Diabetes mellitus is  a metabolic disorder disease characterized by hyperglycemic condition. One of the medicinal treatment to cure diabetes is to inhibit the alpha-glucosidase enzyme activity, so it will reduce post-prandial  blood sugars level. Garcinia daedalanthera Pierre is one of Clusiaceae Family plants which  is known having  an alpha-glucosidase and antioxidant activity on that leaves part. This research was aimed to test the inhibition of alpha-glucosidase and antioxidant activity using DPPH method from n-heksan, ethyl acetate and methanol extracts of Garcinia daedalanthera Pierre stem barks which obtained from extraction with maceration before. The optimization have been done before the test to get an optimum condition for the tests. A wavelength of 400 nm, pH 6,8, temperature 39ºC, substrat concentration of 5 mM, and unit enzyme concentration of 0,025 U/mL were used for an alpha-glucosidase inhibition test. In the other hand, a wavelength of 519 nm was used for antioxidant test. The result showed that ethyl acetate extract is both the most active extract that inhibit alpha-glucosidase activity with IC₅₀ 21,881 μg/mL and on antioxidant test with IC₅₀ value 14,486 μg/mL. Phytochemical screening showed that ethyl acetate as the most active extract contains alkaloids, flavonoids, glycosides, tannins and anthraquinones.

Key Words : Alpha-glucosidase,  antioxidant, diabetes mellitus, DPPH, Garcinia daedalanthera Pierre., maceration, stem barks, phytochemical screenings.