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Engineered enzymes enable greener one-pot amide synthesis for drug manufacturing

A single type of chemical structure that shows up again and again in modern medicine is the amide bond that links a carbonyl group (C=O) to a nitrogen atom. They’re so ubiquitous that 117 of the top 200 small-molecule drugs by retail sales in 2023 feature at least one amide bond. And now, researchers have discovered a clever new way to reengineer natural enzymes to build amides from simple chemicals like aldehydes and amines.

The team chose a naturally abundant enzyme family called aldehyde dehydrogenases (ALDHs), specifically p-hydroxybenzaldehyde dehydrogenase (PHBDD), which can efficiently convert aldehydes into acids. The team turned it into a new catalyst, known as an oxidative amidase (OxiAm), by modifying its internal pocket of the enzyme in two major ways: making it hydrophobic to prevent the formation of unwanted acids and making it bigger to allow larger, diverse chemical parts to fit inside so they could be bonded together.

According to the results published in Science, the team was able to obtain amides directly from commercially available alcohols via a two-step enzymatic cascade reaction carried out in a single container. This approach could enable new, greener methods for producing five major drug molecules, including a key component of imatinib, an essential drug used to treat chronic myeloid leukemia and gastrointestinal stromal tumors.

New CRISPR tool spreads through bacteria to disable antibiotic resistance genes

Antibiotic resistance (AR) has steadily accelerated in recent years to become a global health crisis. As deadly bacteria evolve new ways to elude drug treatments for a variety of illnesses, a growing number of “superbugs” have emerged, ramping up estimates of more than 10 million worldwide deaths per year by 2050.

Scientists are looking to recently developed technologies to address the pressing threat of antibiotic-resistant bacteria, which are known to flourish in hospital settings, sewage treatment areas, animal husbandry locations, and fish farms. University of California San Diego scientists have now applied cutting-edge genetics tools to counteract antibiotic resistance.

The laboratories of UC San Diego School of Biological Sciences Professors Ethan Bier and Justin Meyer have collaborated on a novel method of removing antibiotic-resistant elements from populations of bacteria. The researchers developed a new CRISPR-based technology similar to gene drives, which are being applied in insect populations to disrupt the spread of harmful properties, such as parasites that cause malaria. The new Pro-Active Genetics (Pro-AG) tool called pPro-MobV is a second-generation technology that uses a similar approach to disable drug resistance in populations of bacteria.

Researchers demonstrate organic crystal emitting red light from UV and green from near-infrared

Invisible light beyond the range of human vision plays a vital role in communication technologies, medical diagnostics, and optical sensing. Ultraviolet and near-infrared wavelengths are routinely used in these fields, yet detecting them directly often requires complex instrumentation.

Developing materials that can convert invisible light into visible signals could serve as essential components for measurement technologies and sensors, and play a major role in understanding the fundamental photophysical processes. However, developing those materials remains a key challenge in photonics and materials science.

Broken inversion symmetry lets 3D crystals mimic 2D Ising superconductivity

Two-dimensional (2D) materials, in general, allow the realization of unique quantum phenomena unattainable in the common three-dimensional (3D) world. A prime example is graphene. Transition metal dichalcogenides (TMDs) have a similar structure. Both can be stacked to form van der Waals heterostructures or can be exfoliated into single layers. But TMDs have an extra variety of excellent properties, including strong spin-orbit coupling and superconductivity.

In 2D (single atomic layer film) NbSe2, a prominent example of TMD, the combination of these two effects with the crystal symmetries leads to the so-called Ising superconductivity (IS), which can withstand extremely high magnetic fields oriented parallel to the crystal plane. Perhaps more exciting than this resilience against magnetic fields is the potential application of IS in realizing various exotic phenomena such as equal spin Andreev reflections, topological superconductivity, and Majorana fermions.

However, 2D structures are prone to degradation and impractical for applications. 3D materials are robust, easily scalable and accessible to a larger range of scientific analytical techniques. Therefore, it is desirable to find ways of protecting unique features of 2D materials in their 3D counterparts.

Three-way quantum correlations fade exponentially with distance at any temperature, study shows

The properties of a quantum material are driven by links between its electrons known as quantum correlations. A RIKEN researcher has shown mathematically that, at non-zero temperatures, these connections can only exist over very short distances when more than two particles are involved. This finding, now published in Physical Review X, sets a fundamental limit on just how “exotic” a quantum material can be under realistic, finite-temperature conditions.

A fascinating aspect of quantum physics is the concept that two particles that are spatially separated can communicate with each other. This so-called “spooky action at a distance,” as Einstein referred to it, is crucial for understanding the origin of the exotic properties that arise in some materials, particularly at low temperatures.

These unusual material properties are determined by the exact nature of the quantum correlation, and the material is said to be in a specific quantum phase. This is analogous to the traditional phases of matter—solid, liquid, and gas—being defined by the chemical interactions between the atoms.

