Husnul Khatimah, Elvira Hermawati, Fadjar Mulya, Muhammad Ikhlas Abdjan, Thanawit Kuamit, Ade Danova
Natural products have played an important role in the discovery and development of antibacterial agents. This paper described the isolation of a new ursane-type pentacyclic triterpenoid, (18β,19αH)-3-oxo-urs-12-en-27α-oic acid (2), from the tree bark of Sandoricum koetjape Merr. Along with this, five known compounds—β-caryophyllene oxide (1), bryononic acid (3), 7-deacetylgedunin (4), 7-deacetyl-7-oxogedunin (5), and 12,20-dihydroxydammar-24-en-3-one (6)—were successfully isolated, and one compound, 12β-hydroxydammarenolic acid (7), was reported in our previous report. All compounds (1–7) were tested with their antibacterial properties against two Gram-positive (Enterococcus faecalis and Staphylococcus saprophyticus) and two Gram-negative (Citrobacter freundii and Salmonella enterica) bacteria. The structures of the isolated compounds were elucidated using NMR spectroscopy and mass spectrometry data. A preliminary antibacterial assay showed that only compound 7 inhibited the growth of the tested bacteria, with an inhibition zone diameter of 7.5–9 mm at a concentration of 1 mg/mL. DFT analyses explained electronic profiles with HOMO-LUMO gaps (4.54–6.34 eV) and electrophilicity from 1.73 to 4.39 eV. To elucidate the antibacterial mechanism of compound 7, a molecular docking study was conducted. The findings from both in vitro and in silico analyses suggest that compound 7 is a promising antibacterial candidate for further investigation. © 2025 by the authors.
Organic Chemistry Division, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No.10, Bandung, 40132, Indonesia; Nanotechnology Engineering Program, Faculty of Advanced Technology and Multidiscipline, Universitas Airlangga, Surabaya, 60115, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Surabaya, Surabaya, 60213, Indonesia; Center of Excellence in Computational Chemistry (CECC), Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
