Article
Biochemistry & Molecular Biology
Xiang Sheng, Fahmi Himo
Summary: Quantum chemical calculations play a crucial role in studying enzymatic reaction mechanisms, especially in the research of metal-dependent decarboxylases. Computational mechanistic studies provide important insights for further modification and utilization of these enzymes in industrial processes.
COMPUTATIONAL AND STRUCTURAL BIOTECHNOLOGY JOURNAL
(2021)
Article
Plant Sciences
Chong Qiao, Fei Chen, Zhan Liu, Tianfang Huang, Wei Li, Guolin Zhang, Yinggang Luo
Summary: The research on the CaTDC3 gene from the Camptotheca acuminata plant reveals that this enzyme exhibits strict stereoselectivity towards L-tryptophan and shows high catalytic activity in decarboxylation. Additionally, CaTDC3 is capable of recognizing different structures of L-tryptophan derivatives and analogs. The study findings demonstrate the significant potential of CaTDC3 in synthetic biology applications.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Agriculture, Multidisciplinary
Haixia Xu, Xiaofeng Li, Xuan Xin, Lan Mo, Yucong Zou, Guanglei Zhao
Summary: In this study, an enzymatic route for synthesizing phenolic glycoside azelaic acid esters was successfully established through lipase-catalyzed esterification and transesterification. Candida antarctica lipase B (Novozyme 435) and Thermomyces lanuginosus (Lipozyme TLIM) were found to be efficient catalysts, with the addition of 4A molecular sieves improving substrate conversions. The synthesized esters showed higher bioactivities and inhibitory effects on melanin production compared to phenolic glycosides, azelaic acid, and their physical mixtures, with piceid 6-O-azelaic acid ester (PIA) exhibiting the strongest inhibitory effect against melanin production.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2021)
Article
Environmental Sciences
Zehong Li, Wei Zhang, Zhaohui Chen, Zhaoying Ren, Shuo Ning, Mengting Li
Summary: Using advanced quantum chemistry methods, this study explores the pathways of NOX formation and reduction and determines new kinetic parameters. Energy barrier analysis reveals that NO is mainly produced through a sequence of reactions rather than the traditional reaction. The formation of NO2 depends largely on O and HO2 radicals, while the active O atom promotes both the formation and destruction of NO2.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Chemistry, Physical
K. Shashikala, K. Ashna, J. Aswathi, Deepa Janardanan
Summary: Gas-phase unimolecular decomposition of formic acid via decarboxylation and dehydration pathways was studied using density functional theory. It was found that the activation energies of the decomposition pathways were significantly reduced with the assistance of water, organic and inorganic acids, as well as sulphuric acid-water complex. Dehydration was the preferred catalytic route, except when water was present. The cooperative effect in the sulphuric acid-water complex was proposed as the reason for the lowest activation barrier in this system.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Sebastian Kozuch, Amir Karton, Said Jalife, Gabriel Merino
Summary: The 21-homododecahedryl cation is a unique system with complete fluxionality based on two different rearrangements. Quantum tunneling effects are reported to drive reactions at temperatures where classical kinetics are impossible. It is theorized that the tunnel effect in this system could be used to create a refrigerator operating at arbitrarily low temperatures.
CHEMICAL COMMUNICATIONS
(2021)
Article
Engineering, Environmental
Yihao Li, Lu Jiang, Rui Wang, Pingxiao Wu, Juan Liu, Shanshan Yang, Jiahao Liang, Guining Lu, Nengwu Zhu
Summary: This study investigates the oxidation mechanism of phenolic compounds by ferrate (Fe(VI)), showing increased degradation rates at higher pH levels. It identifies 14 degradation products, proposes two possible pathways, and highlights the crucial role of hydroxyl radicals in the degradation process. Density functional theory calculations reveal preferences for chlorine atom substitution over hydrogen atom and ortho-position substitution over para-position for all four compounds, providing valuable insights for environmental remediation.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Food Science & Technology
Daniel Koval, Katsiaryna Alishevich, Katerina Sasinova, Adela Ramesova, Stepan Marhons, Tereza Nesporova, Ladislav Curda, Monika Kumherova, Jan Barta, Vladimir Filip, Jan Kyselka
Summary: A previously undescribed species of Limosilactobacillus fermentum isolated from wholemeal buckwheat sourdough was identified and its metabolism of 6 hydroxycinnamic acids was studied. The study found that the decarboxylation of free cinnamic acid to potentially toxic styrene was low in all strains tested. Additionally, it was discovered that reduced p-dihydrocoumaric and dihydroferulic acids caused less growth inhibition than their precursors.
