ChemMedChem
·
2018
·Vol. 13
·期 20
·2202-2207
·
IF 3.009
Rong Zhou,Yueguang Sun,Hangbin Li,Weili Long,Xiaojian Liao,Pengju Feng,Shihai Xu
Graphical Sponging up SAR data : The marine sponge Reniochalina stalagmitis is the source of a set of cyclic peptides known as reniochalistatins. Herein we report the total synthesis of reniochalistatins A–E, along with evaluations of their anticancer and antitubercular activities. Our results pave the way for further investigations into the structure–activity relationships of this class of cyclic peptide. The total synthesis of reniochalistatins A–E, along with a reniochalistatin E analogue (inverso-E) was successfully achieved through Fmoc-based solid-phase peptide synthesis and subsequent macrolactamization with PyBOP and DIEA. The biological activities of these reniochalistatins and a key linear peptide intermediate were systematically evaluated. Among these seven synthesized compounds, linear reniochalistatin B was found to have potent activity against several cancer cell lines not shown by the cyclic reniochalistatin B counterpart. In addition, linear reniochalistatin B was found to have antitubercular activity (IC 50 =1.4 μ m ). Inverso-E possesses increasing cytotoxicity against the HeLa and LNCaP cell lines after simple alternation of the sequence of amino acids in reniochalistatin E. The results of these studies provide a feasible method to further investigate the structure–activity relationships (SARs) of reniochalistatins A–E.
研究领域:
有机化学
·
药物化学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
Surfaces and Interfaces
·
2021
·
IF 4.837
Xiao-Ting Zhen,Ya-Ling Yu,Min-Zhen Shi,Si-Chen Zhu,Tian-Ci Yan,Zi-Xuan Yue,Yu-Xin Gu,Hui Zheng,Jun Cao
The Hawthorn kernel activated carbon (HKAC), acquired from food waste (hawthorn kernel) by a two-step method including carbonization operation and thermally activating potassium hydroxide process, was prepared. Morphological integrity and crystalline state of the HKAC were characterized by scanning electron microscopye and X-ray diffraction. Structural feature of the HKAC was investigated by the Brunauer–Emmett–Teller method, Fourier transform infrared spectroscopy , Raman spectroscopy together with zeta potential . The HKAC contained a specific surface area of 1269.92 m 2 /g and pore volume of 0.67 cm 3 /g. The optimized adsorption conditions were to use HKAC with a carbonization temperature of 550 °C were at a concentration of 0.6 g/L for adsorption in a solution with a temperature of 60 °C and a pH of 6.0. The kinetic studies proved that the pseudo-second-order model fitted experimental data best with the high correlation coefficient values of 0.9968–0.9993. Besides, experimental results revealed that Langmuir isotherm model gave the best fit among the studied isotherm models with a maximum adsorption capacity of 100.00 mg/g, the experimental results revealed that the Langmuir isotherm model was more consistent than the Freundlich isotherm model with a maximum adsorption capacity of 100.00 mg/g, and the adsorption of fungicides onto HKAC was endothermic spontaneous process. Moreover, it was confirmed in tap water and Dendrobium that the removal rate of the six fungicides remained at 86.3% to 96.2% after five cycles of HKAC even in a complex matrix. The aforesaid satisfying experimental results proved that HKAC was a cost-effective and green adsorbent for removing water and plant contaminated by fungicides.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 18
·e202300551
·
IF 2.1
Yongchang Bi,Xiaodong Chen,Yafei Xue,Kejun Liu,Yumin Zhang,Qiang Gu
Graphical 1,4-Bis((3-arylisoxazol-5-yl)methyl)piperazines were synthesized in 64–90 % yield by an environment friendly method using 5-(bromomethyl)-3-arylisoxazoles and piperazine as raw materials. Their antibacterial activities were evaluated. A series of piperazine derivatives containing bis-isoxazole were successfully synthesized by the reaction between piperazine and substituted isoxazole derivatives under the optimal reaction condition. The structures of all products were confirmed by IR, HRMS, 1 H and 13 C NMR. The antibacterial activities of all products against Mycobacteria smegmatis in vitro were tested using rifampin as a positive control. Two compounds presented wonderful anti-mycobacterium activity, and their minimum inhibitory concentrations were respectively 2.60±1.11 μmol/mL and 4.35±0.00 μmol/mL, which indicated that they can be regarded as candidates for development of anti-TB drugs.
