This accomplishment is expected to make it possible to produce enough of the promising drugs for use in clinical trials.
In a study featured on the cover of the January issue of the journal ACS Chemical Biology, a scientific team lead by University of Michigan Life Sciences Institute Research Professor David H. Sherman and researcher Zachary Q. Beck found the trick to turning the green gunk into gold—cancer fighting gold.
"It was simply too difficult to use the native blue-green algae for high-level production using traditional fermentation approaches," said Sherman. But the compound, called cryptophycin 1, held so much promise as an anti-cancer drug that organic chemists got busy trying to find ways to make a synthetic form of the compound in large enough quantities for clinical trials.
Developing an efficient synthetic route to natural product compounds and their analogs is often an essential step in drug development. With drugs such as penicillin and tetracycline, it can easily be done, but cryptophycins present more of a challenge. Sherman's team realized that with all cryptophycins, the most difficult step came very late in the synthesis, at the point at which a key part called an epoxide—a highly strained, three-membered ring oxygen-containing group, crucial for the drug's anti-cancer activity—becomes attached to the molecule.
The epoxide group can be attached in two configurations, designated as alpha and beta. Scientists have known for several years that the beta configuration was absolutely required for the anti-cancer properties of the drug, but were unable to devise efficient synthetic strategies that favored that configuration.
Sherman's team accomplished this by isolating the entire set of biosynthetic genes and key enzymes and developing a new, efficient method to manufacture the broad class of cryptophycin natural products, including important analogs with clinical potential. This included characterization of an enzyme, cytochrome P450, that always introduces the epoxide in the desired beta configuration.
Sherman, who is also the John G. Searle Professor of Medicinal Chemistry in the College of Pharmacy, believes that this approach will allow effective new cryptophycin analogs with low levels of side effects to be created for clinical trials.
"This issue represented an exciting target that offered not only an interesting scientific problem, but the potential to do something of practical importance in creating a promising anti-cancer drug," he said.
"Biosynthetic Characterization and Chemoenzymatic Assembly of the Cryptophycins. Potent Anticancer Agents from Nostoc Cyanobionts" by Magarvey N. A.; Beck Z. Q.; Golakoti T. ; Ding Y. ; Huber U. ; Hemscheidt T. K.; Abelson D. ; Moore R. E.; Sherman D. H. appeared online Dec.15 and is the cover story in the print version of ACS Chemical Biology January, 2007.
Robin Stephenson | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences