Overview
Indirubin is a red isomer of indigo, originally isolated from plants like Indigofera tinctoria and Isatis indigotica. It has been used for centuries in traditional Chinese medicine, particularly in formulations like Danggui Longhui Wan for chronic myelogenous leukemia. In modern times, indirubin has gained attention for its potential as a therapeutic agent in cancer treatment due to its ability to inhibit cell proliferation. As a B2B commodity, indirubin is typically supplied as a high-purity standard or raw material for pharmaceutical production. Its procurement requires careful attention to regulatory compliance, especially when used in drug development. The compound is also studied for its anti-inflammatory and neuroprotective effects, expanding its applications beyond oncology.
Physical and Chemical Properties
Indirubin appears as a reddish-brown crystalline powder with a melting point of 356-358°C. Its molecular structure consists of two indole rings connected by a double bond, contributing to its planar configuration and light sensitivity. The compound is stable under recommended storage conditions but may degrade upon prolonged exposure to UV light or moisture. Solubility is a key consideration for formulation. Indirubin dissolves well in dimethyl sulfoxide (DMSO) and moderately in other organic solvents like ethanol, but it has negligible water solubility. This characteristic often necessitates the use of solubilizing agents in pharmaceutical preparations. The compound exhibits strong UV-Vis absorption around 540 nm, which is useful for analytical quantification.
Main Applications
In the pharmaceutical industry, indirubin is primarily investigated for its anticancer properties, particularly against leukemia cells. It functions as a potent inhibitor of cyclin-dependent kinases (CDKs) and glycogen synthase kinase-3β (GSK-3β), making it valuable for both therapeutic development and biochemical research. Traditional medicine applications continue to utilize indirubin in compound formulations for inflammatory conditions. Recent studies explore its potential in treating neurodegenerative diseases and diabetes. In B2B markets, demand comes from pharmaceutical manufacturers, research institutions, and supplement producers, with purity requirements varying from 95% for traditional medicine to 98%+ for clinical research.
Safety and Storage
As a biologically active compound, indirubin requires careful handling. Laboratory personnel should use appropriate PPE including nitrile gloves and safety goggles when working with the powder form. While not highly volatile, airborne particles should be avoided through use of fume hoods or proper ventilation systems. For long-term storage, indirubin should be kept in amber glass containers or light-resistant packaging at temperatures between 2-8°C. Desiccants are recommended to prevent moisture absorption. The compound is relatively stable when properly stored, with typical shelf lives of 2-3 years from production date. Always check for discoloration or clumping before use as these may indicate degradation.
B2B Procurement Guide
When sourcing indirubin for commercial use, prioritize suppliers who provide comprehensive documentation including Certificate of Analysis (COA), Material Safety Data Sheet (MSDS), and preferably GMP certification for pharmaceutical-grade material. Key specifications to verify include HPLC purity (≥98% for research applications), residual solvent levels, and heavy metal content. Bulk pricing becomes economical at quantities above 100 grams, with contract manufacturing options available for kilogram-scale orders. Lead times vary significantly depending on source and purity requirements—standard grades may be available from stock, while customized purifications may require 4-8 weeks. Consider supplier track record with regulatory filings if the material will be used in FDA or EMA submissions.