Variability of the chemical compositions of fatty acids, tocopherols and lipids antioxidant activities, obtained from the leaves of Pistacia lentiscus L. growing in Algeria

Phytochemical characterization of forest leaves extracts and application to control apple postharvest diseases

The study investigated the antifungal and phytochemical properties of three forest plants (Eucalyptus globulus, Pistacia lentiscus, and Juniperus phoenicea) against apple diseases caused by Colletotrichum gloeosporioides and Alternaria alternata. The determination of the total polyphenol and flavonoid contents in the three aqueous extracts of studied plants showed that E. globulus exhibited the highest contents than those of P. lentiscus and J. phoenicea. Furthermore, the three studied extracts showed very appreciable antioxidant activity with decreasing order: E. globulus, P. lentiscus, and J. phoenicea. The phytochemical analysis showed different common phenolic acids in the three studied plants namely: quinic acid, gallic acid, chlorogenic acid, and caffeoylquinic acid as well as other flavonoids mainly quercetin and catechin. The results of the current study demonstrated that the fungistatic activity of E. globulus EO (4 and 2 µl/ml) seemed to be the most effective under laboratory conditions with an inhibition zone diameter above 16 mm. However, the poisoned food technique indicated that the aqueous extract (80%) and the essential oil (4 µl/ml) of E. globulus exhibited the highest mycelial growth (> 67%) and spore germination (> 99%) inhibition. Preventive treatments with essential oils (4 µl/ml) and aqueous extracts (80%) applied to apple fruits inoculated with A. alternata and C. gloeosporioides resulted in the lowest lesion diameter (< 6.80 mm) and disease severity index (< 15%) and the most favorable inhibitory growth (> 85.45%) and protective potentials (> 84.92%). The results suggest that E. globulus has a brilliant future in the management of anthracnose and Alternaria rot of apple and provide a basis for further studies on its effects under field conditions.

Profiling of Essential Oils from the Leaves of Pistacia lentiscus Collected in the Algerian Region of Tizi-Ouzou: Evidence of Chemical Variations Associated with Climatic Contrasts between Littoral and Mountain Samples

Leaves of Pistacia lentiscus were collected from two Algerian sites in the mountains and the littoral of the Tizi-Ouzou region. The harvest was conducted in four consecutive seasons on the same selected set of trees. Essential oils (EOs) were extracted by hydrodistillation; then, they were analyzed by gas chromatography coupled mass spectrometry (GC-MS). Forty-seven constituents could be detected and quantified, including α-pinene (2–13%), β-caryophyllene (8–25%), β-myrcene (0.3–19%), bornyl acetate (0.8–7%), δ-cadinene (3–8%), bisabolol (1–9%), β-pinene (0.9–7%), caryophyllene oxide (4–9%), and α-cadinol (3–11%). Antioxidant (AOx) activities of the EOs were assessed by ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays. Significant differences in EO composition and AOx activities appeared dependent on the season and the site. Variations of AOx activities were significant for the FRAP and ABTS tests but not for DPPH. Characterization of the leaf fatty acyl (FA) profiles was performed by GC-MS. Variability appeared according to season and altitude. Polyunsaturated fatty acids levels were high (27–55%) at the coldest date and place. The levels of linolenic acyl in the leaves were significantly correlated with bisabolol levels in the EOs (Spearman’s correlation coefficient: 0.818). Such results will be useful for the sustainable local valorization of wild P. lentiscus. These data also open new routes for further studies on terpenoid biosynthesis using correlation networks and fluxomic approaches.

Harvest date and variability in lipid bioactive compounds in Pistacia atlantica

BACKGROUND: The present work stands as an endeavor to uncover the ideal harvesting time of leaves in which they exhibits the maximum contents of bioactive molecules such as essential fatty acids, tocopherols and carotenoids. METHODS: A large scale investigation was carried out for the leaves of Pistacia atlantica involving a large number of populations collected over a period of four months during the growing season. The antioxidant activity was evaluated using both DPPH and β-carotene assays. The chemical percentage variability of the fatty acids was investigated using statistical analysis methods (Agglomerative Hierarchical Clustering “AHC”, also cited as CAH). OBJECTIVE: During the growth period, the effects of harvesting date on the total contents of lipids, tocopherols, carotenoids, fatty acids composition and also the antioxidant activities of the lipids were investigated. RESULTS: The content of myristic acid and other saturated fatty acids increased during leaf development, while linoleic, linolenic acids and unsaturated fatty acids decreased. The highest percentages of both linolenic C18:3 (27.25±5.92%) and linoleic acids C18:2 (17.68±3.80%) were obtained for the month of May at the first stage of leaves development (young leaves), but higher percentage levels of C18:1, were obtained for both consecutive months of August & September (28.83±6.50%; 27.79±8.63%, respectively) at intermediate developing stage. The lipids, tocopherols, carotenoids contents and the saturated and unsaturated fatty acids were dependent on the harvest time. The antioxidant activity showed higher powers at the first developing stage (May). Two main clusters and two sub-clusters of the fatty acids were distinguished and were also depending clearly on the period of the collection. CONCLUSIONS: The results showed that the FA were dependent on the period of collection of the leaves. The main result of this study illustrate the nutritional potential (richness in MUFA such as C18:1, 2, 3) of the oil of P. atlantica leaves, which can provide opportunities for rational exploitation in the food industries or for medicinal purposes.

Total Tocopherols, Carotenoids, and Fatty Acids Content Variation of Pistacia atlantica from Different Organs' Crude Oils and Their Antioxidant Activity during Development Stages

The current study investigated the effect of developmental stages on the chemical composition and the antioxidant activity of fifteen crude oil samples obtained from Pistacia atlantica Desf. leaves, galls, and fruits. Twelve fatty acids were detected by GC/FID, linolenic acid (C18 : 3) was the major fatty acid detected in leaves crude oils that registered [41.73 % (P<0.05)] on the last stage. The best content of tocopherols and carotenoids was recorded at the last stage for leaves and galls oils, respectively, with values of [1.530±0.01, 0.52±0.01 (P<0.05) mg α-tocopherol equivalent/g DW] and [86.60±0.95, 69.15±0.13 (P<0.05) μg β-carotene equivalent/g DW]. For fruits oils, the content varied depending on the levels of fruits maturation. The results from DPPH, FRAP, and ABTS assays revealed that the antioxidant activity increased with the increasing content of tocopherols and carotenoids in leaves and galls oils during development stages, and varied for fruits oils depending on the ripening stages. Moreover, according to PCA analysis, the best phytoconstituent content and antioxidant activity were attributed to P. atlantica Desf. fruit's crude oils. Also, a strong relationship was found between the antioxidant activity and bioactive phytochemical components, such as tocopherols, carotenoids, and omega-three fatty acid, which confirmed that P. atlantica Desf. crude oils present a valuable source of natural antioxidant that could be used for pharmaceutical and food industries purposes.