Abstract :Since antiquity, man has used plants to treat common infectious diseases and some of these
traditional medicines are still included as part of the habitual treatment of various maladies. Natural
product chemistry facilitated a vast array of several bioactive secondary metabolites that have been
discovered from marine and terrestrial sources to combat infectious diseases. In this review natural
products and their isolates from various sources are used against microorganisms along with
mechanism of action has been discussed.