Sensitivity‐Enhanced 13C‐NMR Spectroscopy for Monitoring Multisite Phosphorylation at Physiological Temperature and pH

Abundant phosphorylation events control the activity of nuclear proteins involved in gene regulation and DNA repair. These occur mostly on disordered regions of proteins, which often contain multiple phosphosites. Comprehensive and quantitative monitoring of phosphorylation reactions is theoretically achievable at a residue‐specific level using ¹H‐¹⁵N NMR spectroscopy, but is often limited by low signal‐to‐noise at pH>7 and T>293 K. We have developed an improved ¹³Cα‐¹³CO correlation NMR experiment that works equally at any pH or temperature, that is, also under conditions at which kinases are active. This allows us to obtain atomic‐resolution information in physiological conditions down to 25 μm . We demonstrate the potential of this approach by monitoring phosphorylation reactions, in the presence of purified kinases or in cell extracts, on a range of previously problematic targets, namely Mdm2, BRCA2, and Oct4.     

Syntheses of (-)-oleocanthal, a natural NSAID found in extra virgin olive oil, the (-)-deacetoxy-oleuropein aglycone, and related analogues

Phenolic compounds extracted from extra virgin olive oil have attracted considerable recent attention. One of the components, (-)-oleocanthal (1), an inhibitor of the COX-1 and COX-2 enzymes, possesses similar potency as the NSAID ibuprofen. In this, a full account, we disclose the first- and now second-generation syntheses of both enantiomers of the oleocanthals, as well as the first synthesis of the closely related (-)-deacetoxy-oleuropein aglycone and a series of related analogues for structure activity studies. To demonstrate the utility of the second-generation synthesis, multigram quantities of (-)-oleocanthal were prepared in 10 steps (14% overall yield) from commercially available D-lyxose.     

Synthesis of triazole analogues of the nanaomycin antibiotics using ‘click chemistry’

A series of triazole analogues of the nanaomycin family of antibiotics have been prepared using a ‘click’ dipolar cycloaddition of a naphthalene azide to various alkynes, followed by oxidation to the desired pyranonaphthoquinones.     

Oriented O(3P2), Ne(3P2), and He(3S1) atoms emerging from a bent magnetic guide

We describe our observation of strongly oriented total electronic angular momentum J in O(³P₂), Ne(³P₂), and He(³S₁) atoms emerging from a bent magnetic multipole guide, as measured by resonant multiphoton ionisation. This was contrary to our expectation because no additional (uniform) magnetic fields were applied to orient the atoms behind the exit of the guide. Two- and three-photon ionisation techniques were employed to determine the degree of J polarisation, from which we infer that atoms become oriented as a result of a combination of weak fringe fields, possible stray fields, and the fact that molecular beam packets do not oscillate around the geometric center of the bent multipole guide. We conclude that similar effects may exist in other, related experiments and that a detailed characterisation of the degree of orientation is required prior to any study of chemical dynamics or spectroscopy. This paper should serve as a warning for anybody using similar devices not to assume isotropic angular momentum distributions of atoms and molecules emerging from a magnetic guide or a decelerator, particularly when it is bent; whenever possible, the possibility for a J anisotropy should be experimentally checked.