Article
Chemistry, Multidisciplinary
Yanyan Liao, Shunmin Zhang, Xuefeng Jiang
Summary: Thioamide peptides were synthesized in a one-pot process by linking natural amino acids in the presence of thiolphosphonate and trichlorosilane, with minimal racemization. Experimental and computational studies showed that trichlorosilane enables the activation of carboxylic acids and coupling with thiolphosphonate to obtain the intermediate S-acyl dithiophosphate. Silyl-activated quadrangular metathesis transition states resulted in the formation of thioamide peptides.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Analytical
Yang Zhang, Yuxi Huang, Jingjing Fan, Meng Zhang, Aobulikasimu Hasan, Yang Yi, Rong Yu, Xujie Zhou, Min Ye, Xue Qiao
Summary: Accurate metabolite characterization is crucial for targeted metabolomics. However, the limited library of metabolites, especially downstream conjugates, and the time-consuming synthesis of each compound pose challenges. In this study, a green and smart strategy was developed to expand the scope of targeted metabolomics. By synthesizing reference standards in a one-pot microscale reaction, we tailored the analytical method and studied a group of new metabolites, bile acid-amino acid conjugates (BA-AAs). Additionally, we established an ultra-high-performance liquid chromatography /Orbitrap-MS method to profile bile acid derivatives comprehensively. The method was successfully applied to mice with inflammatory bowel disease (IBD) and helped discover rare BA-AAs accumulating in the small intestine and liver. These findings contribute to the understanding of IBD development. The study demonstrates a viable approach for broad-spectrum targeted metabolomics of bile acids.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Organic
Zewei Qi, Honglin Shang, Bingliang Ji, Yanwei Shi, Tongtong Ye, Yiming Li, Jinchong Xiao
Summary: This study strategically prepared two pairs of isomers of heptagon-embedded helical arenes (3/6 and 10/13) and identified the molecular structures of 3 and 13 using single crystal X-ray diffraction analysis. The physical properties of 3, 6, 10, and 13 were comparatively investigated, and the results indicate that the optical enantiomers of 13 obtained from HPLC exhibit promising chiroptical properties.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Food Science & Technology
Barbara Prandi, Martina Di Massimo, Tullia Tedeschi, Laura Rodriguez-Turienzo, Oscar Rodriguez
Summary: The demand for proteins is increasing, calling for green extraction technologies for environmental sustainability. Recovering protein from agri-food by-products, including coffee by-products, is important for circular economy. This study applied innovative extraction technologies to extract protein from non-compliant coffee green beans, and found that ultrasound-assisted extraction had minor impact on protein quality due to refrigeration, while microwave-assisted extraction caused degradation due to high temperatures. Strict temperature control is required during alkaline extraction to preserve protein quality.
FOOD AND BIOPROCESS TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Yong Zuo, Xiaoning Liu, Enguang Fu, Shaodong Zhang
Summary: Without chiral induction, the emergence of homochirality from achiral molecules is accidental due to the ambiguity of the rationale. In this study, we propose a plausible solution: by forming a pair of interconverting cage conformers from achiral precursors, each conformer self-sorts into a homochiral crystal when their interconversion is hindered by intramolecular H-bonding. This self-assembly process is driven by a helical network of multivalent intermolecular interactions. Our findings provide insights for the rational design of homochirality emergence.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Analytical
Makoto Ozaki, Motoshi Shimotsuma, Takefumi Kuranaga, Hideaki Kakeya, Tsunehisa Hirose
Summary: We developed a system to separate and identify racemised and isomerised Asp residues in A beta using a chiral resolution labeling reagent, d-FDLDA. The labeled residues were separated and identified using LC-MS under simple gradient conditions. The labeled A beta fragments remained stable and did not aggregate for at least 1 week at 4 degrees C.
