Non-Enzymatic Detoxification of 2-Chloro-4,6-Bis (Ethylamino)-s-Triazine (Simazine) by Extracts of Zea mays

Castelfranco, Paul A.; Foy, Chester L.; Deutsch, Deborah B.

doi:10.2307/4040808

Cited by 91 publications

(68 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other species have also been reported to metabolize atrazine (18) anlcl simazine (10) to their hydroxy derivatives. Tlle conversion of 2-chlorotriazines to their 2-hydroxy derivatives is probably non-enzymatic (5,12,20) anid appears to be correlated with the presence of a cyclic hydroxamate, 2,4-dihydroxy-3-keto-7-methoxy-1,4-benzoxazine (benzoxazinone), in plants (10).Sorghum, a resistant species, does not contain benzoxazinone and is nlot able to metabolize the chlorotriazine to the hydroxytriazinie (10). In the intcrmediately susceptible pea, atrazine was readily metabolized to the dealkylated derivative, 2-chloro-4-amino-6-isopropylamino-s-triazine (compound I) (23).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Corn seems to be resistant to atrazine and simazine largely because of its abilitv to convert the 2 herbicides rapidly to noni-phytotoxic 2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine (hydroxyatrazine) and 2-hydroxy-4,6-bis (ethylamino) -s-triazine (hydroxysimazine) (5,9,12,21). Other species have also been reported to metabolize atrazine (18) anlcl simazine (10) to their hydroxy derivatives.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Atrazine Metabolism and Herbicidal Selectivity

1967

View full text Add to dashboard Cite

Su immary. Metabolism of the herbicide 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) was investigated in resistant corn (Zea mays L.) and sorghum (Sorghum zlvlgare Pers.), intermediately susceptible pea (Pisuim sativum L.), and highly susceptible heat (Triticum vulgare Vill.) and soybean (Glycine max Merril.). This study revealed that 2 possible pathways for atrazine metabolism exist in higher plants. All species studied were able to metabolize atrazine initially by N-dealkylation of either of the 2 substituted alkylamine groups. Corn and wheat, which contain benzoxazinone, also metabolized atrazine initially by hydrolysis in the 2-position of the s-triazine ring to form hydroxyatrazine. Subsequent metabolism by both pathways resulted in th-e conversion of the parent atraztine to more polar conmpounds and eventually into methanol-insoluble plant residue. No evidence for s-triazine ring cleavage was obtained. Both pathways for atrazine metabolism appear to detoxify atrazine. The hydroxylation pathway results in a direct conversion of a highly phytotoxic compound to a completely non-phytotoxic derivative. The dealkylation pathway leads to detoxication through one or more partially detoxified, stable intermediates. Therefore, the rate and pathways of atrazine metabolism are important in determining the tolerance of plants to the herbicide. Both quantitative and qualitative dififerences in atrazine metabolism were detected between resistant, intermediately susceptible, and susceptible species. The ability of plants to metabolize atrazine by N-dealkylation andl the influence of thhis pathway in determining tolerance of plants to atrazine are discussed.Two substituted s-chlorotriazines that are widely used today as selective herbicides for the control of annual weeds in fields of corn and sorghumii are 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) and 2-chloro-4,6-bis (ethylamino) -s-triazine (simazine). These compounds are effective inhibitors of the Hill reaction in photosynthesis (17) andl are known to reduce the rate of 14COo fixation in V!ants (3,24).Corn seems to be resistant to atrazine and simazine largely because of its abilitv to convert the 2 herbicides rapidly to noni-phytotoxic 2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine (hydroxyatrazine) and 2-hydroxy-4,6-bis (ethylamino) -s-triazine (hydroxysimazine) (5,9,12,21). Other species have also been reported to metabolize atrazine (18) anlcl simazine (10) to their hydroxy derivatives. Tlle conversion of 2-chlorotriazines to their 2-hydroxy derivatives is probably non-enzymatic (5,12,20) anid appears to be correlated with the presence of a cyclic hydroxamate, 2,4-dihydroxy-3-keto-7-methoxy-1,4-benzoxazine (benzoxazinone), in plants (10).Sorghum, a resistant species, does not contain benzoxazinone and is nlot able to metabolize the chlorotriazine to the hydroxytriazinie (10). In the intcrmediately susceptible pea, atrazine was readily metabolized to the dealkylated derivative, 2-chloro-4-amino-6-isopropylamino-s-triazine (comp...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Atrazine Metabolism and Herbicidal Selectivity

1967

View full text Add to dashboard Cite

show abstract

“…Corn is resistant to atrazine and 2-chloro-4,6-bis (ethylamino) -s-triazine (simazine) largely because of its ability to convert the 2 herbicides rapidly to non-phytotoxic, 2-hydroxv -4 -ethylamino-6-isopropyl-amino-s-triazine (hydroxyatrazine), and 2-hydroxy-4,6-bis (ethylamino)-s-triazine (hydroxysimazine) (1,2,5,10,12). The conversion of the 2-chlorotriazines to their 2-hydroxy derivatives is catalyzed non-enzymatically by a cyclic hydroxamate, 2,4-dihydroxy-3-keto-7-methoxy-1,4-benzoxazine (benzoxazinone) present in corn plants ( 1,5,9). The hydroxylation reaction appears to be correlated with the presence of benzoxazinone in different species (4,12).…”

mentioning

confidence: 99%

Atrazine Metabolism in Resistant Corn and Sorghum

Shimabukuro

1968

Plant Physiol.

