Description
Triadimenol is a metabolite of triadimefon (Item No.
18714), a broad-spectrum chiral triazole fungicide, that is formed by reduction of a carbonyl group to the corresponding alcohol.
1 It is teratogenic, inducing cranial nerve and ganglia abnormalities in a rat post-implantation whole embryo culture model when used at concentrations ranging from 12.5 to 125 μM.
2 In vivo, triadimenol induces embryotoxicity in rats and rabbits when administered orally at doses of 100 and 40 mg/kg, respectively. Embryonic exposure to triadimenol (3-3,000 μg/L) induces embryonic mortality as well as decreases fertility and increases the number of female offspring in medaka fish (
O. latipes).
3
Definition
ChEBI: A member of the class of triazoles that is 3,3-dimethyl-1-(1,2,4-triazol-1-yl)butane-1,2-diol substituted at position O1 by a 4-chlorophenyl group. A fungicide for cereals, beet and brassicas used to control a range of diseases including powdery mildew, ru
ts, bunts and smuts.
Production Methods
Triadimenol is commercially produced through a multi-step chemical synthesis involving triazole chemistry. It typically begins with the synthesis of a chlorinated benzyl alcohol derivative, which is then reacted with 1,2,4-triazole to form the core triazole ring structure. This intermediate undergoes further alkylation and oxidation steps to introduce the hydroxyl group and complete the formation of the active fungicidal molecule. The process requires precise control of reaction conditions, such as temperature, solvent choice, and pH, to ensure high yield and purity.
Agricultural Uses
Fungicide: Triadimenol is used to control seed-and soil-borne
diseases and to provide early season control of foliar
diseases. It is applied to seeds of barley, corn, oats, rye,
sorghum and wheat and also to fruits, vegetables and ornamentals. Registered for use in EU countries
. Registered
for use in the U.S.
U.S. Maximum Allowable Residue Levels for Triadimenol
Trade name
BAYFIDAN®; BAYFRDAN EW®;
BAY KWG 0519®; BAYTAN® SEED TREATMENT;
BAYTAN 30® FUNGICIDE; PROTEGE ALLEGIANCE
BAYTAN®; SPINNAKER®; SUMMIT®;
TRIADIMENOL®; TRIAFOL®; TRIAPHOL®
Mechanism of action
Selective with curative, protective and eradicant action. Disrupts membrane function. Sterol biosynthesis inhibitor.
Metabolic pathway
When triadimenol is irradiated by UV light in methanol
solution, two major degradation products are identified
as 1-(4-chlorophenoxy)-3,3-dimethylbutan-2-one and
1-phenoxy-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-
2-ol. When a spray deposit on apple leaves is
exposed outdoors to natural sunlight, the only product
detected is the butanone metabolite. The butanone
metabolite has very low fungicidal activity against
apple powdery mildew, whereas the butanol metabolite
gives some control of infection.
Degradation
When a methanolic solution of triadimenol (1) in borosilicate glass
apparatus was irradiated by a medium pressure mercury lamp for 20
days, 50% of the triadimenol was photodegraded. The products identified
were 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H -1,2,4-triazol-1-yl)butan-2-
one (major product) (2), 4-chlorophenol (3) and 1-phenoxy-3,3-dimethyl-
1-(1H-1,2,4-triazol-1-yl)butan-2-ol(4 ). When triadimenol was irradiated
as a solid deposit, 55% of the parent compound was recovered after 18
days and the same products were identified. Losses may be accounted
for by volatilisation or photodegradation (Clark and Watkins, 1986)
(Scheme 1). The only major product detected 33 days after triadimenol
had been applied to apple tree leaf surfaces exposed to light outdoors
was 2.
References
[1] QIUXUAN SHEN. Enantioselective metabolism of triadimefon and its chiral metabolite triadimenol in lizards[J]. Ecotoxicology and Environmental Safety, 2017, 143: Pages 159-165. DOI:
10.1016/j.ecoenv.2017.05.024[2] E MENEGOLA. In vitro teratogenic potential of two antifungal triazoles: triadimefon and triadimenol.[J]. In Vitro Cellular & Developmental Biology. Animal, 2000, 36 2: 88-95. DOI:
10.1290/1071-2690(2000)036<0088:ivtpot>2.0.co;2[3] SZU-HUNG CHU Pei J C Pei Han Liao. Developmental exposures to an azole fungicide triadimenol at environmentally relevant concentrations cause reproductive dysfunction in females of medaka fish[J]. Chemosphere, 2016, 152: Pages 181-189. DOI:
10.1016/j.chemosphere.2016.02.078
Pesticide Type
Fungicide; Metabolite
;