Volume 4 Issue 5, May 2012

The cost, time and expertise needed for custom fabrication is a limiting factor when it comes to the development and production of new labware. With an increase in the popularity and accessibility of three-dimensional printing techniques, that may be about to change.

Obtaining detailed structural information about the interactions between amyloid-forming proteins and inhibitors can be extremely difficult. Two-dimensional infrared spectroscopy has now risen to this challenge to show the mapping of protein–protein contact sites in real time.

Recent syntheses of the natural product 3-hydroxy-N-methylwelwitindolinone C isothiocyanate are taken as examples to answer an oft-raised question about the value of total synthesis.

The first heavier main-group-14-element analogue of a ketone, which contains a three-coordinate germanium atom multiply bonded to oxygen, has been prepared and characterized.

Recognizing that an analogy can be drawn between steric effects in drug discovery and asymmetric catalysis has led to a powerful technique that can explain and potentially predict the outcome of asymmetric reactions.

A protein is modified to assemble with metal ions through judiciously designed coordination and dimerization sites. This elegantly controlled process arranges the protein into crystalline arrays — a useful form for exploring and exploiting protein properties.

A detailed magnetic, structural and luminescence characterization unveils that what may have looked like mere details have a significant influence on the magnetic properties of a dysprosium complex.

A low-cost 3D printer is used to combine chemical reactions and the reactor to produce an active ‘reactionware’ system for organic and inorganic synthesis. Active elements such as catalysts can be incorporated into the walls of printed reactors, and other printed-in components that enable electrochemical and spectroscopic analysis can also be included.

Molecular inhibitors of amyloid formation could help combat Alzheimer's disease, type 2 diabetes, and other major human diseases. Here, two-dimensional infrared spectroscopy and residue-specific isotope labelling are used to obtain detailed structural information on amyloid-inhibitor complexes. The unexpected behaviour observed helps to explain the moderate activity of the inhibitor studied.

Heavier analogues of ketones — containing a double bond between a group 14 element and oxygen — have so far not been isolated as stable compounds. Now, a stable monomeric germanone with a highly polarized Ge=O double bond has been isolated, stabilized by rigid bulky ligands.

Many parameters have been designed to describe steric size, but few have been able to explain consistently the selectivity of asymmetric catalytic reactions. Here, Sterimol parameters — originally used to develop quantitative structure–activity relationships in medicinal chemistry — have been used to quantify enantioselectivity in a diverse collection of asymmetric catalytic reactions.

The self-assembly of proteins into ordered yet dynamic nanoscale architectures is a crucial biological process and an inspiration for supramolecular chemistry, but has remained largely inaccessible synthetically. A monomeric protein has now been prepared that assembles with zinc ions into one-, two- and three-dimensional crystalline arrays with nano- and microscale order.

When operating at near-ambient conditions, using water as a solvent, a high-turnover iridium catalyst enables a reversible hydrogen storage system that uses carbon dioxide, formate and formic acid. Proton-responsive ligands in the catalyst allow it to be turned on or off by controlling the pH of the solution.

Quantum coherence has been observed in the major light-harvesting complex of photosystem II (LHCII) from green plants. By controlling the laser pulse polarization in two-dimensional electronic spectroscopy, signals from quantum coherence have been separated from other molecular processes, offering insight into the role of quantum coherence in photosynthetic light-harvesting.

Quantum beating has been observed in photosynthetic systems, suggesting that energy-transfer processes in natural light harvesting could involve quantum effects. Now, extensive beating is found in the light-harvesting protein of a cryptophyte alga, and shown to be electronic. The implications of these observations on the free-energy surfaces and exciton delocalization were investigated.

The Cope rearrangement has been known since the 1940s but, until now, no catalytic asymmetric variant has been reported. Here, a gold(I) catalyst is shown to induce an asymmetric Cope rearrangement of achiral 1,5-dienes containing a cyclopropylidene moiety to produce vinyl cyclopropanes in high yield and good to excellent enantioselectivities.

Despite recent progress, solving protein structures using solid-state NMR spectroscopy is not routine. Now, a method for the rapid determination of global protein fold is reported, based on measurements of ¹⁵N longitudinal paramagnetic relaxation enhancements in several protein variants modified with covalently attached cysteine–EDTA–Cu²⁺ tags.

Increasing the efficiency and speed of the water-oxidation reaction is crucial to realizing light-driven water splitting. Now, a mononuclear ruthenium complex achieves fast water-oxidation catalysis with a high reaction rate of more than 300 turnovers per second, comparable to the activity of the oxygen-evolving complex in photosystem II.

Simon H. Friedman explores the various ways in which carbon is inherently tied to our lives — beyond its elegant, treasured role in organic chemistry.