Chemical profile and antifungal potential of essential oils from leaves and flowers of Salvia algeriensis (Desf.): A comparative study

Fatih Medjahed1, Abdelaziz Merouane2*, Abdelkader Saadi1, Ammar Bader3, Pier Luigi Cioni4, and Guido Flamini4
Salvia is a plant genus widely used in folk medicine in the Mediterranean area since antiquity. A large number of Salvia essential oils have been reported against diverse microorganisms. In the current study chemical composition of essential oils from leaves and flowers of Salvia algeriensis (Desf.) was determined using gas chromatography-electron impact mass spectrometry (GC-EIMS) as well as their antifungal activity against phytopathogenic fungi Alternaria solani and Fusarium oxysporum exploring disk method. The GC-EIMS analysis identified 59 compounds (84.8%) in the essential oil obtained from leaves of S. algeriensis. Its major constituents were benzaldehyde (9.7%), eugenol (8.7%) and phenylethyl alcohol (8.4%). In flowers oil, 34 compounds (92.8%) were detected. The main ones were viridiflorol (71.1%) and globulol (8.6%). The essential oil obtained from leaves exhibited the highest antifungal activity, where the effective dose inhibiting 50% of mycelial fungal (ED50) against A. solani was 0.90 μL mL-1 with minimum inhibitory concentration (MIC) equal to 2 μL mL-1, whereas the ED50 and MIC in F. oxysporum culture was 1.84 μL mL-1 and 3 μL mL-1 respectively. The mycelial inhibition by flowers oil varies from 1.77 μL mL-1 (ED50) with A. solani culture (MIC 6.5 μL mL-1) to the lowest effect recorded (ED50 3.00 μL mL-1 and MIC 9.33 μL mL-1) against F. oxysporum. To our best knowledge, this is the first report on S. algeriensis, their leaves oil can constitute an alternative biocontrol against phytopathogenic fungi commonly controlled by chemical fungicides.
Keywords: Alternaria solani, Fusarium oxysporum, GC-EIMS, natural fungicide.
1University of Hassiba Benbouali, Faculty of Sciences, Hay Es-Salam Chlef 02000, Algeria.
2University of Hassiba Benbouali, Institute of Agricultural Sciences, Ouled Fares, Chlef 02010, Algeria. *Corresponding author (merouanaziz@yahoo.com).
3Umm Al-Qura University, Faculty of Pharmacy, Makkah, 21955, Saudi Arabia. 4Università di Pisa, Dipartimento di Farmacia, via Bonanno, 33 56126 Pisa, Italia.