Essential oils (EOs) from the aerial parts of three Launaea species collected from two different habitats were extracted [Launaea mucronata collected from coastal desert (LMC) and from inland desert (LMD), Launaea nudicaulis collected from coastal desert (LNC) and from inland desert (LND), Launaea spinosa (LS)]. The EOs were analysed by gas chromatography mass spectrometry (GC‐MS) and tested for antioxidant activity as well for allelopathic activity against purslane. A total of 117 compounds were identified from all samples, including 64 from LS, 50 from LMC, 39 from LMD, 24 from LNC, and 20 from LND, representing 100% of the total oil mass. The oxygenated sesquiterpenes were the major compounds of the EOs from LS, LMC, LMD, LNC, and LND, representing 62.73, 61.02, 58.35, 43.22, and 48.33%, respectively, whereas the monoterpene hydrocarbons were minor compounds in all samples. α‐Acorenol (31.42%), trans‐longipinocarveol (12.04%), and γ‐eudesmol (6.31%) represented the major compounds of the EO from LS, whereas hexahydrofarnesyl acetone and n‐heneicosane represented the major compounds from LMC, LMD, LNC, and LND. Correlations between the EOs of the five samples were studied via principal component analysis and agglomerative hierarchical clustering, based on the chemical composition of the EOs. There was a significant variation between Launaea species regarding both the quality and the quantity of EO composition, whereas no significant difference was observed based on the habitats (coastal and inland deserts). The EOs of the five Launaea samples exhibited meaningful antioxidant activities, as follows: LND > LNC > LMD > LMC > LS. Moreover, the EOs of the five Lanaea samples exhibited significant allelopathic activity against purslane weed in a concentration‐dependent manner. LMD and LMC showed the highest effect, with germination inhibition of 96.1 and 87.9% at 250 μL L−1, and radicle growth inhibition of 92.6 and 89.7%, but LS was the least effective extract. Our results showed that the variation in the quality and quantity of EO composition is mainly species specific, with a slight correlation with habitats.

Nine flavonoids and one saponin were isolated from the aerial parts of Cleome amblyocarpa. Molecular Docking of isolated compounds on COVID-19 virus main protease showed variable binding affinities with scores...

The variation in habitat has a direct effect on the plants and as a consequence, changes their content of the bioactive constituents and biological activities. The present study aimed to explore the variation in the essential oils (EOs) and phenolics of Heliotropium curassavicum collected from the coastal and inland habitats. Additionally, we determined their antioxidant and allelopathic activity against the weed, Chenopodium murale. Fifty-six compounds were identified as overall from EOs, from which 25 components were identified from the coastal sample, and 52 from the inland one. Sesquiterpenes were the main class in both samples (81.67% and 79.28%), while mono (3.99% and 7.21%) and diterpenes (2.9% and 1.77%) represented minors, respectively. Hexahydrofarnesyl acetone, (-)-caryophyllene oxide, farnesyl acetone, humulene oxide, farnesyl acetone C, and nerolidol epoxy acetate were identified as major compounds. The HPLC analysis of MeOH extracts of the two samples showed that chlorogenic acid, rutin, and propyl gallate are major compounds in the coastal sample, while vanilin, quercetin, and 4′,7-dihydroxyisoflavone are majors in the inland one. The EOs showed considerable phytotoxicity against C. murale with IC50 value of 2.66, 0.59, and 0.70 mg mL−1 for germination, root, and shoot growth, respectively from the inland sample. While the coastal sample attained the IC50 values of 1.58, 0.45, and 0.66 mg mL−1. MeOH extracts revealed stronger antioxidant activity compared to the EOs. Based on IC50 values, the ascorbic acid revealed 3-fold of the antioxidant compared to the EO of the coastal sample and 4-fold regarding the inland sample. However, the ascorbic acid showed 3-fold of the antioxidant activity of the MeOH extracts of coastal and inland samples. Although H. curassavicum is considered as a noxious, invasive plant, the present study revealed that EO and MeOH extracts of the H. curassavicum could be considered as promising, eco-friendly, natural resources for antioxidants as well as weed control, particularly against the weed, C. murale.

Contamination with heavy metals is one of the most serious problems in the aquatic environments. In Egypt, Manzala Lake is suffering from this problem. The objective of this work was to assess heavy metals pollutants and their spatial distribution in Manzala Lake using GIS technique. Georeferenced water and sediment samples were randomly collected from the lake. The detected heavy metals were: Fe, Pb, Cu, Cd, Cr, Zn and Co. The obtained results indicated that the highest concentrations of heavy metals were observed in the northeastern and the southern parts of the lake nearby drains. This could be attributed to industrial, agricultural and municipal wastes coming through the drains especially Bahr El-Baqar drain and the industrial wastes coming from Port Said drains. From the geo-accumulation index, it was noticed that the lake is more polluted with cadmium and lead in the hydrosoils samples. All metals in water are within the EPA standard limit except for cadmium. Geostatistics provides effective methods to quantify the contaminated waters and sediments which support decision-making about redevelopment scenarios or remediation techniques.

