The α-glucosidase inhibitory activity of avicularin and 4-O-methyl gallic acid isolated from Syzygium myrtifolium leaves

• Main Authors: Islan Nor (Author), Komar Ruslan Wirasutisna (Author), Rika Hartati (Author), Muhamad Insanu (Author)
• Format: Book
• Published: Elsevier, 2023-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 1319-0164; 10.1016/j.jsps.2023.06.010
• Keywords: α-glucosidase; Diabetes; Syzygium; Avicularin; 4-O-methyl gallic acid; Therapeutics. Pharmacology; RM1-950
• Source: Saudi Pharmaceutical Journal, Vol 31, Iss 8, Pp 101677- (2023)

Diabetes Mellitus is the main cause of death on a global scale. In 2019, there were 463 million people with diabetes, and WHO predicts that by 2030, there will be 578 million. As an antidiabetic agent, α-glucosidase inhibitors are one of the methods employed to reduce the prevalence of diabetes. Diabetes is traditionally treated with Syzygium as a primary material, medicine, fruit, ornamental plant, and source of carpentry. This investigation aimed to examine the inhibitory effect of seven species of Syzygium against α-glucosidase enzyme using an in vitro assay and isolate active substances and ascertain their concentrations in each sample. As a solvent, ethanol was used in maceration to extract the substance. Afterward, the extract underwent a series of fractionation techniques, including liquid-liquid extraction, vacuum liquid chromatography, column chromatography, and preparative Thin Layer Chromatography (TLC) for purification and isolation. The compound's structures were elucidated using TLC, UV-Visible spectrophotometry, and nuclear magnetic resonance (NMR) spectroscopy. Based on concentrations of 100 and 200 µg/mL, Syzygium myrtifolium exhibited the most significant inhibitory effect, followed by other species of Syzygium. The proportion of ethyl acetate had the strongest activity (IC50 0.40 ± 0.02 µg/mL) contrasted to positive control acarbose (IC50 55.39 ± 0.67 g/mL) and quercitrin (IC50 6.47 ± 0.40 µg/mL). Avicularin and 4-O-methyl gallic acid were discovered in the ethyl acetate fraction of Syzygium myrtifolium with IC50 values of 17.05 ± 0.75 µg/mL and 25.19 ± 0.21 µg/mL, respectively. As α-glucosidase inhibitory, the results of this study indicate Syzygium myrtifolium can be used as a dietary supplement to manage hyperglycemia.