The man's interest in plants and their chemical substances is intertwined with the very history of humanity. We can recognize that the survival of man and other living beings that cohabit the planet is intrinsically associated with the presence of these plants and their fascinating substances. The existence of approximately 320,000 species of plants on the planet, the vast majority of which are unknown from a scientific point of view (only 5% phytochemically), and an even smaller percentage validated from a biological perspective, reveal the promising potential and importance that the chemistry of natural products based on plants represents.
According to the World Health Organization (WHO), 80% of the world's population uses medicinal plants as basic medication; however, this use presents an annual growth rate of 7%1,2. Another no less important aspect is that 25% of currently prescribed drugs are derived from plants, with 70% of all new drugs approved by the United States Food and Drug Administration (FDA) from January 2001 to June 2006 being of natural origin, and only 30% being synthetic in origin. The influence of natural sources is even more prominent in antitumor drugs, when it comes to cancer-fighting medications, where these numbers reach 77.8%1,2.
However, the importance of natural products is not restricted to medicine but also holds significance in other relevant themes of contemporary society. Considering the period from 1998-2009 and using search terms such as “phytochemistry,” “phytochemical,” “phytotherapeutic,” “herbal medicine,” “biopesticide,” “essential oil,” and “natural flavor” as a search strategy, a bibliometric study using the databases of “Web of Science” (Number of publications) and the “Derwent Innovations Index” (Number of Patents) resulted in 32,960 publications (Figure-1) and 18,503 patents3,4. These numbers demonstrate an upward curve in scientific production from 2001, highlighting the last three years of the series, during which the number of publications indexed in the consulted database reached an annual average of 853 scientific publications on phytochemistry.
Figure 1 – Number of scientific publications on “phytochemistry”: 1989-2009
Source: Direct search Web of Science. Accessed in December 2009.
These publications are related to themes such as: biopesticides, aromas, fragrances, and phytotherapeutics. Regarding the global market for phytochemical products, phytotherapeutics have always represented a significant share of the pharmaceutical market. This segment generates globally $36.8 billion per year, and the consumption of phytotherapeutic medicines has increased considerably over the last two decades. The estimated annual growth rate is 6.3% (Table-1), and considering global growth prospects according to the average annual rate of 7%, the phytotherapeutic market could reach values around five trillion dollars by the year 20505,6.
With regard to the biopesticide market, a growth trend has been observed since 2005, and it is predicted that by the end of 2014, this market will exceed one billion dollars, according to an estimated average annual growth rate of 9.9%. In contrast, the synthetic pesticide market shows a declining trend of 1.5% per year, due to the demand for pesticide-free and more organic agricultural products, especially in North America and Western Europe, where revenue from the sale of biopesticides reached $594.2 million in 2008, and demand is expected to double by 2015, with projected revenue of around $1.02 billion7,8.
In the aroma and fragrance segment, according to the American database Comtrade (United Nations Commodity Trade Statistics Database), the largest consumers of essential oils are the USA (40%), the European Union (30%), with France being the leading country in imports, and Japan (7%). The global essential oils market revolves around $15 million a year, showing an approximate growth of 11% per year9,10.
In light of this scenario, the importance of natural products in human life is evident; however, the relevance of plants and their extraordinary substances goes beyond the borders of our knowledge, even though it is often imperceptible to the human eye. The most relevant and extraordinary aspect of this entire magical alchemy, plant/substances, is to reflect on how Nature, expressed through plants and through them, created and orchestrates a whole ecosystem in balance and interdependence that has achieved this fascinating network system that interlinks and supports all life on the planet.
The answer to this reflection through the evolutionary prism starts from the principle that in Nature, combinatorial chemistry has been responsible for millions of years for the relentless search for the selection and production with maximum efficiency of the chemical structures that cells produce. Thus, associated with this fact, we must recognize that the biosynthetic mechanisms used by plants constitute an excellent guide in the discovery of new medicines, nutraceuticals, cosmetics, foods, and new materials.
Natural products represent the final decoding of these biosynthetic mechanisms, which, consequently, are materialized through the primary and secondary metabolites produced by plants.
The immeasurable wealth of the diversity of chemical structures that natural products provide is deeply related to the fact that natural products from plants possess common evolutionary pathways with enzymes, receptors, and regulatory proteins derived from a small number of “mother molecules.” These molecules are present in primitive forms of life that, over time, co-evolved and interacted even though their subsequent functions and structures diverged and differentiated. However, some structural kinship still remains, causing natural products in general to present better responses to questions related to the discovery of new molecules primarily addressed to living organisms such as humans, and equally essential to all forms of life that inhabit the planet.
An example of functional conservation and coding of these mother molecules among secondary metabolites can be evidenced through the pigments lutein and zeaxanthin, which protect the eyes of animals from shortwave radiation and are the same molecules that protect the “photosynthetic machinery” of plants from oxidative damage. These carotenoids likely involved a common, ancestral biochemistry and evolved into a primordial role in cellular photochemistry. However, animals lost the ability to make these compounds and currently need to acquire them from photosynthetic organisms in the form of food.
This is just one example of a possible response pattern among the endless possibilities of interdependent networks that Nature can conceive through the metabolism of plants. However, to neglect all this wisdom acquired, refined, and produced by Nature throughout the entire evolutionary history of life on our planet would be reckless to the memory of our ancestors and negligent towards future generations.
Artur Placeres Neto holds a Bachelor's and Full Licentiate Degree in Chemistry, a Master's in Organic Chemistry in the area of Natural Products, and a Doctorate in Natural Sciences also in the area of Natural Products. He currently works in the Science and Technology of Ingredients area at Natura and is a University Professor.
Contact: arturplaceres@natura.net
1 Brazilian Association of Companies in the Phytotherapeutic Sector. Abifi sa. Dietary Supplement and Health Promotion. 2007. Available at <http:www.abifisa.org.br>. Accessed in Dec 2009. May 10, 2007.
2 Kasim, Z.A.A. Herbal biotechnology development: the way forward & market access opportunities. 2007. Available at <http://www.eumbio.org/papers/Business%20Partnering%20Seminar/ZainalAzman.pdf> Accessed on Dec 12, 2009.
3 ISI Web of Science. Available at: <http://go5.isiknowledge.com>. Accessed on: Dec 2009.
4 Derwent Innovations Index. Available at: <http://go5.isiknowledge.com>. Accessed on: Dec 2009.
5 Kasim, Z. A. A. Herbal biotechnology development: the way forward and market access opportunities. 2007. Available at<http://www.eumbio.org>. Accessed on: Dec 2009
6 Kasim, Z. A. A. Ibid. 2007. Available at <http://www.eumbio.org>. Accessed on: Dec 2009.
7 Lehr, P. The new biopesticide market. Business Communications Company. Report ID CHM029B. February 2010.
8 Agro News. Biopesticides market to reach $1 billion in 2010. 2009. Available at: <http://news.agropages.com/News/NewsDetail-1944.htm>. Accessed in Dec 2009.
9 Frost & Sullivan’s Chemicals and Materials Research & Consulting. North American & Western European biopesticides market. 2010. Summary. Available at: < http://www.frost.com> Accessed on: Dec 2009.
10 US Department of Agriculture. USDA. Foreign Agricultural Service. Imports. Essential oils. 2009. Available at:<http://www.fas.usda.gov/ustrade/USTIMFAS.asp>. Accessed on: Dec 2009.