Burullus Lake is one of most important lakes in north Delta of Egypt. It is exposed to huge amounts of serious pollutants especially heavy metals. The sediments within the lake aid in the dispersion of these metals. The main objectives of this research were to evaluate and map the spatial distribution of heavy metals in Burullus Lake sediments. Accordingly, 37 locations were randomly distributed within the lake. Sediment samples were taken from these locations. These samples were analyzed for seven metals including Fe, Cu, Zn, Cr, Co, Cd and Pb. Also, five indices were used to identify the status of metal pollutants in the Lake. These indices are: enrichment factor (EF), contamination factor (CF), degree of contamination (DC), pollution load index (PLI) and geo-accumulation index (Igeo). Ordinary Kriging was used to interpolate the spatial distribution of the studied elements within the lake. The obtained results indicated that cadmium was the most enriched element in the lake sediments due to industrial and agricultural wastes drained into the lake. The Igeo index revealed that Cd and Pb were the common pollutants in lake sediments. The DC values ranged between low (near El-Boughaz) and moderate (near drainage areas). The spatial distribution of pollutants within the lake indicated that the highly polluted areas are located close to the drains, whereas as the less polluted areas were close to El-Boughaz.

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The use of drainage water in the irrigation of agroecosystem is associated with environmental hazards, and can pose threats to human health. Nine heavy metals (Fe, Mn, Zn, Cu, Co, Cr, Ni, Cd and Pb) along three main drains in the middle Nile Delta were measures in the sediments, roots and shoots of three common macrophytes (Echinochloa stagnina, Phragmites australis and Typha domingensis). The physicochemical characteristics, as well as the enrichment factor (Ef), contamination factor (Cf), geoaccumulation index (Igeo), ecological risk factor (Er), degree of contamination (Dc) and potential ecological risk index (PERI), were determined for sediment. The metal bioaccumulation factor (BAF) and translocation factor (TF) were assessed for plants. Data revealed high contents of Cr, Zn and Cd in the upstream of the drains, while Mn, Cu and Ni were recorded in high concentrations in the downstream. Mn, Cr, Co, Cu, Ni and Zn were recorded to be within EU (2002), CSQGD (2007) and US EPA (1999) limits, while Cd and Pb showed high a ecological risk index. This high concentration of pollutants could be attributed to unremitting industrial activities, which can bioaccumulate in the food chains and cause serious problems for humans. The root of P. australis showed the effective accumulation of most of the elements, while T. domingensis revealed the highest accumulation of Pb. However, the highest BAF shoot value was found in T. domingensis for most of the heavy metals, except for Fe and Zn in P. australis and Mn in E. stagnina. Thus, P. australis could be used as a potential phytoextractor of these hazardous metals, as an eco-friendly and cost-efficient method for remediation of the polluted drains. Further, T. domingensis could be integrated as a hyperaccumulator of Pb. Strict laws and regulations must be taken into consideration by the policymaker against unmanaged industrial activities, particularly near the water streams in the Nile Delta.

Reichardia tingitana is an annual plant growing in different habitats of the Egyptian deserts. Little is known about variation among the habitats occupied by this species, its distribution, chemical composition, and allelopathic activity. The present study aimed to (a) assess the vegetation composition of three different habitats (Western Coast, Delta Coast, and Wadi Hagoul) of R. tingitana in Egypt, (b) determine their correlation to soil factors, (c) identify the changes in the bioactive constituents of R. tingitana in the three regions, and (d) evaluate the allelopathic activity regarding the variation in the habitat. Density and cover of all plant species associated with R. tingitana were estimated within 52 plots, representing three regions. Physical and chemical parameters of soil were analyzed in each plot. R. tingitana aboveground biomass was collected from each habitat, and the bioactive composition was analyzed using HPLC. The allelopathic effect against two weeds (Amaranthus lividius and Chenopodium murale) was assessed. The floristic composition showed the presence of 133 species belonging to 27 families. In the Delta Coast habitat of R. tingitana, Zygophyllum aegyptium and Calligonum polygonoides co-dominate, while Lycium shawii dominate the Western Coast habitat and finally the habitat of Wadi Hagoul was dominated by Haloxylon salicornicum. Soil analysis revealed little variations among habitats, especially salinity and organic matter. Fifteen compounds, mainly phenolics (60% of the total identified compounds) were identified from all R. tingitana samples. The major compounds were quercetin, naringenin, ellagic, gallic, chlorogenic, and caffeic acids. These compounds varied in diversity or quantity among different habitats. The Western Coast sample was the richest in species, followed by Delta Coast sample. Our study showed that salinity is the crucial factor that induces the production of bioactive constituents in R. tingitana, especially phenolics and flavonoids. The R. tingitana extracts significantly reduced the germination and growth of Chenopodium and Amaranthus. However, the Western Coast sample showed potent allelopathic activity, where the germination was wholly inhibited at 75 mg L−1 and 50 mg L−1, respectively. Thereby, this extract could be used as eco-friendly bioherbicide and may be integrated into weed control strategies.