Leaves essential oils of Syzygium cumini L. Cupressus sempervirens L. and Lantana camara L., from Alexandria, Egypt were analysed by Gas chromatography-mass spectrometry (GC-MS). The antibacterial and antioxidant activities were assessed for each oil using minimum inhibitory concentrations (MICs) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods; respectively. The main oil constitutes were α-pinene (17.53%), α-terpineol (16.67 %) and alloocimene (13.55%) in S. cumini, trans-caryophyllene (15.57%) and α-humulene (9.16%) in L. camara and cedrol (21.29%), ∆ 3 -carene (17.85%) and α-pinene (6.9%) in C. Sempervirens. The antibacterial activity was studied against some bacterial strains. The oil of S. cumini demonstrated strong inhibition activity against the tested bacterial strains. The total antioxidant activity (TAA %) was 11.13, 9.13, 3.13% for S. cumini, L. camara and C. sempervirens, respectively. Our work revealed that the studied leaf oils are new promising potential sources of antioxidants and antibacterial compounds and good future practical applications for human and plant health.

In the present study, the antifungal activity of wood treated with Pinus halepensis branch n-hexane oily liquid extract (OLE) and Schinus terebinthifolius branch essential oil (EO) was evaluated against the growth of four phytopathogenic fungi—Bipolaris oryzae, Fusarium oxysporum, Fusarium solani, and Rhizoctonia solani. Air-dried wood samples of Pinus roxburghii were autoclaved, and each wood received 100 µL of the concentrated oils from P. halepensis and S. terebinthifolius. The main compounds identified in S. terebinthifolius branch EO were terpinen-4-ol (18.25%), cis-β-terpineol (15.60%), γ-terpinene (12.46%), sabinene (9.83%), α-terpinene (8.56%), and 4-thujanol (6.71%), while the main compounds in P. halepensis branch HeO were 2-undecenal (22.25%), 4-hydroxy-10-methyl-3,4,7,8,9,10-hexahydro-2H-oxecin-2-one (8.43%), (Z)-2-decenal (6.88%), nonanal (5.85%), (2E)-2-decenal (4.65%), (E,E)-2,4-decadienal (4.41%), arachidonic acid methyl ester (4.36%), and 2-(7-heptadecynyloxy)tetrahydro-2H-pyran (4.22%). P. halepensis OLE at a concentration of 3% showed the highest inhibition percentage of fungal growth (IPFG) of B. oryzae, followed by S. terebinthifolius EO at 3% and 2%, with IPFG values of 80%, 74.44%, and 71.66%, respectively. At a concentration of 3%, branch oils from S. terebinthifolius and P. halepensis were found to have the highest IPFG values with 45.55% and 40.55%, respectively, against F. oxysporum growth. Moderate to weak activity was found against F. solani when S. terebinthifolius EO and P. halepensis OLE were applied to wood. EO and OLE-treated wood samples at 3% produced inhibitions of 54.44% and 41.11%, respectively, against R. solani.

The crude methanolic extracts from leaves of Eucalyptus camaldulensis L., E. camaldulensis var obtusa and E. gomphocephala grown in Egypt were investigated to explore their chemical composition as well as their antibacterial, antifungal and antioxidant activities. Major phenolics found were ellagic acid, quercetin 3-O-rhamnoside, quercetin 3-O-b-D-glucuronide, caffeic acid and chlorogenic acid. The antioxidant activities were examined by the 2,2'-diphenypicrylhydrazyl (DPPH) and β-Carotene-linoleic acid assays. E. camaldulensis extracts showed the highest phenolic content, antioxidant and antimicrobial activities compared to other cultivars. MIC values reported for antibacterial activity of E. camaldulensis ranged from 0.08 μg/mL (Bacillus cereus) to 0.22 μg/mL (Staphylococcus aureus), while MBC values ranged from 0.16 μg/mL (Dickeya solani and B. cereus) to 0.40 μg/mL (S. aureus). The inhibitory activities against growth of bacteria and fungi used is an indication that E. camaldulensis a might be useful resource for the development and formulation of antibacterial and antifungal drugs.

