What is a "natural product"?
A "natural product" is a chemical compound or substance made by a living organism.
This sponge in the genus Spongosorites makes the compound topsentin, which is used as an anti-inflammatory. Image courtesy of Amy Wright. Download image (jpg, 2.19 MB).
Almost 50% of the medicines we use today come from nature. For example, medicines like morphine and penicillin are chemical compounds made by plants or microorganisms (bacteria and fungi) that treat pain or fight infection; peptides derived from animal venom have been used to treat autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. Many of these compounds are not essential to sustain the life of an organism’s individual cells, yet it requires energy to produce them. So why bother? Presumably, these chemicals made by nature, commonly referred to as “natural products,” provide some type of evolutionary advantage to make their production worthwhile.
Many marine plants and animals are rich producers of natural products. Animals such as corals and sponges are sessile as adults, meaning they grow attached to something and do not generally (or easily) move. This makes it difficult to defend themselves against things that want to eat them, keep other animals from moving into their space, find mates for reproduction, or protect themselves from infections.
One solution to these problems is to produce chemical compounds. If you taste bad, smell bad, or are toxic, you are less likely to get eaten. The same applies to keeping the neighbors from moving in on you. Natural products may attract sperm and eggs released by sessile invertebrates, ensuring that they find each other for reproduction. They may also act as chemical "lighthouses," guiding larvae back to the adult organism. Or these compounds may act to stop the larvae of other species from settling on top of the original inhabitants. Many natural products are strong antibiotics, antifungal, and/or antiviral agents, and may be produced to ward off infections caused by bacteria, fungi, and viruses.
As for most of the compounds encountered, scientists do not fully understand why they are present. Fortunately, however, we do not have to understand why they are there. It is enough that they exist, as natural products are important sources for new drugs and the identification of compounds suitable for further modification during drug development.
During some ocean exploration expeditions, scientists are looking for new microorganisms, sponges, corals, and other marine organisms rich in natural products that can be turned into biopharmaceutical products or used as biomedical research tools.
Published on May 2, 2022
By Amy Wright, Research Professor, Harbor Branch Oceanographic Institute, Florida Atlantic University
Adapted from “What is a Natural Product?” by Amy Wright
Relevant Expedition: Exploring the Blue Economy Biotechnology Potential of Deepwater Habitats