Ethylene bisdithiocarbamate

Bertinuson, T. A., H. LeCoultre, and W. C. Waterman. The inhibitory effect of zinc ethylene bisdithiocarbamate dust on weather fleck of Connecticut shade-grown tobacco. Tobacco Sci. 5 28-30, 1961. 

Ethvlenethiourea (2-mercaptoimidazolinej imidazolidine-2-thione imidazoline-2-thiol, VIII) is a water-soluble white crystalline solid used extensively in curing elastomers (rubbers, e.g., polychloroprenes, polyacrylates, etc.) It is also present as an impurity in the ethylene bisdithiocarbamates widely used as fungicides. When the fungicides are present as a contaminant in heated foods, they may be converted to the ethylenethiourea (ref. 

U.S. Environmental Protection Agency, Ethylene bisdithiocarbamates (EBDCs) Notice of intent to cancel and conclusion of Special Review. Fed. Reg. 57 7434, 1992. 

ETU is a trace contaminant and metabolic degradation product of a widely used class of ethylene bisdithiocarbamate fungicides such as Maneb and Zineb. Half-life in H20 is 7-13 days. Octanol/water partition coefficient as log Pow -0.66 (calculated). 

Chlorthalonil, 2,4,5,6-tetrachloro-isophthalonitrile (13), is a fungicide with a wide range of action similar to ethylene bisdithiocarbamates, and is effective against Phytophthora and rust fungi (Turner et al., 1964). 

Several researchers participated in the elucidation of the structure of dithiocarbamates (Van der Kerk et al., 1955 Chatt et al., 1956). Today it has been esteblished unequivocally that the salts of dithiocarbamic acid formed with metals are complex compounds (5) and that the compounds of ethylene-bisdithiocarbamate formed with bivalent metals even have a highly polymeric character (6). Little information pertinent to their structure is available, but a coordination structure such as (7) is conceivable (Vonk, 1975). 

The members of the second subgroup are prepared from ethylene diamine (20) or its derivatives by reaction with carbon disulfide. In a sodium hydroxyde medium the disodium salt nabam, in an ammonium hydroxide medium, the diammonium salt amobam is formed (21). The sodium-ammonium salt, nambam, can also be prepared. These active substances are soluble in water. They cannot be used as foliage fungicides because of their phytotoxicity. On the other hand, they can be applied with good results for seed treatment. These compounds are intermediate products of the water-insoluble metal salts of N,N-ethylene-bisdithiocarbamic acid. c... 

Mancozeb is the manganese-zinc double salt of N,N-ethylene-bisdithiocarbamic acid. This compound is more stable than the derivatives described above (Bontoyan and Looker, 1973) this property has been attributed to the polymeric structure of mancozeb. Mancozeb is not phytotoxic. The polymer generally contains 20% manganese and 2% zinc besides ethylene-bisdithiocarbamate ions. 

Matolcsy et al. (1977) prepared the copolymer of linear structure (28) by the reaction of the piperazinium salt of ethylene-bisdithiocarbamic acid with formaldehyde. The preparation of this product (proposed common name pireb) was motivated partly by their earlier finding that the S-aminomethyl derivatives of biologically active dithiocarbamic acids have a strong fungicidal effect, in contrast to the S-alkyl derivatives, because the atomic group =N—CS—S—CHj—N= facilitates the cleavage of the dithiocarbamate ion ultimately responsible for the action (Matolcsy et al., 1973). The product they obtained is the first pesticide with copolymer structure. 

Ethylene-bisdithiocarbamates in themselves are only moderately fungitoxic, but they are very unstable, particularly to water and oxygen. Several workers therefore studied the decomposition of these compounds under various conditions to find the carrier of the fungitoxicity. The decomposition mechanism of the well-defined sodium salt, nabam, has been investigated extensively, but similar results were also obtained in the investigations of the decomposition of the metal complexes (zineb, maneb) (Engst and Schnaak, 1970). Results concerning the decomposition mechanism of ethylene-bisdithiocarbamates are summarised in Scheme 5.1. 

Klopping and Van der Kerk (1951) presumed that, analogous to the mode of action of N-monoalkyldithiocarbamates, in the case of ethylene-bisdithiocarbamates, ethylene-bisisothiocyanate is the toxic agent. This decomposition product was detected later by thin-layer chromatography on tomato treated with maneb and in an aerated aqueous solution of nabam (Engst et al., 1968 Engst and Schnaak, 1970). Recently, the attention of the researchers has also turned to the other decomposition products. 

DIDT easily penetrates the lipid phase of the fungal spores and cells, and its subsequent conversion into diisothiocyanate may be the mechanism of the fungitoxic action of DIDT and ultimately of ethylene-bisdithiocarbamates. 

One of the degradation products of ethylene-bisdithiocarbamic acid is N,N -ethylene thiourea (ETU) (Barratt and Horsfall, 1947 Thom and Ludwig, 1954 Engst and Schnaak, 1970), also named 2-imidiazolidinethione (45) ... 

ETU is not fungitoxic—thus, this degradation product cannot be the toxic agent of ethylene-bisdithiocarbamates. Investigations suggest that this product is probably formed from the active substance entering the spores, then rapidly leaving the... 

Ethylene-bisdithiocarbamates do not inhibit the function of aldehyde oxidase (Van Logten, 1972), nor do they form conjugates in mammals, but all their decomposition products are present. These metabolites are excreted within a relatively short time in the urine and the feces. Twenty-four hours after feeding, 55% of the nabam introduced into the stomach of rats was excreted in the urine and feces, while the thyroid, liver, kidney, spleen and brain contained only 1.2% in the form of metabolites, and even this quantity was reduced after 5 days to 0.18% (Seidler f t al., 1970). Carbon disulfide has also been detected in the breath of rats fed with neviram (Thuranszky and Botos, 1976 Botos, 1979). 

The general action of ethylene-bisdithiocarbamates is centred on the thyroid gland. A series of goitrogenic effects has been observed in animal experiments (Seifter et al., 1948 Blackwell-Smith et al., 1953 Ivanova-Chemishanska et al., 1968 Bankowska et al., 1970). 

The decomposition products of ethylene-bisdithiocarbamates were also detected in formulations of the active substances (Clarke et ai, 1951 Bontoyan et al, 1972). The quantity of ETU varied between 0.02 and 2%, but this quantity can increase during storage, partly through an increase in temperature, partly through higher atmospheric humidity (Petrosini, 1962 Czegledi-Janko and Hollo, 1967 Bontoyan and Looker, 1973). 

Disodium [[N,N -ethylenebis [N-(carboxymethyl) glycinato]] (4-)-N,N, 0,0, 0N,0N ] cuprate (2-). See Disodium EDTA-copper Disodium ethylene bisdithiocarbamate Disodium ethylene-1,2-bisdithiocarbamate. 

Classification Ethylene bisdithiocarbamate Definition Mixt. of ammoniates of ethylenebis (dithiocarbamate) zinc, ethylenebisdithiocarbamic acid cyclic anhydrosulfides and disulfides Properties Lt. yel. solid, dithiocarbamate odor insol. in org. soivs. 

Manganese-ethylene bisdithiocarbamate, Maneb , is used as an agricultural /wn-gicide for controlling crop and cereal diseases. 

A coordination product of zinc ion and manganese ethylene bisdithiocarbamate 80%... 

Maneb (Manganese ethylene bisdithiocarbamate) Inert Ingredients ... 

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