Article
Plant Sciences
Mengsha Wei, Liping Huang, Qin Li, Xinyi Qiao, Ziming Zhao, Jie Yin, Aimin Fu, Jieru Guo, Xincai Hao, Lianghu Gu, Jianping Wang, Chunmei Chen, Hucheng Zhu, Yonghui Zhang
Summary: Five aromatic ergosterols with unique ring systems, named spectasterols A-E (1-5), were isolated from Aspergillus spectabilis. Compound 3 demonstrated cytotoxic activity and anti-inflammatory effects, inducing cell cycle arrest and apoptosis in HL60 cells, and inhibiting COX-2 levels and NF-kappa B p65 nuclear translocation.
JOURNAL OF NATURAL PRODUCTS
(2023)
Article
Chemistry, Inorganic & Nuclear
Yuanbin She, Kewei Xu, Xiaoli Fang, Yun-Fang Yang, Weiwei Lou, Ying Hu, Qisheng Zhang, Guijie Li
Summary: A series of novel tetradentate Pt(II) and Pd(II) complexes containing fused 6/6/6 or 6/6/5 metallocycles with ACzCz-based ligands were developed, showing different electrochemical and photophysical properties influenced by both ligand structures and central metal ions. Pt(II) complexes exhibit mixed metal-to-ligand charge transfer and ligand-centered characters, while Pd(II) complexes have decreased MLCT characters and enhanced LC compositions. Additionally, Pd(ACzCz-1) exhibits ultralong low-temperature phosphorescence, and Pt(ACzCz-2)-based green OLED shows promising performance.
INORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Xue-Qing Zhang, Zhen-Hong Lu, Guan-Mei Tang, Li-Ping Duan, Zhao-Hang Wang, Zhi-Yong Guo, Peter Proksch
Summary: In this study, seven novel isocoumarins, prunolactones A-G (1-7), with an unusual spiropentacyclic skeleton were isolated from the endophytic fungus Phomopsis prunorum. The structures and absolute configurations of these compounds were determined through spectroscopic analysis, X-ray diffraction, and ECD calculations. Additionally, three of these compounds showed significant in vivo proangiogenic activity in transgenic zebrafish.
BIOORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Dan Xiao, Xin Zhao, Jiang Lei, Mengqian Zhu, Liang Xu
Summary: A new synthesis method has been developed to form the bridged [6-6-6] ABE tricyclic ring analogues of methyllycaconitine with C-1 oxygenated substituents, using efficient aza-annulation of beta-enamino ketone followed by a facile decarboxylation to form BE rings. Subsequent elaboration to form the A ring was achieved by a transannular acyl radical cyclization with concomitant equipment of the key C-1 oxygen functionality.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Organic
Juan Hua, Yan-Chun Liu, Shi-Hong Luo, Yan Liu, Chao-Jiang Xiao, Xiao-Nian Li, Sheng-Hong Li
Summary: Two novel triterpenoid saponins, colqueleganoids A and B, were isolated from the root of Colquhounia elegans, featuring a unique carbon skeleton colquelegane with methyl-30. These compounds were found to significantly enhance TNF-alpha production and IL-6 production in RAW264.7 macrophages stimulated with lipopolysaccharide, suggesting their potential as immunostimulants for immunotherapy and vaccination.
Article
Chemistry, Organic
Seulah Lee, Chung Sub Kim, Jae Sik Yu, Heesun Kang, Min Jeong Yoo, Ui Joung Youn, Rhim Ryoo, Han Yong Bae, Ki Hyun Kim
Summary: A new ergosterol derivative, ergopyrone, along with five related metabolites, was isolated and characterized from a mushroom. The unprecedented hexacyclic 6/5/6/6/6/5 skeleton of ergopyrone suggests a unique biosynthetic pathway. Compound 6 was found to significantly regulate lipid metabolism through mRNA expression modulation.