研究领域:
有机化学
·
药物化学
·
微生物学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Lanxiadi Chen,Chao Peng,Jingchuan Chen,Jie Chen,Wenjun Gu,Xiaohong Jia,Zhijun Wu,Qiyuan Wang,Mingjin Tang
Mineral dust is an important type of ice nucleating particles in the troposphere; however, the effects of heterogeneous reactions on ice nucleation (IN) activities of mineral dust remain to be elucidated. A droplet-freezing apparatus (Guangzhou Institute of Geochemistry Ice Nucleation Apparatus, GIGINA) was developed in this work to measure IN activities of atmospheric particles in the immersion freezing mode, and its performance was validated by a series of experimental characterizations. This apparatus was then employed to measure IN activities of feldspar and Arizona Test Dust (ATD) particles before and after heterogeneous reaction with NO 2 (10±0.5 ppmv) at 40% relative humidity. The surface coverage of nitrate, θ (NO 3 − ), increased to 3.1±0.2 for feldspar after reaction with NO 2 for 6 hr, and meanwhile the active site density per unit surface area ( n s ) at -20°C was reduced from 92±5 to <1.0 cm −2 by about two orders of magnitude; however, no changes in nitrate content or IN activities were observed for further increase in reaction time (up to 24 hr). Both nitrate content and IN activities changed continuously with reaction time (up to 24 hr) for ATD particles; after reaction with NO 2 for 24 hr, θ (NO 3 − ) increased to 1.4±0.1 and n s at -20°C was reduced from 20±4 to 9.7±1.9 cm −2 by a factor of ∼2. Our work suggests that heterogeneous reaction with NO 2 , an abundant reactive nitrogen species in the troposphere, may significantly reduce IN activities of mineral dust in the immersion freezing mode.
研究领域:
大气科学
·
环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
·
2025
·Vol. 130
·期 5
·e2024JD041920
·
IF 3.4
Chun Xiong,Binyu Kuang,Xueyan Chen,Xiaolei Ding,Huichao Liu,Xiangyu Pei,Zhengning Xu,Fei Zhang,Shikuan Yang,Huan Hu,Zhibin Wang
Organic oxidized sulfur (OOS) compounds, particularly surface-active ones like organosulfates and organosulfonates, constitute a significant atmospheric sulfur reservoir and play a crucial role in cloud formation. Due to limited measurements, the physical characteristics of OOS aerosols under high relative humidity (RH) and subsequent cloud activation potential remain unclear. In this study, we measured phase state, surface tension and morphology of mixtures containing inorganic salts (sodium chloride (NaCl) and ammonium salfate (AS)) and OOS under high RH (>99.5%), and investigated their cloud condensation nuclei (CCN) activity. We found that the κ CCN of the studied OOS ranged from 0.15 to 0.37, showing a negative relationship with molar volume. κ CCN and chemistry-derived κ Chem agreed well for mixtures containing OOS with short carbon chain length (≤4), which could be explained by the ideal solution because of the liquid phase and slight surface tension reduction compared to that of water. However, κ Chem overpredicted κ CCN by 35% and 17% on average for NaCl–OOS and AS–OOS with long carbon chain length (seven and eight), respectively, which was the opposite of results from inorganic–dicarboxylic acid mixtures we previously reported. Although surface tension notably decreased by 25%–44%, inorganic–OOS mixtures exhibited core-shell morphology and the OOS shell suppressed water uptake, whereas inorganic–dicarboxylic acid particles exhibited homogeneous state thus not inhibiting water uptake. Based on the results, we emphasize the pivotal role of surfactant in determining aerosol morphology and thereby CCN activations. Key Points Inorganic–OOS mixtures exhibited liquid phase at high relative humidity and surface tension was affected by organic carbon chain length Slightly reduced surface tension in short carbon chain systems could explain the closure between predicted and measured cloud condensation nuclei (CCN) activity CCN ability of the mixtures with long carbon chain length was mainly affected by initial morphology rather than surface tension Plain Language Summary Ubiquitous surface-active organic oxidized sulfur (OOS) compounds significantly influence the aerosol physical properties and subsequent cloud droplet activation. In this study, phase state, surface tension, morphology, and cloud condensation nuclei (CCN) activity of submicron particles containing inorganic salt and OOS were investigated. For mixtures containing OOS with short organic carbon chain length (≤4), the liquid phase and slight reduction in surface tension compared to that of water under nearly saturated conditions indicate ideal solution, leading to good closure between predicted and measured CCN activity. Inorganic-OOS mixtures exhibited core-shell morphology and water uptake suppression by the outer OOS shell contributed to the overprediction of CCN ability, whereas inorganic-dicarboxylic acid particles were homogeneous and water uptake was not inhibited. This study sheds light on the significance of OOS compounds in influencing submicron aerosol morphology and subsequent cloud formation.
