1-Naphthaleneacetic acid (NAA) is an
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...
C
10H
7CH
2CO
2H. This colorless solid is soluble in organic solvents. It features a carboxylmethyl group (CH
2CO
2H) linked to the "1-position" of
naphthalene
Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white Crystal, crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 Parts-per notation ...
.
Use and regulation
NAA is a synthetic
plant hormone
Plant hormones (or phytohormones) are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of plant growth and development, including embryogenesis, the regulation of Organ (anat ...
in the
auxin
Auxins (plural of auxin ) are a class of plant hormones (or plant-growth regulators) with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essent ...
family and is an ingredient in many commercial
horticultural
Horticulture (from ) is the art and science of growing fruits, vegetables, flowers, trees, shrubs and ornamental plants. Horticulture is commonly associated with the more professional and technical aspects of plant cultivation on a smaller and mo ...
products; it is a rooting agent and used for the
vegetative propagation
Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is a form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specializ ...
of plants from stem and leaf
cuttings. It is also used for
plant tissue culture
Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues, or organs under sterile conditions on a nutrient culture medium of known composition. It is widely used to produce clones of a plant in a method know ...
.
The hormone NAA does not occur naturally, and, like all auxins, is toxic to plants at high concentrations. In the United States, under the
Federal Insecticide, Fungicide, and Rodenticide Act
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) is a United States federal law that set up the basic U.S. system of pesticide regulation to protect applicators, consumers, and the environment. It is administered and regulated by t ...
(FIFRA), products containing NAA require registration with the
Environmental Protection Agency (EPA) as
pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...
s.
Use and analysis
NAA is widely used in agriculture for various purposes. It is considered to be only slightly toxic but when at higher concentrations it can be toxic to animals. This was shown when tested on rats via oral ingestion at 1000–5900 mg/kg. NAA has been shown to greatly increase cellulose fiber formation in plants when paired with another phytohormone called gibberellic acid. Because it is in the auxin family it has also been understood to prevent premature dropping and thinning of fruits from stems. It is applied after blossom fertilization. Increased amounts can actually have negative effects however, and cause growth inhibition to the development of plant crops. It has been used on many different crops including apples, olives, oranges, potatoes, and various other hanging fruits. In order for it to obtain its desired effects it must be applied in concentrations ranging from 20–100 μg/mL. NAA present in the environment undergoes oxidation reactions with hydroxyl radicals and sulfate radicals. Radical reactions of NAA were studied using pulse radiolysis technique. Hydroxyl adduct radical was formed as the intermediate during the reaction of hydroxyl radical with NAA. The intermediate naphthyl methyl radical was formed during the reaction of sulfate radical anion with NAA.
In
micropropagation
Micropropagation or tissue culture is the practice of rapidly multiplying plant stock material to produce many progeny plants, using modern plant tissue culture methods.
Micropropagation is used to multiply a wide variety of plants, such as ...
of various plants, NAA is typically added to a medium containing nutrients essential to the plants' survival. It is added to help induce root formation in various plant types. It can also be applied by spraying it onto plants and which is typical in agricultural use. It is prohibited in many areas to use it in high concentrations due to the health concerns towards humans and other animals.
NAA can be detected by
HPLC
High-performance liquid chromatography (HPLC), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify specific components in mixtures. The mixtures can origina ...
-tandem mass spectrometry (HPLC-MS/MS).
[M.J. Benotti, F.P. Lee, R.A. Rieger, C.R. Iden, C.E. Heine, B.J. Brownawell HPLC/TOF-MS: an alternative to LC/MS/MS for sensitive and selective determination of polar organic contaminants in the aquatic environment Ferrer Imma, E.M. Thurman (Eds.), Liquid Chromatography/Mass Spectrometry, MS/MS and Time of Flight MS, American Chemical Society, New York (2003), pp. 109–127]
Derivative uses
*RSD 1000
69191-56-4
See also
*
1-Naphthaleneacetamide
*
Micropropagation
Micropropagation or tissue culture is the practice of rapidly multiplying plant stock material to produce many progeny plants, using modern plant tissue culture methods.
Micropropagation is used to multiply a wide variety of plants, such as ...
*
Tissue culture
Tissue culture is the growth of tissue (biology), tissues or cell (biology), cells in an artificial medium separate from the parent organism. This technique is also called micropropagation. This is typically facilitated via use of a liquid, semi-s ...
*
Indole-3-butyric acid - Another chemical used as a plant rooting agent.
References
{{DEFAULTSORT:Naphthaleneacetic acid, 1-
Acetic acids
Auxins
1-Naphthyl compounds
Plant growth regulators