In the present work, the aim is to compare the chemical composition and antibacterial activity of two lavender Species "Lavandula stoechas L." and "Lavandula dentata L.", belonging to wild flora of Morocco. Thus, a phytochemical screening was performed on the aerial part of invested plants, and no qualitative difference was detected between the studied species. Indeed, both contain catechin and gallic tannins, flavonoids (anthocyanins, flavones and catechols), sterols and triterpenes, in addition to combined anthracene compounds (C-glycosides). Whereas, the dosage of crude aqueous extracts showed that the contents of secondary metabolites, such as polyphenols, flavonoids and total and condensed tannins were higher in L. dentata. Also, the essential oils of the aerial part, obtained by hydrodistillation gave higher yields in L. dentata than L. stoechas. Finally, antibacterial activity tests were performed on four strains of bacterial pathogens (Staphylococcus aureus "Gram+," and Escherichia coli; Klebsiella pneumoniae and Proteus mirabilis which are Gram -) with both essential oils and crude aqueous extracts. The results obtained showed that essential oils have a powerful effect, particularly that of L. dentata on S. aureus, with an inhibition diameter about 30 mm. The crude extracts showed moderate antibacterial activity against Gram - and had no effect on Gram +.

The aim of the present work is to compare the chemical composition, antibacterial and antifungal activity of two spontaneous species of lavender "Lavandula stoechas L." and "Lavandula dentata L." in Morocco. A phytochemical screening was performed on the aerial part of invested plants. The qualitative variation was revealed in the secondary metabolites of the species studied. Subsequently, the dosage of the crude organic extracts showed that the polyphenol content was higher in the methanol fraction, with an important yield in L. dentata. Also, the essential oils of the aerial part, obtained by hydrodistillation gave higher yields in L. dentata than L. pedunculata. Finally, tests of the antibacterial and antifungal activity of the essential oils of the two species were performed on four strains of bacterial pathogens (Staphylococcus aureus "Gram+," and Escherichia coli; Klebsiella pneumoniae and Proteus mirabilis which are Gram-), and three phytopathogenic fungi : Rhizopus stolonifer, Aspergillus brasiliensis and Penicillium expansum, The results obtained showed that the essential oil of L. dentata showed a strong antibacterial activity against the studied strains, particularly against S. aureus. While the antifungal activity revealed that L. pedunculata has a remarkable antifungal power against the fungi tested in comparison with L. dentata.