Isoflavones from green vegetable soya beans and their antimicrobial and antioxidant activities

J Sci Food Agric. 2018 Mar;98(5):2043-2047. doi: 10.1002/jsfa.8663. Epub 2017 Oct 24.

Abstract

Background: Green vegetable soya beans, known as Maodou in China, are supplied as vegetable-type fruits of the soybean plant. Previous study indicated that green vegetable soya beans exhibited antioxidative and anti-inflammatory activities. However, the material basis and pharmacological activities of green soybean plant were not unravelled clearly. In this study, we investigated the chemical ingredients and their pharmacological activities.

Results: Investigation of the chemical ingredients indicated that two new isoflavones, 2'-hydroxyerythrin A (1), and daidzein-7-O-β-d-{6″-[(E)-but-2-enoyl]}glycoside (2), together with seven known ones - 7,4'-dihydroxy-6-methoxyisoflavone (3), daidzein (4), daidzin (5), genistein (6), formononetin (7), ononin (8), and isoerythrinin A (9) - were obtained. The structures of compounds 1-9 were elucidated on the basis of spectroscopic and chemical analysis. We evaluated the antimicrobial efficacies and free-radical scavenging potential of the isolated compounds (1-9). Compounds 1 and 9 exhibited the most pronounced efficacy against the tested bacterial strains with IC50 values ranging from 10.6 to 22.6 μg mL-1 . The isolated compounds showed moderate radical scavenging properties with compound 6 being the most active, followed by compounds 3, 1 and 4.

Conclusions: This study indicated that the isoflavones from soya beans could be considered as potential antioxidants or antimicrobials in the food, cosmetics and pharmaceutical industries. © 2017 Society of Chemical Industry.

Keywords: Glycine max; antimicrobial activity; antioxidant activity; green vegetable soya beans; isoflavones; structure identification.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Antioxidants / chemistry
  • Antioxidants / isolation & purification
  • Antioxidants / pharmacology*
  • Bacteria / drug effects
  • Glycine max / chemistry*
  • Isoflavones / chemistry
  • Isoflavones / isolation & purification
  • Isoflavones / pharmacology*
  • Plant Extracts / chemistry
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology*
  • Vegetables / chemistry

Substances

  • Anti-Bacterial Agents
  • Antioxidants
  • Isoflavones
  • Plant Extracts