Dunes are one of the most dynamic ecosystems in the nature and they are considered as a special habitat type hosting valuable genetic resources. Dunes located in Turkey are very rich in terms of plant diversity. Istanbul has special place for the richness of endemic and rare species in its dune vegetations. Biochemical characteristics of some plant species growing in Istanbul dunes, which are under immense threat during the recent years have been examined in the present study. Seed samples and aerial parts of the plants have been analysed for fatty acid and amino acid compositions. The higher concentrations of α-linolenic acid were quantified in Euphorbia paralias (48.24%) and Diplotaxis tenuifolia (24.47%). Linoleic acid concentrations were detected at the higher levels in Xanthium strumarium (68.51%) and Otanthus maritimus (66.62%). Eryngium campestre (44.97%), Cyperus capitatus (44.27%) and Eryngium maritimum (41.88%) were found to have high oleic acid concentrations. 20,32% punicic acid was detected in Ecballium elaterium. The higher concentrations of some essential amino acids were observed in the seeds. Proline is the dominant amino acid in the aerial parts of all taxa examined. Significant correlations between amino acid concentrations were calculated. The data obtained in the present study reveal that regarding plants as novel crops can be efficient for utilization in biochemical and biotechnological applications in many fields such as human nutrition, health and other industrial purposes.