Scientific Publication! They Might Have Discovered a "Goldmine" of Chirality.

In the 1960s, the sedative drug thalidomide, due to lack of chiral purification, caused over 12,000 cases of deformed "seal-like" babies born without heads or limbs within 4 years globally. "This deeply made people realize the close relationship between chirality, drug efficacy, and health," Ouyang Zheng, a professor in the Department of Precision Instruments at Tsinghua University and President of the Shenzhen International Graduate School, told the "China Science Daily." In the development of new drugs, chirality refers to two types of molecules that are mirror images of each other, just like left and right hands, but cannot completely overlap. Chiral molecules are widely present in natural systems, and chiral molecules in living organisms usually exist in a single chiral form. Therefore, chirality and chiral purification are of great significance to drug development. Recently, Ouyang Zheng and Associate Professor Zhou Xiaoyu from the Department of Precision Instruments at Tsinghua University published a paper in "Science" for the first time, demonstrating that physical methods can achieve separation of enantiomers (mirror-image molecules) without relying on high enantiomeric purity. This achievement has important applications in drug development and medical diagnosis, and is expected to help solve important problems in asymmetric synthesis and the origins of chirality in basic scientific research. The mysterious and important "chirality" Chiral molecules are widely present in natural systems, and their relationship is similar to that of people's left and right hands, collectively referred to as enantiomers. What is intriguing is that chiral molecules in living organisms usually exist in a single chiral form. For example, the human body mainly contains L-amino acids and hardly any of their enantiomer, D-amino acids. "Living systems are environments of high enantiomeric purity, and a chiral molecule has good pharmacological effects, while its enantiomer may have harmful side effects," Ouyang Zheng said. "It is precisely because of the lesson from thalidomide that in the process of new drug development, rigorous biological activity and toxicity tests must be conducted on chiral enantiomers to avoid harm to the human body." Currently, both the U.S. Food and Drug Administration and the China National Medical Products Administration stipulate that in drug development, even if two enantiomers can be used in certain conditions, the effects of each enantiomer must be investigated. The premise of understanding the effects is chiral purification, separating them and describing their individual activities and side effects. Traditionally, chemical methods have been used for chiral purification. Chemical methods first require the addition of another high-purity chiral compound, and then separation and analysis using chromatography. This process relies on trial and error, is cumbersome and complex, has limited universality, and requires a large amount of sample. Sometimes, after great effort, the sample may not meet the chromatographic separation conditions. In the latest research, Ouyang Zheng's team achieved efficient separation and mass spectrometry analysis of chiral substances using electric field-induced gas phase ion orientation rotation. "We first convert biocompounds into ions and suspend and rotate them in an electric field. Then, we use the electric field to induce ion motion and collide with the surrounding neutral molecules to achieve spatial separation of enantiomers," said Zhou Xiaoyu.Using traditional chemical separation methods, the quantity required is in milligrams or more. However, by using this physical method, the quantity needed is in nanograms or less, and it can simultaneously separate and identify the mass spectrometry structure, providing chiral purity and molecular structure within 1 minute. In addition, in the study of the origin of life, an unexplained question is - if chiral purification relies on existing chemical chiral methods, then where does the first chemical environment with high chiral purity for the formation of life come from? "This is actually a 'chicken or egg' question," said Ouyang Zheng. "Our research suggests that the chemical environment for chiral purification may be achieved through physical methods, and such conditions (electric field) may exist in nature, providing new perspectives for the study of the origin of life." Unexpectedly discovered a "gold mine." The team consists of 5 independent principal investigators (PIs) and nearly 30 doctoral students and postdoctoral fellows. The PIs of the team have returned from Purdue University in the United States to join the Department of Precision Instruments and Department of Chemistry at Tsinghua University. They are dedicated to research on instrument technology and bio-molecular structure analysis methods based on new physical principles and are pushing them towards practical applications. The small mass spectrometry analysis system developed by the team is at the forefront internationally. To commercialize their achievements, they have established Qingpu Technology Company. In 2020, the team developed a method for achieving ultra-high-resolution mobility analysis using an ion trap mass spectrometer, greatly improving the resolution. At that time, the best mass spectrometer resolution internationally was around 400, while the mass spectrometer they developed can achieve a resolution of over 10,000. Ouyang Zheng explained that mobility analysis is an innovative technology in the field of biomolecular analysis. People collide two molecules with the same molecular weight and similar structures with gas. Because their cross sections are different, their velocities after collision are also different, so they can be separated. "It's like two people, one short and fat, the other tall and thin, both weighing the same but have different wind resistance when running," said Ouyang Zheng. "But in enantiomers, the two molecules are like left and right hands, highly similar in structure and cross-section, so even conventional mobility analysis techniques usually cannot distinguish them."Due to the significantly higher resolution of the team-developed mass spectrometer compared to counterparts both domestically and internationally, Ouyang Zheng and Zhou Xiaoyu led the team in conducting multiple experiments with a trial-and-error mindset. On June 29, 2021, they obtained affirmative results for the first time. "To our surprise, we discovered that the two chiral enantiomers can be separated at high resolution." Zhou Xiaoyu stated. Upon receiving the results, the team couldn't believe it: were they truly separated, or did they observe some kind of illusion? To investigate further, the team adjusted the concentration ratio of the chiral enantiomers to 1:2 for the analysis, and found that the analytical result was also 1:2. "By changing the relative concentration of the two enantiomers and comparing the changes in the spectra, we are certain that the chiral enantiomers have been separated," Zhou Xiaoyu said. "Not only can we separate the two chiral enantiomers, but the separation efficiency is also very high." "I know this is a significant discovery because there is consensus on the importance of chiral purification. Being able to separate them using physical methods is valuable for the pharmaceutical field and has great significance for the study of the origin of life," Ouyang Zheng said. "I realize that we may have struck a 'gold mine'." In an instant, surprise and two-year-long challenges. After the ecstatic joy, Ouyang Zheng knew that the real challenge had just begun. "In scientific research, happiness only lasts for a moment," Ouyang Zheng said. "Because afterward, I realized soberly that we had only observed the phenomenon and knew nothing about the underlying mechanism. This immediately 'dragged' us back." During the research, they also encountered a tricky problem: the relative positions of the peaks of the enantiomers seemed uncontrollable—sometimes a single peak, other times two peaks—and their positions and spacings would vary. This had troubled the researchers for over two years. "Einstein once said that significant discoveries are unlikely to be deduced, but rather require a conceptual breakthrough first," Ouyang Zheng encouraged team members. "We need to use our imagination, boldly conceive various possible scenarios, and then seek theoretical foundations."Through extensive literature research and internal discussions, researchers speculate that it is the electric field inside the ion trap that allows chiral molecules to achieve directional spin and results in differences in their collision processes compared to other molecules. Through theoretical calculations and simulations, the team eventually verified this hypothesis and understood the physical conditions for controlling ion spin direction. Subsequently, the team collaborated with Clear Spectrum Technology to modify the instrument control system and used a dual AC signal resonance excitation method to control the rotation direction of ions, thereby generating stable differences in collision cross-sections for enantiomeric ions. By manipulating the ion rotation direction and trajectory, they ultimately achieved stable and controllable high-resolution enantiomer spectra. "This is a fascinating study," stated one of the peer reviewers. Another reviewer believes that this research makes it possible to "develop rapid and simplified techniques and methods for determining chiral components." Please scan the QR code below for 3 seconds.Scienceenantiomersseparationdrug developmentmedical diagnosticsasymmetric synthesischirality originmass spectrometry analysis systemClear Spectrum Technology Companyindustrialization.