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Ethnobotanically in Indonesia, Diospyros celebica Bakh is recognized as having antidiabetic activity. This study aimed to isolate antidiabetic compounds from the leaves of Eboni (Diospyros celebica). D. celebica leaves were dried and extracted with 96% ethanol, then fractionated and purified guided by antioxidant activity test, a-glucosidase inhibitory test, and dipeptidyl peptidase-4 (DPP-4) inhibitory test until bioactive isolates were obtained. The isolates were identified and their structures were determined based on NMR 1H, 13C, 2D, and LCMS/MS spectroscopic data. Extracts and fractions have potential antioxidant (DPPH), glucosidase inhibitor, and DPP-4 inhibitor activities as well as containing flavonoids and polyphenols. From the ethyl acetate fraction, isolate 26a-2 namely 3,5-digalloyl-(-)- epiafzelechin was obtained which was active as a DPPH scavenger, glucosidase inhibitor, and DPP4 inhibitor. The extracts, fractions, and flavonoid compounds in D. celebica leaves have the potential for antidiabetic drug candidates. [ABSTRACT FROM AUTHOR]

Introduction: The prevalence of diabetes mellitus type 2 in the world is more than 230 million people, increases about 3% in a year. Kayu Sarampa or Nyirih batu (Xylocarpus moluccensis (Lam.) M. Roen) has traditionally been used to treat diabetic patient by native people in Ratahan, North Celebes, Indonesia. Therefore, this research was sequentially extracted bioactive component from stem bark of kayu sarampa showed alpha glucosidase inhibitor. Objective: To assess antioxidants and alpha glucosidase inhibitory activity of hexane, ethyl acetate, and methanol extract from stem bark of Kayu Sarampa. Method: The Stem bark was extracted with Reflux method using hexane, ethyl acetate, and methanol as mobile phae/solvent. The Hexane Extract (HE), Ethyl Acetic Extract (EAE) and Methanol Extract (ME) were subjected to the antioxidant activity assay by the 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and the ferric-reducing antioxidant power (FRAP) method. Antidiabetic activity was determined by enzymatic alpha-glucosidase inhibitor. Results: The extract which had the highest activity based on the DPPH test and FRAP test was the ME compared with EAE, and HE with IC50 values of 16.51 µg/mL, 34.10 51 µg/mL, and 38.82 51 µg/mL, respectively. Ferrous equivalent antioxidant capacity (FeEAC) method, methanolic extract had a higher reduction capacity than the EH and EEA which were 148.96 µmol/gr, 48.96 µmol/gr, and 148.96 µmol/gr, respectively. The result showed that kayu sarampa stem bark exhibited antidiabetic activity due to its high inhibition compared with control (acarbose). ME showed inhibition of 53,11% followed with EAE 49,7%, HE 44,53%, and acarbose as control 29,32%.Conclusion: stem bark of kayu sarampa have bioactive component as alpha glucosidase inhibitor. [ABSTRACT FROM AUTHOR]