View full text Add to dashboard Cite

Abstract. The metabolism of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) in the resistant species, corn (Zea inays L.) and scrghum (Sorghum vulgare Pers.) was not the same. In corn, atrazine was metabolized via both the 2-hydroxylation and N-dealkylation pathways while sorghum metabolized atrazine zvia the N.dealkylation pathway. Atrazine metabolism in corn yielded the metabolites, 2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine (hydroxyatrazine), 2-hydroxy-4-amino-6-isopropylamino-s-triazine (hydroxycompound I), and 2-hydroxy-4-amino-6-ethylamino-s-triazine (hydroxycompound II). None of these hydroxylated derivatives appeared as metabolites of atrazine in sorghum.Hydroxycompounds I and II were formed in 2 ways in corn: (1) by benzoxazinone-catalyzed hydrolysis oif 2-chloro-4-amino-6-isopropylamino-s-triazine (compound I) and 2-chloro.4-aminc-6-ethylamino-s-triazine (compound II) that were formed by N.deadkylation of atrazine and (2) by N-dealkylation of hydroxyatrazine, the major atrazine metabolite in corn. The interaction of the 2-hydroxylation and N-detilkylation pathways in corn results in the formation of the 3 hydroxylated non-phytotoxic derivatives of atrazine.Metabolism of 2-chloro-4-ethl-laiinio-6-isopropylamiiino-s-triazine (atrazine) in hligher plants was shown to be an important factor in herbilcidal selectivity. Detoxication of atrazine was reported to occur via the 2-hydroxylation and N-dealkylation pathways in higher plants (12). Corn is resistant to atrazine and 2-chloro-4,6-bis (ethylamino) -s-triazine (simazine) largely because of its ability to convert the 2 herbicides rapidly to non-phytotoxic, 2-hydroxv -4 -ethylamino-6-isopropyl-amino-s-triazine (hydroxyatrazine), and 2-hydroxy-4,6-bis (ethylamino)-s-triazine (hydroxysimazine) (1,2,5,10,12). The conversion of the 2-chlorotriazines to their 2-hydroxy derivatives is catalyzed non-enzymatically by a cyclic hydroxamate, 2,4-dihydroxy-3-keto-7-methoxy-1,4-benzoxazine (benzoxazinone) present in corn plants ( 1, 5, 9). The hydroxylation reaction appears to be correlated with the presence of benzoxazinone in different species (4,12). N-Dealkylation of atrazine occurred in higher plants to form 2-chloro-4-amino-6-isopropylamino-striazine (compound I) and 2-chloro-4-amino-6-ethylamino-s-triazine (compound II) (12,13,14). In resistant sorghum, only the N-dealkylation pathway was reported to be active, but in, corn both hydroxylation and N-dealkylation pathways were active.Autoradiographic evidence indicated that after a 48-hr atrazine treatment period, corn and sorghum yielded at least 1 common water-soluble metabolite of atrazine, but corn produced 2 other metabolites, neither of which was hydroxyatrazine (12).Hydroxylation of compounds I and II to fornm hydroxycompounds I and II (fig 1) is pos-sible in benzoxazinone-containing corn, but not in sorghum. N-Dealkylation of hydroxvatrazine (fig 1) could also occuir in corn to give hydroxyconu ounds I ande II. Such a reaction would not occur in sorghumi since atrazin.e is not conve...

show abstract

“…Castel franco, Foy & Deutsch (1961) showed that maize extracts may hydrolyse simazine non-enzymatically in the presence of DIMBOA or its 2-glucoside_ Hamilton (1964a;1964b) reported a maize mutant deficient in DIMBOA whjch lowered the tolerance to atrazine. He also reported on the difference in DIMBOA content of several species of Poaceae.…”

Section: Introductionmentioning

confidence: 99%

Screening for DIMBOA (benzoxazinone) concentration among South African inbred maize lines and sorghum cultivars

Malan¹,

Visser

Venter

1984

South African Journal of Plant and Soil

View full text Add to dashboard Cite

Twenty-seven popular South African inbred maize lines, four commercial maize cultivars, two sweet corn cultivars and two grain sorghum cultivars were screened by means of a rapid, semi-quantitative method to determine DIMBOA concentration_ Significant differences were found between inbred lines. Sweet corn cultivars exhibited a relatively high concentration of DIM BOA, while grain sorghum contained a very low concentration. Although differences in concentration between plants cultivated from different seed sizes were found, no definite trend could be established.S. Atr. J. Plant Soil 1984, 1: 99-102 'n Eenvoudige en vinnige metode is gebruik om 27 populere Suid-Afrikaanse ingeteelde mielielyne, vier kommersiele kultivars, twee suikermieliekultivars ,l'ln twee graansorghumkultivars te sif vir DIMBOA-konsentrasie. Betekenisvolle verskille het tussen ingeteelde mielielyne voorgekom. In die suikermieliekultivars het 'n relatief hoe konsentrasie DIMBOA voorgekom terwyl 'n baie lae konsentrasie in graansorghum gevind is. Tussen plante wat van verskillende saadgroottes gekweek is, is verskille in DIMBOAkonsentrasie verkry, alhoewel geen definitiewe tendens vir 'n hoer konsentrasie by plante wat van groot sade gekweek is, gevind kon word nie.S.-Atr. Tydskr. Plant Grond 1984, 1: 99-102

show abstract

Non-Enzymatic Detoxification of 2-Chloro-4,6-Bis (Ethylamino)-s-Triazine (Simazine) by Extracts of Zea mays

Cited by 91 publications

References 0 publications

Atrazine Metabolism and Herbicidal Selectivity

Atrazine Metabolism and Herbicidal Selectivity

Atrazine Metabolism in Resistant Corn and Sorghum

Screening for DIMBOA (benzoxazinone) concentration among South African inbred maize lines and sorghum cultivars

Contact Info

Product

Resources

About