Article
Chemistry, Organic
Keiko Hojo, Yuki Manabe, Tomoyo Uda, Yuko Tsuda
Summary: The development of protecting group-free synthesis in peptide synthesis has shown potential in reducing side reactions and offering a greener approach to peptide synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Kosho Makino, Kumi Tozawa, Yuki Tanaka, Akiko Inagaki, Hidetsugu Tabata, Tetsuta Oshitari, Hideaki Natsugari, Hideyo Takahashi
Summary: The study revealed that the photoracemization reaction of chiral alkyl aryl sulfoxides is extremely fast and influenced by various substitution patterns. However, chiral sulfoxides with easily oxidizable functional groups are not suitable for this photo-isomerization.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Rajesh Mannancherry, Tomas Solomek, Diana Cavalli, Juraj Malincik, Daniel Haussinger, Alessandro Prescimone, Marcel Mayor
Summary: The study involves the synthesis and characterization of two sulfonyl-bridged Gelander helices obtained from oxidation of sulfide bridged precursors. NMR, mass spectrometry, optical spectroscopy, and X-ray diffraction were used for full characterization. The results show a significant increase in enantiomerization barrier for 1a upon transformation from sulfide to sulfone, challenging previous assumptions about the correlation between bridging structures and enantiomerization Gibbs free energy.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Agricultural Engineering
Wenyu Zhang, Shuguang Xu, Xiaoyan Wang, Yancheng Liu, Ruofeng Yang, Jianmei Li, Changwei Hu
Summary: Biomass valorization towards chiral lactic acid (LaA) production through chemocatalysis is important, but faces the obstacle of low enantioselectivity. Researchers found that alkaline earth metal oxide can assist in the configuration inversion of pure lactic acid enantiomer, a process previously reported only in enzymatic catalysis. The proposed racemization mechanism involves keto-enol tautomerization, leading to the production of racemic LaA.
INDUSTRIAL CROPS AND PRODUCTS
(2023)
Article
Computer Science, Information Systems
Ye-Chan Choi, Sheriff Murtala, Beom-Chae Jeong, Kang-Sun Choi
Summary: In this paper, a machine learning-based method is proposed to extract reliefs from rough stele surfaces. By utilizing various features to select relief segments from candidate segments, the proposed method successfully recognizes the inscription on the Musul-ojakbi stele made during the Silla Dynasty in AD 578. The experimental results show that the proposed method outperforms conventional methods in terms of F1-score and SIRI, achieving a higher performance in extracting reliefs from rough stele data.
Article
Multidisciplinary Sciences
Zheng Gan, Vijayan Gangadharan, Sheng Liu, Christoph Koerber, Linette Liqi Tan, Han Li, Manfred Josef Oswald, Juhyun Kang, Jesus Martin-Cortecero, Deepitha Maennich, Alexander Groh, Thomas Kuner, Sebastian Wieland, Rohini Kuner
Summary: The primary motor cortex (M1) regulates the sensory and aversive-emotional components of neuropathic pain through distinct pathways, offering potential for pain relief.
Article
Chemistry, Organic
Masato Hisada, Daiki Shimizu, Kenji Matsuda
Summary: This article describes the synthesis and characterization of doubly diphenylene-fused 2,3,6,7-tetraazanaphthalene 1. X-ray diffraction analysis showed a highly twisted structure of 1, with a large degree of twisting. In the crystal, the molecules of 1 formed an orthogonal one-dimensional column with pi-stacking of diphenylene moieties and exhibited a rare example of lone-pair/pi* interaction in a supramolecular assembly.
Article
Chemistry, Organic
Yves Yeboue, Marion Jean, Gilles Subra, Jean Martinez, Frederic Lamaty, Thomas-Xavier Metro
Summary: Peptides can be produced in high yields with minimal epimerization through mechanochemical coupling of peptide fragments containing highly epimerization-prone and/or highly hindered amino acids at the C-terminus, with ball milling identified as the key element enabling such results.
Article
Cell Biology
Xiang-Jia Zhu, Ke-Ke Zhang, Wen-Wen He, Jiao Qi, Yi Lu
Summary: Compared to age-related cataracts, diabetic cataracts exhibit a distinct pattern of protein racemization, which may influence the progression of the disease over time.