Peer review of the pesticide risk assessment of the active substance metribuzin

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. 2023 Aug 24;21(8):e08140. doi: 10.2903/j.efsa.2023.8140

Code/trivial name ^(a)	IUPAC name/SMILES notation/InChiKey ^(b)	Structural formula ^(c)
metribuzin, active substance, a.s., BCS‐AA51359	4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one O=C1C(=NN=C(SC)N1N)C(C)(C)C FOXFZRUHNHCZPX‐UHFFFAOYSA‐N
DA‐metribuzin, M01, desamino‐metribuzin, BCS‐AA91084	6‐tert‐butyl‐3‐(methylsulfanyl)‐1,2,4‐triazin‐5(4H)‐one CC(C)(C)C1=NN=C(SC)NC1=O MIWRSUQXSCLDNV‐UHFFFAOYSA‐N
DK‐metribuzin, M02, diketo‐metribuzin, BCS‐AG59919	4‐amino‐6‐tert‐butyl‐1,2,4‐triazine‐3,5(2H,4H)‐dione O=C1N(N)C(=O)NN=C1C(C)(C)C AHBXXEZLRFCZSF‐UHFFFAOYSA‐N
DADK‐metribuzin, M03, desaminodiketo‐metribuzin, BCS‐AA68848	6‐tert‐butyl‐1,2,4‐triazine‐3,5(2H,4H)‐dione O=C1NC(=O)NN=C1C(C)(C)C ZARIFGFXSIZTAK‐UHFFFAOYSA‐N
t‐BuOH‐DADK‐metribuzin, M04, hydroxy‐t‐butyl‐DADK	6‐(1‐hydroxy‐2‐methylpropan‐2‐yl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione OCC(C)(C)C1=NNC(=O)NC1=O KPRRHPBFRZPBBH‐UHFFFAOYSA‐N
4‐methyl‐DADK‐metribuzin, M17, BCS‐AA10228	6‐tert‐butyl‐4‐methyl‐1,2,4‐triazine‐3,5(2H,4H)‐dione O=C1N(C)C(=O)NN=C1C(C)(C)C HAMOEZWHUZLDGI‐UHFFFAOYSA‐N
Desmethylthio‐metribuzin, M18, U1, BCS‐AA10033	4‐amino‐6‐tert‐butyl‐1,2,4‐triazin‐5(4H)‐one O=C1C(=NN=CN1N)C(C)(C)C GMHFNNALALGFKT‐UHFFFAOYSA‐N
Sulfamate‐metribuzin, M15, Sulfamate‐conjugate #8, #8a, #8b	[6‐tert‐butyl‐3‐(methylsulfanyl)‐5‐oxo‐1,2,4‐triazin‐4(5H)‐yl]sulfamic acid OS(=O)(=O)NN1C(=NN=C(C1=O)C(C)(C)C)SC CFTYOBVLLJEBCM‐UHFFFAOYSA‐N
Butylthione‐metribuzin, M10, BCS‐AA66387	4‐amino‐6‐tert‐butyl‐3‐sulfanylidene‐3,4‐dihydro‐1,2,4‐triazin‐5(2H)‐one O=C1N(N)C(=S)NN=C1C(C)(C)C OFKAVNQBCRJBJE‐UHFFFAOYSA‐N	Other tautomeric forms are possible (condition dependent)
Cystein‐DA‐metribuzin, M12, Cystein‐DA, DA‐N‐Ac‐Cys	N‐acetyl‐S‐(6‐tert‐butyl‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazin‐3‐yl)cysteine CC(C)(C)C1=NN=C(SCC(NC(C)=O)C(=O)O)NC1=O NPYMOMKXKZUXGG‐UHFFFAOYSA‐N
DK‐metribuzin glucuronide conjugate, M16, Glucuronide‐conjugate (of DK) #9	3‐[(6‐tert‐butyl‐3,5‐dioxo‐2,5‐dihydro‐1,2,4‐triazin‐4(3H)‐yl)amino]‐3‐deoxyhexopyranuronic acid OC1C(NN2C(=O)C(=NNC2=O)C(C)(C)C)C(O)C(OC1O)C(=O)O PDOLDXBUGCKOLV‐UHFFFAOYSA‐N

Code/trivial name ^(a)

IUPAC name/SMILES notation/InChiKey ^(b)

