E. coli engineered to produce important class of antibiotic, anti-cancer drugs
Researchers have taken a major step forward in the field of metabolic engineering, successfully using the bacterium Escherichia coli to synthesize a class of natural products known bacterial aromatic polyketides, which include important antibiotic and anticancer drugs.
Sulfurous ping-pong in the urinary tract
Researchers studying transfer processes among sulfurylated molecules discovered a protein, sulfotransferase, whose function is known but which exhibits a previously unknown structure.
Nanoscience researchers at Lund University in Sweden have shown that they can control the growth and crystal structure of nanowires down to the single atom level.
How this can be done is described in an article in the January, 2009, issue of Nature Nanotechnology, with Philippe Caroff and Kimberly Dick as the main authors.
[Image by Mats Nygren]
Study on cytotoxicity of carbon nanotubes
Owing to the novel properties of carbon nanotubes, a series of problems associated with in vitro toxicity assessments of carbon nanotubes have appeared in a lot of literature. In order to properly evaluate the potential risk to human health, the cell toxicity assay of carbon nanotubes can not be conducted by traditional methods employed in common toxicology.
New method for tracing metal pollution back to its sources
A new way of pinpointing where zinc pollution in the atmosphere comes from could improve pollution monitoring and regulation, says research out in the journal Analytical Chemistry.
Sweet molecule could lead us to alien life
Scientists have detected an organic sugar molecule that is directly linked to the origin of life, in a region of our galaxy where habitable planets could exist.
Scientists have identified
chemical structures in pollen - shown above covering the face and
legs of a Marmelade fly- that could help provide a real-time
pollen detection and warning system to help allergy sufferers.
Image by André Karwath
Researchers in Germany are reporting an advance
toward development of technology that could make life easier for
millions of people allergic to plant pollen. It could underpin the
first automated, real-time systems for identifying specific kinds of
allergy-inducing plant pollen circulating in the air. Their study is
in the current issue of ACS' Analytical Chemistry, a semi-monthly
journal.
In the study, Janina Kneipp and colleagues explain
that current pollen counts and allergy warnings are based on visual
identification of the specific kind of pollen by examining pollen
grains under a microscope. That procedure takes time, making it
impossible for allergy-sufferers to know the kinds of pollen that are
airborne on an hour-by-hour basis.
The researchers describe using a common laboratory
procedure to identify chemical structures in pollen grains that
distinguish oak and maple pollen, for instance, from maple and other
kinds. They obtained these chemical "signatures" for 15 different
kinds of tree pollen with the procedure, termed Raman spectroscopy.
The researchers say that it could provide the basis for a real-time
pollen detection and warning system to help allergy sufferers. - MTS
Waste coffee grounds offer new source of
biodiesel fuel
Researchers in Nevada are reporting that waste
coffee grounds can provide a cheap, abundant, and environmentally
friendly source of biodiesel fuel for powering cars and trucks. Their
study appears in the current online issue of ACS' Journal of
Agricultural and Food Chemistry, a bi-weekly publication.
In the new study, Mano Misra, Susanta Mohapatra,
and Narasimharao Kondamudi note that the major barrier to wider use of
biodiesel fuel is lack of a low-cost, high quality source, or
feedstock, for producing that new energy source. Spent coffee grounds
contain between 11 and 20 percent oil by weight. That's about as much
as traditional biodiesel feedstocks such as rapeseed, palm, and
soybean oil.
Growers produce more than 16 billion pounds of
coffee around the world each year. The used or "spent" grounds
remaining from production of espresso, cappuccino, and plain
old-fashioned cups of java, often wind up in the trash or find use as
soil conditioner. The scientists estimated, however, that spent coffee
grounds can potentially add 340 million gallons of biodiesel to the
world's fuel supply.
To verify it, the scientists collected spent coffee
grounds from a multinational coffeehouse chain and separated the oil.
They then used an inexpensive process to convert 100 percent of the
oil into biodiesel.
