Acetylation of γ-mangostin Isolated from the Mangosteen Pericarp (Garcinia mangostana Linn.) and Their Antidiabetic Activity

Mangosteen (Garcinia mangostana Linn) is one of the most well-known plants in Indonesia. Mangosteen contains many derivatives of oxygenated and prenylated xanthones from phenolics which exhibit diverse biological activities such as antioxidants, antimalarials, anti-allergies, anti-tumors, antiviral, antibacterial, anti-inflammatory, anti-fungal, anticancer, and antidiabetic. Modification of xanthone compounds is known to increase antidiabetic activity and it is known that α- and β-mangostin acetylated can be produced from the modification of α- and β-mangostin using acetic anhydride. In this study, as many as 1.43 grams (1.59%) of the γ-mangostin compound were successfully isolated from the ethyl acetate extract of mangosteen pericarp. Modification of γ-mangostin through the acetylation reaction produces acetylated γ-mangostin in the form of 3,6,7-tri-methylester-γ-mangostin as much as 32.9 mg (63%). Antidiabetic test results showed γ-mangostin had an IC50 value of 8.55 μM, while the IC50 value of 3.6.7-tri-methylester-γ-mangostin was 1.82 μM. Acarbose as a positive control has an IC50 value of 4.48 μM. This shows that modification can increase antidiabetic activity