The objective of this study was to identify the chemical composition and antimicrobial activity of acetone extracts of Pinus halepensis Mill (needles and bark) and Olea europaea L. (leaves and bark) obtained from three different altitudes in AL-Jabal AL-Akhder, Libya. The chemical compositions were analyzed by GC/MS. The analyses of the extracts from needles of P. halepensis led to the identification of 38, 15 and 18 different components, representing 93.34, 100 and 97.00% of the total extract at three different altitudes (125, 391 and 851 respectively). However, the extracts from bark contained 6, 4 and 8 compounds, representing 100% of the total extract at three different altitudes, respectively. For the leaf extracts from O. europea, 5, 8 and 10 compounds were identified, representing 100% of the total extracts at three different altitudes (125, 391 and 851 respectively). However, the crud extracts from bark led to the identification of 13, 16 and 15 compounds, representing 97.55, 99.70 and 98.05% of the total extract at three different altitudes, respectively. The chemical classes of the detected compounds confirmed that these extracts contained a complex mixture consisting of sugars, monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, triterpenes, tetraterpenoids, phenylethanoids, steroids, resins and phthalates. Four pathogenic bacteria and one fungal strain were used to determine the antimicrobial activity. The extracts exhibited antibacterial potency with varying degrees of inhibition with MIC values ranging from 480 to 1300mg/L and the best MICs values observed were 525, 530, 410 and 645mg/L against the growth of Agrobacterium tumefaciens, Erwinia carotovora, Corynebacterium fascians and Pseudomonas solanacearum, respectively for the extract from O. europaea at altitude I. The extracts all extracts exhibited a significant antifungal potency against Botrytis cinerea with varying degrees of inhibition of growth with EC 50 values ranging from 71.10 to 154.71mg/L.

No abstract

The utilization of branchwood as lignocellulosic raw material source for paper production may have the potential of solving the problem of the availability of raw material in the pulp and paper industry. This study therefore compared the chemical composition and fiber morphological indices (according to Franklin’s method) of stemwood and branchwood in Eucalyptus camaldulensis and Pinus halepensis trees grown in Egypt. The statistical analysis showed a significant effect of species, wood type (stem and branchwood), and their interaction on the measured chemical constituents and fiber morphological indices at 0.05 significance level. In both genera, the stemwood exhibited a higher percentage of cellulose and hemicellulose and was lower in lignin, total extractives, and ash than those measured in branchwood. Also in both genera, the stemwood was higher in fiber length, Runkel ratio, rigidity coefficient, Muhlsteph ratio, and Luce’s shape factor, and lower in basic density and flexibility coefficient than those in branchwood. Based on the chemical analysis and the fiber morphological indices, the stemwood and branchwood of both species were suitable for paper production with various qualities. Moreover, good correlations were found in both stem and branchwood between the basic density and the fiber wall thickness and fiber lumen diameter. ln contrast, there was an independent association between the stemwood basic density and the fiber length, and this relationship in branchwood was positive for both genera.

Background: Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts. Methods: Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea. Results: The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively. Conclusion: Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.