Nature is the ever evolving source for compounds of medicinal importance, polyphenols among these compounds constitute ubiquitous group with wide range of physiological activities i.e. antioxidant, immune-stimulant, antitumor and antiparasitic. Yellow fever and dengue fever are mosquito-borne infectious diseases transmitted by bites of Aedes aegyptii, the presence of yellow fever in sub-Sahara of Africa and dengue fever in Saudi Arabia are threats to Egypt with the reemerging of Aedes aegyptii in Aswan and Toshka districts and hence, larvae control is more feasible than flying adults' control. This work was conducted targeting estimation of the relative levels of total phenolic content, antioxidant potential and larvicidal activity of one hundred and ten selected Egyptian plant species. The highest total phenolic contents were estimated in aqueous extracts of Coronilla scorpioides L.,

Rumex dentatus L. and Rumex vesicarius L., of the family Polygonaceae, are edible herbs growing wild in Egypt. Their lipoid constituents were examined by both liquid chromatography/mass spectrometry (LC/MS) and by gas chromatography/mass spectrometry (GC/MS). Their essential oil compositions consisted mainly of thujene, limonene, fenchon, estragole, and anethole but at largely different concentration. Fatty acid compositions were similar among the two species and consisting of palmitic, oleic, linoleic and linolenic acids, with R. vesicarius containing much higher level of omega-3-fatty acids. Both of the crude lipid extracts of the two species showed strong antioxidant activity as a radical quenching agent against 2,2-diphenyl-1-picrylhydrazyl (DPPH) systems. Antioxidant activities were mostly associated with the polar lipid fractions. High performance thin layer chromatography (HPTLC), both in the normal and reversed phase, as well as liquid chromatography/mass spectrometry (LC/MS) in the positive and negative electrospray ionization (ESI), showed unique chemical profile for each species that can be useful for species identification and quality control of herbal drug formulations. R. vesicarius was characterized by abundances of flavonoids and R. dentatus was abundant in anthraquinones and chromones.

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