Sae Rom Parka,1, Jang Hoon Kimb,1, Hae Dong Jangc, Seo Young Yanga,*, Young Ho Kima,*
aCollege of Pharmacy, Chungnam National University, Daejeon 34134, Republic of Korea
bAdvanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeoungeup, Jeollabuk-do 56212, Republic of Korea
cDepartment of Food and Nutrition, Hannam University, Daejeon 34134, Republic of Korea
1These authors contributed equally to this work
*Corresponding authors : Seo Young Yang, Young Ho Kim
Abstract
α-Glucosidase is an enzyme that plays a key role in raising blood sugar level and is considered a good target for developing drugs to treat type 2 diabetes. This study was performed to evaluate the inhibition of the catalytic reaction of α-glucosidase by minor phlorotannin derivatives (1-5) from Ecklonia cava. These derivatives demonstrated inhibitory activity, with IC50 values ranging from 2.3± 0.1 to 59.8 ± 0.8 μM. Among the phlorotannins identified, compounds 2 and 3-5 were revealed to be non-competitive and competitive inhibitors, respectively. Furthermore, a fluorescence-quenching study of receptor-ligand binding was performed to calculate the kinetic parameters (Ksv, Kq, and K). These signal data indicated a 1:1 ratio of ligand-receptor binding. The binding conformations of the phlorotannin ligands were visually solved through molecular simulation. In conclusion, these minor phlorotannins may serve as α-glucosidase inhibitors targeted for the treatment of type 2 diabetes.
Keywords : Ecklonia cava, Laminariaceae, Phlorotannin, α-Glucosidase inhibitor, Fluorescence quenching, Molecular docking