研究领域:
大气科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 86
·83321-83327
·
IF 3.289
Zhangyu Huang,Huiping Gao,Yanli Mao
In this study, the energy transfer (ET) mechanism among Yb3+/Er3+/Mn2+ has been revealed by download conversion (DC) and upconversion (UC) transients and steady-state fluorescence spectra. Moreover, the novel structure, inert-core/active-shell/inert-shell cubic NaYF4@NaYF4:Er3+/Yb3+/Mn2+@NaYF4, has been synthesized via a convenient hydrothermal method. With the excitation of a 980 nm laser diode, bright single-red upconversion (UC) fluorescence is observed, which shows the longest UC lifetime and highest efficiency compared with the other structures of NaYF4:Er3+/Yb3+/Mn2+, NaYF4:Er3+/Yb3+/Mn2+@NaYF4, and NaYF4@NaYF4:Er3+/Yb3+/Mn2+. The inert-core/active-shell/inert-shell nanocubes are homogeneous with an ultra-small (sub-20 nm) size, which is suitable for distribution and elimination in biological tissue. Our results indicate that the Mn2+ doping of δ-doped structures is an effective method to significantly improve UC single-red light, which shows great potential application in vivo bioimaging.
研究领域:
材料科学
·
生物成像
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2020
·
IF 3.693
Zhang Heying,Zhang Jie,Qu Wei,Xie Shuyu,Huang Lingli,Chen Dongmei,Tao Yanfei,Liu Zhenli,Pan Yuanhu,Yuan Zonghui
Tuberculosis and fungal infections can pose serious threats to human health. In order to find novel antimicrobial agents, 26 novel quinoxaline-1,4-di-N-oxides containing a thiazolidinone moiety were designed and synthesized, and their antimycobacterial activities were evaluated. Among them, compounds 2t, 2u, 2y, and 2z displayed the most potent antimycobacterial activity against Mycobacterium tuberculosis strain H37Rv (minimal inhibitory concentration [MIC] = 1.56 μg/mL). The antifungal activity of all the compounds was also evaluated against Candida albicans, Candida tropicalis, Aspergillus fumigatus, and Cryptococcus neoformans. Compounds 2t, 2u, 2y, and 2z exhibited potential antifungal activities, with an MIC between 2 and 4 μg/mL. Comparative molecular field analysis (CoMFA: q2 = 0.914, r2 = 0.967) and comparative molecular similarity index analysis (CoMSIA: q2 = 0.918, r2 = 0.968) models were established to investigate the structure and antimycobacterial activity relationship. The results of contour maps revealed that electronegative and sterically bulky substituents play an important role in the antimycobacterial activity. Electronegative and sterically bulky substituents are preferred at the C7 position of the quinoxaline ring and the C4 position of the phenyl group to increase the antimycobacterial activity. Additionally, more hydrogen bond donor substituents should be considered at the C2 side chain of the quinoxaline ring to improve the activity.