The chemical composition of the essential oil from the leaves of Eucalyptus camaldulensis, Eucalyptus camaldulensis var. obtusa and Eucalyptus gomphocephala grown in northern Egypt was analysed by using GC-FID and GC-MS techniques. The antibacterial (agar disc diffusion and minimum inhibitory concentration methods) and antioxidant activities (2,2'-diphenypicrylhydrazyl) were examined. The main oils constituents were 1,8-cineole (21.75%), β-pinene (20.51%) and methyleugenol (6.10%) in E. camaldulensis; spathulenol (37.46%), p-cymene (17.20%) and crypton (8.88%) in E. gomphocephala; spathulenol (18.37%), p-cymene (19.38%) and crypton (16.91%) in E. camaldulensis var. obtusa. The essential oils from the leaves of Eucalyptus spp. exhibited considerable antibacterial activity against Gram-positive and Gram-negative bacteria. The values of total antioxidant activity were 70 ± 3.13%, 50 ± 3.34% and 84 ± 4.64% for E. camaldulensis, E. camaldulensis var. obtusa and E. gomphocephala, respectively. The highest antioxidant activity value of 84 ± 4.64% could be attributed to the high amount of spathulenol (37.46%).

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The aim of this work is to identify the chemical constituents and the bioactivity of essential oil (EO), acetone extract (ACE) and n-hexane extract (HexE) of S. terebinthifolius ripened fruits using GC-MS. Total phenolic content and antioxidant activity of extracts were determined using the Folin-Ciocalteu and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assays, respectively. The toxicity against the growth of Acinetobacter baumannii, Bacillus subtilis, Escherichia coli, Micrococcus flavus, Pseudomonas aeruginosa, Sarcina lutea, and Staphylococcus aureus was determined with measuring the inhibition zones (IZs) using the disc diffusion method at the concentrations from 125 to 2000 μg/mL, also, the minimum inhibitory concentrations (MICs) using 96-well micro-plates and ranged from 4 to 2000 μg/mL. The major components in EO were α-pinene (36.9%), and α-phellandrene (32.8%). The major components in ACE were oleic acid (38.7%), α-phellandrene (13.33%), and δ-cadinene (11.1%), while the major methyl esters of fatty acids detected in HexE were oleic (12.8%), and palmitic (10.9%). The EO showed good activity against the growth of Staph. aureus and P. aeruginosa with MIC values of 16 μg/mL and 32 μg/mL, the ACE showed broad activity against the studied bacterial pathogens with MIC values ranged from of 4-128 μg/mL against the studied bacterial isolates, while HexE, however, showed weak antibacterial activity. The IC values of EO, ACE and HexE were 15.11 ± 0.99, 118.16 ± 1.7 and 324.26 ± 2.45 μg/mL, respectively, compared to IC of Tannic acid (23.83 ± 1.9 μg/mL) and butylated hydroxytoluene (BHT, 2.9 ± 0.1 μg/mL). Data suggested that the ripened fruits of S. terebinthifolius have potent antioxidant and antibacterial activities.

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Background: early blight disease caused by Alternaria solani is one of the most destructive diseases of the tomato, reducing tomato production globally. Methods: four fungal isolates were collected from four tomato cultivars and identified through morphological characterization and polymerase chain reaction (PCR) amplification of the internal transcript spacer (ITS) region. Plectranthus neochilus and Parthenocissus quinquefolia methanol extracts and the bioagents Trichoderma viride and Pseudomonas fluorescens were used as antifungal agents in vitro and in vivo and compared with chlorothalonil, a reference chemical fungicide. HPLC analysis of the plant extracts was used to identify the main flavonoid compounds, namely, rutin and myricetin. Results: molecular characterization showed that the fungal isolates belonged to A. solani. The results of in vitro antifungal activity studies revealed that chlorothalonil, at a concentration of 2500 mg/L, showed the highest inhibition percentage of fungal growth (IPFG) against A. solani (84.4%), followed by the bioagents T. viride and P. fluorescens, with IPFG values of 72.9% and 67.9%, respectively. Moderate to weak activity was found against A. solani when P. neochilus and P. quinquefolia extracts were applied at a concentration of 2500 mg/L, with an IPFG value of 54% for both extracts. The results of in vivo spray application showed that T. viride and chlorothalonil, as well as P. fluorescens, significantly reduced the disease index of early blight, and followed by the P. neochilus and P. quinquefolia extracts. By HPLC, the flavonoid compounds rutin and myricetin were identified in P. neochilus (leaf) with amounts of 2429.60 and 75.92 mg/100 g of extract, and in P. quinquefolia (fruit), with amounts of 1891.60 and 241.06 mg/100 g of extract, respectively. Conclusions: the results of the bioactivity of plant extracts and the bioagents indicate a vital role as antifungal activity against A. solani.