Article
Chemistry, Physical
Mitsuo Shoji, Yuya Kitazawa, Akimasa Sato, Natsuki Watanabe, Mauro Boero, Yasuteru Shigeta, Masayuki Umemura
Summary: High enantiomeric excesses (ee's) of L-amino acids, including non-proteinogenic amino acid isovaline (Iva), were discovered in the Murchison meteorite. However, the molecular mechanism responsible for the observed ee of amino acids remains elusive. Accurate ab initio calculations and evaluation of photolysis-induced ee were conducted for amino acids and their precursors. It was found that only the aminonitrile precursors have positive ee in the Lyman alpha region, explaining the homochirality of L-amino acids induced by right-handed circularly polarized Lyman alpha.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Mitsuo Shoji, Yuya Kitazawa, Akimasa Sato, Natsuki Watanabe, Mauro Boero, Yasuteru Shigeta, Masayuki Umemura
Summary: High enantiomeric excesses (ee's) of L-amino acids, including non-proteinogenic amino acid isovaline (Iva), were discovered in the Murchison meteorite. However, the molecular mechanism responsible for their ee remains unclear. By using accurate ab initio calculations, this study shows that the homochirality of amino acids is produced at the aminonitrile precursors stage.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Daniel P. Demarque, Michael Kemper, Christian Merten
Summary: In this study, the IR and VCD spectra of azithromycin were reported, with computational analysis revealing the importance of a single water molecule in stabilizing the hydrogen bonding network and determining the VCD spectral signatures. The presence of this water molecule was essential for understanding the conformational dynamics of azithromycin.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Datong Wu, Fangqin Wang, Cong Ma, Lilan Tan, Wenrong Cai, Junyao Li, Yong Kong
Summary: In this study, two novel achiral aromatic carboxylic acids were synthesized and used as chiroptical sensors for the real-time discrimination and enantiomeric excess determination of chiral amines and amino alcohols, especially for UV-silent chiral compounds.
Article
Physics, Applied
H. R. Barnard, G. R. Nash
Summary: The characteristics of four-layer chiral metamaterials, optically active in the mid-infrared region, have been studied through simulations and experiments. The spectral response of the materials can be tailored while maintaining the magnitude of circular dichroism relative to standard double layer metamaterials. Analysis shows that these four-layer structures offer greater design freedom in coupling than expected from simple consideration of double layer structures.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Qin Yang, Josef Kapitan, Petr Bour, Julien Bloino
Summary: Combining Raman scattering and Raman optical activity (ROA) with computer simulations allows for the characterization of chiral molecules' fine structure and physicochemical properties. This study presents an accurate and simple approach based on three-quanta anharmonic perturbative mode, showing the significance of anharmonic Raman and ROA spectroscopies in understanding chiral molecules' vibrations and calibrating computational models.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Tao Wu, Josef Kapitan, Petr Bour
Summary: Chiral metal complexes have rich photophysical properties and are important for various applications. This study combines experimental and computational approaches to investigate the energies and transition moments of excited electronic states in two chiral metal complexes. The experimental protocol involves multiple techniques, and a formula for subtracting interfering effects is provided. Density functional theory calculations are used to analyze the spectra and reveal the geometric and electronic structures of the molecules. This insight into molecular electronic states can be useful for understanding and manipulating the photochemical properties of metal-containing complexes, biomolecules, and supramolecules.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Asfandyar Sikandar, Alexander Popoff, Ravindra P. Jumde, Attila Mandi, Amninder Kaur, Walid A. M. Elgaher, Lara Rosenberger, Stephan Huettel, Rolf Jansen, Maja Hunter, Jesko Koehnke, Anna K. H. Hirsch, Tibor Kurtan, Rolf Mueller
Summary: The absolute configuration of amidochelocardin was revised using a combination of XRD, NMR spectroscopy, experimental ECD spectra, and TDDFT-ECD calculations. Based on the biosynthetic engineering of chelocardin and the results of TDDFT-ECD calculations, it is proposed that chelocardin has the same absolute configuration. The evaluation of spectral data of two related analogues further supports this conclusion.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Optics
G. P. Katsoulis, Z. Dube, P. B. Corkum, A. Staudte, A. Emmanouilidou
Summary: We propose a measure that quantifies chirality in the ionization process of achiral atoms and validate it under realistic experimental conditions. This measure is based on the sign of the scalar triple product of the electron final momentum and the probability of ionization, integrated over all momentum components.
