Antibacterial activity of faloak (Sterculia quadrifida) leaves extract

Purwantiningsih TI, Widyobroto BP, Suranindyah YY, Artama WT. 2023. Antibacterial activity of faloak (Sterculia quadrifida) leaves extract. Biodiversitas 24: 6613-6620. Restrictions on the use of antibiotics have made people start looking for alternatives to antibiotics, one of which is ingredients that come from nature. Faloak (Sterculia quadrifida R. Br) leaves are a source of secondary
metabolites that have not been widely utilized. The aim of this study was to assess the antibacterial activity of S. quadrifida leaves extract in inhibiting Staphylococcus aureus (gram-positive bacteria) and Escherichia coli (gram-negative bacteria). Powdered S. quadrifida leaves were macerated with 96% ethanol solvent. After obtaining the crude extract, it was fractionated using the liquid-liquid
method using methanol, hexane, distilled water and ethyl acetate as solvents. The crude extract of S. quadrifida leaves was then dissolved into several concentrations. The crude extract of S. quadrifida leaves and the fractions obtained were tested for antibacterial activity in vitro using the Kirby Bauer method against Staphylococcus aureus and Escherichia coli. The most active fraction in
inhibiting the tested bacteria was then screened for bioactive compounds using instrument LC-HRMS. The results showed that S. quadrifida leaves extract and its fractions were able to inhibit Staphylococcus aureus and Escherichia coli bacteria. The ethyl acetate fraction was the most active fraction in inhibiting bacteria and the most occurring bioactive compounds appeared in LC-HRMS testing were luteolin, rutin and corchorifatty acid. The total flavonoid compound in the crude extract was 227.281 QE µg/mL and the highest i.e. 351.456 QE µg/mL total flavonoid compound was in methanol fraction.