The resulting coffee-based fuel - which actually
smells like java - had a major advantage in being more stable than
traditional biodiesel due to coffee's high antioxidant content, the
researchers say. Solids left over from the conversion can be converted
to ethanol or used as compost, the report notes. The scientists
estimate that the process could make a profit of more than $8 million
a year in the U.S. alone. They plan to develop a small pilot plant to
produce and test the experimental fuel within the next six to eight
months. - MTS
Better antifreezes to preserve donor organs for
transplantation
Chemists have developed a method
to better preserve organs for transplantation.
Image by The American Chemical
Society
Chemists in Canada have developed a new approach
for producing more effective medical antifreeze fluids for preserving
kidneys, hearts, and other organs donated for transplantation. These
next-generation antifreezes can decrease damage to organs caused by
ice crystals, and thus prolong the time a donated organ will remain
viable prior to transplantation. This could increase the number of
available organs for potential recipients. Their study is scheduled
for the current issue of the Journal of the American Chemical Society,
a weekly publication.
Robert N. Ben and colleagues note that the growth
of ice crystals is a major cause of damage to cells, tissues and
organs during cryopreservation, which leaves them unusable for
transplantation. To address this challenge, the researchers developed
synthetic antifreeze materials, called C-linked antifreeze
glycoprotein analogues (C-AFGP). These proteins contain a sugar
coating and have custom-tailored antifreeze activity.
Now the scientists describe the development of
"hydration index" that can be used to more reliably predict how
prospective antifreeze materials will behave. Their index provides a
clearer picture of how water molecules interact with the sugar
component (as well as native AFGP) and affect their chemical behavior.
This is a key to understanding their ability to resist the formation
of ice crystals when chilled. - MTS
Producing a more effective oral form of a
powerful disease-fighting protein
Scientists in Japan are reporting an advance toward
using a natural disease-fighting protein in pills or syrups that
patients can take by mouth rather than injection. Their study is the
first to show that coating the protein with a polymer material already
in wide medical use can increase its absorption by the intestine. The
research appears in the current issue of ACS' Bioconjugate Chemistry,
a monthly journal.
In the study, Atsushi Sato and colleagues note that
the protein - lactoferrin (LF) - occurs in saliva, breast milk and
other body fluids, where it has powerful effects in fighting bacteria,
viruses, and inflammation. LF is sparking excitement as a potential
treatment for cancer, gangrene, hepatitis, and a host of other
diseases. Although LF is available as a dietary supplement and as an
experimental oral drug, acid in the stomach quickly destroys existing
forms of LF, reducing the protein's effects.
The scientists found that laboratory rats absorbed
10 times more LF if the protein is coated with the polymer, called
polyethylene glycol (PEG). In addition, the coated PEG remained active
in the bloodstream longer than the uncoated protein. The scientists
also showed that the coated drug retained most of its disease-fighting
potency, including antibacterial, antioxidative and anti-inflammatory
activity, compared to the uncoated drug. The PEG-coating technique not
only is a promising advance toward making lactoferrin an oral drug,
but also may be used to convert other healthful food proteins into
useful drugs, the researchers note. - MTS
The trees of Christmas future may be safer from an
insect pest that makes Ebenezer Scrooge's famous nightmare pale in
comparison - killing millions of pine trees, according to an scheduled
for the December 22 issue of Chemical & Engineering News, ACS' weekly
newsmagazine. That tiny beetle, which is decimating the certain
populations of pine trees, has led chemists to develop new, more
effective control methods that could help save these economically and
environmentally important trees, it added.
In the article, C&EN Associate Editor Rachel
Petkewich points out that the mountain pine beetle has killed millions
of acres of pine trees. About the size of a grain of rice, the beetles
damage trees by boring into bark and depositing their eggs. Dead trees
also pose a forest fire risk, the article notes.
Scientists now are fighting back with a combination
of chemistry and forestry management techniques. The management
techniques involve removing infected trees, diversifying tree species,
monitoring beetle populations, and thinning forests in advance of an
outbreak. Researchers are also experimenting with chemical protection
and control methods using bug-repelling plant hormones and
insecticides, according to the article.
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