Natural Products in Drug Discovery: Antibacterial and Antifungal Activity of Essential Oil of Compound Isolated from Senecio royleanus oleh Chandra Mohan Singh Bisht, S.M. Shakeel Iqubal, Aejaz A. Khan, Tasneem Mohammed, Areej Dawoud, Mohammed Gamal, S.K. Singh, Basim H. Asghar