The adzuki bean (Vigna angularis L.) is a red-grained legume that has a number of essential nutrients and is used in traditional dishes in Asia. Adzuki bean industrial by-products are also a potential low-cost source of some unique bioactive polyphenols. Hence, here, the authors aimed to perform a comparative study of the phytochemical profiles of the leaves and seeds of the adzuki bean and compare their antioxidant, α-glucosidase inhibition, and tyrosinase inhibition activity. The authors assessed antioxidant activity by DPPH, ABTS, FRAP, PR, TPC, and SOD assays, which showed wide variation, respectively. From the relative antioxidant capacity index results, 10 adzuki bean landraces were selected to compare for phytochemicals and bioactivity using leaf and seed extracts. Antioxidant, α-glucosidase inhibition, and tyrosinase inhibition activity in the leaf extracts were higher than in the seed extracts, and there were more flavonols and isoflavones in the leaf extracts than in the seed extracts. This study demonstrated that adzuki bean leaf extracts could be a new natural antioxidant or antidiabetic agent and a skin whitener and can also be used in industrial applications.

Abstract
 Introduction
 Materials and Methods
  Collection of plant material
  Adzuki bean extraction for antioxidant activity
  DPPH assay
  ABTS assay
  Ferric reducing antioxidant power assay
  Reducing power assay
  SOD assay
  Total polyphenol content assay
  Analysis of flavonol content in KABL
  Analysis of isoflavone content in KABLs
  α-Glucosidase inhibition activity assay
  Determination of Tyrosinase inhibition activity
  Data analysis
 Results
  The distribution of antioxidant activity in leaf extractsfrom the 223 KABLs
  Selecting adzuki bean landraces with high or low antioxidantactivity using RACI
  Comparison of flavonoid content between the high andlow antioxidant groups
  Comparison of α-glucosidase and tyrosinase inhibitionactivity between the high and low antioxidant groups
  Correlations among antioxidant activity, phytochemicals,and α-glucosidase and tyrosinase inhibition activity in adzukibean extr
  Comparison of antioxidant activity, phytochemicals, andα-glucosidase and tyrosinase inhibition activity betweenleaf and seed ex
 Discussion
 References

• Kyung Jun Lee(National Agrobiodiversity Center, National Institute of Agricultural Sciences (NAS), RDA)
• Jung-Ro Lee(National Agrobiodiversity Center, National Institute of Agricultural Sciences (NAS), RDA)
• Myoung-Jae Shin(National Agrobiodiversity Center, National Institute of Agricultural Sciences (NAS), RDA)
• Gyu-Taek Cho(National Agrobiodiversity Center, National Institute of Agricultural Sciences (NAS), RDA)
• Ho-Sun Lee(International Technology Cooperation Center, RDA)
• Kyung-Ho Ma(National Agrobiodiversity Center, National Institute of Agricultural Sciences (NAS), RDA)
• Gi-An Lee(National Agrobiodiversity Center, National Institute of Agricultural Sciences (NAS), RDA)
• Jong-Wook Chung(Department of Industrial Plant Science & Technology, Chungbuk National University) Corresponding author