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The environmentally friendly synthesis of nanoparticles process is a revolutionary step in the field of nanotechnology. In recent years plant mediated biological synthesis of nanoparticles has been gaining importance due to its simplicity and eco-friendliness. In this study, a simple and an efficient eco-friendly approach for the biosynthesis of stable, monodisperse silver nanoparticles using aqueous extracts of four Terminalia species, namely, Terminalia catappa, Terminalia mellueri, Terminalia bentazoe and Terminalia bellerica were described. The silver nanoparticles were characterized in terms of synthesis, capping functionalities (polysaccharides, phenolics and flavonoidal compounds) and microscopic evaluation by UV-visible spectroscopy, Fourier transform infrared spectroscopy and transmission electron microscopy. The results showed a simple and feasible approach for obtaining stable aqueous monodispersive silver nanoparticles. Furthermore, biological activity of the biosynthesized silver nanoparticles was examined. Concerning this, dose-dependent antioxidant activity of silver nanoparticles imparted by the plant phenolic and flavonoidal components was evaluated using in vitro 2,2-diphenyl-1picrylhydrazyl (DPPH) assay and found to be comparable to standard ascorbic acid. The same holds true for the anti-inflammatory activity where Terminalia catappa and Terminalia mellueri have a high-test inhibition percentage better than that of ascorbic acid in the carrageenan induced hind paw edema. The results also revealed that the aqueous extract of Terminallia catapa and its silver nanoparticles recorded the most potent in vivo antioxidant effect.

Brachychiton acerifolius, or Sterculia acerifolia as formerly known, is a member of a genus reported for a myriad of bioactive compounds. Metabolome analysis of B. acerifolius--leaves, flowers and seeds--and quantification of its major compounds are demonstrated in this study. Metabolites were analysed via UPLC-PDA-qTOF-(±) ESI-MS and UPLC/ITMS, with a total of 56 metabolites characterised including 30 flavonoids, 2 anthocyanins, 6 phenolic acids (i.e. citric and hydroxycitric acid conjugates) and 8 fatty acids (FAs). Multivariate data analyses (i.e. principle component analysis and orthogonal partial least square-discriminate analysis) were applied to identify metabolite markers for each organ. Pelargonidin-O-glucoside and naringenin-O-glucuronide were found exclusively in flowers versus flavone enrichment in leaves (i.e. luteolin-O-glucuronide and apigenin-O-rhamnosyl glucuronide). Gas chromatography/mass spectrometry analysis revealed the presence of toxic cyclopropene FAs in seeds which may restrict its use. Antioxidant activity assessment for the three organs was performed in comparison with vitamin C as positive control. Leaves showed the highest activity (IC50 0.015 mg/mL).

2 ry metabolites of bioactive chloroform/ methanol extract of Conyza dioscoridis using chromatographic techniques and spectroscopic analysis led to identify five major compounds; β-amyrin-3-acetate, β-lupeol-3-acetate, β-amyrenone, dotriacontane and 5,4ʹ-dihydroxy-6,7-dimethoxyflavone. The percentage of cumulative mortalities during pupal and adult stages reached to 76.6% and 83.3%, respectively after feeding 4 th larval instar of Spodoptera littoralis on C. dioscoridis crude extract with insecticidal activity in a dose-dependent manner. Whereas, β-amyrenone, lupeol acetate and 5,4ʹ-dihydroxy-6,7dimethoxyflavone suppressed 50, 60 and 73.3% of 4 th instar larvae of S. littoralis at concentration 0.3, 0.5 and 0.5%, respectively. Also, the extract showed marked decreasing in acetyl cholinesterase activity, total lipids and protein contents. The GC/MS analysis of volatile oil of C. dioscoridis aerial part led to identify 63 sensory metabolites that represent 93.68% of total volatile constituents. The oil was characterized by a high percentage of oxygenated sesquiterpenes (36.00%) and sesquiterpene hydrocarbons (21.09%), in addition phenylated and aliphatic hydrocarbons (15.43% and 14.58%, respectively). C. dioscoridis exhibited acute toxicity on both sexes, reduced adult longevity, oviposition deterrents and reduced fertility on S. littoralis. So, it used as new natural target insecticidal agent for S. littoralis, biodegradable alternatives to chemical insecticides and can used as a natural tool in pest management program.