Article
Chemistry, Inorganic & Nuclear
Yulu Sun, Feng Zhan, Disheng Huang, Xia Wang, Lijie Dou, Kewei Xu, Yun-Fang Yang, Guijie Li, Yuanbin She
Summary: A series of novel tetradentate 6/6/6 Pt(II) complexes containing an 8-phenylquinoline-benzo[d]imidazole-carbazole ligand were synthesized; their large π-conjugation allowed them to exhibit high quantum efficiencies (1.2-1.5%) in dichloromethane at room temperature. Experimental and theoretical studies showed that modification of the quinoline moieties of the Pt(II) complexes could tune their electrochemical, photophysical, and excited-state properties. This work provides valuable reference for the design and development of monomer NIR emitters.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Hui Zheng, Xiaoqin Wang, Xiao Li, Chan Wang, Junshen Liu
Summary: A trinuclear compound [Fe-3(4-C(3)trz)(6)(H2O)(6)] (ClO4)(6) (1) was synthesized by reacting iron (II) salts with 4-cyclopropl-1,2,4-triazole. Single-crystal X-ray diffraction showed that compound 1 crystallizes in the orthorhombic space group R (3) over bar, and temperature-dependent magnetic susceptibility and heat capacity tests revealed the presence of spin transitions.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Zhan-Peng Ge, Yao-Yue Fan, Wen-De Deng, Cheng-Yu Zheng, Ting Li, Jian-Min Yue
Summary: Cephalodiones A-D (1-4), the first known examples of C-19-norditerpenoid dimers, were isolated and characterized from a Cephalotaxus plant. These compounds share a unique tricyclo[6.4.1.1(2,7)]tetradeca-3,5,9,11-tetraene-13,14-dione core and show significant inhibition on Th17 cell differentiation. The biosynthesis of compounds 1-4 involves the [6+6]-cycloaddition of two identical C-19-norditerpenoid troponoids, as validated by semisyntheses of dimers 2-4.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Cheng-Yo Ho, Po-Hsun Chen, Ching-Feng Yang, U-Ser Jeng, An-Chung Su
Summary: The Brill transition in nylon 6/6 is not a direct solid-solid transformation, but a continuous melting-recrystallization process due to the presence of a mesomorphic intermediate phase. The existence of this mesomorphic phase has implications for addressing the mechanical properties of nylons near the Brill transition temperature both during cooling and heating processes.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Chemistry, Organic
Aobha Hickey, Julia Merz, Hamad H. Al Mamari, Alexandra Friedrich, Todd B. Marder, Gerard P. McGlacken
Summary: The Ir-catalyzed C-H borylation of fluoroquinolines has been achieved, leading to the formation of quinoline boronic esters that can undergo important transformations relevant to medicinal chemistry. The strategic choice of the substituent at C4 on the quinoline enables the unmasking of fluoroquinolone, which serves as the core structure for many antibiotics.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Xingrong Peng, Rongcan Luo, Xiaoqian Ran, Yarong Guo, Yong-Gang Yao, Minghua Qiu
Summary: Ganoapplins A and B (1 and 2) with a 6/6/6/5/6-fused pentacyclic skeleton containing an aromatic E ring were isolated from Ganoderma applanatum. Their structures were determined through spectroscopic analyses, quantum chemical calculations, and the study of their roles in autophagy activation. Cellular assays demonstrated that 1 and 2 can inhibit tau pathology by inducing autophagy, indicating their potential as a treatment for Alzheimer's disease (AD).
BIOORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Gurupada Hazra, Gitanjali Mishra, Rambabu Dandela, Barla Thirupathi
Summary: The dibenzobicyclo[3.2.1]octadienone scaffold, found in various compounds such as naphthocyclinones, engelharquinones, and rubialatin A, has been successfully synthesized using a mild transition metal-free aryne insertion reaction. The methodology has been applied to the synthesis of the 6/6/5/6/6 scaffold of rubialatin A. H-1 NMR experimental studies confirm the reaction mechanism involves the formation of a benzocyclobutane followed by a 7-member carbocycle ring.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Zhi-Hui He, Chun-Lan Xie, You-Jia Hao, Lin Xu, Chao-Feng Wang, Man-Yi Hu, Shu-Jin Li, Tian-Hua Zhong, Xian-Wen Yang
Summary: A unique C30 steroid, solitumergosterol A, was isolated from the deep-sea-derived fungus Penicillium solitum. Its planar structure and relative configuration were determined through extensive NMR and mass spectrometry analysis, while the absolute configuration was confirmed by comparing experimental and theoretical ECD spectra. This compound exhibited weak in vitro anti-tumor activity against MB231 cells through a RXR alpha-dependent mechanism.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Hang Li, Si Shu, John A. Kalaitzis, Zhuo Shang, Daniel Vuong, Andrew Crombie, Ernest Lacey, Andrew M. Piggott, Yit-Heng Chooi
Summary: Activation of a cryptic polyketide synthase gene cluster hkn from Aspergillus hancockii by overexpressing the gene-cluster-specific transcription factor HknR led to the discovery of a novel polycyclic metabolite named hancockinone A. This compound, featuring a unique prenylated tetracyclic skeleton, exhibits moderate antibacterial activity and the role of cytochrome P450 HknE in constructing the five-membered ring in hancockinone A has been confirmed through heterologous expression, substrate feeding, and in vitro assays.