Synthesis, Antibacterial Activity, and Structure–Activity Relationship of Fusaric Acid Analogs

Qing-Yan Zhang,Yang Fei‐Yu,Liao Shang‐Gao,Wang Bing,Li Rui,Dong Yong‐Xi,Zhou Meng,Yang Yuan‐Yong,Xu Guo‐Bo 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.4

Forty-one fusaric acid analogs possessing a pyridine carboxylic acid scaffold have been synthesized. The antibacterial activity results demonstrated that compounds 5b, 7b, 8c, and 8d displayed strong antibacterial activities against Staphylococcus aureus ATCC25923 with minimum inhibitory concentrations (MICs) of 4–16 μg/mL. Molecular docking study indicated that these compounds have strong hydrogen-bonding interactions with TyrRS. Meanwhile, 8c and 8d showed promising antibacterial activities against Pseudomonas aeruginosa ATCC9027. Compound 4 exhibited pronounced antibacterial activities against a clinically isolated multidrug-resistant strain of Escherichia coli (MIC: 64 μg/mL as compared 64 μg/mL of levofloxacin and 1024 μg/mL of ceftriaxone sodium). Moreover, compound 17e displayed strong synergistic antibacterial effect with levofloxacin against the multidrug-resistant strain, decreasing the MIC value of levofloxacin to 1/16 of its original MIC. No obvious cytotoxic activities against LO2 was observed for compounds 4, 5b, 8c, 8d, 17d, and 17e at 50 μM. The preliminary structure–activity relationship of fusaric acid analogs was also discussed.

Contact toxicity and transcriptomic analysis of terpinen-4-ol exposure in Tribolium castaneum

Shan-shan Gao,Yong-lei Zhang,Kun-peng Zhang,Wang Xing-yun,Qing-bo Tang,Yuan-chen Zhang 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

The terpene, terpinen-4-ol (T4ol), exhibits contact toxicity in Tribolium castaneum. However, the molecular mechanisms underlying this toxicity have not been elucidated. This study examined changes in the expression of four classic enzymes after exposure of T. castaneum to T4ol. Acetylcholinesterase and glutathione S-transferase activities were markedly inhibited after exposure to T4ol, while that of the detoxifying enzyme cytochrome oxidase P450 increased markedly. Carboxylesterase activity did not show significant changes. Furthermore, RNA sequencing revealed 260 differentially expressed genes (DEG) between the T4ol-treated and control samples, and qRT-PCR was used to validate the RNA-Seq data. The Gene Ontology analysis classified the DEGs into 36 functional groups, including the immune system processes, response to stimulus, and developmental processes. T4ol altered the response to stimulus and the immune system process of beetles by inducing the expression of the genes Stabilin-1, Attacin 1, and Defensin 1. Furthermore, the DEGs receptor tyrosine kinase Torso-like protein (RTKTsl), Frizzled 4 (Fz4), Protein Wnt-5b, Ecdysone-induced protein 78C (E78), Zinc finger protein GLIS1 (ZFPGLIS1) were classified as participating in beetle development, and Fz4 and Protein Wnt-5b also mapped to the Wnt signaling pathway. This indicated that pathways associated with development are inhibited after exposure to T4ol. T4ol also induced CYP9Z6/GSTs7 overexpression, and RNAi targeting these genes significantly increased larvae mortality on T4ol exposure, supporting the participation of CYP9Z6/GSTs7 in the response to T4ol in T. castaneum. The results of this study will facilitate understanding of the toxic mechanisms of T4ol and provide a basis for controlling the pests of stored products.

