Chemical and biological diversity in fourteen selections of four Ocimum species

Abstract

Biomass, essential oil yield, essential oil composition diversity, and antibacterial and antifungal activities of 14 selections of 4 Ocimum species [Ocimum basilicum L. (selections: T 1-T 10), O. gratissimum L. (selections: T 11-T 12), O. tenuiflorum L.f., syn. O. sanctum L. (selection: T 13) and O. kilimandscharicum Baker ex. Guerke (selection: T 14)] were investigated. O. basilicum selections T 9 (methyl chavicol: 87.0%) and T 10 {(Z)- and (E)-methyl cinnamate: 69.1%} produced higher biomass (67.8 and 56.7 t/ha) and oil (203.4 and 141.7 kg/ha) yields relative to 8 (T 1-T 8) linalool (up to 58.9%), or methyl chavicol (up to 61.8%) rich selections. O. gratissimum selection T 12 (eugenol: 84.1%, 254.6 kg/ha oil yield) was significantly superior to T 11 (62.1% eugenol and 18.4% camphor). O. tenuiflorum (T 13, methyl eugenol: 72.5%) and O. kilimandscharicum (T 14, camphor: 51.7%) produced 171.7 and 96.2 kg/ha essential oil, respectively. The essential oils exhibited broad spectrum antibacterial (against 5 Gram-positive and 7 Gram-negative bacteria) and antifungal (against 10 fungi) activities. The bacterial species Bacillus subtilis, Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis, and the fungal species Epidermophyton floccosum, Microsporum gypseum, and Sporothrix schenckii were more sensitive to the essential oils.