| East meets West: A new memory enhancing drug
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2000-08-22
Susan Trulove
Blacksburg, Va.,
August 22, 2000 -- Huperzine A, a compound isolated from the Chinese
Medicinal Herb "Qian Ceng Ta," has shown good efficacy in
improving the memory in patients suffering from Alzheimer's Disease.
Despite these promising results, Huperzine A has not been developed
as a drug in the West due to scarcity of the natural source, a
complicated molecular structure, and the lack of intellectual
property protection for this material. Virginia Tech researcher Paul
R. Carlier, an associate professor of chemistry, has come up with a
novel solution to these problems.
Carlier will
present his research at the 220th national meeting of the American
Chemical Society Aug. 20-24 in Washington, D.C.
Working in
collaboration with researchers at the Hong Kong University of Science
and Technology (HKUST) and the Mayo Clinic, Carlier found that a
highly simplified fragment of the Huperzine A molecule could be
easily synthesized from cheap, commercially available chemicals. In
isolation this fragment is ineffective as a memory enhancer. However,
based on a detailed analysis of acetylcholinesterase, the brain
enzyme with which Huperzine A interacts, Carlier prepared dimeric
analogs by joining two of these fragments with a molecular tether.
"Remarkably,
the optimum drug obtained by this approach, ('Huperzine A Fragment
Dimer') is more than twice as potent as Huperzine A itself," he
reports. "The enhanced potency observed is due to two-point
attachment of the dimeric drug to acetylcholinesterase," he
says.
Carlier stresses
that all of the tests have been in animals, including a behavioral
assay in rats that establishes improved memory.
"No work
has been done in humans; and, even if the compounds prove effective
in human, it will be as a treatment of the memory loss in the early
stages of the disease," he says. "This approach could never
cure Alzheimer's; and, after the disease progresses to a certain
point, these drugs could not restore mental function."
Carlier will
present the paper, "Dimerization of natural product fragments: A
new strategy for drug design (ORGN 354)," at 2 p.m. Tuesday,
August 22, 2000, in convention center room 21-22 as part of the symposium
on biosynthesis, enzyme inhibitors, and mimetics, saccharids and
lipids. Co-authors are Carlier, Da-Ming Du of the HKUST chemistry
department, Yi-Fan Han and Jing Liu of the HKUST biochemistry
department, Emanuele Perola of the Mayo Clinic Cancer Center
pharmacology department, Ian D. Williams of the HKUST chemistry
department, and Yuan-Ping Pang of the Mayo Cancer Center pharmacology
department.
A patent has
been applied for.
PR Contact:
Susan Trulove
540-231-5646 strulove@vt.edu
http://www.eurekalert.org/pub_releases/2000-08/VT-EmWA-2208100.php
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