Peroxidizing Phytotoxicities of 1, 2-Alkylene-1, 2, 4-triazolidines and 3, 4-Alkylene-1, 3, 4-thiadiazolidines

Abstract

The influence of 1, 2-alkylene-l, 2, 4-triazolidines and 3, 4-alkylene-1, 3, 4-thiadiazolidines on peroxidizing phytotoxicities was investigated using corn etioplast protoporphyrinogen-IX oxidase (Protox), autotrophic Scenedesmus acutus cells and Echinochloa utilis. Both types of compounds inhibited Protox, caused ethane formation, decreased chlorophyll content and inhibited growth of Scenedesmus and root-growth of Echinochloa, like peroxidizing herbicides such as p-nitrodiphenyl ethers and cyclic imides. All compounds were identified as peroxidizing herbicides. Among the 1, 2-alkylene-l, 2, 4-triazolidines, tetramethylene-triazolidines exhibited the strongest peroxidizing phytotoxicity, trimethylene-triazolidines and pentamethylene-triazolidines were found to be less active peroxidizers. The tetramethylene moiety of the triazolidine-type compounds appears to be essential for producing active peroxidizing compounds.Phytotoxicities by triazolidin-one-thiones and triazolidine-dithiones were more than 10 times stronger than those of triazolidine-diones.Replacing carbonyl groups in the five-membered moiety by at least one thiocarbonyl group produces stronger peroxidizing phytotoxities. Although the Protox inhibition of triazolidine-peroxidizers was 10-70 times stronger than that of the corresponding thiadiazolidineperoxidizers, the level of other phytotoxic activities was quite similar with both types of peroxidizers. This fact may be caused by isomerization of thiadiazolidines to triazolidines.

Comparison of Phytotoxicities between 4-Fluorinated and Non-fluorinated 2-Chloro-5-(3, 4, 5, 6-tetrahydrophthalimido)benzoates

“…The phytotoxicities caused by alkyl 2-chloro-5-(3, 4, 5, 6-tetrahydro-phthalimido)benzoates (3)(4)(5)(6)(7)(8)(9)(10)(11)(12), alkyl 2-chloro-4-fluoro-5-(3, 4, 5, 6-tetrahydrophthalimido)benzoates (3'-9') and eight reference peroxidizing herbicides (1, 2, 1', 2' and 13-16) were determined by inhibition of corn Protox, and light-induced ethane formation, chlorophyll decrease and growth inhibition of green microalgae S. acutus cells. The results are shown as PI5o in Tables 1 and 2.…”

“…While 2-chloro-5-(3, 4, 5, 6-tetrahydrophthalimido)benzoic acid (2) was an about 75-fold less active Protox inhibitor than chlorophthalim (1), its alkyl esters (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) were 50 to 2000 times stronger Protox inhibitors than the free acid (2). Also the reference diphenyl ether herbicide with an ester group: acifluorfen-methyl [methyl Table 1 Phytotoxic activities of 5-(3, 4 5-(2-chloro-4-trifluoromethylphenoxy)-2-nitrobenzoate, 16], was found ca.…”

“…Peroxidizing Activity of Alkyl 2-chloro-5-(3, 4, 5, 6 tetrahydrophthalimido)benzoates and Alkyl 2-chloro-4 fluoro-5-(3, 4, 5, 6-tetrahydrophthalimido)-benzoates Ethane formation (PI5o (Ethane)), chlorophyll decrease (pI5o (Chlorophyll)) and growth inhibition (PI5o (Growth)) of S. acutus cells can be used conveniently to assay peroxidizing phytotoxicity of compounds. 1, 2, 4) All alkyl 2-chloro-5-(3, 4, 5, 6-tetrahydrophthalimido)benzoates (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) and alkyl 2-chloro-4-fluoro-5-(3, 4, 5, 6-tetrahydrophthalimido)benzoates (3'-9') tested caused ethane formation, chlorophyll decrease and cell-growth inhibition, as indicated by the PI5o in Table 1. The above three peroxidative phytotoxic parameters obtained were quite similar to those shown by the reference peroxidizing herbicides (1, 1' and 13-16 of Table 2).…”

Isomerization of 3,4-Dialkyl-1,3,4-thiadiazolidines and 3,4-Alkylene- 1,3,4-thiadiazolidines by Glutathione 5-Transferase

“…According to the methods of Shouda et al, (1996), ethane was determined by Shimadzu GC-6A gas chromatography system equipped with a flame-ionization detector, using Unipack S glass column (i.d. 32 mm, G L Science).…”