International Journal of Plant Science and Ecology Vol. 1, No. 6, 2015, pp. 237-240 http://www.aiscience.org/journal/ijpse ISSN: 2381-6996 (Print); ISSN: 2381-7003 (Online) * Corresponding author E-mail address: ahmad_botany@yahoo.com (N. Ahmad), shinwari2002@yahhoo.com (Z. K. Shinwari), javidhej@yahoo.com (J. Hussain), drijaz_chem@yahoo.com (I. Ahmad), raziaperveen98@yahoo.com (R. Perveen), Salim rehman@yahoo.com (S. Rehman) Phytochemical Screening and Biological Activities of Different Parts of Centaurea montana Nisar Ahmad 1, * , Zabta Khan Shinwari 2 , Javid Hussain 3 , Ijaz Ahmad 4 , Razia Perveen 5 , Salim Rehman 1 1 Department of Botany, Kohat University of Science and Technology, Kohat, Pakistan 2 Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan 3 School of Biological Sciences and Chemistry, University of Nizwa, Sultanate of Oman 4 Department of Chemistry, Kohat University of Science and Technology, Kohat, Pakistan 5 Department of Biotechnology, Kohat University of Science and Technology, Kohat, Pakistan Abstract The crude extracts and its derived fractions {n-hexane, chloroform, ethyl acetate, n-butanol and residual aqueous fraction} of rhizome, leaves and flowers of medicinal plant Centaurea were subjected to microbicidy against Vibrio cholerae (ATTC9459), Salmonella typhe (ATTC700931), Acinitobacter baumanni (ATTC17978), Shigella dysenteriae (ATTC13313), Bacillus anthrax (ATTC14578), Moraxella lacunata (ATTC17967), Penicillium chrysogenum (ATTC28089), Candida albicans (ATTC2876), Aspergillus fumigatus (ATTC3626) and evaluation of chemical profile. The results revealed that n - hexane fraction obtained from rhizome of the plant showed outstanding (87.40% inhibition) antibacterial activity against Moraxella lacunata followed by crude extract of rhizome against Acinitobacter baumanni showing 82.50% inhibition. The crude extract and its derived fractions obtained from leaves of the plant showed moderate inhibition against all tested bacterial strains. The crude extracts/fractions obtained from the flowers of the plant were found inactive against all tested bacterial and fungal strains. Surprisingly none of the crude extracts/ fractions of the plant showed antifungal activity against the three tested fungal pathogens. Preliminary phytochemical screening of plant showed that rhizome and leaves are the rich source of fatty acids, flavonoids, alkaloids and glycoside. Keywords Medicinal Plants, Centaurea montana, Asteraceae, Antibacterial Activity, Antifungal Activity, Phytochemical Screening Received: July 10, 2015 / Accepted: September 12, 2015 / Published online: January 5, 2016 @ 2015 The Authors. Published by American Institute of Science. This Open Access article is under the CC BY-NC license. http://creativecommons.org/licenses/by-nc/4.0/ 1. Introduction Plants have the ability to synthesize a wide variety of chemical compounds that are used to perform important biological functions. These phytochemicals also defend plants against the attack from predators such as insects, fungi and herbivorous mammals. The medicinal properties of plants have been explored in the light of up-to-date scientific expansion all over the world, due to their exciting pharmacological activities and little toxicity [Sharma et al., 1992; Vaquero et al., 2010]. Medical plants are extensively used in the cure of different diseases. Plant extracts and their diverse formulations in the healing and reduction of several diseases in folk remedy have been dated back to the primeval times. Further, some natural products also exist in vegetables, fruits and beverages [Ozturk and Ercisli 2006]. Natural products from medicinal plants are known to be chemically balanced, effective and least injurious with none or much