TOXICON
·
2013
·
IF 2.924
Ying Zhang,Li Zhong,Bin Zhou,Jin-yu Chen,Chun-mei Li
To more fully understand the mechanism by which persimmon tannin (PT) inhibited phospholipase A 2 (PLA 2 ) and the structural requirements of PT for the inhibition, the interactions between PLA 2 and seven characteristic structural elements of PT including epigallocatechin-3-gallate (EGCG), myricetin, epicatechin-3-gallate (ECG), epicatechin-3-gallate-(4β → 8, 2β → O → 7)-epicatechin-3-gallate (A-type ECG dimer), epigallocatechin-3-gallate-(4β → 8, 2β → O → 7)-epigallocatechin-3-gallate (A-type EGCG dimer), epicatechin-(4β → 8, 2β → O → 7)-epicatechin (A-type EC dimer) and epicatechin-(4β → 8)-epicatechin (B-type EC dimer) were studied by enzymatic and spectroscopic methods. Molecular docking was also used to explore the possible residues involved in the interactions. The results revealed that A-type EGCG dimer and A-type ECG dimer showed higher inhibitory effects on the catalytic activity of PLA 2 than monomers and B-type dimer. They induced greater conformational changes in PLA 2 than other structural elements. In addition, molecular docking studies revealed that expect for lysine residues, other residues such as Trp18, Try27, Gly29, His47 and Tyr63 were involved in the interactions. We propose that A-type EGCG and ECG dimer units may be structural requirements for the interaction between PT and PLA 2 . Our data provide an additional structural basis for anti-PLA 2 activity of persimmon tannin.
研究领域:
生物化学
·
药理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2019
·Vol. 20
·期 8
·1961
·
IF 4.183
Bing Yu,Qingye Meng,Hao Hu,Tao Xu,Youqing Shen,Hailin Cong
Polymeric micelles (PMs) have been applied widely to transport hydrophobic drugs to tumor sites for cancer treatment. However, the low load efficiency of the drug in the PMs significantly reduces the therapeutic efficiency. We report here that disulfide-linked camptothecin (CPT) as a kind of dimeric drug can be effectively embedded in the core of poly(ε-caprolactone)–poly(ethylene glycol)–poly(ε-caprolactone) (PCL–PEG–PCL) PMs for improving drug-loading efficiency, and PEG can be used as a hydrophilic shell. Moreover, the dimeric CPT-loaded PCL–PEG–PCL PMs exhibited excellent solubility in phosphate-buffered saline (PBS) media and significant cytotoxicity to cancer cells.Keywords:dimeric drug;camptothecin;micelles;cancer therapy
研究领域:
药学
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2024
·
IF 2.4
Xin Zhang,Deyuan Yao,Xiaomei Pan,Erqiao Xue,Peng Cheng,Tingting Ye,Junfeng Ding
The crystal structures of liquid crystals, particularly various oligomers, have garnered significant attention, laying the groundwork for developing new materials and devices. Here, we demonstrate pressure plays a crucial role in the structure of liquid crystals. High-pressure Raman and photoluminescence spectra were on 5CB (4-cyano-4’−pentylbiphenyl) liquid crystal. Upon compression, the appearance of prominent fluorescence peaks suggests a phase transition. The Raman peaks, reflecting the C–H and C≡N bonds, exhibit splitting at a pressure of 3.2 GPa, further confirming the pressure-induced phase transition. The splitting is consistent with earlier calculations on the stretching vibration of the C≡N bond for various oligomers and indicates a phase transition from monomers to dimers in 5CB liquid crystal. The opposite shifts in Raman modes under pressure, specifically the blue-shift of C–H bonds and the red-shift of C≡N bonds, indicate that pressure enhances intermolecular interactions and leads to conjugation between the electrons on the C≡N bonds and the C–H bonds, resulting in dimer formation. Our findings not only reveal a novel strategy for producing oligomers in liquid crystals through the application of high pressure but also highlight that Raman spectroscopy is a valid, non-contact method for investigating the mechanisms of oligomerization.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2010
·
IF 3.898
Jinqiang Jiang,Qiaozhen Shu,Xin Chen,Yiqun Yang,Chenglin Yi,Xiaoqing Song,Xiaoya Liu,Mingqing Chen