Genetic variation and phylogenetic relationships of the ectomycorrhizal Floccularia luteovirens on the Qinghai-Tibet Plateau

Rui Xing,Qing-bo Gao,Fa-qi Zhang,Peng-cheng Fu,Jiu-li Wang,Hui-ying Yan,Shi-long-Chen 한국미생물학회 2017 The journal of microbiology Vol.55 No.8

Floccularia luteovirens, as an ectomycorrhizal fungus, is widely distributed in the Qinghai-Tibet Plateau. As an edible fungus, it is famous for its unique flavor. Former studies mainly focus on the chemical composition and genetic structure of this species. However, the phylogenetic relationship between genotypes remains unknown. In this study, the genetic variation and phylogenetic relationship between the genotypes of F. luteovirens in Qinghai-Tibet Plateau was estimated through the analysis on two protein-coding genes (rpb1 and ef-1α) from 398 individuals collected from 24 wild populations. The sample covered the entire range of this species during all the growth seasons from 2011 to 2015. 13 genotypes were detected and moderate genetic diversity was revealed. Based on the results of network analysis, the maximum likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) analyses, the genotypes H-1, H-4, H-6, H-8, H-10, and H-11 were grouped into one clade. Additionally, a relatively higher genotype diversity (average h value is 0.722) and unique genotypes in the northeast edge of Qinghai- Tibet plateau have been found, combined with the results of mismatch analysis and neutrality tests indicated that Southeast Qinghai-Tibet plateau was a refuge for F. luteovirens during the historical geological or climatic events (uplifting of the Qinghai-Tibet Plateau or Last Glacial Maximum). Furthermore, the present distribution of the species on the Qinghai-Tibet plateau has resulted from the recent population expansion. Our findings provide a foundation for the future study of the evolutionary history and the speciation of this species.

Theoretical and experimental study of robustness based design of single-layer grid structures

Hui Wu,Cheng Zhang,Bo-qing Gao,Jun Ye 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.1

Structural robustness refers to the ability of a structure to avoid disproportionate consequences to the original cause. Currently attentions focus on the concepts of structural robustness, and discussions onmethods of robustness based structural design are rare. Firstly, taking basis in robust H∞ control theory,structural robustness is assessed by H∞ norm of the system transfer function. Then using the SIMP material model, robustness based design of grid structures is formulated as a continuum topology optimization problem, where the relative density of each element and structural robustness are considered as the design variable and the optimization objective respectively. Generalized elitist genetic algorithm is used to solve the optimization problem. As examples, robustness configurations of plane stress model and the rectangular hyperbolic shell model were obtained by robustness based structural design. Finally, two models of single-layer grid structures were designed by conventional and robustness based method respectively. Different interference scenarios were simulated by static and impact experiments, and robustness of the models were analyzed and compared. The results show that the H∞ structural robustness index can indicate whether the structural response is proportional to the original cause. Robustness based structural design improves structural robustness effectively, and it can provide a conceptual design in the initial stage of structural design.

Theoretical and experimental study of robustness based design of single-layer grid structures

Wu, Hui,Zhang, Cheng,Gao, Bo-Qing,Ye, Jun Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.1

Structural robustness refers to the ability of a structure to avoid disproportionate consequences to the original cause. Currently attentions focus on the concepts of structural robustness, and discussions on methods of robustness based structural design are rare. Firstly, taking basis in robust $H_{\infty}$ control theory, structural robustness is assessed by $H_{\infty}$ norm of the system transfer function. Then using the SIMP material model, robustness based design of grid structures is formulated as a continuum topology optimization problem, where the relative density of each element and structural robustness are considered as the design variable and the optimization objective respectively. Generalized elitist genetic algorithm is used to solve the optimization problem. As examples, robustness configurations of plane stress model and the rectangular hyperbolic shell model were obtained by robustness based structural design. Finally, two models of single-layer grid structures were designed by conventional and robustness based method respectively. Different interference scenarios were simulated by static and impact experiments, and robustness of the models were analyzed and compared. The results show that the $H_{\infty}$ structural robustness index can indicate whether the structural response is proportional to the original cause. Robustness based structural design improves structural robustness effectively, and it can provide a conceptual design in the initial stage of structural design.

