HPLC-FRAP methodology and biological activities of different stem bark extracts of Cajanus cajan (L.) Millsp

Sinan K. I., Mahomoodally M. F., EYUPOĞLU O. E., Etienne O. K., Sadeer N. B., Ak G., ...More

Journal of Pharmaceutical and Biomedical Analysis, vol.192, 2021 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 192
  • Publication Date: 2021
  • Doi Number: 10.1016/j.jpba.2020.113678
  • Journal Name: Journal of Pharmaceutical and Biomedical Analysis
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Analytical Abstracts, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, EMBASE, International Pharmaceutical Abstracts, MEDLINE, Veterinary Science Database
  • Keywords: Antioxidants, Bioactive compounds, Pigeon pea, Enzyme inhibition, Natural products
  • Istanbul Medipol University Affiliated: Yes


Cajanus cajan. (L.) Millsp. (C. cajan) (Family: Fabaceae) also known as pigeon pea, is a famous food and cover/forage crop bearing a high amount of key amino acids (methionine, lysine and tryptophan). This study investigated into the total phenolic (TPC), flavonoid content (TFC), antioxidant [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity, total antioxidant capacity (TAC) (phosphomolybdenum) and metal chelating] activities and enzyme [α-amylase, α-glucosidase, tyrosinase, acetyl-(AChE), butyryl-(BChE) cholinesterase] inhibitory effects of four extracts (methanol, hexane, ethyl acetate, aqueous) prepared from C. cajan stem bark. Direct identification of antioxidants was also conducted using the high performance liquid chromatography-ferric reducing antioxidant power (HPLC-FRAP) system. The highest TPC and TFC were recorded with the methanolic (23.22 ± 0.17 mg GAE/g) and ethyl acetate extracts (19.43 ± 0.24 mg RE/g), respectively. The methanolic extract exhibited important antioxidant activity with DPPH (38.41 ± 0.05 mg Trolox equivalent (TE)/g), ABTS (70.49 ± 3.62 mg TE/g), CUPRAC (81.86 ± 2.40 mg TE/g), FRAP (42.96 ± 0.59 mg TE/g) and metal chelating (17.00 ± 1.26 mg ethylenediaminetetraacetic acid equivalent/g). p-coumaric and caffeic acid were the predominant antioxidants in the samples. Results from enzymatic assays showed the potential abilities of hexane extract in inhibiting the AChE, BChE, α-amylase and α-glucosidase enzymes. From the results obtained in this study, it can be concluded that C. cajan can be considered as a promising source of antioxidants and key enzyme inhibitors that can be exploited for future bioproduct development.