A novel photosensitive C-PNIPAAm comprising hydrophilic PNIPAAm conjugated with a relatively short but very hydrophobic coumarin part was designed and prepared using a coumarin-containing disulfide derivative (C-S-S-C) as transfer agent in the presence of Bu3P and water. It was found that C-PNIPAAm can form polymer micelles in aqueous solution. And the micellar morphology in aqueous solution can be photoswitched into hollow spheres according to the photodimerization of coumarin end groups upon 365 nm irradiation and reform the micellar morphology after the subsequent photoscission of dimers upon 254 nm. This instant morphology changing phenomenon was successfully monitored by dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. TEM observations showed the small spherical shape of micelles with diameter at 30−50 nm before photo-cross-linking, the big vesicles with diameter at 200−350 nm after photo-cross-linking, and the small micelles with diameter at 30−50 nm after the subsequent photo-de-cross-linking in the first irradiation cycle. The reason for this significant morphology switching can be attributed to the reversible photoinduced amphiphilic structure transformation between the telechelic “hydrophobic end−hydrophilic chain” structure and the ABA type of “hydrophilic chain−hydrophobic center−hydrophilic chain” one upon alternating irradiation.
研究领域:
高分子化学
·
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 40
·期 6
·584-592
·
IF 3.815
Xiao Yang,He Chong,Yang Zi-Fan,Chen Er-Qiang,Lu Huan-Jun,Li Xiao-Hong,Tu Ying-Feng
We demonstrate here a novel method for the design of liquid crystals (LCs) via the cyclization of mesogens by flexible chains. For two azobenzene-4,4′-dicarboxylate derivatives, the cyclic dimer, cyclic bis(tetraethylene glycol azobenzene-4,4′-dicarboxylate) (CBTAD), shows LC properties with smectic A phase, while its linear counterpart, bis(2-(2′-hydroxyethyloxy)ethyl azobenzene-4,4′-dicarboxylate (BHAD), has no LC phase. The difference is ascribed to the shackling effect from the cyclic topology, which leads to the much smaller entropy change during phase transitions and increases the isotropic temperature greatly for cyclics. In addition, the trans -to- cis isomerization of azobenzene groups under UV-light is also limited in CBTAD. With the reversible isomerization of azobenzene groups, CBTAD showed interesting isothermal phase transition behaviors, where the LC phase disappeared upon photoirradiation of 365 nm UV-light, and recovered when the UV-light was off. Combined with the smectic LC nature, a novel UV-light tuned visible light regulator was designed, by simply placing CBTAD in two glass plates. The scattered phase of smectic LC was utilized as the “OFF” state for light passage, while the UV-light induced isotropic phase was utilized as the “ON” state. The shackling effect outlined here should be applicable for the design of cyclic LC oligomers/polymers with special properties.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 46
·26318-26324
·
IF 2.936
Xianbin Huang,Jinsheng Sun,Kaihe Lv,Jingping Liu,Haokun Shen
This study presents an alternative method to enhance the emulsion stability of oil based drilling fluids (OBMs). Modified dimer acid (MDA) was synthesized with a molecular structure having two hydrophilic heads and two hydrophobic tails. Theoretically, the adsorption of MDA on an oil–water interface makes it possible to increase hydrogen bonding between water droplets and form three dimensional networks which benefit emulsion stability. The influence of MDA on the stability of base emulsions was studied by visual observation. Then the stabilization mechanism of MDA was analyzed from the micro and macro points of view by morphology study using a cryo-scanning electron microscope (cryo-SEM) and rheological measurements including viscosity vs. shear rates, zero-shear viscosity (η0), and creep and recovery tests. Experimental results showed that a substantial improvement in emulsion stability was visually observed when the MDA concentration was 2 g L−1. From cryo-SEM observation, a honeycomb structure was observed in the emulsion containing 2 g L−1 MDA, which can provide a physical barrier to restrain the movement of water droplets. In comparison with the rheological behaviors of the emulsion without MDA, a remarkably larger zero-shear viscosity, a solid-like behavior and a greater elasticity were observed when 2 g L−1 MDA was present. Finally, the application in OBMs shows that MDA can largely enhance electrical stability (ES) and reduce the filtration volume. The method proposed in the paper could be used to enhance the stability of w/o emulsions in a variety of fields.