Structural formula ^(c)

metribuzin,

active substance, a.s.,

BCS‐AA51359

4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one

O=C1C(=NN=C(SC)N1N)C(C)(C)C

FOXFZRUHNHCZPX‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g004.jpg

DA‐metribuzin,

M01,

desamino‐metribuzin,

BCS‐AA91084

6‐tert‐butyl‐3‐(methylsulfanyl)‐1,2,4‐triazin‐5(4H)‐one

CC(C)(C)C1=NN=C(SC)NC1=O

MIWRSUQXSCLDNV‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g011.jpg

DK‐metribuzin,

M02,

diketo‐metribuzin,

BCS‐AG59919

4‐amino‐6‐tert‐butyl‐1,2,4‐triazine‐3,5(2H,4H)‐dione

O=C1N(N)C(=O)NN=C1C(C)(C)C

AHBXXEZLRFCZSF‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g010.jpg

DADK‐metribuzin,

M03,

desaminodiketo‐metribuzin,

BCS‐AA68848

6‐tert‐butyl‐1,2,4‐triazine‐3,5(2H,4H)‐dione

O=C1NC(=O)NN=C1C(C)(C)C

ZARIFGFXSIZTAK‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g001.jpg

t‐BuOH‐DADK‐metribuzin,

M04,

hydroxy‐t‐butyl‐DADK

6‐(1‐hydroxy‐2‐methylpropan‐2‐yl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione

OCC(C)(C)C1=NNC(=O)NC1=O

KPRRHPBFRZPBBH‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g006.jpg

4‐methyl‐DADK‐metribuzin,

M17,

BCS‐AA10228

6‐tert‐butyl‐4‐methyl‐1,2,4‐triazine‐3,5(2H,4H)‐dione

O=C1N(C)C(=O)NN=C1C(C)(C)C

HAMOEZWHUZLDGI‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g008.jpg

Desmethylthio‐metribuzin,

M18,

U1,

BCS‐AA10033

4‐amino‐6‐tert‐butyl‐1,2,4‐triazin‐5(4H)‐one

O=C1C(=NN=CN1N)C(C)(C)C

GMHFNNALALGFKT‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g009.jpg

Sulfamate‐metribuzin,

M15,

Sulfamate‐conjugate #8, #8a, #8b

[6‐tert‐butyl‐3‐(methylsulfanyl)‐5‐oxo‐1,2,4‐triazin‐4(5H)‐yl]sulfamic acid

OS(=O)(=O)NN1C(=NN=C(C1=O)C(C)(C)C)SC

CFTYOBVLLJEBCM‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g003.jpg

Butylthione‐metribuzin,

M10,

BCS‐AA66387

4‐amino‐6‐tert‐butyl‐3‐sulfanylidene‐3,4‐dihydro‐1,2,4‐triazin‐5(2H)‐one

O=C1N(N)C(=S)NN=C1C(C)(C)C

OFKAVNQBCRJBJE‐UHFFFAOYSA‐N

Other tautomeric forms are possible (condition dependent)

Cystein‐DA‐metribuzin,

M12,

Cystein‐DA, DA‐N‐Ac‐Cys

N‐acetyl‐S‐(6‐tert‐butyl‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazin‐3‐yl)cysteine

CC(C)(C)C1=NN=C(SCC(NC(C)=O)C(=O)O)NC1=O

NPYMOMKXKZUXGG‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g002.jpg

DK‐metribuzin glucuronide conjugate,

M16,

Glucuronide‐conjugate (of DK) #9

3‐[(6‐tert‐butyl‐3,5‐dioxo‐2,5‐dihydro‐1,2,4‐triazin‐4(3H)‐yl)amino]‐3‐deoxyhexopyranuronic acid

OC1C(NN2C(=O)C(=NNC2=O)C(C)(C)C)C(O)C(OC1O)C(=O)O

PDOLDXBUGCKOLV‐UHFFFAOYSA‐N

graphic file with name EFS2-21-e08140-g007.jpg

^(a)

The name in bold is the name used in the conclusion.

^(b)

ACD/Name 2021.1.3 ACD/Labs 2021.1.3 (File Version N15E41, Build 123232, 07 July 2021).

^(c)

ACD/ChemSketch 2021.1.3 ACD/Labs 2021.1.3 (File Version C25H41, Build 123835, 28 August 2021).