Bioassay-guided isolation and identification of antidiabetic compounds from Garcinia cowa leaf extract

Piyaporn Phukhatmuen; Achara Raksat; Surat Laphookhieo; Rawiwan Charoensup; Thidarat Duangyod; Wisanu Maneerat

doi:10.1016/j.heliyon.2020.e03625

Bioassay-guided isolation and identification of antidiabetic compounds from Garcinia cowa leaf extract

Heliyon. 2020 Apr 25;6(4):e03625. doi: 10.1016/j.heliyon.2020.e03625. eCollection 2020 Apr.

Authors

Piyaporn Phukhatmuen¹, Achara Raksat¹, Surat Laphookhieo¹, Rawiwan Charoensup^{2

3}, Thidarat Duangyod^{2

3}, Wisanu Maneerat^{1

3}

Affiliations

¹ Center of Chemical Innovation for Sustainability (CIS) and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.
² School of Integrative Medicine, Mae Fah Luang University, Chiang Rai 57100, Thailand.
³ Medicinal Plant Innovation Center of Mae Fah Luang University, Chiang Rai 57100, Thailand.

Abstract

Garcinia cowa Roxb. ex Choisy (Clusiaceae) is a Thai local edible plant, which has been used for the treatment of diabetes. The aim of this study is to discover and identify bioactive compounds related to antidiabetic properties from the leaf extract of G. cowa. α-Glucosidase inhibitory bioassay-guided isolation of the ethyl acetate extract of the leaves of G.cowa resulted in the isolation and identification of 11 compounds. Of these, a decahydro-1H-xanthene derivative, garciniacowone K (1), was identified as a novel compound. Their structures were characterized by spectroscopic data and by comparison of their NMR spectroscopic data with those previously reported. All compounds were evaluated for their α-glucosidase inhibitory and glucose consumption activities. Compound 2 showed the highest efficacy in inhibiting α-glucosidase enzyme and promoting glucose consumption activity by 3T3-L1 cells, with IC₅₀ values of 0.5 μM and 13.1 μM, respectively, without causing toxicity to cells.

Keywords: Antidiabetic activity; Bioactive compounds; Bioassay-guided isolation; Garcinia cowa; Natural product chemistry; Pharmaceutical chemistry.