Paclobutrazol

Paclobutrazol
Names
	IUPAC name (2RS,3RS)-1-(4-Chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)-3-pentanol
	Other names PP333
Identifiers
CAS Number	PBZ: 76738-62-0 ;
3D model (JSmol)	PBZ: Interactive image;
Abbreviations	PBZ
ChEBI	PBZ: CHEBI:73162;
ChemSpider	(2R,3R) isomer: 139083; (2S,3S) isomer: 66322;
ECHA InfoCard	100.121.374
PubChem CID	(2R,3R) isomer: 158076; (2S,3S) isomer: 73671;
UNII	PBZ: 6PLV42R3ZA ;
CompTox Dashboard (EPA)	PBZ: DTXSID30216556 ;
	InChI InChI=1S/C15H20ClN3O/c1-15(2,3)14(20)13(19-10-17-9-18-19)8-11-4-6-12(16)7-5-11/h4-7,9-10,13-14,20H,8H2,1-3H3/t13-,14+/m0/s1 Key: RMOGWMIKYWRTKW-UONOGXRCSA-N; PBZ: InChI=1/C15H20ClN3O/c1-15(2,3)14(20)13(19-10-17-9-18-19)8-11-4-6-12(16)7-5-11/h4-7,9-10,13-14,20H,8H2,1-3H3/t13-,14+/m0/s1 Key: RMOGWMIKYWRTKW-DUXBJXIBNA-N; (2R,3R) isomer: Key: RMOGWMIKYWRTKW-KGLIPLIRSA-N; (2S,3S) isomer: Key: RMOGWMIKYWRTKW-UONOGXRCSA-N;
	SMILES PBZ: CC(C)(C)[C@@H]([C@H](CC1=CC=C(C=C1)Cl)N2C=NC=N2)O;
Properties
Chemical formula	C15H20ClN3O
Molar mass	293.80 g·mol−1
Appearance	White crystalline solid
Density	1.23 g/cm3
Melting point	165-166°C
Boiling point	460.9 °C (861.6 °F; 734.0 K) at 760 mHg
Solubility in water	22.9 mg/L (20 °C)
log P	3.11
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Xn
Flash point	232.6 °C (450.7 °F; 505.8 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Paclobutrazol (PBZ) is the ISO common name for an organic compound that is used as a plant growth retardant and triazole fungicide.^[2]^[3] It is a known antagonist of the plant hormone gibberellin, acting by inhibiting gibberellin biosynthesis, reducing internodal growth to give stouter stems, increasing root growth, causing early fruitset and increasing seedset in plants such as tomato and pepper. PBZ has also been shown to reduce frost sensitivity in plants. Moreover, paclobutrazol can be used as a chemical approach for reducing the risk of lodging in cereal crops. PBZ has been used by arborists to reduce shoot growth and shown to have additional positive effects on trees and shrubs. Among those are improved resistance to drought stress, darker green leaves, higher resistance against fungi and bacteria, and enhanced development of roots. Cambial growth, as well as shoot growth, has been shown to be reduced in some tree species.

^ Pesticide Properties Database. "Paclobutrazol". University of Hertfordshire.
^ "Compendium of Pesticide Common Names: paclobutrazol". BCPC.
^ Tesfahun, Wakjira (January 1, 2018). Yildiz, Fatih (ed.). "A review on: Response of crops to paclobutrazol application". Cogent Food & Agriculture. 4 (1): 1–9. doi:10.1080/23311932.2018.1525169. S2CID 134517280.

[PPDB-1] Pesticide Properties Database. "Paclobutrazol". University of Hertfordshire.

[BCPC-2] "Compendium of Pesticide Common Names: paclobutrazol". BCPC.

[Wakjira-3] Tesfahun, Wakjira (January 1, 2018). Yildiz, Fatih (ed.). "A review on: Response of crops to paclobutrazol application". Cogent Food & Agriculture. 4 (1): 1–9. doi:10.1080/23311932.2018.1525169. S2CID 134517280.

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