Тиабендазол

Описание

Thiabendazole is also a broad-spectrum systemic fungicide against many fungal pathogens, although this compound was originally introduced as an anthelminthic (25).

Химические свойства

Light yellow powder

Использование

Thiabendazole is widely used as a post-harvest systemic fungicide on citrus and bananas. It is active against fruit rots in bananas, citrus, apples and pears; bulb and corm rots in ornamentals; storage rots in sweet potato and potato and is also used to control Dutch elm disease. It is the original benzimidazole anthelmintic for both human and animal health usages.

Определение

ChEBI: A member of the class of benzimidazoles carrying a 1,3-thiazol-4-yl substituent at position 2. A mainly post-harvest fungicide used to control a wide range of diseases including Aspergillus, Botrytis, Cladosporium and Fusarium.

Общее описание

White or cream-colored odorless, tasteless powder. Sublimes above 590°F. Fluoresces in acidic solution. Formulated as a dust, flowable powder or wettable powder for use as a systemic fungicide and anthelmintic.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

Thiabendazole is incompatible with a number of pesticides, including copper-containing fungicides, and with highly alkaline materials. Thiabendazole is a chelating agent, binding many metals including iron, but not calcium

Пожароопасность

Flash point data for Thiabendazole are not available; however, Thiabendazole is probably combustible.

Фармацевтические приложения

Thiabendazole; a thiazolyl benzimidazole available for oral administration. It is active against most common intestinal nematodes. As a result of its larvicidal and ovicidal activity, it is effective in strongyloidiasis, trichinosis, visceral larva migrans and cutaneous larva migrans.
It is well absorbed from the small intestine. Peak plasma levels are reached about 1–2 h after a single oral dose of the suspension. It is extensively metabolized in the liver to the 5-hydroxy derivative, which is inactive. Most of the drug is excreted within 24 h. About 90% is excreted in the urine, chiefly as glucuronide or sulfate conjugates; the remainder is passed in the feces.
A wide range of unpleasant side effects occur, including nausea and other gastrointestinal upsets, fever and neurological effects. It has been largely replaced by the less toxic benzimidazole carbamates. Although active against Ascaris lumbricoides, E. vermicularis and hookworms, it should not be used as primary therapy for these infections.

Торговое название

AGROSOL? AGROSOL?T, (with thiram); APL-LUSTER? ARBOTECT? BOVIZOLE? BRODEX? CHEM-TEK? CITRUS LUSTR? DECCO SALT NO.19? E-Z-EX? EPROFIL? EQUIVET TZ? EQUIZOLE? FRESHGARD? FUNGICIDE 4 T? GRANOX? IRGAGUARD? LOMBRISTOP? MERTEC? MERTECT 160? METASOL TK-100? MINTEZOL? MINZOLUM? MK-360? MYCOZOL? NEMAPAN? NSC 525040? OMNIZOLE? POLIVAL? RIVAL? (captan + PCNB + thiabendazole); RPH? RTU-VITAVAX-EXTRA? STA-FRESH? TBZ 6? TECTO? TECTO RPH? TECTO 10P? TECTO 40 F? TESTO? THIABEN? THIABENDAZOLUM? THIABENZAZOLE? THIABENZOLE? THIBENZOL? THIBENZOLE? THIBENZOLE 200? THIBENZOLE ATT? TIABENDAZOLE? TOBAZ? TOP FORM WORMER? VITAVAX?Thiabendazole Chemical class: Benzimidazole

Контактные аллергены

This fungicide and vermifuge agent is widely used in agriculture (for example, forcitrus fruits), and in medical and veterinary practice as an anthelmintic drug.

Механизм действия

Thiabendazole is an antihelmintic drug with a broad spectrum of action. Although the details of its mechanism of action are not conclusively known, it seems likely that its action is mediated by the inhibition of a specific enzyme of helminthes—fumarate reductase. Thiabendazole is active with respect to most nematode infections, including Angyostrongylus cantonesis, Strongyloides stercoralis, Trichinella spiralis, Toxocara canis, Toxocara cati, Ancylostoma caninum, A. braziliense
, A. duodenale, Dracunculus medinesis, Capillaria philippinesis, as well as for treating Acaris cantonesis and Shistosoma stercoralis. Synonyms of this drug are mintezol, minzolum, and others.

Клиническое использование

2-(4-Thiazolyl)benzimidazole (Mintezol) occurs as a whitecrystalline substance that is only slightly soluble in waterbut is soluble in strong mineral acids. Thiabendazole is abasic compound with a pKa of 4.7 that forms complexeswith metal ions.
Thiabendazole inhibits the helminth-specific enzymefumarate reductase. It is not known whether metal ionsare involved or if the inhibition of the enzyme is related tothiabendazole’s anthelmintic effect. Benzimidazole anthelminticdrugs such as thiabendazole and mebendazolealso arrest nematode cell division in metaphase by interferingwith microtubule assembly. They exhibit a highaffinity for tubulin, the precursor protein for microtubulesynthesis.
Thiabendazole has broad-spectrum anthelmintic activity.It is used to treat enterobiasis, strongyloidiasis (threadworminfection), ascariasis, uncinariasis (hookworm infection), andtrichuriasis (whipworm infection). It has also been used torelieve symptoms associated with cutaneous larva migrans(creeping eruption) and the invasive phase of trichinosis. Inaddition to its use in human medicine, thiabendazole iswidely used in veterinary practice to control intestinalhelminths in livestock.

Профиль безопасности

Moderately toxic by ingestion. An experimental teratogen. A questionable carcinogen. Experimental reproductive effects. Mutation data reported. When heated to decomposition it emits toxic fumes of SOX and NOX. See also SULFIDES.

Экологическая судьба

Thiabendazole does not hydrolyze readily, nor it is metabolized in soil under aerobic or anaerobic conditions. While it photodecomposes in minutes in aqueous solutions, photodecomposition of thiabendazole in soil did not cause more than 40% reduction. Thiabendazole is also only slightly water soluble, and does not migrate in soil. Thus, it is unlikely to contaminate groundwater. If released into the atmosphere, it exists primarily in the particulate phase. In the vapor phase, it will degrade in the atmosphere by reacting with photochemically produced hydroxyl radicals with an estimated half-life of 6 h.

Метаболический путь

The primary photolytic degradation of thiabendazole involves the cleavage of the thiazole-benzimidazole ring linkage. In animals, thiabendazole is extensively oxidised in bluegill sunfish, hens, goats, sheep, cattle, mice, rats and humans, followed by conjugation. When foliarly applied to plants, degradation to benzimidazole and its conjugates occurred. Benzimidazole formed in plants is mainly due to photolytic action. The primary degradation/metabolic pathways of thiabendazole in water, soil, plants and animals are depicted in Scheme 1.