Uji Bioaktivitas Antidiabetes dan Identifikasi Senyawa Fenolik dari Fraksi Etil Asetat Kulit Buah Kembang Merak (Caesalpinia pulcherrima (L.) Sw.)

Abstract

Peacock flower plant (Caesalpinia pulcherrima (L.) Sw.) is traditionally used in medicine and is thought to be influenced by the presence of secondary metabolites. This study aims to test the antidiabetic bioactivity and isolate pure compounds from ethyl acetate fraction from pods of peacock flower plant. Pods of peacock flower plant as much as 3 kg was macerated using methanol solvent to produce 469 g (15.65%) methanol extract, followed by extraction with ethyl acetate to produce 261. 75 g (8.72%) ethyl acetate extract, and then ethyl acetate extract that had been dissolved with methanol was then partition extracted using n-hexane to produce 65.24 g (2.17%) ethyl acetate fraction. The results of phytochemical screening showed that the ethyl acetate fraction contained alkaloid, phenolic, flavonoid, and saponin compounds. Determination of total phenolic content was determined by the Folin-Ciocalteu method with a linear regression equation of y = 0.106x + 0.0764 with R2 = 0.9278 at 765 nm measurement and obtained a total phenolic content of 326.038 mgGAE/g extract. Antidiabetic bioactivity tested in test animals was divided into 6 groups, namely the normal group, the negative control group (CMC 1%), the positive control group (Glibenclamide), and the comparison group with a dosse of ethyl acetate fraction of 100 mg/KgBB, 200 mg/KgBB, and 400 mg/KgBB. This study used the oral glucose tolerance test method and data analysis was carried out using One-Way ANOVA and Post Hoc test. The result showed that the ethyl acetate fraction of peacock flower pods with dose of 400 mg/KgBB was able to significantly reduced blood sugar levels compared to negative control (p < 0.05) and the results were not different from the positive control glibenclamide (p > 0.05), so it was necessary to isolate active compounds from ethyl acetate fraction of peacock flower pods. After isolated the compound and elucidated the structure used UV-Vis, FT-IR, 1H-NMR, 13C-NMR, DEPT, and LC-MS/MS data, it was concluded that isolated compound was a non-flavonoid compound of the phenolic acid group derived from cinnamic acid, namely ferulic acid.