Herbicide dithiocarbamate

D (2,4-dichlorophenoxyacetic acid) patented as a plant growth regulator and later as a general herbicide dithiocarbamate fungicide marketed... 

Dithiocarbamate (DTC) pesticides are primarily used in agriculture as fungicides, insecticides, and herbicides. Additional uses are as biocides for... 

Warshawsky, A., Rogachev, I., Patil, Y., Baszkin, A., Weiner, L. and Gressel, J. (2001). Copper-specific chelators as synergists to herbicides 1. Amphiphilic dithiocarbamates, synthesis, transport through lipid bilayers, and inhibition of Cu/Zn superoxide dismutase activity, Langmuir, 17, 5621-5635. 

Toxicological Significance of Oxidation and Rearrangement Reactions of iS -Chloroallyl Thio-and Dithiocarbamate Herbicides... 

Proherbicides. Thio- and dithiocarbamates probably require metabolic activation prior to exerting their herbicidal effects. Sulfoxide metabolites of the -alkyl thiocarbamates are generally more potent herbicides than the parent compounds ( -5). The herbicidal action of these sulfoxides probably results from their carbamylating action for thiols, although the specific target site or receptor is not defined (23, 24). It is conceivable that the -chloroallyl thiocarbamate herbicides may act in the same way, since their sulfoxides are also potent carbamylating agents... 

Some Reactions of Diallate, Trlallate and Sulfallate of Possible Importance to Their Mutagenic and/or Garcinogenic Properties. Current knowledge of the oxidation and rearrangement reactions of -(2-chloroallyl) thio- and dithiocarbamate herbicides in relation to their mutagenic activities is illustrated in Figures 1 and 2. The mutagenesis data (6, 2 is from the... 

N,N-Dialkylthlo- and dithiocarbamate herbicides include several -alkyl and -benzyl compounds without mutagenic activity and three -chloroallyl derivatives which are promutagens,... 

This response is absolute nonsense. Sweden had banned the herbicide amitrole and several bis-dithiocarbamate fungicides because of flawed scientific evaluations that misinterpreted thyroid tumors in rodents, known to lack relevance for humans, as indicators of a human risk associated with normal usage. In contrast to Sweden s action, IARC and the U.S. Environmental Protection Agency cleared all of them of suspicions of causing cancer at current exposure levels,45 and the EU has approved amitrole for general use. Sweden s Minister of the Environment, Kj ell Lars-son, has declared that Sweden will fight all the way to the European Court of Justice to stop reintroduction of these horribly dangerous pesticides. 

Carbamates and ureas constitute important groups of pesticides that are used as herbicides (phenylureas, sulfonylureas, phenylcarbamates, and alkylthiocarbamates), insecticides (ben-zoylureas, methylcarbamates, and oximemethylcarbamates), or fungicides (dithiocarbamates, alkylenebisdithiocarbamates, and benzimidazolecarbamates) in different crops to control various weeds, pests, and diseases. 

Carbamates are substituted esters of carbamic acid (NH2COOH) with aliphatic or aromatic substituents on the oxygen and nitrogen atoms. Carbamate insecticides have an aryl or oxime N-methylcarbamate structure, and their mode of action is based on the inhibition of the enzyme acethylcholine esterase (1). However, this inhibition is reversible, and recovery from sublethal doses occurs rapidly. Some carbamate fungicides have a dithio, bisdithio, or benzimidazole carbamate basic structure, and dithiocarbamate fungicides inhibit the enzyme aldehyde deshydro-genase (2). The herbicides have an /V-alkylthiocarbamate or A-phenylcarbamate structure and interfere with photosynthetic activity or affect meristematic activity or lipid metabolism (3). Representative structures of carbamate pesticides are shown in Fig. 1. 

Despite the chemical diversity of the several hundred structures representing herbicidal activity, most reactions of herbicides fall within only a limited number of mechanistic types oxidation, reduction, nucleophilic displacements (such as hydrolysis), eliminations, and additions. "Herbicides", after all, are more-or-less ordinary chemicals, and their principal transformations in the environment are fundamentally no different from those in laboratory glassware. Figure 2 illustrates three typical examples which have received their share of classical laboratory study—the alkaline hydrolysis of a carboxylic ester (in this case, an ester of 2,4-dichlorophenoxyacetic acid, IX), the cycloaddition of an alcohol to an olefin (as in the acetylene, VI), and the 3-elimination of a dithiocarbamate which provides the usual synthetic route to an isothiocyanate (conversion of an N.N-dimethylcarbamic acid salt, XI, to methyl isothiocyanate). Allow the starting materials herbicidal action (which they have), give them names such as "2,4-D ester" or "pronamide" or "Vapam", and let soil form the walls of an outdoor reaction kettle the reactions and products remain the same. 

N,N-diallyl-2,2- seed or corn dichloroacetamide herbicide sorghum (R-25788) formulation barley wheat rice thiocarbamates acetanilides carbamates dithiocarbamates others... 

Substituted phenols Chlorophenoxy compounds Substituted acetic and propionic acids Amides and thioamides Substituted ureas Carbamates and dithiocarbamates Symmetrical triazines Benzoic acid derivatives Miscellaneous herbicides... 

Pesticides Carbamate insecticides and herbicides, chlorinated pesticides (for example aldrin, dieldrin, heptachlor, DDT, DDE, HCB, HCH isomers), dithiocarbamate fungicides, organic phosphates, triazine herbicides... 

A wide variety of organosulfur compounds show useful biological activity examples include the sulfonamide antibacterials and diuretics, penicillin and cephalosporin antibiotics, the antiulcer drug ranitidine, and agrochemicals such as the thiophosphoryl (P=S) insecticides like malathion, herbicides like chlorsulfuron, many fungicides like the dithiocarbamates (see Chapter 9, p. 148) and captan (see Chapter 9, p. 151), and sulfone acaricides like tetradifon (see Chapter 7, p. 104). 

Carbamate compounds are usually subdivided into at least three main groups with respect to their structure and general use (see Figure 1) insecticides, herbicides, and thio- or dithiocarbamates. A variety of R groups may be substituted in the molecule producing, as is the case for insecticides, a variety of alkyl or aryl esters of carbamic acid. Although technically characterized as carbamate pesticides, thio- and di-thiocarbamate fungicides are not included in this... 

Most dithiocarbamates are used as fungicides. Dithiocarbamates are also used as herbicides and, at least one compound, metham, is used as nematocide. Ziram is also used as an accelerant in the rubber industry, as a biocide in water treatment, and as an ingredient in adhesives. 

Zinc ethyienebis(dithiocarbamate) (Zineb) [12122-67-7] M 249.7. Crystallise this herbicide several times from hot toluene or from hot CHCI3 by addition of EtOH. It is a skin irritant. [Beilstein 4 IE 149, 4 IV 234.]... 

Sobti RC, Kaur H, Sharma M. 1987. Mutagenicity of dithiocarbamate herbicide Dithane M-45 (mancozeb). Chromosome Inf Serv 42 20-22. 

Two dithiocarbamates, sodium methyldithiocarbamate (metham, SMDC, 2) and 2-chloroallyl diethyldithiocarbamate (sulfallate, CDEC, 3) have been introduced as herbicides. These compounds were developed before the thiocar-bamate herbicides discussed in the preceding chapter. 

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