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
(2022)
Article
Chemistry, Physical
Chi Zhang, Xiurong Yang, Zihan Zhang, Jiachen Li, Wujing Jin, Haixia Ma
Summary: In this study, the decomposition mechanism of ammonium perchlorate (AP) on graphitic carbon nitride (g-C3N4) catalyst was investigated using density functional theory calculation. The main decomposition pathway of AP was found to be HClO4 -> ClO3- -> ClO2- -> ClO- -> Cl-. Additionally, the oxidation of g-C3N4 surface weakened its catalytic capacity for AP decomposition but enhanced its catalytic capacity for the adsorption and dehydrogenation of NH3.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Alexander R. Epstein, Jeremy Demarteau, Brett A. Helms, Kristin A. Persson
Summary: The design of circular polymers is necessary due to the lack of efficient recycling methods for many commodity plastics. Polydiketoenamines (PDKs) stand out for their ability to undergo selective depolymerization in strong acid, allowing monomers to be recovered. The chemistry of the cross-linker, far from the reaction center, has been found to affect the depolymerization rate of PDKs, with a proximal amine in the cross-linker significantly accelerating the process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Environmental Sciences
Ruisi Huang, Hongyu Cao, Ting Huang, Hongjiang Li, Qian Tang, Lihao Wang, Xuefang Zheng
Summary: The abuse of fluoroquinolones antibiotics causes resistance and pollution. This study investigates the photodegradation mechanisms and environmental factors affecting the degradation of fleroxacin. Six possible photodegradation reaction paths were proposed and simulated. The main reactions involve the departure of the piperazine ring and the substitution of fluorine atom. Factors such as pH and substances like NaN3 and Ca2+ were found to influence the photodegradation process.
Article
Biotechnology & Applied Microbiology
Yeri Choi, Sang-Woo Han, Jun-Sung Kim, Youngho Jang, Jong-Shik Shin
Summary: The study demonstrates that AADC-BA from Bacillus atrophaeus has a broad substrate specificity, allowing for efficient synthesis of various aromatic biogenic amines, including neurotransmitters. Experimental results show that AADC-BA can be used for the production of serotonin and other substances.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2021)
Article
Chemistry, Physical
Ryan A. Daley, Aaron S. Morrenzin, Sharon R. Neufeldt, Joseph J. Topczewski
Summary: This study investigates the mechanistic details of a gold-catalyzed decarboxylative cross-coupling, suggesting a high-valent Au(I/III) pathway with a turnover-limiting oxidative addition. The dominant pathway likely involves a silver-mediated decarboxylation followed by an Ag(I) to Au(III) transmetalation. These findings provide insight into the significant counterion effects observed between SbF6- and NTf2-.
Article
Biochemistry & Molecular Biology
Meagan S. Oakley, Laura Gagliardi, Donald G. Truhlar
Summary: The study utilized CAS and SP wave functions to simulate the bond dissociation of transition metal silicides and predict experimental results, with typical errors of 0.2 eV and 0.3 eV, respectively. The ground and low-lying excited states were explored to predict state ordering for each molecule, and potential energy curves were calculated for comparison to experimental results. English Summary: The study utilized CAS and SP wave functions to simulate the bond dissociation of transition metal silicides and predict experimental results, with typical errors of 0.2 eV and 0.3 eV, respectively.
