Hydroxymethylfurfural

Hydroxymethylfurfural, HMF or 5-(Hydroxymethyl)furfural is an aldehyde and a furan compound formed during the thermal decomposition of sugars and carbohydrates. HMF has been identified in a wide variety of heat processed foods including milk, fruit juices, spirits, honey, etc. Recent studies proved HMF is also found in cigarettes.

History
This organic compound was studied by French chemist Louis Maillard in 1912 while doing research about non enzymatic reactions from glucose and lysine.

Production
Just like the production of furfural, HMF can be produced from biomass.

In 2006 a chemical and biological engineering professor from University of Wisconsin-Madison claimed to have discovered a new way of creating HMF from fructose:


 * [[Image:NewhydroxymethylfurfuralSynthesis.png|500px|New method for prodcution of hydroxymethylfurfural from fructose]]

In this new method, fructose is reacted with hydrochloric acid in an aqueous phase and the formed HMF (very water-soluble) is then continuously extracted into Methyl isobutyl ketone as an organic phase at 180°C (think pressure cooker). The water phase is modified with DMSO and PVP, reducing the amount of side product to a minimum. The organic is modified with 2-butanol in order to improve the amount of HMF in the organic phase. In an optimized system for fructose (but not raw biomass), conversion is 77% with half the HMF ending up in the organic phase. Removing the (high boiling) solvents remains an issue.

In the image above are displayed in a series of chemical equilibria: fructopyranose 1, fructofuranose 2, two intermediate stages of dehydration (not isolated) 3,4 and finally HMF 5.

June 2007 - Researchers at Pacific Northwest National Laboratory (PNNL) claim to have discovered an easy, inexpensive process (using chromium chloride as catalyst) to directly convert both fructose (yielding 90%+) and glucose (yielding 70%+) into a HMF, leaving very little residual impurities. This discovery has great relevance for the manufacturing of plastics and synthetic fuels directly from biomass, since glucose can be derived directly from starch and cellulose, both widely available in nature.

Uses
HMF is identified as a biofuel with great potential. Organic oxidation of this compound also gives 2,5-furandicarboxylic acid which may replace terephthalic acid as a monomer in the production of plastics.

5-HMF is under investigation as a treatment for sickle cell disease.

Biological hazards
The National Institute of Environmental Health Sciences nominated HMF based on the potential for widespread exposure in the diet, evidence for carcinogenic potential of other members of this class, and the fact that little is known about HMF toxicity. NTP plans to develop protocols to investigate the metabolism, toxicity and carcinogenicity of HMF.