Heterocyclic compounds constitute one of the largest and most versatile families
of organic compounds. There are many heterocyclic compounds that are being isolated from
natural sources and day by day the number is increasing rapidly due to their enormous utility.
Nitrogen containing heterocyclic compounds have a prominent role in medicinal chemistry,
biochemistry and other streams of science. In this review, we have covered most of the
biologically active nitrogen containing heterocyclic compounds obtained from the natural
sources including indole, carbazole, quinoline, isoquinoline and benzothiazole ring system.
These isolated nitrogen containing heterocyclic compounds render wide spectrum of biological
activities including antifungal, anti-inflammatory, antibacterial, antioxidants, anticonvulsant,
anti-allergic, herbicidal and anticancer activities.