Insects and their chemical weaponry: New potential for drug discovery

Insects make up the largest and most diverse group of organisms on earth, with nearly 1 million species described and millions more estimated to remain undiscovered. Like all other organisms, insects and related arthropods mainly utilize chemistry to adapt to these environments in a wide variety of ways, such as for defense against predation or infection, communication and socialization, life cycle development, and surviving environmental conditions. Arthropods harbor a large variety of chemical substances used for these ecological adaptations, and this is the overarching theme of the field of chemical ecology. Progress in the field has advanced rapidly, and this comprehensive review summarizes the enormous potential for discovery of new natural products with medicinal value from among the phylum Arthropoda. This review: (1) introduces the topic of arthropod chemical biodiversity; (2) reviews cultural uses of arthropods as medicines; (3) provides an overview of insect chemical defense studies and modern natural product analytical methods; (4) describes examples from the literature of insect-derived substances with medicinally relevant biological properties; and (5) summarizes the aforementioned topics to emphasize the value of arthropods as reservoirs of potentially useful new natural products.