Aldehyde Volatiles Emitted in Succession from Mechanically Damaged Leaves of Poplar Cuttings

( Zeng Hui Hu ),( Ying Bai Shen ),( You Qing Luo ),( Fan Yi Shen ),( Hai Bo Gao ),( Rong Fu Gao ) 한국식물학회 2008 Journal of Plant Biology Vol.51 No.4

Plant aldehydes are volatiles necessary to defenses against environmental stress. To explore their emissions in response to wounding, we performed gas chromatography-mass spectrometry (GC-MS) on cuttings from poplar (Populus simonii×P. pyramidalis ``Opera 8277``) that were mechanically damaged to mimic herbivore attack. We detected 16 aldehydes, including 11 linear saturated aldehydes, 3 linear unsaturated aldehydes, and 2 non-linear aldehydes. Emissions of these aldehydes were clearly enhanced by such treatment, and exhibited a similar pattern of change, i.e., increasing in the first 2 h, then sharply decreasing before rising again at about 12 h. Two release peaks for these aldehydes were observed. Therefore, we propose two pathways for the mediation of aldehyde emissions following damage. The first peak may represent emissions from plant storage pools, whereas the second release peak might result from greater formation de novo through an activated synthesis pathway.

Follow-Up of 58 Traumatic Carotid-Cavernous Fistulas after Endovascular Detachable-Balloon Embolization at a Single Center

Xiao-Quan Xu,Sheng Liu,Qing-Quan Zu,Lin-Bo Zhao,Jin-Guo Xia,Chun-Gao Zhou,Wei-Zhong Zhou,Hai-Bin Shi 대한신경과학회 2013 Journal of Clinical Neurology Vol.9 No.2

Background and Purpose This study evaluated the clinical value of detachable-balloon embolization for traumatic carotid-cavernous fistula (TCCF), focusing on the frequency, risk factors, and retreatment of recurrence. Methods Fifty-eight patients with TCCF underwent transarterial detachable-balloon embolization between October 2004 and March 2011. The clinical follow-up was performed every 3months until up to 3 years postprocedure. Each patient was placed in either the recurrence group or the nonrecurrence group according to whether a recurrence developed after the first procedure. The relevant factors including gender, fistula location, interval between trauma and the interventional procedure, blood flow in the carotid-cavernous fistula, number of balloons, and whether the internal carotid artery (ICA) was sacrificed were evaluated. Results All 58 TCCFs were successfully treated with transarterial balloon embolization, including 7 patients with ICA sacrifice. Recurrent fistulas occurred in seven patients during the follow-up period. Univariate analysis indicated that the interval between trauma and the interventional procedure (p=0.006) might be the main factor related to the recurrence of TCCF. The second treatments involved ICA sacrifice in two patients, fistula embolization with balloons in four patients, and placement of a covered stent in one patient. Conclusions Detachable balloons can still serve as the first-line treatment for TCCFs and recurrent TCCFs despite having a nonnegligible recurrence rate. Shortening the interval between trauma and the interventional procedure may reduce the risk of recurrence.

Vibration control of a stay cable with a rotary electromagnetic inertial mass damper

Zhi Hao Wang,Yan Wei Xu,Hui Gao,Zheng Qing Chen,Kai Xu,Shun Bo Zhao 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.23 No.6

Passive control may not provide enough damping for a stay cable since the control devices are often restricted to a low location level. In order to enhance control performance of conventional passive dampers, a new type of damper integrated with a rotary electromagnetic damper providing variable damping force and a flywheel serving as an inertial mass, called the rotary electromagnetic inertial mass damper (REIMD), is presented for suppressing the cable vibrations in this paper. The mechanical model of the REIMD is theoretically derived according to generation mechanisms of the damping force and the inertial force, and further validated by performance tests. General dynamic characteristics of an idealized taut cable with a REIMD installed close to the cable end are theoretically investigated, and parametric analysis are then conducted to investigate the effects of inertial mass and damping coefficient on vibration control performance. Finally, vibration control tests on a scaled cable model with a REIMD are performed to further verify mitigation performance through the first two modal additional damping ratios of the cable. Both the theoretical and experimental results show that control performance of the cable with the REIMD are much better than those of conventional passive viscous dampers, which mainly attributes to the increment of the damper displacement due to the inertial mass induced negative stiffness effects of the REIMD. Moreover, it is concluded that both inertial mass and damping coefficient of an optimum REIMD will decrease with the increase of the mode order of the cable, and oversize inertial mass may lead to negative effect on the control performance.

