Indole-3-acetic acid

Indole-3-acetic acid (IAA, CAS 87-51-4) is the principal naturally occurring auxin plant hormone, serving as a foundational scaffold for agricultural biotechnology, plant physiology research, and medicinal chemistry. This molecule integrates an indole core—a privileged nitrogen heterocycle prevalent in bioactive natural products—with an acetic acid side chain at the C3 position, creating the optimal spatial arrangement for auxin receptor (TIR1/AFB) binding and downstream signaling activation. The two-carbon linker between the indole ring and carboxylic acid moiety provides the precise conformational geometry required for high-affinity receptor engagement, while the carboxyl group enables salt formation, esterification, or amide coupling for formulation optimization. Compared to its synthetic analog indole-3-butyric acid (IBA, CAS 133-32-4), IAA offers direct physiological relevance but reduced stability due to rapid metabolic degradation, making it ideal for mechanistic studies, gene expression research, and controlled-release formulations. Beyond agriculture, this scaffold serves as a valuable building block for synthesizing CNS-penetrant drug candidates, serotonin receptor modulators, and tryptophan-mimetic therapeutics. Manufactured with purity ≥98-99% under controlled conditions, it supports research programs requiring authentic auxin standards for tropism assays, root development studies, and crop optimization research.