Abstract
Achilea fragmentisma plant is widely distributed along northern regions of Saudi Arabia with various traditional medical uses. The plant was collected from Tabuk and Arar regions to study the effect of the variation in habitat on the chemical compositions, antimicrobial and antioxidant activities of the plant. The results showed significant differences between the two studied region regarding the parameters of the weather in years from 2010-2016.The antioxidant and antimicrobial of the plant showed significant variation in two habitats. Plant collected from Arar showed high antioxidant activity with IC50 (0.21 ± 0.01 g/L) by DPPH radical scavenging methods, and good antibacterial activity with gram-positive bacteria (Staphylococcus epidermidis, Bacillus cereus and Staphylococccus aureus clinical isolate), antibacterial activity ranging between high to no activity (between 14.5 ± 0.5-6.0 ± 0.0 mm zone of inhibition), On the other side the tested plant extracts showed no effect on, all gram-negative bacteria. GC/MS data showed marked variation in chemical compositions of both phenolic and alkaloid compounds in plants collected from both regions. Phenolic compounds were accumulated with higher amounts(Ferulic acid, Eugenol and Salicylic acid ester) in Arar region, while the alkaloid fractions (Ethyl isoallocholate, Pterin 6-carboxylic-acid and kadain) showed higher concentrations in plants collected from Tabuk region. The results reflect the variation in of weather parameter, affect on chemical compositions and biological activities of the plant in two studied regions.