Knockdown of HMGN5 Expression by RNA Interference Induces Cell Cycle Arrest in Human Lung Cancer Cells

Chen, Peng,Wang, Xiu-Li,Ma, Zhong-Sen,Xu, Zhong,Jia, Bo,Ren, Jin,Hu, Yu-Xin,Zhang, Qing-Hua,Ma, Tian-Gang,Yan, Bing-Di,Yan, Qing-Zhu,Li, Yan-Lei,Li, Zhen,Yu, Jin-Yan,Gao, Rong,Fan, Na,Li, Bo,Yang, Jun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

HMGN5 is a typical member of the HMGN (high mobility group nucleosome-binding protein) family which may function as a nucleosomal binding and transcriptional activating protein. Overexpression of HMGN5 has been observed in several human tumors but its role in tumorigenesis has not been fully clarified. To investigate its significance for human lung cancer progression, we successfully constructed a shRNA expression lentiviral vector in which sense and antisense sequences targeting the human HMGN5 were linked with a 9-nucleotide loop. Inhibitory effects of siRNA on endogenous HMGN5 gene expression and protein synthesis were demonstrated via real-time RT-PCR and western blotting. We found HMGN5 silencing to significantly inhibit A549 and H1299 cell proliferation assessed by MTT, BrdU incorporation and colony formation assays. Furthermore, flow cytometry analysis showed that specific knockdown of HMGN5 slowed down the cell cycle at the G0/G1 phase and decreased the populations of A549 and H1299 cells at the S and G2/M phases. Taken together, these results suggest that HMGN5 is directly involved in regulation cell proliferation in A549 and H1299 cells by influencing signaling pathways involved in cell cycle progression. Thus, our finding suggests that targeting HMGN5 may be an effective strategy for human lung cancer treatment.

Spinosin, a C-Glucosylflavone, from Zizyphus jujuba var. spinosa Ameliorates Ab1-42 Oligomer-Induced Memory Impairment in Mice

( Sang Yoon Ko ),( Hyung Eun Lee ),( Se Jin Park ),( Se Jin Jeon ),( Bo Seong Kim ),( Qing Tao Gao ),( Dae Sik Jang ),( Jong Hoon Ryu ) 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.2

Alzheimer’s disease (AD) is a neurodegenerative disorder associated with progressive memory loss and neuronal cell death. Although numerous previous studies have been focused on disease progression or reverse pathological symptoms, therapeutic strategies for AD are limited. Alternatively, the identification of traditional herbal medicines or their active compounds has received much attention. The aims of the present study were to characterize the ameliorating effects of spinosin, a C-glucosylflavone isolated from Zizyphus jujuba var. spinosa, on memory impairment or the pathological changes induced through amyloid-b1-42 oligomer (AbO) in mice. Memory impairment was induced by intracerebroventricular injection of AbO (50 μM) and spinosin (5, 10, and 20 mg/kg) was administered for 7 days. In the behavioral tasks, the subchronic administration of spinosin (20 mg/kg, p.o.) significantly ameliorated AbO-induced cognitive impairment in the passive avoidance task or the Y-maze task. To identify the effects of spinosin on the pathological changes induced through AbO, immunohistochemistry and Western blot analyses were performed. Spinosin treatment also reduced the number of activated microglia and astrocytes observed after AbO injection. In addition, spinosin rescued the AbO-induced decrease in choline acetyltransferase expression levels. These results suggest that spinosin ameliorated memory impairment induced through AbO, and these effects were regulated, in part, through neuroprotective activity via the anti-inflammatory effects of spinosin. Therefore, spinosin might be a useful agent against the amyloid b protein-induced cognitive dysfunction observed in AD patients.