Isolasi dan Identifikasi Zat Antibakteri dan Antikuorum Sensing dalam Ekstrak Kelopak Bunga Rosela (Hibiscus sabdariffa L.)

Abstrak

This research was dried powder of Rosela calyx macerated with ethanol 70%-HCl (99:1) and then fractionated using n-hexane, ethyl acetate, n-butanol and water. All fraction was tested for antibacterial and antibiofilm activities by using the diffusion methods against S. aureus and E. coli. Quorum sensing inhibition was tested against Pseudomonas aeruginosa. Further fractionation was performed on the most active fraction by using VLC, followed by preparative TLC. Bioautography was done to guide the isolation of the active compound. Structure identification of the active compound was performed by analysing 1H-NMR, 13C-NMR, COSY, HMBC and LCMS data. The ethyl acetate fraction was the most active fraction against S. aureus showed by growth inhibition zone ,15.89 ± 0.37 mm (concentration of 10%) and 15.93 ± 0.72 mm (concentration of 20%), while against E . coli, 17.25 mm (concentration of 10%) and 17.35 mm (concentration of 20%). Formation inhibition of S. aureus biofilm observed at 62.05% ± 17.83 and 11.11% ± 23.13 in E.coli. Antiquorum sensing activity was observed as 19.23 ± 1.52 mm (concentration of 10%) and 20.89 ± 2.35 m at a concentration of 20%. Identification of the partial structure of the active compounds resulted a benzofuran derivative compounds.