Thesis (Ph.D.) - Cairo University - Faculty of Pharmacy - Department of Pharmacognosy

This thesis includes a phytochemical and biological study of Citrus peel and Psidium guajava seeds beside the physiochemical and compositional analysis of the extracted freeze-dried mucilage from the Colocasia esculenta L. Schott mucilage tubers and explore its sustain release matrix pattern. The GC/MS analysis of the four Citrus peels essential oils composition revealed that they all have high percentage of monoterpene hydrocarbons where limonene is the most abundant. The highest content of total phenolic content was observed in grapefruit peels, while sweet orange peel showed the highest flavonoid content. The UPLC/MS classification of secondary metabolities in citrus peels revealed that flavonoids amounted for the most abundant secondary metabolites class and contributed to the discrimination between them. Madarain n-hexane peel extact has the highest concentration of the isolated nobiletin as revealed from HPLC. Five compounds were isolated from the agro-waste peels of mandarin which are nobiletin, 4{u00B4}, 5, 7, 8- tetramethoxyflavone, limonin, deacetylnomilin and 4-hydroxybenzoic acid methyl ester. While, two compounds were isolated from the agro-waste seeds of guava fruit which are p-hydroxybenzoic acid and Ý-sitosterol. Eight components of fatty acid methyl ester were identified in guava seeds, where pentadecylic (25.18%) and palmitic (13.99%) acids are the major saturated fatty acids while; linoleic acid was the major unsaturated fatty acid (26.40%). Eleven phenolic compounds were revealed in the in the methanolic extracts of guava seeds by HPLC rapid quantification of phenolic compounds; out of which rutin, vanillic acid, p-hydroxybenzoic acid, vanillin and salicylic acid represent the major constituents. The Colocasia esculenta mucilage is a promising alternative matrix capable of sustaining the release of a freely water soluble model drug over 8 h. The biological study showed an antioxidant, cytotoxic, anti-diabetic and hypocholesterolemic, molluscicidal and antimicrobial (for peels, pectin and essential oils of Citrus), anti-inflammatory and cytotoxic (Colocasia esculenta mucilage), antioxidant and cytotoxic effects (for Psidium guajava seeds)

Issued also as CD