研究领域:
药物化学
·
微生物学
·
计算化学
✓ 已验证
DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-14
·
IF 15.7
Wang Xiaochen,Zhang Ning,Shang Huishan,Duan Haojie,Sun Zhiyi,Zhang Lili,Lei Yuanting,Luo Xuan,Zhang Liang,Zhang Bing,Chen Wenxing
Owing to their synergistic interactions, dual-atom catalysts (DACs) with well-defined active sites are attracting increasing attention. However, more experimental research and theoretical investigations are needed to further construct explicit dual-atom sites and understand the synergy that facilitates multistep catalytic reactions. Herein, we precisely design a series of asymmetric selenium-based dual-atom catalysts that comprise heteronuclear SeN 2 –MN 2 (M = Fe, Mn, Co, Ni, Cu, Mo, etc.) active sites for the efficient oxygen reduction reaction (ORR). Spectroscopic characterisation and theoretical calculations revealed that heteronuclear selenium atoms can efficiently polarise the charge distribution of other metal atoms through short-range regulation. In addition, compared with the Se or Fe single-atom sites, the SeFe dual-atom sites facilitate a reduction in the conversion energy barrier from *O to *OH via the coadsorption of *O intermediates. Among these designed selenium-based dual-atom catalysts, selenium-iron dual-atom catalysts achieves superior alkaline ORR performance, with a half-wave potential of 0.926 V vs. a reversible hydrogen electrode. In addition, the SeN 2 –FeN 2 -based Zn–air battery has a high specific capacity (764.8 mAh g −1 ) and a maximum power density (287.2 mW cm −2 ). This work may provide a good perspective for designing heteronuclear DACs to improve ORR efficiency.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
·
2023
·Vol. 128
·期 24
·e2023JD039971
·
IF 4.4
Lanxiadi Chen,Soleil E. Worthy,Wenjun Gu,Allan K. Bertram,Mingjin Tang
Mineral dust is one of the most abundant types of ice nucleating particles in the atmosphere. During atmospheric transport, mineral dust particles can become coated with inorganic and organic solutes, which can impact their ice nucleation activity. Aminium cations formed from amines are one type of organic solute that can coat mineral dust particles in the atmosphere, but their effects on the ice nucleation activity of mineral dust have not been studied. We investigated the effects of primary, secondary, and tertiary aminium cations with methyl and ethyl groups, as well as ammonium cations, on the ice nucleation activity of K-feldspar, an important type of mineral dust, in the immersion freezing mode at low cation concentrations (0.2–20 mM) using a droplet-freezing apparatus. Ammonium cations substantially increased the ice nucleation activity of K-feldspar, consistent with previous studies. In contrast, primary aminium cations significantly reduced K-feldspar ice nucleation activity, and secondary and tertiary aminium cations had no significant effect (the effect was less than the uncertainty of our measurements). Our combined results are consistent with the following mechanisms: ammonium cations undergo ion exchange with K-feldspar, providing exposed N–H groups for hydrogen bonding with ice; primary aminium cations undergo ion exchange with K-feldspar, exposing a hydrophobic tail that is not effective at nucleating ice; secondary and tertiary aminium cations do not undergo ion exchange with K-feldspar due to steric effects caused by the multiple hydrophobic groups on the cation. Key Points Ammonium cations significantly increased the ice nucleation activity of K-feldspar Primary aminium cations substantially reduced the ice nucleation activity of K-feldspar Secondary and tertiary aminium had limited effects on the ice nucleation activity of K-feldspar due to their inability for ion exchange Plain Language Summary Ice nucleating particles are particles in the atmosphere that can initiate the formation of ice in liquid clouds, impacting cloud properties, precipitation, and climate. Mineral dust is a dominant type of ice nucleating particles in the atmosphere. During atmospheric transport, aminium cations, formed from amine gases which can be abundant in the atmosphere, can coat mineral dust particles altering their ability to nucleate ice. However, the effect of aminium cations on the ice nucleation ability of mineral dust particles has not been studied. We investigated the effects of aminium and ammonium cations on the ice nucleation ability of K-feldspar, an important type of mineral dust and ice nucleating particles in the atmosphere. Our results show that secondary and tertiary aminium cations have no effect on the ice nucleating ability of K-feldspar, but primary aminium cations greatly reduce the ice nucleating ability of K-feldspar. This has possible implications for predicting cloud formation in the atmosphere. We also present a mechanism related to ion exchange that can explain our ice nucleation results.
