Featured Research

from universities, journals, and other organizations

Chemists Synthesize Herbal Alkaloid

Date:
April 20, 2009
Source:
Vanderbilt University
Summary:
Synthetic chemists have found an efficient way to create one of the complex alkaloids found in club moss, a plant used in traditional Chinese medicine, so that it can be made in sufficient quantity to test the compound's therapeutic value.

Lycopodium serrata, also known as Huperzia serrata, is a traditional Chinese herbal remedy. Lycopods are some of the oldest vacular plants to populate the earth's surface. In the early Devonian period, members of the Lycopod family dominated the landscape as large trees, but today they are only found lining the forest floor. The species has been used for thousands of years as a diuretic, analgesic, hemostyptic and antispasmodic.
Credit: Tom Rau

The club moss Lycopodium serratum is a creeping, flowerless plant used in homeopathic medicine to treat a wide variety of ailments. It contains a potent brew of alkaloids that have attracted considerable scientific and medical interest. However, the plant makes many of these compounds in extremely low amounts, hindering efforts to test their therapeutic value.

That is no longer a problem for what is arguably the most complex of these alkaloids, a compound called Serratezomine A: an alkaloid that could have anti-cancer properties and may combat memory loss. A team of synthetic chemists at Vanderbilt University report in the March 18 issue of the Journal of the American Chemical Society that they have created an efficient way to make this molecule from scratch.

It took six years to develop the process because the researchers had to invent some entirely new chemical methods to complete the synthesis. These methods should make it easier to synthesize other Lycopodium alkaloids as well as other natural compounds with therapeutic potential.

In addition to their therapeutic possibilities, the Vanderbilt chemists were attracted to these compounds because they are among the most intricately structured and functionally dense of all the small molecules produced by living organisms. The compounds consist of carbon and nitrogen atoms assembled in unique ring structures.

"This was a challenging problem," says Professor of Chemistry Jeffrey Johnston, who led the research effort. 'It takes years to develop a new chemical reaction and then apply it to the natural product target. So, once we start, we don't stop."

In the world of total synthesis chemistry, it is not enough to figure out a way to synthesize a naturally occurring molecule. The process has to produce large enough quantities of the molecule that it can be tested for biological activity. That means that the number of sequential steps in the process – what chemists refer to as the longest linear sequence – should be as small as possible to maximize production. For example, if a sequence has 30 steps and each step has an 80 percent yield, the overall yield of the sequence is about one-tenth of a percent. At the same time, one low-yield step will knock a process out of contention.

The longest linear sequence in the Serratezomine A synthesis is 15 steps and it has an overall yield of 1.7 percent, Johnston says. That is an average yield of 77 percent per step. The chemists kept the sequence this short by using a strategy called convergence. They prepared one of the key fragments in the synthesis in parallel to the main sequence.

Johnston has handed over the Serratezomine A that his group has produced to Vanderbilt's drug discovery program, which identifies novel agents suitable for preclinical testing, in order to evaluate its therapeutic value.

Members of Johnston's research team are doctoral student Aroop Chandra; Julie A. Pigza, who is now a post-doctoral associate at the University of California, San Diego; Jeong-Seok Han, who now works at CJ Pharmaceuticals in South Korea; and Daniel Mutnick, who is now an associate scientist at Novartis in San Diego. The research was supported by grants from the National Institute of General Medical Sciences and Eli Lilly and Company and by a Pfizer Diversity Fellowship.


Story Source:

The above story is based on materials provided by Vanderbilt University. Note: Materials may be edited for content and length.


Cite This Page:

Vanderbilt University. "Chemists Synthesize Herbal Alkaloid." ScienceDaily. ScienceDaily, 20 April 2009. <www.sciencedaily.com/releases/2009/04/090415172239.htm>.
Vanderbilt University. (2009, April 20). Chemists Synthesize Herbal Alkaloid. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2009/04/090415172239.htm
Vanderbilt University. "Chemists Synthesize Herbal Alkaloid." ScienceDaily. www.sciencedaily.com/releases/2009/04/090415172239.htm (accessed September 17, 2014).

Share This



More Health & Medicine News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obesity Rates Steady Even As Americans' Waistlines Expand

Obesity Rates Steady Even As Americans' Waistlines Expand

Newsy (Sep. 17, 2014) Researchers are puzzled as to why obesity rates remain relatively stable as average waistlines continue to expand. Video provided by Newsy
Powered by NewsLook.com
President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Obama Orders Military Response to Ebola

Obama Orders Military Response to Ebola

AP (Sep. 16, 2014) Calling the Ebola outbreak in West Africa a potential threat to global security, President Barack Obama is ordering 3,000 U.S. military personnel to the stricken region amid worries that the outbreak is spiraling out of control. (Sept. 16) Video provided by AP
Powered by NewsLook.com
UN: 20,000 Could Be Infected With Ebola by Year End

UN: 20,000 Could Be Infected With Ebola by Year End

AFP (Sep. 16, 2014) Nearly $1.0 billion dollars is needed to fight the Ebola outbreak raging in west Africa, the United Nations say, warning that 20,000 could be infected by year end. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins