Formation of ethylenethiourea from 5,6‐dihydro‐3H‐imidazo[2, 1‐c]‐1,2,4‐dithiazole‐3‐thione by microorganisms and reducing agents

Abstract

Microorganisms formed readily ethylenethiourea (ETU) from 5,6‐dihydro‐3H‐imidazo[2, 1‐c]‐1,2,4‐dithiazole‐3‐thione (DIDT), a spontaneous decomposition product of ethylenebisdithiocarbamates. This conversion also takes place after addition of reducing compounds like cysteine, glutathione or ascorbic acid. It consists of two steps: reduction of the S‐S bond of DIDT with subsequent release of CS₂, to form ETU.

DIDT was reduced by NADH in the presence of enzyme extracts from Pseudomonas fluorescens or Aspergillus niger, or by commercial glutathione reductase or lipoamide dehydrogenase. ETU was formed as a result of this enzymatic reduction. The flavin compounds FMN and FAD were also able to promote the reduction of DIDT by NADH.

Key words:

• Ethylenethiourea
• ETU
• DIDT
• ethylenebisdithiocarbamates
• microorganisms
• conversion
• enzymes