Category Archives: Uncategorized

Researchers close in on making a natural malaria drug.

Westfall, PJ, DJ Pitera, JR Lenihan, D Eng, FX Woolard, R Regentin, T Horning, H Tsuruta, DJ Melis, A Owens, S Fickes, D Diola, KR Benjamin, JD Keasling, MD Leavell, DJ McPhee, NS Renninger, JD Newman and CJ Paddon. 2012. Production of amorphadiene in yeast, and its conversion to dihydroartemisinic acid, precursor to the antimalarial agent artemisinin. Proceedings of the National Academy of Sciences http://dx.doi.org/10.1073/pnas.1110740109.

Synopsis by Jean-Philip Lumb

A new approach to making the natural malaria drug artemisinin will increase supply and avoid the chemical steps now used to extract the drug from plants. The drug is meant to replace medicines that no longer control the malaria parasite spread by mosquitoes.

An affordable treatment for malaria is closer thanks to a process using both biology and chemistry to make artemisinin – an effective drug currently extracted from plants.

The method bypasses plants as the source of the drug. Instead, modified yeast change sugar into an advanced chemical that can be converted into artemisinin. Skirting plants decreases the cost, increases supply and avoids chemical extractions. A team of industrial and academic researchers in Berkeley, Calif., developed the biochemical route to the drug.

The process provides an alternative to traditional extractive procedures and highlights the increasing use of biotechnology in greener drug manufacturing.

Globally, the mosquito-borne infectious disease claims nearly 1 million lives per year. Health organizations estimate that 300 – 500 million people are infected on an annual basis, a population based primarily of children in Africa and Asia.

New medicines are needed because the current drugs do not work as well as they once did and controlling mosquitoes with insecticides – such as DDT – can harm the environment and human health.

Artemisinin is a desirable substitute to the widely used chloroquine-based antimalarial drugs. The Plasmodium parasite that causes malaria has become resistant to these traditional drugs.

While faster acting and more effective, artemisinin is expensive and supplies are often limited. Artemisinin is currently extracted from plants. Unfortunately, the extraction makes large-scale production too costly for countries where the drug is needed most. The methods also employ volatile organic solvents that levy a heavy environmental toll.

To overcome the current limitations in supply, a consortium of industry and academic researchers in California developed a new strain of yeast that can convert glucose into an artemisinin precursor. Standard organic chemistry practices are used for the remaining steps of the drug’s synthesis.

The combined biotechnology/synthetic chemistry approach promises to be an effective alternative to the extraction techniques currently in use. The cost is estimated as low as 300 million cures at 50 cents a treatment. A recent press-release, issued on the Amyris website, announced a partnership between Amyris, The Institute for OneWorld Health and Sanofi-Aventis to make doses of artemisinin available later this year.

Read more science at Environmental Health News.

Confessions of a chemistry professor…

By Mana Sassanpour
Over the past few months, I have had the opportunity to interview many
distinguished chemistry professors who are also leaders in their
fields of research. What I have found is that many of these reknowned
researchers see the need for the uses of the tenants of green
chemistry in their research, yet are hesitant to apply those tenants
and practices when they teach in the university setting to the future
chemists of our nation. How and why is this?
Example one:  A professor sat down and explained three different
research projects that his group was involved in. For each one of
them, he was suggesting using the principles of green chemistry:
lower temperatures, catalysts, renewable resources, and the list goes
on. He realizes the need to reduce waste and energy consumption as we
face a population boom and growing dependence on foreign oil. The
professor stated that he sees problems with how we currently run
reactions, and wants to address these issues and improve them through
green chemistry – like most successful green chemists.
So why do such established researchers who realize the need for green
chemistry, refuse to teach it to their students – our future problem
solvers?
The answer I got was “we are here only to teach techniques; the
students can apply those techniques to green chemistry if they want.”
Well, most students do not make that connection. If they learn a
technique and procedure in lab that leads to a product of 0% yield
with the use of toxic solvents, they are not going to imagine a
greener way of doing the lab. Instead, they are going to assume those
techniques and solvents are the norm and standard way of doing things,
and carry that into their future professions as our nation’s chemists.
If we took the time to teach the tenants of green chemistry and
incorporate them into our lab protocols, the students would learn from
example and practice, and not have to rely on “figuring out” green
chemistry later when having to go back and reteach themselves how to
do chemistry the more efficient and environmentally friendly way.
While the professor may have a point in only teaching the
‘techniques,’ green chemistry should be the technique taught. If every
student was equipped with a green chemistry mindset from their
undergraduate education, there would not be as much struggle to
understand how to make reactions and procedures more efficient; we
could save time and money.
turner

Green Chemistry at Virginia Tech Part II

For my second interview in the Virginia Tech series, I had the privilege of interviewing Dr. Richard Turner. Like Dr. Long, he worked in the chemical industry and saw that most of the companies that practice green chemistry do so for regulatory and financial reasons. While working in the private sector Dr. Turner worked on plastics made without solvents – in ‘melt phase reactions.’ Melt phase processes eliminate energy consuming steps or the need to add something else to the waste stream.  They are inherently more environmentally friendly. They work by placing solids (which don’t react very fast) into solution so that the molecules can have the mobility to find each other and react.

