Essential oil of citronella grass ( Cymbopogon nardus ) was screened for antibacterial
compounds by high-performance thin-layer chromatography (HPTLC) combined with direct
bioautography using soil bacterium Bacillus subtilis , marine bacterium Aliivibrio
fischeri , and plant pathogens Pseudomonas syringae pv. maculicola and Xanthomonas
euvesicatoria . The parallel derivatization using HPTLC–anisaldehyde reagent also
revealed the bioactive compounds separated with n -hexane–isopropyl acetate (9:1,
v/v ), which were analyzed by offline solid-phase microextraction–gas chromatography–electron
ionization-MS (SPME–GC–EI-MS) after scraping off and elution. The compounds responsible
for the antibacterial effect were identified as citronellal, geranial, neral, geraniol,
α-cadinol, and elemol. These compounds inhibited all studied bacterial strains except
elemol that demonstrated activity only against B. subtilis and X. euvesicatoria .
