There are probably at least 500 medically useful chemicals awaiting discovery in plant species whose chemical constituents have not yet been evaluated for their potential to cure or treat disease, according to a new analysis by a New York Botanical Garden scientist who has more than 15 years of experience in collecting plants for natural-products discovery programs.
Currently, 135 drugs on the market are derived directly from plants; the analysis indicates that at least three times as many disease-fighting substances have yet to be found that could be developed into drugs or used as the basis for further drug research.
"Clearly, plant diversity has not been exhausted, and there is still great potential in the plant world," said James S. Miller, Ph.D., Dean and Vice President for Science at the Botanical Garden.
Dr. Miller's analysis, "The Discovery of Medicines from Plants: A Current Biological Perspective," is published in the December issue of the peer-reviewed journal Economic Botany.
To arrive at his estimate, Dr. Miller used a formula based on the ratio of the number of drugs that have been developed from plants to the number of plants that were screened to find those drugs. He then applied that ratio to the number of plant species that have not yet been screened.
Because of uncertainties in some of those numbers, the formula yields a range of potential drug discoveries. While there is no general agreement among botanists about the number of plant species that are likely to exist, Dr. Miller concluded that there are 300,000 to 350,000 species of plants. Of those, he determined that the chemistry of only 2,000 species has been thoroughly studied, and perhaps only 60,000 species have been evaluated even partially for medicinally useful chemicals.
Working with those numbers, Dr. Miller calculated that there are likely to be a minimum of 540 to 653 new drugs waiting to be discovered from plants; the actual number could be much greater.
"These calculations indicate that there is significant value in continuing to screen plants for the discovery of novel bioactive medicinally useful compounds," concludes Dr. Miller, who has run natural-products discovery programs that have collected specimens in North America, Central and Southeast Asia, and Africa for government agencies, pharmaceutical companies, and academic programs.
As part of his Economic Botany paper, Dr. Miller reviews the disappointing history of past plant-screening efforts and evaluates the potential for future programs.
Technological advances in the 1970s and 1980s gave medical researchers the capacity to evaluate large numbers of plant samples. That prompted the federal government and large pharmaceutical companies to institute aggressive plant collecting and screening programs. Those programs led to the development of several important drugs such as Taxol from Taxus brevifolia (used in cancer treatment) and Camptothecin from Camptotheca acuminata (derivatives of which are used to treat cancer). Other drugs indirectly trace their discovery to natural-products research, including the anti-viral Oseltamivir, which derives from Illicium anisatum and is marketed in the United States as Tamiflu.
The number of drug discoveries, however, was substantially less than anticipated. By the early 2000s, many of the large pharmaceutical companies had abandoned their efforts.
Dr. Miller argues that one possible explanation for the low yield is the relatively crude way in which plant extracts were tested for their pharmaceutical potential. Plants may contain as many as 500 to 800 different chemical compounds, but the screening programs of the late 20th century used extracts made from a whole plant or at best extracts that contained many hundreds of compounds.
Under those circumstances, one compound may interfere with the action of another, or the amount of one compound may be too small to register in a mix of hundreds of chemicals.
To correct this problem, new technologies now allow researchers to separate complex mixtures of natural products into a "library" of relatively pure compounds that can be tested individually. A 2002 study demonstrated that testing such libraries dramatically improves discovery rates.
Bringing these advances together with refinements in collecting strategies could lead to what Dr. Miller calls a "second renaissance" of natural-products discovery.
Miller undertook his analysis to highlight the fact that despite past collecting programs, the plant world represents a poorly explored source of potentially lifesaving drugs. That adds urgency, he said, to efforts to conserve natural habitats so that species are not driven to extinction before they can be studied.
"The natural world has a great and diverse array of interesting chemicals that have been only minimally studied and still hold considerable potential," he writes.
Stevenson Swanson | EurekAlert!
Observing the cell's protein factories during self-assembly
15.06.2018 | Charité - Universitätsmedizin Berlin
Scientists unravel molecular mechanisms of Parkinson's disease
13.06.2018 | The Francis Crick Institute
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering
18.06.2018 | Life Sciences