CHICAGO At least 70 percent of all new drugs
introduced in the United States in the past 25 years come from
nature despite the use of sophisticated techniques to design
products in the lab, researchers reported on Monday.
Their study indicates that a back-to-nature approach might
yield better possibilities for companies looking for the next
Drug discovery hit a 24-year low in 2004, with just 25
unique compounds known as new chemical entities introduced that
year, said David Newman, who runs the U.S. National Cancer
Institute's natural products branch.
"Chemists started making libraries of hundreds of thousands
to millions of compounds. But they were simple compounds," he
said in a telephone interview.
"Mother Nature doesn't make simple compounds. Mother Nature
wants compounds that fit into particular places."
Newman links a dearth of new drug development at U.S. drug
companies with the shift away from nature as a main source of
"Wyeth and Merck are the only two U.S. manufacturers of
that size that still use natural products as one of their
sources to look for drugs," he said.
Newman's study found more than two-thirds of all drugs
discovered in the last quarter-century have come from nature.
He believes linking nature with advanced chemistry techniques
that combine a vast array of molecules to speed drug
development will likely yield much more fruitful results.
Newman and colleague Gordon Cragg reviewed the origins of
new drugs developed in the past quarter-century and found that
despite the introduction of a host of high-tech drug discovery
tools, natural products continue to be the inspiration for most
Aspirin, a staple in most medicine cabinets, was originally
obtained from the willow tree. The widely used chemotherapy
treatment Taxol was derived from Pacific yew tree.
"Even though it is made in a different way now, it is
absolutely identical to the material that comes from the yew,"
Likewise, the colon cancer treatment irinotecan, a standard
chemotherapy that interferes with the growth of cancer cells,
and topotecan, a chemotherapy used for ovarian cancer and lung
cancer, are both modifications of the tree Camptotheca
acuminata, a native of China.
In fact, Newman and Cragg found that about half of all
anti-cancer drugs introduced since the 1940s are either natural
products or medicines derived directly from natural products.
Newman's study, to be published in the March 23 issue of
the Journal of Natural Products, is an expanded and updated
version of reports published in 1997 and in 2003.
The researchers sought to trace how nature has inspired
drugs currently on the market.
"A chemist would never conceive of making Taxol unless he
or she had seen Taxol first," Newman said. "So what we looked
back at was, what was the intellectual underpinning of the
drugs that were currently on the market."
Newman said the advent of new drug discovery techniques
such as combinatorial chemistry in the 1990s diverted many drug
company resources away from a rich source of new drug
The technique allows for the rapid combination of many
different but similar compounds -- basically industrializing
the role of the chemist.
"Mother Nature's influence is alive and well," Newman said.
"But you have to look for it in a subtle way. She doesn't come
out and wave a broom in your face."