Mariposa Christia vespertilionis (MCV) is also known as butterfly wing plant, or commonly known as ‘pokok rerama’ in Malaysia. This plant belongs to the Fabaceae family. Its bioactive compounds including triterpenes, alkaloids, fatty acids, phenol, alkanes and alcohol have shown antioxidant activity. The objective of this study is to synthesis silver nanoparticles together with MCV leaves extract using ultrasonic-assisted extraction (UAE) as an extraction method and to evaluate its antioxidative activity. The best conditions (concentration of silver nitrate and incubation temperature) for formation of AgNPs were visualised by UV-Vis spectroscopy. The absorbance peaks for both conditions were 450 nm and 430 nm respectively. Both MCV extract and synthesized nanoparticles have been characterized by Fourier-transform infrared spectroscopy (FTIR) to determine the functional group that responsible in reduction of silver ions. The AgNPs was also characterized by using Transmission Electron Microscopy (TEM) to determine the morphology and size of the synthesised silver nanoparticles (30 to 50 nm). Total phenolic content and total flavonoids content were also conducted for MCV extracts thus the value achieved was 0.429 ± 0.046 mg GAE/g and 0.033 ± 0.033 mg QU/g. Antioxidant activity was done by using DPPH solution. The scavenging activity for MCV extract was higher compared to the synthesised AgNPs. As conclusion, MCV leaves has potential as antioxidant agent which may be beneficial in preventing degenerative diseases.
