Résumé
Three different seaweeds Gracilaria corticata J.Agardh ,Grateloupia lithophila Boergesen and Chaetomorpha antennina(Bory) kuetz used for the study were subjected for the estimation of carbohydrates, proteins, aminoacids, lipids and pigments such as chlorophyll a, chlorophyll b, carotenoid and phycobilins. They were also used for the nanoparticles synthesis and also checked for the blood glucose level changes by the oral administration of the seaweeds (0.5 g/day) to 6 mice for 20 days and with 3 mice as controls. The chaetomorpha, grateloupia and gracilaria estimation results showed 18.4%, 5.5%, 3.6% for carbohydrates, 15.8%, 30.5%, 23.7% for proteins, 4.9%, 22.94%, 11.04% for amino acids, 0.3%, 1.8%, 1.2% for lipids, 33.93, 1.35, 2.97 (mg/g fresh sample) for total chlorophyll, 0.2, 0.6, 5.49 (mg/g fresh sample) for carotenoid, 1.75, 2.1, 5.04 (μg/g fresh sample) for phycoerythrin respectively. They were also investigated for the extracellular biosynthesis of silver and gold nanoparticle and have achieved rapid formation of gold nanoparticles using Chaetomorpha antennina and Gracilaria corticata. It has been confirmed with the surface plasmon resonance.