Mycobiology.  2008 Jun;36(2):121-133.

Flavone Biotransformation by Aspergillus niger and the Characterization of Two Newly Formed Metabolites

• Mahmoud YA
• Assawah SW
• El-Sharkawy SH
• Abdel-Salam A

Abstract

Aspergillus niger isolated from Allium sativum was used at large scale fermentation (150 mg flavone/200 ml medium) to obtain suitable amounts of the products, efficient for identification. Then spectral analysis (UV, IR, 1H-NMR, 13C-NMR) and mass spectrometry were performed for the two products, which contributed to the identification process. The metabolite (1) was identified as 2'-hydroxydihydrochalcone, and the metabolite (2) was identified as 2'-hydroxyphenylmethylketone, which were more active than flavone itself. Antioxidant activities of the two isolated metabolites were tested compared with ascorbic acid. Antioxidant activity of metabolite (1) was recorded 64.58% which represented 79% of the antioxidant activity of ascorbic acid, and metabolite (2) was recorded 54.16% (67% of ascorbic acid activity). However, the antioxidant activity of flavone was recorded 37.50% which represented 46% of ascorbic acid activity. The transformed products of flavone have antimicrobial activity against Pseudomonas aeruginosa, Aspergillus flavus and Candida albicans, with MIC was recorded 250 microg/ml for metabolite (2) against all three organism and 500, 300, and 300 microg/ml for metabolite (1) against tested microorganisms (P. aeruginosa, Escherichia coli, Bacillus subtilis, and Klebsiella pneumonia, Fusarium moniliforme, A. flavus, Saccharomyces cerviceae, Kluveromyces lactis and C. albicans) at this order.

Keyword

Anit-microbial; Antioxidant; Aspergillus; Biotransformation; Flavone

MeSH Terms

Ascorbic Acid
Aspergillus
Aspergillus flavus
Aspergillus niger
Bacillus subtilis
Biotransformation
Candida albicans
Escherichia coli
Fermentation
Flavones
Fusarium
Garlic
Klebsiella
Mass Spectrometry
Pneumonia
Pseudomonas aeruginosa
Saccharomyces
Ascorbic Acid
Flavones