Indole-3-acetic acid Property

Melting point:

165-169 °C (lit.)

Boiling point:

306.47°C (rough estimate)

Density 

1.1999 (rough estimate)

refractive index 

1.5460 (estimate)

Flash point:

171°C

storage temp. 

-20°C

solubility 

DMSO:30.0(Max Conc. mg/mL);171.25(Max Conc. mM)

pka

4.75(at 25℃)

form 

crystalline

color 

off-white to tan

Water Solubility 

Soluble in ethanol (50 mg/ml), methanol, DMSO, and chloroform (sparingly). Insoluble in water.

Decomposition 

167 ºC

Sensitive 

Light Sensitive

Merck 

14,4964

BRN 

143358

Stability:

Stable. Incompatible with strong oxidizing agents. Light sensitive.

LogP

1.410

CAS DataBase Reference

87-51-4(CAS DataBase Reference)

NIST Chemistry Reference

Indole-3-acetic acid(87-51-4)

EPA Substance Registry System

Indole-3-acetic acid (87-51-4)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

22-24/25

WGK Germany 

3

RTECS 

NL3150000

F 

8-10-23

Hazard Note 

Irritant

TSCA 

Yes

HS Code 

29339990

Toxicity

LD50 intraperitoneal in mouse: 150mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P405Store locked up.

Indole-3-acetic acid Chemical Properties,Usage,Production

Chemical Properties

white to tan crystals

Uses

It is applied as plant growth hormone. is an inducer of plant cell elongation and division shown to cause uncontrolled growth.

Uses

Plant growth regulator.

Definition

ChEBI: A monocarboxylic acid that is acetic acid in which one of the methyl hydrogens has been replaced by a 1H-indol-3-yl group.

Biosynthesis

3-Indolylacetic acid is biosynthesised in plants from tryptophan by two pathways, the indolylpyruvic acid pathway being quantitatively the more important. Experiments with tomato shoots have shown the existence of a tryptophan transaminase, which catalyses the formation of indolylpyruvic acid, and a tryptophan decarboxylase, which catalyses the formation of tryptamine. The decarboxylation of indolylpyruvic acid is catalysed by indolylpyruvate decarboxylase, while indolylacetaldehyde dehydrogenase catalyses the oxidation of indolylacetaldehyde to indolylacetic acid.

The biosynthesis of 3-indolylacetic acid

Biological Functions

3-Indolylacetic acid (indole-3-acetic acid, IAA) is one of the auxins, which together with the gibberellins and abscisic acid, cyto- kinins and ethylene are hormones regulating the growth and development of plants. IAA is a ubiquitous constituent of higher plants and the most important auxin. Some other, non-indolic compounds, including phenyl- acetic acid biosynthesised in plants from phenylalanine, have similar properties and synthetic auxins have also been prepared.
In the plant, IAA conjugates with many compounds, including glucose and other sugars, and with aspartic and glutamic acids. This is probably a way of storing the hormone for future use.
IAA initiates many growth effects in plants, including geotropism and phototropism, development of the ovary, division of cells, enlargement in callus tissue, root formation and apical dominance. When fed to plants, the hormone causes growth up to a maximum, which depends on the type of tissue being fed, and thereafter inhibits further growth, probably through the formation of ethylene, which is growth-inhibitory. Stern tissues tolerate the highest levels of IAA and root tissues the lowest. In the plant, the most active sites of IAA synthesis are the young, expanding leaves.

General Description

3-Indoleacetic acid is a highly effective, growth promotor in lower plant life, formed by a variety of fungi, including yeast and has been isolated from Aspergillus niger and Rhizopus sp. It is commonly employed in horticulture and industry.

Agricultural Uses

Indoleacetic acid (IAA), synthesized in the plant shoot tips, is a naturally occurring auxin. It is a plant growth promoter.

storage

Store at -20°C

Purification Methods

Recrystallise heteroauxin from EtOH/water [James & Ware J Phys Chem 89 5450 1985]. [Beilstein 22 III/IV 65.] Alternatively recrystallise 30g of the acid with 10g of charcoal in 1L of hot water, filter and cool when 22g of colourless acid separate. Dry it and store it in a dark bottle away from direct sunlight [Johnson & Jacoby Org Synth Coll Vol V 654 1973]. The picrate has m 178-180o. [Beilstein 22 H 66, 22 I 508, 22 II 50, 22 III/IV 1088.] It is a plant growth substance.