specific sequence	Assays for thrombin and other clotting factors

Important Safety Note

Like all laboratory chemicals, it must be handled with care. While not considered highly toxic, it is an irritant to the eyes, skin, and respiratory system. Standard laboratory safety practices (wearing gloves, safety glasses) are required when handling it.

Conclusion

Ethyl N-benzoyl-L-argininate hydrochloride is not a drug or a naturally occurring metabolite. It is a specialized synthetic biochemical tool. Its sole purpose is to act as a sensitive and specific "signal molecule" that allows scientists to monitor and quantify the action of the enzyme trypsin in a test tube. Its design is a elegant example of creating a molecule tailored for a specific diagnostic analytical technique.