Abstract Phoenix dactylifera L. has traditionally been used as a medicine in many cultures. The aim of this study was to evaluate the nutritional properties, aromatic compounds, total phenolic content and the antioxidant activity of ten ripe date fruit varieties grown in Tunisia. Sugar profiles were analyzed by high performance liquid chromatography, while fatty acid compounds were detected by gas chromatography and aromatic compounds were analyzed by GC-Electron Impact Mass Spectroscopy. Total phenolic contents were measured using colorimetric methods, whereas antioxidant capacities were evaluated in vitro using DPPH and ABTS radicals. It has been found that total sugars are the predominant component in all date varieties, followed by moisture, along with moderate amounts of proteins, ash, and fats. Multivariate tests based on the volatile compounds profile showed significant differences among varieties. Between the sixty-two volatile compounds detected, alcohols, aldehydes and unsaturated hydrocarbons constituted the main chemical classes. The date varieties exhibited strong antioxidant potential that correlated with phenolic content. In conclusion date varieties can play a major role in human nutrition and health because of their wide range of valuable nutritional components and natural antioxidants that could potentially be considered as a functional food ingredient.

The in-vitro antioxidant activity of Rhaponticum acaule essential oil (RaEO) was evaluated using β-carotene/linoleic acid bleaching, chelating activity, and lipid peroxidation inhibition (TBARS) assays. The antimicrobial activity of RaEO was assessed by disc diffusion and microdilution methods against 8 bacteria and 4 yeast. Finally, the allelopathic activity of RaEO on the seed germination and the shoot and root elongation of lettuce (Lactuca sativa L.) seedlings were investigated. According to our results, the RaEO exhibited significant antioxidant activity, similar to those of standards (BHT and ascorbic acid) with IC50 values of 0.042 and 0.045 mg/mL obtained by β-carotene bleaching and TBARS assays, respectively. On the other hand, despite its interesting ferrous chelating activity, RaEO possesses moderate IC50 value (0.35 mg/mL) as compared with that of EDTA (0.015 mg/mL). RaEO exhibited a strong antimicrobial activity against all the tested microorganisms, with IZ, MIC and MBC values being in the range of 7.67 ± 0.58 to 13.33 ± 0.58 mm, 1.25 to 5.00 and 5.00 to 10.00 mg/mL, respectively. The results reveled also that RaEO inhibited the shoot and root growth of Lactuca sativa L. seedlings. Our data suggested that the RaEO had pharmaceutical benefits and could be used as a potential natural herbicide resource.

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.

The aim of this study was to investigate the chemical composition of the essential oils of three populations of Daucus aureus from three sites in Eastern Algeria (Setif, Constantine and Oum Elbouaghi) and to test their antibacterial and antioxidant activities. The essential oils were obtained by hydrodistillation and analyzed by GC and GC/MS. The major components were sabinene (30.6% and 36.2%), n-nonane (8.0% and 7.9%), α-pinene (5.5% and 6.3%) and 4-terpineol (4.4% and 6.0%) in D. aureus from Setif and Constantine populations essential oils, respectively; whereas, α-pinene (19.4%), β-pinene (12.0%) and p-cymene (12.2%) were the major components in Oum Elbouaghi essential oil population. The chemical compositions of D. aureus from Eastern Algeria are markedly different from those from Western Algeria, and likely represent new chemotypes. The antimicrobial activity of the essential oils was evaluated against four bacteria and one fungus, using the disc-diffusion method and minimal inhibitory concentration (MIC), whereas, the antioxidant activity of the essential oils was evaluated using the DPPH test. The results showed that the oils have an antimicrobial activity against the microorganisms tested, with minimal inhibitory concentration (MIC) values between 0.97 and 3.23 mg/mL and weaker antioxidant and DPPH radical scavenging activities were found in comparison to butylated hydroxyl toluene (BHT).