Comparative Extraction Using Steam and Simultaneous Extraction Techniques, Chemical Profiling, and Antibacterial Activity of Essential Oil from Tagetes erecta and Tagetes patula

The extraction of essential oil can be done in several ways, with some emphasizing quality and others emphasizing quantity. Essential oil components of Tagetes erecta and Tagetes patula were analyzed and compared using two common extraction techniques, i.e., steam distillation (SD) and simultaneous distillation extraction (SDE), coupled with GC-MS for their chemical composition and antimicrobial activity. In both species, the highest % yield was obtained by the SD with yields of 0.05% and 0.12%, respectively. Thus, the comparative study of extraction methods unveiled SD as the best method for the extraction of essential oil, providing a high yield with a greater percentage of major compounds. The GC-MS analysis unveiled 24 different compounds in T. erecta and 27 compounds in T. patula. SD of T. erecta and T. patula revealed a higher concentration of β-Caryophyllene with compositions of 37.25% and 65.47%. A comparative analysis of the antibacterial activity of essential oil extracted using SD revealed that T. erecta is effective against all four tested bacterial strains, i.e., Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae and Salmonella Typhi. Notably, the largest zone of inhibition (ZOI) was observed against K. pneumoniae (12 mm) for T. erecta. In contrast, T. patula demonstrated activity against two bacterial strains, i.e., K. pneumoniae and S. typhi, with a maximum ZOI of 11 mm, observed against K. pneumoniae. The stronger antibacterial activity of T. erecta oil might be due to the synergistic interaction of the most abundant bioactive compounds obtained through SD.