Article
Chemistry, Applied
Maciej Spiegel, Katarzyna Cel, Zbigniew Sroka
Summary: Polyphenols are widely consumed exogenous antioxidants that can prevent the accumulation of radicals and oxidative stress. However, they may also have prooxidant potential, resulting in increased radical production. DFT studies on nine common polyphenolic compounds showed that there is a fine line between antioxidant and prooxidant activities and that higher pH values promote prooxidant behavior. Anthocyanidins were found to be the most potent radical scavengers, followed by flavonoids and phenolic acids. The antiradical activity is higher in polar solvents due to the possibility of dissociation.
Article
Chemistry, Physical
Xiang Sheng, Masoud Kazemi, Anna Zadlo-Dobrowolska, Wolfgang Kroutil, Fahmi Himo
Article
Biochemistry & Molecular Biology
Gerhard Hofer, Xiang Sheng, Simone Braeuer, Stefan E. Payer, Katharina Plasch, Walter Goessler, Kurt Faber, Walter Keller, Fahmi Himo, Silvia M. Glueck
Summary: Benzoic acid decarboxylases from microbial sources are efficient biocatalysts with broad substrate tolerance, excellent regioselectivity, and independence from sensitive cofactors. They can catalyze the reversible non-oxidative (de)carboxylation of a variety of electron-rich (hetero)aromatic substrates analogously to the chemical Kolbe-Schmitt reaction, making them attractive for preparative-scale applications due to their robustness under process conditions. The presence of a catalytically relevant Mg2+ in the active site of 2,3-dihydroxybenoic acid decarboxylase from Aspergillus oryzae is verified through elemental mass spectrometry, crystal structure elucidation, and quantum chemical calculations, which is unique compared to other decarboxylases with Zn2+ or Mn2+ as catalytically active metals.
Article
Biochemistry & Molecular Biology
Haicheng Liu, Santosh Panjikar, Xiang Sheng, Yushi Futamura, Chenghua Zhang, Nana Shao, Hiroyuki Osada, Hongbin Zou
Summary: Strictosidine synthase (STR), a key enzyme in the biosynthesis of monoterpenoid indole alkaloids, catalyzes Pictet-Spengler reaction with the assistance of indole sandwich stabilization. A new nonindole sandwich binding mode was discovered and the role of Tyr151 hydroxyl group in the reaction was revealed. Further experiments resulted in the synthesis of compounds with antimalarial activity.
ACS CHEMICAL BIOLOGY
(2022)
Article
Chemistry, Physical
Yingying Jiang, Ge Qu, Xiang Sheng, Feifei Tong, Zhoutong Sun
Summary: This study demonstrates the control of product chirality in asymmetric reduction reactions through the exchange of key residues, enabling efficient synthesis of chiral compounds under mild conditions.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Mario Prejano, Xiang Sheng, Fahmi Himo
Summary: In this study, DFT calculations were used to investigate the reaction mechanism and enantioselectivity origin of IRED from Amycolatopsis orientalis. Results show that the calculated energies and transition states geometries are consistent with experimental observations, providing insights into the origins of enantioselectivity of this enzyme.
Article
Chemistry, Physical
Xuanzhong Liu, Zhenbo Yuan, Hao Su, Xiaodong Hou, Zhiwei Deng, Huibin Xu, Baodang Guo, Dejing Yin, Xiang Sheng, Yijian Rao
Summary: This study reveals the formation mechanism of the seven-membered methylenedioxy bridge in cercosporin biosynthesis, providing molecular insights into the biosynthetic pathways of natural products containing MDBs.
Article
Chemistry, Physical
Yijie Dong, Tang Li, Shiqing Zhang, Joaquin Sanchis, Heng Yin, Jie Ren, Xiang Sheng, Guangyue Li, Manfred T. Reetz
Summary: In this study, the unexpected mechanistic intricacies of Baeyer-Villiger monooxygenases (BVMOs) were discovered, providing insights for expanding their applications in synthetic organic chemistry and biotechnology. The investigation utilized complete mutational deconvolution and experimental construction of a fitness-pathway landscape to elucidate the structural changes of Criegee intermediates and their effects on the evolutionary process.
