Sweet success for bio-battery

Green Chemistry International


An enzyme cascade strips electrons from glucose and turns it into electricity that could be used to power a mobile phone © NPG

Sugar is an excellent source of energy. Most living cells generate their energy from glucose by passing it down an enzymatic chain that converts it into different sugars. This enzymatic cascade provides the necessary energy to create an electrochemical gradient. This, in turn, can be used to power an enzyme that synthesises adenosine triphosphate (ATP) – the universal biological energy currency. However, extracting this energy from a sugar if you’re not a biological organism is tricky – short of combustion, which is impractical to power handheld electronics.

To fuel their battery the team used maltodextrin – a polymer made up of glucose subunits. They then created an entirely new synthetic enzymatic pathway to extract energy from the sugar. Using 13 different enzymes they were able to strip…

View original post 22 more words

Chemical Process Development

Lamentations on Chemistry

Lots of semi-batch process development and safety work going on in my lab. We use our reaction calorimeter for a variety of studies now. Naturally we want to know about energy accumulation with a given feed rate or any unforeseen induction or initiation problems in a reaction. We can also home in on recommendations for safe feed rates of reactants into a reaction mass.

What I am beginning to learn from the RC1 work is that running a reaction at low temperature is frequently done for sketchy reasons. Unless there are selectivity or side product issues, you really have to question why the reaction is specified to be run at low temperature. I think some of it comes from habit gained in grad school.  Low temperature may introduce dangerous situations with abrupt initiation by accumulation of unreacted reagents. Or it may lead to overly long feed time with the associated costs of added…

View original post 74 more words

Transporters in Drug Development: A Fast-Moving Field


Bente SteffansenBente Steffansen, Ph.D., is associate professor in Biopharmacy and program director for Pharmacy Education at the Faculty of Health and Medical Sciences, University of Copenhagen. She concentrates her research on optimizing drug bioavailability and drug targeting, including development of experimental in vitro models relevant for regulatory sciences.

Membrane transporters play important roles throughout drug development, from discovery to life-cycle management. Understanding their role in pharmacology and pharmacokinetics leads to new drug targets and/or delivery strategies and may even play a role in life-cycle management and refinement of treatment protocols.

View original post 296 more words

Sweet crystallography – the crystal structure of sucrose


What does it look like?

What is it?

What’s within that sugar cube floating in your coffee?  There a number of forms of sugars, but the one that sits as a white powder in our cupboards is sucrose.   The sucrose molecule itself is a combination of a glucose and fructose molecule (you can see that each of the molecule have two parts to them).   This means it has a very specific way of packing together to form a solid.   Each sucrose molecule is made of carbon (brown), oxygen (red) and hydrogen (pink).

Where did the structure come from?

Given how important sucrose is to our diets, and how much money is made from sugar, finding its crystal structure was very important question of early crystallography.  One of the challenges to finding its structure was the fact that it is composed entirely of ‘light elements’ only carbon, oxygen and hydrogen.  The…

View original post 69 more words