Essential oil of Syzygium boisianum (Gagnep.) Merr. & LMPerry: Chemical compositions, antimicrobial activity, and molecular docking

Essential oil obtained from hydrodistillation of the Vietnamese Syzygium boisanum leaves was analyzed by the GC/FID-MS (gas chromatography/flame ionization detection-mass spectrometry). Forty-five compounds (90.08%) were namely identified, in which sesquiterpene hydrocarbons (73.07%) were the major chemical class. Among identified compounds, beta-caryophyllene (18.21%) and bicyclogermacrene (25.47%) were the principal compounds. This essential oil was comparable with the positive control streptomycin in an antimicrobial assay against three Gram-positive bacteria Enterococcus faecalis ATCC299212, Staphylococcus aureus ATCC25923, and Bacillus cereus ATCC14579. Docking study of two major sesquiterpene hydrocarbons beta-caryophyllene and bicyclogermacrene against bacterial DNA gyrase B showed that these two compounds mainly interacted with hydrophobic residues at the rim of the pocket, thereby they are possible inhibitors.

Automated summary

The essential oil extracted from the Vietnamese Syzygium boisanum leaves was analyzed using GC/FID-MS. Forty-five compounds were identified, with sesquiterpene hydrocarbons being the major chemical class. The antimicrobial assay showed that the essential oil exhibited similar activity to streptomycin against three Gram-positive bacteria. Docking studies suggested that the major compounds in the essential oil could potentially inhibit bacterial DNA gyrase B.