In search of new natural fatty acid sources, extract of 10 different Turkish Klasea species were studies. Fatty acids of Klasea species were studied by GC and GC-MSD. Oleic acid (4.8-45.8%), palmitic acid (15.6-51.8%), linoleic acid (0.3-45.5%), palmitoleic acid (0.8-28.4%) and linolenic acid (15.6-34.6%) were the main fatty acids elucidated. All extracts were also subjected to acetylcholinesterase, butyrylcholinesterase, tyrosinase, β-carotene-linoleic acid, DPPH • scavenging, CUPRAC and ferrous ion-chelating ability activities. Total flavonoid and phenolic contents were determined as quercetin and pyrocatechol equivalents. All extracts showed significant antioxidant activity in all tests, except hexane extracts of K. serratuloides and K. cerinthifolia that showed weak inhibition against BChE and AChE. The hexane extract of K. coriaceae and methanol extract of K. serratuloides exhibited notable tyrosinase inhibitory activity.