研究领域:
大气科学
·
环境化学
·
物理化学
·
气候学
✓ 已验证
产品关联
DOI
高影响因子
LIFE SCIENCES
·
2024
·
IF 5.2
Qiuwen Fei,Jian Zhang,Liangqiong Chen,Manqi Shi,Qinglan Wang,Feifan Xu,Jiahai Shi,Yongwei Qin
Background Mycobacterium tuberculosis infection triggers various forms of host cell death, including ferroptosis in lung epithelial cells; YY1, a critical transcription factor, plays a pivotal role in regulating ferroptosis, however, the underlying mechanisms are not fully understood. Methods To investigate Mycobacterium marinum ( M.marinum )infection in lung epithelial cells A549 and H1299, we utilized flow cytometry to evaluate cell death and measure reactive oxygen species (ROS). Colony-forming unit (CFU) assays determined the intracellular bacterial load. Ferroptosis was analyzed using a specific detection kit to measure malondialdehyde (MDA) and glutathione (GSH) levels. The interaction between the transcription factor YY1 and the iNOS promoter was assessed through a dual-luciferase reporter assay. Results M.marinum induced ferroptosis in lung epithelial cells through invasion. This effect is most pronounced at 8 h of infection and decreases over time but increased with a higher multiplicity of infection (MOI). YY1 knockdown decreases the expression of SLC7A11 and GPX4, attenuates cellular ferroptosis, while YY1 overexpression has the opposite phenomenon, enhancing the expression of bactericidal molecules such as iNOS and MPEG1, thereby markedly reducing the intracellular bacterial load. We identified substantial binding of YY1 to the iNOS promoter region (−655 to −1018 bp), enhancing mycobactericidal activity in YY1-overexpressing cells. Conclusions Our study demonstrates that YY1 inhibits ferroptosis induced by Mycobacterium marinum infection and reduces intracellular bacterial proliferation in lung epithelial cells. These findings provide a crucial basis for developing anti-tuberculosis therapies that target YY1 modulation, potentially offering new clinical avenues for the treatment of tuberculosis.
研究领域:
微生物学
·
细胞生物学
·
传染病学
·
药理学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Wenquan Huang,Zhiqiang Li,Weiqi Liu,Shiyuan Liu,Rujin Zhou,Yanbin Jiang
Zein is an excellent protein-based pharmaceutical excipient , which has been extensively studied as a carrier for drug delivery system (DDS). However, the poor target ability of zein has limited its efficient delivery and in vivo applications. In this study, the B16 cancer cell membrane coated α-zein biomimetic drug delivery system was prepared to enhance homotypic target ability. The solubility and self-assembly behavior of α-zein were studied using different solvents, the particle size uniformity, stability and toxicity were evaluated. Then B16 cancer cell membrane (CCM) modified α-zein based nanocarrier was prepared by using the co-extrusion method. The AFM analysis showed that Young’s modulus (530.53 ± 66.55 MPa) of CCM-α-zein was smaller than that of membrane-derived vesicles, but bigger than that of α-zein. After coating the CCM on the surface of α-zein, the surface adhesion force of CCM-α-zeinα-zein (56.4 ± 4.6 nN) was significantly reduced. The results of protein electrophoresis showed that CCM-α-zein could completely retain the proteins of α-zein and CCM after co-extrusion. The safety of the DDS prepared was proved by the hemolysis test and non-tumor cells experiment. Paclitaxel was selected as the model drug to prepare DDS nanoparticles , the results of the cell experiment showed that the migration area of B16 cells was reduced by 5.79%, which indicated the strong inhibition migration ability of DDS. The nuclear activity analysis showed that the nuclei of B16 cells were broken into fragments. Qualitative and quantitative studies suggested that the prepared CCM-α-zein possessed homologous targeting ability. Therefore, this work presents an effective strategy to enhance the targeting ability, which will extensive biomedical applications of zein.
研究领域:
药学
·
生物医学工程
·
纳米技术
·
癌症研究
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）