N.I. Wilujeng, S. Subandi, M. Muntholib, T.H.P. Brotosudarmo, R.R. Mariana
Obesity is often caused by high levels of blood fats and can lead to the emergence of chronic diseases such as high blood pressure, coronary heart disease, and type II diabetes. One of the known anti-obesity drugs is orlistat, that works as pancreatic lipase inhibitor. Methanol extract and flavonoid isolate from watermelon mesocarp have been shown to have activity as pancreatic lipase inhibitor, but the flavonoid species is not known yet. The aims of this study are to: isolate the flavonoid from ethanol extract of watermelon mesocarp, determine the activity of isolates as pancreatic lipase inhibitor and determine the types of flavonoid isolate spectrophotometrically by UV-Vis, FT-IR, and LC- MS/MS. This descriptive laboratory study using methanol in extraction stage and then TLC to isolate the flavonoid. Inhibitory activity assay had been done by titrimetric method, using porcine pancreatic lipase (Sigma) as enzyme, olive oil as substrate and orlistat as standard inhibitor. The results have shown that: there are six flavonoid isolates from ethanol extract of watermelon mesocarp, that has pancreatic lipase inhibition power of 73.8% (1st and 2nd isolate), 67.8% (3rd isolate), 88.5% (4th isolate), 98.9% (5th isolate), and 91.62% (6th isolate), respectively, relative to Orlistat at the same mass and based on the spectrum of UV-Vis, FT-IR, and LC-MS/MS, all of the six flavonoid isolates contains a flavan-3ol compound, namely catechin or polymer of catechin. © 2024 American Institute of Physics Inc.. All rights reserved.
Department of Chemistry, Faculty of Mathematic and Natural Science, Universitas Negeri Malang, Malang, Indonesia; Machung Research Center for Photosynthetic Pigments (MRCPP), Universitas Ma Chung, Malang, Indonesia; Department of Cullinary and Fashion Education, Faculty of Engineering, Universitas Negeri Malang, Malang, Indonesia