Beta-hexadecyl maltoside-d₃₁, the surfactant produced at the ESS chemical deuteration lab; and the SANS data it contributed to (collected on the D11 instrument at the ILL).

The ESS DEMAX team held its first pilot call for scientific proposals earlier this year, in order to establish a system that runs smoothly in time for the first science to be performed on ESS instruments. The call offered a range of biologically and chemically deuterated materials as well as support for crystallisation. Nineteen proposals were received, requesting services across the three areas of expertise.

In June and July, the first deuterated molecules were delivered to proposers, and in July, one of these molecules was utilised in a SANS experiment on the D11 instrument at ILL. Johan Larsson, the principle investigator in the work, studies the self-assembly of sugar-based surfactants with applications in the formulations field, including shampoos and cosmetics. In order to tune the properties of the surfactants, he is investigating the use of combinations of sugar-based surfactants and other surfactant-like components. Using deuterated sugar-based surfactants allowed him to discriminate between the different components in the mixture.

Surfactants such as this one; lipids; monomers and other small molecules were requested from the ESS chemical deuteration during the first proposal call. Part of the significance of chemical deuteration is that it can be used to produce unnatural molecules, and we can introduce deuterium judiciously into the molecule. This unnatural surfactant molecule can be produced at ESS, with deuterium located at very specific locations – those which are required for the SANS experiment.

The ESS DEMAX platform recently published its first call for proposals for deuteration and crystallisation support. Nineteen proposals were received, covering chemical deuteration, biological deuteration and crystallisation. The review process is underway and results will be communicated by the end of May. Thanks to all those neutron experimenters who submitted proposals!

BrightnESS² is a three-year, EU-funded project within the European Commission’s Horizon 2020 Research and Innovation programme which focuses on the long-term sustainability of ESS and neutron scattering in Europe, and to further strengthen the network of facilities for research using neutrons. A total of 15 institutes and universities from Europe and South Africa are participants within the project.

As part of BrightnESS² the Deuteration Facility at the SFTC (UK) and the ESS Chemical Deuteration Laboratory (SE) are collaborating on the synthesis of structured deuterated phospholipids. At the moment, a limited number of deuterated, mixed acyl phospholipids (Figure 1) are available, and those that are available and prohibitively expensive for many neutron users and experiments.

The STFC Deuteration Laboratory has a wealth of experience in the synthesis of homo-acyl phospholipids and an active user community which continuously requests new phospholipid analogues for neutron experiments. The ESS Chemical Deuteration Laboratory is researching the application of enzymatic catalysis to the synthesis of deuterated molecules. Together, the facilities are working together to establish a new, modular method for the synthesis of tail-deuterated, mixed-acyl phospholipids, using enzymes to allow the regiospecific substitution of tails at the 1- and 2-positions. The modularity of the approach should mean that a large number of molecules can be accessed. The first target molecules are 1-palmitoyl-d31-2-oleoyl-d33-sn-3-phosphocholine (POPC-d64, Figure 2a) and 1-palmitoyl-d31-2-(9-oxononanoyl)-sn-3-phosphocholine (PoxnoPC-d31, Figure 2b).

The ESS Deuteration and Macromolecular Crystallisation (DEMAX) Platform will publish its first call for service requests for deuterated materials and support for large crystal growth for neutron experiments. The call be open from February – April 2019 – watch this space for more information!

The ESS DEULAB installed its first Parr reactor during the summer. The Parr reactor is capable of operating under conditions of high temperature (up to 350 °C) and high pressure (up to 131 bar) and is used in deuteration laboratories for hydrothermal, metal-catalysed H/D exchange reactions.

The first reaction performed in the DEULAB using the Parr reactor was the deuteration of lauric acid:

Under these conditions, lauric acid with 89% deuteration of the non-exchangeable hydrogen atoms was obtained. The deuteration incorporation was determined by analysis of the isotopologue ratios in the mass spectrum:

This process can be repeated to produce very highly deuterated lauric acid (>98% deuteration of the non-exchangeable hydrogen atoms). It is applicable to other saturated fatty acids and will facilitate the synthesis of many classes of deuterated molecules with fatty acid synthons, such as lipids and surfactants, at the ESS DEULAB.