Article
Chemistry, Multidisciplinary
Archita Sripada, Yushra Thanzeel, Christian Wolf
Summary: The impracticalities of optical chiral compound sensing have limited the potential and acceptance of high-throughput experimentation. A new strategy using CD analysis has been introduced for quantitative sensing of amines and amino acids, eliminating the need for UV and fluorescence measurements. This unified CD sensing outperforms traditional methods and offers speed, labor, and cost benefits with reduced chemical waste production.
Article
Chemistry, Physical
Ashish Jain, Jean-Luc Begin, Ravi Bhardwaj
Summary: A novel chiroptical sensing technique using the helical phase of structured light as a chiral reagent was introduced. This technique can differentiate enantiopure chiral liquids by their differential absorbance of helical light, which is significantly higher compared to conventional linear techniques. The origin of the helicity dependent absorption is explained in terms of induced multipole moments in nonlinear light-matter interaction, opening up possibilities for using helical light as a primary chiral reagent in nonlinear spectroscopic techniques.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
P. Radhakrishnan, B. Geisler, K. Fuersich, D. Putzky, Y. Wang, S. E. Ilse, G. Christiani, G. Logvenov, P. Wochner, P. A. van Aken, E. Goering, R. Pentcheva, E. Benckiser
Summary: The study uses resonant x-ray reflectometry to investigate the electronic structure of YVO3/LaAlO3 heterostructure, revealing an artificial, layered orbital polarization phenomenon where the occupation of orbitals near LaAlO3 interface planes is reversed compared to the central part of YVO3. This phenomenon is stable down to 30 K and is attributed to a combination of epitaxial strain and spatial confinement by the LaAlO3 layers.
Article
Chemistry, Organic
Kosuke Oki, Masayoshi Takase, Nagao Kobayashi, Hidemitsu Uno
Summary: The synthesized HPHAC exhibits unique electronic properties, undergoing reversible multistep oxidations at low potentials and forming various ionic salts and charge-transfer complexes. The compound demonstrates clear aromaticity and shows distinctive absorption characteristics in UV-vis/NIR spectra.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Plant Sciences
Zeinab Y. Al Subeh, Laura Flores-Bocanegra, Huzefa A. Raja, Joanna E. Burdette, Cedric J. Pearce, Nicholas H. Oberlies
Summary: This article reports a relatively young class of fungal metabolites, macrocyclic alkaloids with a cyclopenta[b]fluorene ring system, which were first discovered in 2013. The structures of these compounds were identified by analyzing high-resolution electrospray ionization mass spectrometry data and one-dimensional and two-dimensional NMR spectra. The relative and absolute configurations of these alkaloids were determined through various spectroscopic techniques. These compounds showed cytotoxic activity against human cancer cell lines.
JOURNAL OF NATURAL PRODUCTS
(2023)
Article
Chemistry, Physical
Jan Blasius, Katrin Drysch, Frank Hendrik Pilz, Tom Froembgen, Patrycja Kielb, Barbara Kirchner
Summary: In this study, a novel cluster approach is presented for the fast and robust calculation of mole fraction dependent infrared and vibrational circular dichroism spectra using the example of acetonitrile/(R)-butan-2-ol mixtures. By assigning weights to a limited number of quantum chemically calculated clusters, vibrational spectra at any desired composition can be obtained through a weighted average. The study demonstrates accurate modeling of mole fraction dependent peak shifts and high accuracy in reproducing experimentally recorded infrared spectra over the entire mixing range. This approach provides a valuable and computationally efficient tool for accessing mole fraction dependent spectra of mixtures.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Biochemical Research Methods
Alexandra Mayer, Brent Copp, Ben Bogun, Gordon Miskelly
DRUG TESTING AND ANALYSIS
(2020)
Article
Plant Sciences
Yun-Seo Kil, April L. Risinger, Cora L. Petersen, Huiyun Liang, Tanja Grkovic, Barry R. O'Keefe, Susan L. Mooberry, Robert H. Cichewicz
JOURNAL OF NATURAL PRODUCTS
(2020)
Article
Biochemistry & Molecular Biology
Tanja Grkovic, Rhone K. Akee, Christopher C. Thornburg, Spencer K. Trinh, John R. Britt, Matthew J. Harris, Jason R. Evans, Unwoo Kang, Susan Ensel, Curtis J. Henrich, Kirk R. Gustafson, Joel P. Schneider, Barry R. O'Keefe
ACS CHEMICAL BIOLOGY
(2020)
Article
Plant Sciences
Petra J. Pederson, Shengxin Cai, Chase Carver, Douglas R. Powell, April L. Risinger, Tanja Grkovic, Barry R. O'Keefe, Susan L. Mooberry, Robert H. Cichewicz
JOURNAL OF NATURAL PRODUCTS
(2020)
Article
Chemistry, Medicinal
Cary F. C. Lam, Melissa M. Cadelis, Brent R. Copp
Article
Chemistry, Medicinal
Melissa M. Cadelis, Steven A. Li, Marie-Lise Bourguet-Kondracki, Marine Blanchet, Hana Douafer, Jean Michel Brunel, Brent Copp
Summary: The discovery of new antibiotic adjuvants is crucial for combating antimicrobial resistance. Some newly discovered compounds show good antibiotic adjuvant activities with lower cytotoxic and haemolytic properties, indicating their potential for further development as treatment options.