Article
Biochemistry & Molecular Biology
Yuanying Li, Pengpeng Zhang, Zhoutong Sun, Huanhuan Li, Ran Ge, Xiang Sheng, Wuyuan Zhang
Summary: This study developed an enzymatic approach for the synthesis of calcitriol, achieving high selectivity and yield. The use of AaeUPO as a catalyst allowed for efficient hydroxylation reactions and direct synthesis from vitamin D3.
Article
Chemistry, Organic
Xianke Sang, Feifei Tong, Zhigang Zeng, Minghu Wu, Bo Yuan, Zhoutong Sun, Xiang Sheng, Ge Qu, Miguel Alcalde, Frank Hollmann, Wuyuan Zhang
Summary: Propargylic alcohols and amines are versatile building blocks in organic synthesis. This study demonstrates a straightforward enzymatic cascade reaction to synthesize enantiomerically pure propargylic alcohols and amines from readily available racemic starting materials with yields of 70-99%.
Article
Chemistry, Physical
Dongdong Meng, Meixia Liu, Hao Su, Haiyan Song, Lijie Chen, Qiangzi Li, Ya-nan Liu, Zhiguang Zhu, Weidong Liu, Xiang Sheng, Chun You, Job Zhang
Summary: In this study, the catalytic efficiency of glucose-6-phosphate dehydrogenase (G6PDH) on oxidized nicotinamide mononucleotide (NMN+) was improved by coenzyme engineering, resulting in a 112-fold enhancement. Structural analysis revealed that the mutant enzyme had a more compact substrate/coenzyme-binding site, favoring the binding of the substrate and NMN+. Furthermore, a glucose biosensor based on the NMN+-dependent G6PDH was constructed, demonstrating the potential of using biomimetic nicotinamide coenzymes in biocatalysis and biosensing applications.
Article
Chemistry, Physical
Fuqiang Chen, Yipei Zhao, Chenghua Zhang, Wei Wang, Jian Gao, Qian Li, Huimin Qin, Yujie Dai, Weidong Liu, Fufeng Liu, Hao Su, Xiang Sheng
Summary: In this study, the substrate binding mode and reaction mechanism of salicylic acid decarboxylase (SDC) were investigated. The findings reveal that SDC is a Mg-dependent enzyme, and the substrate is bidentately coordinated to the metal center during catalysis. These insights provide important information for the rational design of the enzyme.
Review
Chemistry, Multidisciplinary
Xiang Sheng, Fahmi Himo
Summary: The quantum chemical cluster approach has been used for over two decades to model enzyme active sites and reaction mechanisms. This methodology involves selecting a small part of the enzyme as a model and using quantum chemical methods to calculate energies and properties. Over the years, this approach has been used to solve various enzyme mechanisms and has been expanded to address new questions.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Mingqi Mou, Chenghua Zhang, Shiqing Zhang, Fuqiang Chen, Hao Su, Xiang Sheng
Summary: This study reveals the reaction mechanism of strictosidine synthase (STR) in the formation of a rare seven-membered azepino-indole skeleton molecule through the Pictet-Spengler reaction. The findings are important for understanding the promiscuous activity of STR and for designing STR enzymes for the synthesis of other new alkaloid skeleton molecules.
Article
Biochemistry & Molecular Biology
Xiang Sheng, Fahmi Himo
Summary: Quantum chemical calculations play a crucial role in studying enzymatic reaction mechanisms, especially in the research of metal-dependent decarboxylases. Computational mechanistic studies provide important insights for further modification and utilization of these enzymes in industrial processes.
COMPUTATIONAL AND STRUCTURAL BIOTECHNOLOGY JOURNAL
(2021)
Article
Chemistry, Physical
Xiang Sheng, Fahmi Himo