Pyrabactin is a synthetic sulfonamide that mimics abscisic acid (ABA), a naturally produced stress hormone in plants that helps them cope with drought conditions by inhibiting growth. ABA can be manufactured for agricultural use; however, ABA is light-sensitive and costly to make. Pyrabactin is relatively inexpensive, easy to make, and not sensitive to light. Unlike ABA, pyrabactin activates only a few of the 14 ABA receptors in the plant needed for effective drought tolerance.^[2] Its role as an ABA mimic may make pyrabactin an important tool for protecting crops against drought and cold weather.^[3][4]

Quick Facts Names, Identifiers ...

Pyrabactin

Names
Preferred IUPAC name 4-Bromo-N-[(pyridin-2-yl)methyl]naphthalene-1-sulfonamide
Other names 4-Bromo-N-(pyridin-2-ylmethyl)naphthalene-1-sulfonamide
Identifiers
CAS Number	419538-69-5 Y
3D model (JSmol)	Interactive image
ChemSpider	958087
ECHA InfoCard	100.212.933
PubChem CID	1125790
UNII	L9PM5Q6DDW Y
CompTox Dashboard (EPA)	DTXSID80360553
InChI InChI=1S/C16H13BrN2O2S/c17-15-8-9-16(14-7-2-1-6-13(14)15)22(20,21)19-11-12-5-3-4-10-18-12/h1-10,19H,11H2 Key: GJSDYQXOSHKOGX-UHFFFAOYSA-N InChI=1/C16H13BrN2O2S/c17-15-8-9-16(14-7-2-1-6-13(14)15)22(20,21)19-11-12-5-3-4-10-18-12/h1-10,19H,11H2 Key: GJSDYQXOSHKOGX-UHFFFAOYAQ
SMILES Brc2c1c(cccc1)c(cc2)S(=O)(=O)NCc3ncccc3
Properties
Chemical formula	C16H13BrN2O2S
Molar mass	377.26 g·mol−1
Appearance	White to off-white powder[1]
Solubility in DMSO	>10 mg/mL[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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The discovery of pyrabactin by Sean Cutler was named a breakthrough research of 2009 by Science magazine.^[5]

Pyrabactin (for pyridyl containing ABA activator) is a naphthalene sulfonamide hypocotyl cell expansion inhibitor. A combination of genetic, transcriptomic and physiological evidence demonstrated that pyrabactin activates the ABA pathway in a manner very similar to ABA^[6]. As such, pyrabactin is the first ABA agonist that is not an ABA analog and may ultimately lead to the development of a new family of synthetic plant growth regulators.