Antimicrobial Activity of β-Sitosterol Isolated from Kalanchoe tomentosa Leaves Against Staphylococcus aureus and Klebsiella pneumonia.

<b>Background and Objective:</b> <i>Kalanchoe tomentosa</i> is identified and their different characteristics regarding the antibacterial and antioxidant properties have a vast effect. Fresh <i>K. tomentosa</i> leaves obtained from Bandung, Indonesia was extracted using n-hexane followed by serial dichloromethane maceration. <b>Materials and Methods:</b> N-hexane and ethyl acetate were used to separate the dichloromethane extract using vacuum liquid chromatography and the isolated compounds were recrystallized with n-hexane. <b>Results:</b> About 37 mg of dichloromethane extract was obtained from the extraction process. Recrystallized compound isolates were identified as stigmast-5-en-3-ol or β-sitosterol. Both dichloromethane extract and β-sitosterol isolated compounds showed strong bacteriostatic activity against <i>S. aureus</i> with MIC = 15.63 and 7.81 μg mL<sup></sup><sup>1</sup> and<i> K. pneumonia</i> with MIC = 7.81 and 31.25 μg mL<sup></sup><sup>1</sup>, respectively. However, only dichloromethane extract exhibited a bactericidal effect (7.81 μg mL<sup></sup><sup>1</sup>). <b>Conclusion:</b> The pure β-sitosterol compound was isolated from<i> K. tomentosa</i> dichloromethane extract. Both the dichloromethane extract and the isolated β-sitosterol compound had antibacterial effects against <i>S. aureus</i> and <i>K. pneumonia.</i&gt.