研究领域:
化学工程
·
石油工程
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2025
·Vol. 122
·期 13
·e2426006122
·
IF 9.1
Fengwei Li,Mengmeng Zhang,Chao Liu,Jie Cheng,Yawen Yang,Xiangda Peng,Zhifeng Li,Wenfeng Cai,Haipeng Yu,Junjie Wu,Yuyu Guo,Hongkun Geng,Yun Fa,Youming Zhang,Dalei Wu,Yizhen Yin
Macrocyclic peptides have emerged as promising drug candidates, filling the gap between small molecules and large biomolecules in drug discovery. The antiapoptotic protein myeloid cell leukemia 1 (MCL1) is crucial for numerous cancers, yet it presents challenges for selective targeting by traditional inhibitors. In this study, we identified a macrocyclic peptide, 5L1, that strongly binds to MCL1, with a dissociation constant (KD) of 7.1 nM. This peptide shows the potential to specifically inhibit the function of MCL1, and demonstrates effective antitumor activity against several blood tumor cell lines with the half maximal inhibitory concentration (IC50) values for cell-penetrating peptide-conjugated 5L1 in the range of 0.6 to 3 μM. Structural analysis revealed that it functions similarly to molecular glue, capable of binding to two MCL1 molecules simultaneously and inducing their homodimerization. This unique mechanism of action distinguishes it from traditional small-molecule MCL1 inhibitors, underscoring the potential of macrocyclic peptides functioning as molecular glues. Moreover, it inspires the development of highly selective inhibitors targeting MCL1 and other related targets with this glue-like mechanism.
研究领域:
药物化学
·
癌症生物学
·
结构生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS & DESIGN
·
2021
·
IF 7.991
Dandan Li,Dinggen Hu,Jihuai Tan,Qinghao Zhu,Zhulan Liu,Chen Su,Jianbin Chen,Yunfeng Cao
Paper derived from lignocellulose has great advantages over plastics as packaging material, nevertheless, the poor water- and oil-resistances of paper-derived products limited their application in high-end field. Herein, novel dimer acid-based waterborne polyurethanes (DWPUs) with different content of dimer acid-based polyester polyol (DG) were prepared and used as water- and oil-resistant coating for paper substrate. The effects of DG contents on water- and oil-resistances, mechanical properties and thermal stability of DWPUs coated papers were systematically investigated. When the content of DG reached up to 7 wt% (based on polyester glycol), the paper coated by DWPU exhibited 88.06% decrease in Cobb 60 value, 8.7 times increase in kit rating compared with uncoated paper. Meanwhile, DWPUs coated papers showed good mechanical properties and thermal stability. These improvements are attributed to the flexible long-alkyl chain, and six-ring structure of DWPUs as well as the continuous and homogeneous DWPU-derived membrane on the surface of paper. This study provides a new framework for the preparation of high quality, multifunctional, environmentally friendly water- and oil-resistant coatings for paper substrates.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 53
·47498-47508
·
IF 3.289
Yan Yuan,Yulin Zhang,Ren Liu,Jingcheng Liu,Zhiquan Li,Xiaoya Liu
In this study, 7-(4-vinylbenzyloxyl)-4-methylcoumarin (VM) and maleic anhydride (MA) were polymerized through free radical copolymerization to form a photosensitive alternating copolymer P(VM-alt-MA) (PVMA). PVMA was used as a soft template to achieve the oxidative polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT). We obtained a stable PEDOT:PVMA photosensitive aqueous dispersion with an average diameter in the range of 140 to 210 nm. We then used this aqueous dispersion as the ink for fabricating humidity sensors through inkjet-printing on a paper substrate. The printed photosensitive conductive film PEDOT:PVMA could be cross-linked after photo-dimerisation of coumarin groups, leading to a small decrease of electrical conductivity, but also appreciable improvements in water resistance and sensor robustness. The humidity sensing ability of these PEDOT:PVMA/paper sensors was investigated by exposing them to a wide range of relative humidity, namely 11–97% at room temperature. These paper sensors could selectively and reversibly detect water vapor with a significant linear relationship. The response strength and the response/recovery time of the sensors show a substantial improvement compared with those of previous reports. The photo-dimerisation of PEDOT:PVMA improves the stability of humidity response and the response/recovery time of the sensors.