Article
Oncology
Julia Krushkal, Simarjeet Negi, Laura M. Yee, Jason R. Evans, Tanja Grkovic, Alida Palmisano, Jianwen Fang, Hari Sankaran, Lisa M. McShane, Yingdong Zhao, Barry R. O'Keefe
Summary: Investigation revealed associations between gene expression and the response of cancer cells to specific categories of natural products, suggesting potential mechanisms of action and paving the way for future targeted cancer chemotherapy agent discovery and design.
MOLECULAR ONCOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Alex J. Lee, Melissa M. Cadelis, Sang H. Kim, Simon Swift, Brent R. Copp, Silas G. Villas-Boas
Review
Infectious Diseases
Melissa M. Cadelis, Brent R. Copp, Siouxsie Wiles
Article
Biochemistry & Molecular Biology
Melissa M. Cadelis, Soeren Geese, Benedict B. Uy, Daniel R. Mulholland, Shara J. van de Pas, Alex Grey, Bevan S. Weir, Brent R. Copp, Siouxsie Wiles
Summary: Antimicrobial bioassay-guided fractionation of the endophytic fungi Neofusicoccum australe resulted in the isolation of a new unsymmetrical naphthoquinone dimer, neofusnaphthoquinone B (1), along with four known natural products. The antimicrobial activity of all the compounds was investigated, with compound 1 showing moderate activity against methicillin-resistant Staphylococcus aureus (MRSA) at a minimum inhibitory concentration of 16 μg/mL.
Article
Biochemistry & Molecular Biology
Melissa M. Cadelis, Hugo Gordon, Alex Grey, Soeren Geese, Daniel R. Mulholland, Bevan S. Weir, Brent R. Copp, Siouxsie Wiles
Summary: Fungi are a valuable source of bioactive natural products, and a recent study on Neodidymelliopsis sp. led to the discovery of several new compounds, including a polyketide that is sensitive to environmental conditions. Additionally, it was confirmed that pachybasin is biosynthesized through the acetate polyketide pathway.
Article
Chemistry, Organic
Quan T. Khong, Donghao Li, Brice A. P. Wilson, Kalina Ranguelova, Masoumeh Dalilian, Emily A. Smith, Antony Wamiru, Ekaterina I. Goncharova, Tanja Grkovic, Donna Voeller, Stanley Lipkowitz, Martin J. Schnermann, Barry R. O'Keefe, Lin Du
Summary: A new dimeric alkaloid, Plakoramine A, was discovered from a marine sponge. It showed potent inhibition of ubiquitin ligase activities. The study also revealed a previously undescribed route to form this compound through photochemical conversion.
Article
Chemistry, Multidisciplinary
Jason R. Evans, Rhone K. Akee, Shaurya Chanana, Grant D. McConachie, Christopher C. Thornburg, Tanja Grkovic, Barry R. O'Keefe
Summary: The National Cancer Institute (NCI) has launched a new initiative, the Program for Natural Product Discovery, to develop new technologies for drug discovery based on natural products. In this study, we developed a bioinformatics platform using neural network-based algorithms to visualize and analyze high-throughput screening data from NCI's 60 human tumor cell anticancer drug screen. Our results demonstrate the platform's capability to group biological profiles of the NCI-60 based on similar chemical and taxonomic patterns, providing a user-friendly interface for researchers.
Review
Biochemistry & Molecular Biology
Brice A. P. Wilson, Christopher C. Thornburg, Curtis J. Henrich, Tanja Grkovic, Barry R. O'Keefe
NATURAL PRODUCT REPORTS
(2020)
Review
Biochemistry & Molecular Biology
Anthony R. Carroll, Brent R. Copp, Rohan A. Davis, Robert A. Keyzers, Michele R. Prinsep
NATURAL PRODUCT REPORTS
(2020)
