Nutrients and Main Secondary Metabolites Characterizing Extracts and Essential Oil from Fruits of Ammodaucus leucotrichus Coss. & Dur. (Western Sahara)

The ethnobotany of the Sahrawi people considers various species of plants and crude drugs as food, cooking spices and traditional health remedies. From among these, the fruits of Ammodaucus leucotrichus Coss. & Dur. (Apiaceae), known as Saharan cumin, were chosen for our research. The present paper reports a proximate composition and mineral element analysis of various samples of A. leucotrichus fruits, collected during the balsamic period (full fruiting) from plants grown in Bir Lehlu (Western Sahara) and purchased in a local market (Tindouf). These analyses pointed out interesting nutritional values of the crude drug. Decoction and alcoholic extract, analyzed by HPLC-DAD, evidenced ammolactone-A and R-perillaldehyde as the two main isolated constituents, particularly in the ethanolic extracts (ammolactone-A, market sample: 51.71 ± 0.39 mg/g dry extract; wild sample: 111.60 ± 1.80 mg/g dry extract; R-perillaldehyde, market sample: 145.95 ± 0.35 mg/g dry extract; wild sample: 221.40 ± 0.30 mg/g dry extract). The essential oils, obtained through hydrodistillation, were characterized by GC-MS and evidenced R-perillaldehyde (market sample: 53.21 ± 1.52%; wild sample: 74.01 ± 1.75%) and limonene (market sample: 35.15 ± 1.68%; wild sample: 19.90 ± 1.86%) as the most abundant compounds. The R configuration of perillaldehyde was ascertained and a complete description of the ¹H and ¹³C NMR spectra of ammolactone-A was performed.

Synergistic Anticandidal Effects of Six Essential Oils in Combination with Fluconazole or Amphotericin B against Four Clinically Isolated Candida Strains

The development of opportunistic pathogenic Candida strains insensitive to several classes of antifungals has emerged as a major health care problem during the last years. Combinational therapy of natural products (e.g., essential oils, EOs) with conventional antifungals has been suggested as a promising alternative to overcome this medical problem. The present study investigates the potential antifungal activity of EOs extracted from some selected medicinal plants, alone and in combination with two common conventional antifungals (fluconazole and amphotericin B) against four clinical Candida isolates. MIC assays indicated that EOs induced strong anticandidal activities with MIC values ranging from 0.162 to 4.950 mg/mL. The combination of amphotericin B with Thymus leptobotrys, Origanum compactum and Artemisia herba alba EOs provided a synergistic effect against C. krusei only, with MIC gain of four-fold, and additive effect against remaining strains (MIC gain = two-fold). Interesting synergistic interactions were observed by combining all studied EOs with fluconazole, with reduction rates of their MICs ranging from 16 to 512-fold. This synergistic effect was very pronounced with the combination of T. leptobotrys EO and fluconazole. These findings indicate that studied EOs can be used as anti-candidals in combination with antifungals, particularly fluconazole, to counteract the emergence of resistant Candida spp.

Composition and Chemical Variability of the Cone Oil from Algerian Tetraclinis articulata

Very little is known about the yield and chemical composition of the essential oil isolated from cones of Tetraclinis articulata (Vahl) Masters (Cupressaceae). In continuation of our on-going work devoted to the valorisation of medicinal and aromatic plants from Tlemcen Province (North-Western Algeria), cones have been harvested in eight locations (coastal township and highlands) and 40 oil samples have been isolated by hydrodistillation. Six oil samples were analyzed by a combination of chromatographic [GC(Retention indices)] and spectroscopic techniques (GC-MS, 13C NMR). Then, the remaining 34 oil samples were analyzed by [GC(RI)] and 13C NMR and the 40 compositions were submitted to statistical analysis. Essential oil yields varied substantially from sample to sample (0.17 to 1.13%, w/w). The cone oils consisted mainly of monoterpenes, with α-pinene (47.1-73.6%) and limonene (6.5-21.9%) being the main components. (E)-β-Caryophyllene and germacrene D were the major sesquiterpenes. Diterpenes, ( Z) and ( E)-biformene were identified for the first time in T. articulata essential oil. PCA analysis of the data allowed the distinction of two groups, the second group being sub-divided into two sub-groups. Groups and sub-groups were differentiated with respect to their contents of α-pinene and limonene and, to a lesser extent, of sesquiterpenes.

Chemical Composition and Antimicrobial Activity of the Essential Oil from Aerial Parts of Algerian Pulicaria Mauritanica

One oil sample isolated from aerial parts of Pulicaria mauritanica Coss. from Western Algeria has been analyzed by GC(RI), GC-MS and 13C NMR. In total, 21 components, accounting for 97.0% of the oil, were identified. Then, 36 oil samples coming from plants harvested at two flowering periods in three locations were analyzed by GC(RI) and 13C NMR. Although all the oil samples exhibited similar composition, dominated by carvotanacetone (89.2–96.1%), the yield of essential oil varied drastically from sample to sample (0.35–1.44%), depending on the location of harvest. The essential oil displayed moderate antimicrobial effect against bacteria, yeast and filamentous fungi (MIC = 2–4 μL/mL).