Abstract
This study presents the profile of chemical compounds by LC-MS/MS and evaluates antioxidant and antibacterial properties of Caesalpinia pubescens fruits extracts. The study aimed to evaluate the antioxidant activity and antibacterial activity of Caesalpinia pubescens fruits extract and determine the active extract's chemical compounds by LCMS/MS. Total phenolic content (TPC) and total flavonoids content (TFC) were determined by the colorimetric assay, respectively. The antioxidant activity was performed by TLC-bioautography, determination of the IC50, antioxidant activity index (AAI), and the inhibition of β-carotene bleaching. This study also determined the correlation between TPC, TFC, and antioxidant activities. Evaluation of antibacterial activity was performed against S. aureus and E. coli. The results showed that the highest TPC was obtained in methanol extract (108.54 ± 1.92 mg GAE/g extract), and the highest TFC was obtained in dichloromethane extract (33.38 ± 0.86 mg QE/g extract). Methanol and ethyl extracts have powerful DPPH free radical scavenging with the IC50 value range of 8.27 - 11.24 µg/ml and AAI values of 2.74 - 3.72. The DPPH radical free scavenging capacity has a high positive correlation with the TPC values with an r-value of 0.950. The increased concentration of extracts correlated with the increased inhibition of β-carotene bleaching, with Pearson’s coefficient (r) in a range of 0.624 - 0.962. The 1000 ppm of methanol extract had the best antioxidant activity, significantly different from positive control and other extracts (P<0.05). The dichloromethane and methanol extracts possess moderate antibacterials against S. aureus with a MIC value of 256 µg/mL. This study is the new on the antibacterial and antioxidant activity of C. pusbescens fruit extracts, and the first study regarding flavonoid and phenolic contents and the other chemical composition in the C. pusbescens fruit extracts.