Article
Chemistry, Organic
Taewan Kim, Samhwan Kim, Garam Chung, Kiyoung Park, Sunkyu Han
Summary: The determination of complex natural product structures involves establishing atom connectivity using NMR data and assigning stereochemistry, which remains challenging. This study utilizes TDDFT computations to analyze ECD spectra and elucidate the structure of suffruticosine. By comparing TDDFT-assisted ECD assignments with experimental ECD spectra, the true structure of suffruticosine is found to be the enantiomer of the initially reported structure.
ORGANIC CHEMISTRY FRONTIERS
(2023)
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
Physics, Applied
Alexandre Belsley, Jonathan C. F. Matthews
Summary: The concentration of a chiral solution is a key parameter that can be estimated to high precision using circular birefringence or circular dichroism. By using the quantum Fisher information formalism, researchers have found that bright-polarization squeezed state probes provide a quantum advantage over classical strategies, resulting in four-fold precision enhancement.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Analytical
Vinayaka Harshothama Damle, Hagit Aviv, Yaakov R. Tischler
Summary: This study successfully identifies enantiomers using low-frequency Raman spectroscopy. By comparing the spectral intensity on different polarization planes, chiral and nonchiral molecules can be distinguished. This technique is of great importance for the pharmaceutical industry.
ANALYTICAL CHEMISTRY
(2022)
Article
Plant Sciences
Chuan Li, Yang Xu, Peinan Fu, Liangdong Guo, Yongsheng Che
Summary: Four new diphenyl ether derivatives were isolated from cultures of the plant endophytic fungus, and their structures were determined by NMR experiments. Two of the compounds exhibited modest cytotoxicity against HepG2 cells.
JOURNAL OF NATURAL PRODUCTS
(2022)
Article
Plant Sciences
Peinan Fu, Yang Zhang, Chenyin Wang, Shuyi Si, Xingzhong Liu, Yongsheng Che
Summary: Four new 9,11-secosteroid-derived gamma-lactones, called Altersteroids A-D (1-4), were isolated from a culture of the ascomycete fungus Alternaria sp. Their structures were determined primarily by NMR experiments. The absolute configuration of compound 1 was established through X-ray crystallographic analysis, while the configurations of compounds 2-4 were assigned using quantum-chemical calculations. These compounds feature a gamma-lactone moiety fused to the steroid D ring at C13/C-14. Compound 3 exhibited moderate cytotoxicity against four tumor cell lines and induced apoptosis in A549 cells. Notably, compound 3 showed equipotent activity against cisplatin-sensitive and cisplatin-resistant MB49 cells, with an IC50 value of 12.7 μM.
JOURNAL OF NATURAL PRODUCTS
(2023)
Article
Biochemistry & Molecular Biology
Marcin Gorecki, Jadwiga Frelek
Summary: The main objective of this paper is to demonstrate the importance of considering various factors and using chiroptical methods in solving stereochemical problems. Based on the study of different models, the paper presents a comprehensive analysis of circular dichroism (CD) spectra to confidently determine the stereochemistry of beta-lactam derivatives. The choice of chiroptical methods depends on the specific case and structural features.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Koichiro Omasa, Masato Ito, Yuji Kubo
Summary: The newly synthesized quaterphenyl-5-carbaldehyde 1 with metal ion coordination ability was applied for chiral analyte-binding and chiroptical sensing, demonstrating its potential as a probe for detecting chiral analytes and responding to changes in concentration with fluorescence.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Giulia Marsico, Umberto Calice, Patrizia Scafato, Sandra Belviso, Antonio Evidente, Stefano Superchi
Summary: This study compares the computational analysis of electronic circular dichroism (ECD) spectra and the application of biphenyl chiroptical probes in the absolute configuration assignment. The results highlight the usefulness of biphenyl probes in the determination of conformationally mobile and ECD silent compounds, which cannot be handled by computational analysis methods.
Article
Multidisciplinary Sciences
Dawrin Pech-Puch, Pedro Joseph-Nathan, Eleuterio Burgueno-Tapia, Carlos Gonzalez-Salas, Diana Martinez-Matamoros, David M. Pereira, Renato B. Pereira, Carlos Jimenez, Jaime Rodriguez
Summary: This study isolated six new briarane diterpenoids from the gorgonian coral collected from the Mexican Caribbean Sea and elucidated their structures using NMR and MS measurements. The structure of briarane B-3 was confirmed, and the use of VCD in briarane diterpenoids was reported for the first time. Biological evaluation showed moderate anti-inflammatory activity for some compounds but no other significant activities were observed.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Analytical
Mohamed Nadjib Rebizi, Khaled Sekkoum, Antonella Petri, Gennaro Pescitelli, Nasser Belboukhari
Summary: Four racemic iminoflavan derivatives were synthesized by simple condensation at the C-4 position of flavanone. The compounds were characterized using UV-visible, infrared, and NMR spectroscopic techniques. Chiral chromatography and electronic circular dichroism detector were used to determine the absolute configuration of each enantiomer and establish the elution order.
JOURNAL OF SEPARATION SCIENCE
(2021)
Article
Plant Sciences
Vimal K. Sharma, Radhakrishnan Srivedavyasasri, Zulfiqar Ali, Jordan K. Zjawiony, Samir A. Ross, Daneel Ferreira, Nicole Ashpole, Ikhlas A. Khan
Summary: Mirabilis multiflora is a hallucinogen traditionally consumed by the Hopi Indians. The root extract yielded new and known compounds, some of which showed high affinity for opioid and cannabinoid receptors.
JOURNAL OF NATURAL PRODUCTS
(2021)
Article
Chemistry, Multidisciplinary
Weihong Wang, Chanhyeok Jeong, Yongjin Lee, Chanyoon Park, Eunseok Oh, Kyu-Hyung Park, Youbin Cho, Eunmo Kang, Jun Lee, Yeon-Jin Cho, Jung Han Yoon Park, Young-Jin Son, Ki Won Lee, Heonjoong Kang
Summary: This study isolated and identified chemical compounds from Ulmus macrocarpa Hance bark that have inhibitory activity on osteoclast differentiation. The compounds were elucidated using spectroscopic analyses and were found to downregulate NFATc1, a master regulator of osteoclast formation. This is the first report of their inhibitory activities on RANKL-induced osteoclast differentiation in murine bone marrow-derived macrophages.
Article
Chemistry, Multidisciplinary
Alessia Rosetti, Giulio Apolloni, Claudio Villani, Tiziana Benincori, Roberto Cirilli
Summary: In this study, a new atropisomeric C-2-symmetry chiral monomer based on the 3,3'-bithiophene core was synthesized and resolved by high-performance liquid chromatography (HPLC). The enantioseparation was optimized using a cellulose-type Chiralpak IB-3 column and a specific mobile phase. Scale-up of the enantioseparation process led to notable deformations in the HPLC profile, which were investigated and addressed. The optimized chromatographic conditions were then used to obtain milligram amounts of enantiopure sample for further characterization studies.
APPLIED SCIENCES-BASEL
(2023)
Article
Biochemistry & Molecular Biology
Assunta Summa, Patrizia Scafato, Sandra Belviso, Guglielmo Monaco, Riccardo Zanasi, Giovanna Longhi, Sergio Abbate, Stefano Superchi
Summary: A novel alpha-tetrazole-substituted 1,1'-binaphthylazepine chiral catalyst has been synthesized and its absolute configuration has been determined using DFT computational analysis of the VCD spectrum. The catalyst showed low enantioselectivity in the synthesis of chiral flavanones.