Chinese Name: Tos-Ala-OPPy

English Name: 3-(N-Tosyl-L-alaninyloxy)-5-phenylpyrrole

Abbreviation: Tos-Ala-OPPy

CAS Number: 99740-00-8

Molecular Formula: C20H20N2O4S

Molecular Weight: 384.45

Specifications: 1 g / 5 g / 25 g (Custom packaging supported)

Form: Off-white crystalline powder

Product Number: G02070003

Stock: In stock

Signal: Azo dye color development

Tos-Ala-OPPy is an amino acid-coupled chromogenic substrate, and its detection system is based on the azo dye color development method. This method converts leukocyte esterase activity into an observable color signal through an enzymatic reaction, enabling the detection and analysis of leukocyte esterase.

1. Target recognition and reaction triggering

Leukocyte esterase recognizes the structure of the Tos-Ala-OPPy substrate and catalyzes the hydrolysis of its ester bond. The molecular structure of Tos-Ala-OPPy has been precisely designed to mimic natural substrate structures, ensuring high specificity for leukocyte esterase recognition.

2. Signal generation

After the ester bond is cleaved, the hydrolysis product further undergoes a coupling reaction with the diazonium salt in the detection system, forming an azo dye signal with a color change.

3. Signal quantification

The color intensity of the resulting azo dye is related to the leukocyte esterase activity in the sample. Detection results can be read in two ways:

• Visual colorimetry: Qualitative or semi-quantitative analysis based on color intensity.

• Instrument detection: Color signals are read using urine analyzers or other instruments for automated detection.

1. Leukocyte detection in urinalysis

Used in the development of urinalysis detection systems. By detecting leukocyte esterase activity in urine samples, it helps reflect leukocyte-related indicators. It can serve as a raw material for the leukocyte detection module in urine dry chemistry test strips, routine urinalysis strips, and related analysis platforms.

Suitable detection systems:

• Chromogenic raw material for leukocyte detection module in routine urinalysis strips

• Supporting strip development for automated urine analyzers

• Formulation construction of rapid screening test strips for UTIs

Helping manufacturers of urinalysis test strips and automated detection platforms solve core raw material issues such as insufficient color development sensitivity, slow reaction speed, and poor batch-to-batch stability in the leukocyte detection module.

2. Leukocyte esterase detection in gynecological secretions / bacterial vaginosis (BV) multiplex assays

Used in the development of rapid detection systems for gynecological secretions. By detecting leukocyte esterase activity in vaginal secretions, it helps evaluate local inflammatory response status and serves as one of the detection items related to vaginitis and vaginal microecological abnormalities.

Supports product development:

• Development of gynecological secretion test strips

• R&D of vaginal microecological testing products

Helping gynecological testing reagent companies develop rapid and convenient secretion testing solutions.

3. Leukocyte esterase activity detection

Used in the development of leukocyte esterase-related enzyme activity analysis systems. Through substrate hydrolysis producing a color signal, it enables the detection and analysis of leukocyte esterase activity.

Meets research needs:

• Leukocyte esterase enzyme kinetics and catalytic mechanism analysis

• Biochemical detection system optimization

Helping IVD companies and research institutes solve the methodological tool needs for precise quantitative detection of leukocyte esterase activity.

✅ Mature substrate, reliable performance

• Long-term market validation: Tos-Ala-OPPy has a well-established application foundation for leukocyte esterase detection, with high technological maturity and low raw material risk.

• Methodological recognition: As a classic substrate for the leukocyte esterase azo dye method, it has been cited in numerous publications and patents, with broad recognition in both academic and industrial circles.

• Reduced screening costs: The substrate's performance parameters are clearly defined, helping R&D personnel establish and optimize detection protocols while shortening the preliminary raw material screening cycle.

✅ Rapid color development, high sensitivity

• Good catalytic efficiency: Tos-Ala-OPPy exhibits a fast catalytic reaction rate with leukocyte esterase, meeting the performance requirements for rapid color development after test strip contact with samples.

• Clean color development background: High-purity product with free pyrrole content controlled at low levels, providing a clean color development background and reliable results for both visual and instrument-based interpretation.

• Suitable for automated detection: The color development kinetics meet the reading window requirements of automated urine analyzers, compatible with mainstream detection platforms.

✅ High specificity, anti-interference

• Precise molecular recognition: The chemical structure of Tos-Ala-OPPy has been optimized for high specificity towards leukocyte esterase.

✅ Stable supply, flexible delivery

• In-stock supply: Available from stock, supporting custom specifications from gram to kilogram scale, reducing the impact of supply cycle fluctuations on project development and procurement plans.

• Stable supply: Key synthetic routes and purification processes are fully independently controlled, ensuring long-term stable supply from the source.

• Excellent batch-to-batch consistency: Validated by HPLC and methodology, the mature quality control system ensures minimal batch-to-batch variation and stable performance parameters.