New monoterpenoid by biotransformation of thymoquinone using Aspergillus niger

Abstract

Microbial transformation of thymoquinone (5-isopropyl-2-methyI-cycIohexa-2,5-diene-l ,4- dione) ( l) by suspended cell-cultures of the plant pathogenic fungus Aspergillus niger resulted in the production of three metabolites. These metabolites were identified as 5-isopropyl-2- methyl-2,4-cycIohexenone lactone (2), hydroxythymoquinone (3), and 4-hydroxy-2-isopropyl- 5-methylphenol (4) by different spectroscopic methods. Metabolite 2 was found to be a new compound. Compound 4 showed potent antioxidant activity.