CHEMICAL COMPOSITION AND EVALUATION OF ANTIBACTERIAL ACTIVITY OF ESSENTIAL OIL OF Tithonia diversifolia (HEMSL.) A. GRAY (ASTERACEAE) COLLECTED IN MERIDA STATE - VENEZUELA

The essential oil of fresh leaves and flowers of Tithonia diversifolia (Hemsl.) A. Gray, obtained by hydrodistillation method using the Clevenger trap. It was obtained 1.2 mL of oil from 1 kg of leaves and 0.6 mL of oil in relation to 1,320 kg of flowers, and it was characterized by chromatography gas-mass spectrometry (GC/MS), being able to identify as major components: a-pinene (54.44%), limonene (19.26%), trans-ss-ocimene (10.90%), alpha-farnesene (4.17%) and sabinene (4.03%) for the leaves; and a-pinene (53.55%), limonene (11.57%), 2-4-hexadienal (8.99%), trans-ss-ocimene (4.42%), 1,8-cineole ( 3.68%), alpha-farnesene (3.17%) and terpineol (3.05%) for the flowers. The antibacterial activity was determined by the agar disk diffusion method against international reference bacteria Staphylococcus aureus ( ATCC 27923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 23357), Pseudomonas aeruginosa (ATCC 27853). The essential oil from the flowers of T. diversifolia inhibited the bacterial growth of Escherichia coli with an MIC of 12.5 ppm and Enterococcus faecalis with an MIC of 50 ppm.