In his own labs on campus, Dr. Turner has a few projects in melt phase rather than in solution as described above. His lab is also trying to make polymers that capture carbon dioxide. He describes:

“Carbon dioxide build-up in the atmosphere is going to be an increasingly large issue – we have to invest in the research now to learn how to capture and sequester the carbon dioxide. Polymer particles have huge surface areas, with ligands that can capture CO2. The sorbent (“a material used to absorb liquids or gases,” according to Wikipedia; yes, I had to look it up) and ligands capture CO2 and then moves it to reactor where it releases it, concentrating the CO2.”

Dr. Turner is also on the science advisory board of the company, Novomer, which was featured in a previous article on converting oranges to plastic. He works on biodegradability and reducing the overall energy footprint. “We have to make sure we do really tough and detailed analysis of our choices.”

In the classroom, Dr. Turner teaches a course called: “Future Industrial Professionals in Science and Engineering”. The course caters to scientists and engineers who want to go into industry. He divides the class into groups who run individual projects; this year all the projects were sustainability driven. There were three projects in total: the first worked to extend the shelf life of food; the second worked to improve battery life; the third worked to make a better membrane for reverse osmosis.

Outside of his own class, Dr. Turner was impressed with Tech’s sustainability. He discussed the accomplishments of the College of Natural Resources and the Environment, while also noting the strong Renewable Resources Group.

AGC applauds Dr. Turner’s hard work with sustainable chemistry, and hopes it serves as inspiration to other chemists.

 

BPA: What’s the alternative?

Posted by Evan Beach at Nov 12, 2010 03:30 PM | Permalink

Science News and other outlets reporting on BPA-free receipts identify for the first time a substitute chemical being used by one of the largest manufacturers of thermal paper. It has been referred to incorrectly in blogs as “bisphenol sulfonate” or “diphenyl sulfone,” but it is actually a chemical known as bisphenol S (Update, 11/15/10: 4,4′-sulfonylbisphenol). As the name indicates, it is structurally very similar to bisphenol A (BPA). And although it has not been studied as much as BPA, preliminary studies show that it shares hormone-mimicking properties as well.

In 2005, a group of Japanese scientists compared BPA and 19 other related compounds for their ability to mimic the female hormone estrogen. They tested the effects on human cells and found that bisphenol S was slightly less potent than BPA, but not by much: bisphenol S was active at 1.1 micromolar concentration, BPA at 0.63 micromolar. One micromolar is roughly equivalent to a packet of sugar in 3,000 gallons of water.

Other researchers have found that bisphenol S is much less biodegradable than BPA. In their study of eight bisphenol compounds, bisphenol S was the most persistent.

While much more is known about the effects of BPA – particularly at ultra-low doses – the existing data on bisphenol S suggests the substitution should be made with caution. Hormone-mimicking behavior and environmental persistence are intrinsic hazards that should be avoided. As the Science News story mentions, an assessment by the U.S. Environmental Protection Agency’s Design for the Environment program may shine more light on the matter.

New book: “Recoverable and Recyclable Catalysts” by Maurizio Benaglia

recoverable solvents

Recoverable and Recyclable Catalysts Wiley | 2009 | ISBN: 0470681950 | 500 pages | PDF |

There is continued pressure on chemical and pharmaceutical industries to reduce chemical waste and improve the selectivity and efficiency of synthetic processes. The need to implement green chemistry principles is a driving force towards the development of recoverable and recyclable catalysts.

The design and synthesis of recoverable catalysts is a highly challenging interdisciplinary field combining chemistry, materials science engineering with economic and environmental objectives. Drawing on international research and highlighting recent developments, this book serves as a practical guide for both experts and newcomers to the field.

Topics covered include:

* An introduction to the principles of catalyst recovery and recycling
* Catalysts on insoluble and soluble support materials
* Thermomorphic catalysts, self-supported catalysts and perfluorous catalytic systems
* The development of reusable organic catalysts
* Continuous flow and membrane reactors

Each chapter combines principles with practical information on the synthesis of catalysts and strategies for catalyst recovery. The book concludes with a comparison of different catalytic systems, using case studies to illustrate the key features of each approach.

Recoverable and Recyclable Catalysts is a valuable reference source for academic researchers and professionals from a range of pharmaceutical and chemical industries, particularly those working in catalysis, organic synthesis and sustainable chemistry.

GC Awards and Competitions

Awards and Competitions in Green Chemistry with up-coming deadlines:

Presidential Green Chemistry Challenge Awards

Nominations are due December 31 each year.

The annual Presidential Green Chemistry Challenge Awards recognize outstanding chemical technologies that incorporate the principles of green chemistry into chemical design, manufacture, and use.

Nominations – The program invites nominations that describe the technical benefits of a green chemistry technology as well as its human health and environmental benefits.

Nominations are accepted from:
* Individuals
* Groups
* Non-profit and for-profit organizations
* Academia
* Industry

The nominated green chemistry technology must have reached a significant milestone within the past five years in the United States (i.e., it must been researched, demonstrated, implemented, applied, patented, etc.).

Selection of the Recipients – An independent panel, selected by the American Chemical Society, evaluates nominations for the awards.

Presidential Green Chemistry Challenge Awards recipients receive national public recognition for their outstanding accomplishments in the research, development, and/or implementation of green chemical technologies.

Other Awards and Competitions:
* January 4, 2010 – Call for Nominations for the National Academy of Engineering (NAE) Awards begins.
* August 27, 2009 – January 5, 2010 – EPA:  P3: People, Prosperity and the Planet
Student Design Competition for Sustainability.
* Generation Green: Youth Voices and Visions – a writing contest for youth, part of  “The New Green Economy” The National Council for Science and the Environment (NCSE)conference held in Wash, DC January 20-22, 2010.