Abstract:The objective of the study was to analyze chemical structure of date palm (Phoenix dactylifera L.) by employing ultimate, proximate and thermo-gravimetric techniques. Samples from different anatomical parts of date palm, namely trunk, frond base, frond midrib, leaflets, coir, fruit stem, date stone, and fruit empty bunches were considered for the experiments. Based on the findings in this work palm leaflet samples gave the highest amount of extractives content (32.9%), followed by date palm stone specimens with 31.5%. Cellulose content values of 32.8% and 47.5% were obtained for date palm stone and palm coir samples, respectively. Overall the hemicellulose contents of all samples were relatively similar to those of typical wood or non-wood lignocellulosic materials with the two exceptions of palm coir and palm leaflets. Both palm coir and palm leaflet specimens had 12.6% and 16.1% hemicellulose content. Volatile matter values of 74.3% and 87.5% were determined for leaflets and fruit empty bunch samples. The ash content of the samples ranged from 1.4% for date stone to 15.2% for palm leaflet samples. The thermal decomposition was completed below a temperature of 500˝C with an exception of those samples taken from palm leaflets. Taken together the data indicate that date palm stone and palm coir revealed could be more viable for renewable energy production than the other specimens considered in this work.

In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, 10, 15, 20, and 25 µL were studied for their antibacterial activity against three pathogenic bacteria, Agrobacterium tumefaciens, Dickeya solani, and Erwinia amylovora. The main EO compounds in the leaves/twigs were 4-terpineol (22.59%), D-limonene (16.67%), 4-carvomenthenol (12.84%), and linalool (7.82%). In small green branches, they were D-limonene (71.57%), dodecane (4.80%), oleic acid (2.72%), and trans-palmitoleic acid (2.62%), while in branch bark were D-limonene (54.61%), γ-terpinene (6.68%), dodecane (5.73%), and dimethyl anthranilate (3.13%), and in branch wood were D-limonene (38.13%), dimethyl anthranilate (8.13%), (-)-β-fenchol (6.83%), and dodecane (5.31%). At 25 µL, the EO from branches showed the highest activity against A. tumefaciens (IZ value of 17.66 mm), and leaves/twigs EO against D. solani and E. amylovora had an IZ value of 17.33 mm. It could be concluded for the first time that the wood and branch bark of C. aurantium are a source of phytochemicals, with D-limonene being the predominant compound in the EO, with potential antibacterial activities. The compounds identified in all the studied parts might be appropriate for many applications, such as antimicrobial agents, cosmetics, and pharmaceuticals.

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Callistemon viminalis (C. viminalis) is a plant that has been reported to have various medicinal values such as antibacterial, antifungal, antioxidant activities and other pharmaceutical and insecticidal properties. This review covers the potentials, applications and properties of different extracts from different parts (branches, flowers, fruits, bark, leaves) of C. viminalis. Furthermore, the chemical structures of the bioactive compounds were reported for biological activities. All the results supported the traditional uses of C. viminalis in folk medicine. In addition, some researches supported the use of C. viminalis extracts for the preparation of metal oxide nanoparticles.

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The present study described the possibility of using wood-treated oil-fungicide of lemon-scented gum (Corymbia citriodora) from newly emerged leaves and unripened fruits against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum. Air-dried wood samples of Melia azedarach were treated with the extracted oils from leaves and unripened fruits from C. citriodora. The main chemical constituents identified in the essential oil (EO) from leaves were citronellal (55.31%), citronellol (21.03%) and isopulegol (10.79%), while in unripened fruits were α-pinene (17.86%), eudesmol (13.9%), limonene (9.19%), γ-terpinen (8.21%), and guaiol (7.88%). For recovered oils (ROs), the major components from leaves were D-limonene (70.23%), γ-terpinene (13.58%), β-pinene (2.40%) and isopregol (2.23%), while, 4-terpineol (21.35%), cis-β-terpineol, (19.33%), D-limonene (14.75%), and γ-terpinene (7.42%) represented the main components in fruits. EOs from leaves and fruits at the amounts of 100, 50 and 25 µL showed the highest inhibition percentage (IP) of 100% against F. culmorum and P. chrysogenum compared to control treatment, while at the amounts of 100, and 50 µL showed 100% IP of R. solani. Wood treated with ROs from leaves and fruits showed IPs of 96.66% and 93.33%, respectively, against the growth of R. solani. The mass spectra of the main components of C. citriodora leaves and fruits’ EOs have been recorded in electron ionization mode at 70 eV and fragmentation has been reported and discussed. On the other hand, different quantum parameters such as the heat of formation, ionization energy total energy, binding energy, electronic energy and dipole moment using the modified neglect of diatomic overlap (MNDO) semi-empirical method have been calculated.

Natural compounds from certain timber trees are highly valued and recommended to protect wood and wood products against mold fungi. This study highlighted the use of some natural extracts and Paraloid B-72 against the growth of two mold fungi, namely Alternaria tenuissima and Fusarium culmorum. From the in vitro experiment, the methanol extracts of Callistemon viminalis bark were effective against the growth of F. culmorum, as were Magnolia grandiflora leaves against A. tenuissima. Environmental scanning electron microscopy (ESEM) and electron dispersive X-ray spectroscopy (EDX) analysis of treated Acacia saligna wood with the two fungi and Paraloid B-72 demonstrated the clear hyphal growth of F. culmorum and A. tenuissima and changes in elemental chemical composition. After three months, no fungal growth on the wood surface treated with the methanol extract of M. pomifera bark was found. After three months of treating wood with Paraloid B-72 at 5% and 10%, the mold growth was visible. Almost all of the wood treated with methanol extracts showed growth of the A. tenuissima hypha, as well as some contamination by other microorganisms, except for the wood treated with the methanol extract of M. pomifera bark.

This study was conducted to evaluate the suitability of date palm midribs as an alternative source for energy production. The physical properties, chemical constituents, and fuel characteristics of the midribs of five common date palm cultivars (Barhi, Khalas, Khodry, Sukkari, and Sullaj) were determined. In addition to the frond base, the midribs were divided into three distinct parts (base, middle, and top) along the frond. The results showed that both the fibre saturation point and volumetric shrinkage of the date palm midribs were much higher than those of solid wood. There were significant differences in all of the chemical constituents of the midribs between the five date palm cultivars. The date palm midribs were characterised by higher levels of extractives (19.3% for Barhi to 21.7% for Sullaj) and ash contents (3.3% for Khodry to 5.8% for Khalas). The other chemical constituents were within the ranges found for other lignocellulosic materials, including softwood and hardwood. The heating values for the midribs ranged between 17.30 MJ/kg for the Barhi cultivar and 17.89 MJ/kg for the Khodry cultivar. The higher ash content and lower density of date palm midribs makes them less desirable for energy production. It can therefore be concluded that the frond base is not suitable for energy production.