New 3D method maps Paleolithic engravings at submillimeter resolution

A team of archaeologists from the Universitat Jaume I, the University of Barcelona, and the Catalan Institution for Research and Advanced Studies (ICREA) has developed a new methodology that allows for a much more detailed, precise, and objective analysis of Late Paleolithic portable art pieces. Thanks to this study, the research team was able to review several previously published pieces from Matutano Cave (Vilafamés), a reference site in the Iberian Mediterranean, with greater accuracy and demonstrate that some of the marks previously interpreted as artistic motifs are not anthropic engravings but natural surface reliefs.

Late Paleolithic art is usually characterized by very fine engravings, barely visible to the naked eye, often affected by taphonomic alterations, surface irregularities, and unclear morphologies, which complicates their identification and interpretation. This new methodology allows for a more precise analysis of the remains using photogrammetry and microtopographic analysis techniques.

The results are published in the Journal of Archaeological Science: Reports.

Stabilized iron catalyst could replace platinum in hydrogen fuel cells

Japan and California have embraced hydrogen fuel-cell technologies, a form of renewable energy that can be used in vehicles and for supplying clean energy to manufacturing sectors. But the technology remains expensive due to its reliance on precious metals such as platinum. Engineers at Washington University in St. Louis are working on this challenge, finding ways to stabilize ubiquitous iron components for use in fuel cells to replace the expensive platinum metals, which would make hydrogen fuel-cell vehicles more affordable.

Cost challenges for fuel-cell vehicles

“The hydrogen fuel cell has been successfully commercialized in Japan and California in the U.S.,” said Gang Wu, a professor of energy, environmental and chemical engineering at the McKelvey School of Engineering. “But these vehicles struggle to compete with the battery vehicle and combustion engine vehicle, with cost being the main issue.”

Study reveals microscopic origins of surface noise limiting diamond quantum sensors

A new theoretical study led by researchers at the University of Chicago and Argonne National Laboratory has identified the microscopic mechanisms by which diamond surfaces affect the quantum coherence of nitrogen-vacancy (NV) centers—defects in diamond that underpin some of today’s most sensitive quantum sensors. The study has appeared in Physical Review Materials and was selected to be an Editors’ Suggestion paper.

“One long-standing challenge has been understanding why shallow NV centers lose coherence so quickly,” said Giulia Galli, professor at the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) and senior scientist at Argonne National Laboratory. “By combining first-principles surface models with quantum dynamics simulations, we understood that the culprit of decoherence is not just which spins live on the diamond surface, but how they move: surface noise is dynamical.”

The findings of the study provide clear, physics-based guidelines for engineering diamond surfaces that help preserve quantum coherence, a key requirement for quantum sensing and emerging quantum information technologies.

Measuring time at the quantum level depends on material symmetry

EPFL physicists have found a way to measure the time involved in quantum events and found it depends on the symmetry of the material. “The concept of time has troubled philosophers and physicists for thousands of years, and the advent of quantum mechanics has not simplified the problem,” says Professor Hugo Dil, a physicist at EPFL. “The central problem is the general role of time in quantum mechanics, and especially the timescale associated with a quantum transition.”

Quantum events, like tunneling, or an electron changing its state by absorbing a photon, happen at mind-bending speeds. Some take only a few tenths of attoseconds (10-18 seconds), which is so short that light would not even cross the width of a small virus. But measuring time intervals this small is notoriously difficult, also because any external timing tool can distort the very thing we want to observe.

“Although the 2023 Nobel prize in physics shows we can access such short times, the use of such an external time scale risks inducing artifacts,” says Dil. “This challenge can be resolved by using quantum interference methods, based on the link between accumulated phase and time.”

When silicon fills the role of carbon: Debut of all-silicon cyclopentadienides

Carbon’s unique chemical properties allow it to be an essential building block for life on Earth and many other molecules we rely on for day-to-day life—but what about carbon’s neighbor? Silicon is located one row below carbon in the periodic table of elements, and similarly has many possible uses, and is a key component of semiconductors, silicon carbide fibers, and silicones. However, silicon has some key weaknesses compared to carbon.

For example, carbon forms very stable π-electron compounds (compounds linked by pi bonds, or π-bonds, which affect a molecule’s reactivity) called benzene and fullerene. In comparison, silicon cannot readily form these compounds, as the π-bonds forming π-electron compounds are not strong in this element. Synthesizing such silicon-based π-electron compounds consequently becomes increasingly difficult as the number of silicon atoms increases. However, researchers at Tohoku University found a way to overcome these limitations.

A research group led by Professor Takeaki Iwamoto, Graduate Student Tomoki Ishikawa, and Associate Professor Shintaro Ishida at the Graduate School of Science, Tohoku University, has successfully synthesized π-electron compounds with a pentagonal silicon framework, “pentasilacyclopentadienide,” and elucidated their molecular structures. The study is published in the journal Science.

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