研究领域:
材料科学
·
传感器技术
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMBIOCHEM
·
2024
·
IF 2.6
Yi Yang,Zhiyi Zhao,Xiaoying Li,Yian Chen,Lu Liu,Shao-Lin Zhang,Aimin Yang
Graphical Our study designs and synthesizes a series of peptides targeting the dimerization of SARS-CoV-2 M pro . Several peptides display potential inhibitory activities. Specifically, N8-A24 shows most efficient suppression of the M pro activity via inhibiting its dimerization. The severe acute respiratory syndrome virus 2 (SARS-CoV-2) seriously impacted public health. The evolutionarily conserved viral chymotrypsin-like main protease (M pro ) is an important target for anti-SARS-CoV-2 drug development. Previous studies have shown that the eight N-terminal amino acids (N8) of SARS-CoV M pro are essential for its dimerization, and are used to design inhibitors against SARS-CoV M pro dimerization. Here, we established a simple readout assay using SDS-PAGE and Coomassie blue staining to measure inhibitory activity of N8 peptide derived from SARS-CoV-2 M pro . To optimize its inhibitory effect, we then modified the side-chain length, charge, and hydrophilicity of the N8 peptide, and introduced a mutated M pro recognition sequence. As a result, we obtained a series of potent peptide inhibitors against SARS-CoV-2 M pro , with N8-A24 being the most efficient with an IC 50 value of 1.44 mM. We observed that N8-A24 reduced M pro dimerization with an IC 50 value of 0.86 mM. Molecular docking revealed that N8-A24 formed hydrogen bond interactions with critical dimeric interface residues, thus inhibiting its dimerization and activity. In conclusion, our study not only discovers a series of peptide inhibitors targeting the SARS-CoV-2 M pro dimerization, but also provides a promising strategy for the rational design of new inhibitors against COVID-19.
研究领域:
病毒学
·
药物开发
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
CROP PROTECTION
·
2020
·
IF 2.381
Guanglong Ding,Jingyue Tang,Wenbing Zhang,Yanran Li,Junfan Niu,Weichen Wang,Hong Huo,Jianqiang Li,Yongsong Cao
Auxinic herbicides are widely used to control broadleaf weeds in cereal crop fields due to their excellent herbicidal activities. However, volatile drifting caused by their high vapor pressures is a great threat to neighbouring susceptible crops and environment and severely limits auxinic herbicide applications. In this study, a series of auxinic herbicide dimers were synthesized using 2,4-D, dicamba and MCPA as monomers to reduce their vapor pressures. The results showed that all of the dimers significantly reduced volatilities due to larger molecular weight. The dimers linked with two ester bonds had 2-fold higher herbicidal efficacies than their corresponding monomers in filed experiments. The dimers linked with amide bonds appeared to function as contact action and systemic action herbicides. The dimers, 3a-2(ethane-1,2-diylbis (2-(2,4-dichlorophenoxy)acetate)), 3a-4(2-((2-(2,4-dichlorophenoxy)acetyl)thio)ethyl 2-(2,4-dichlorophenoxy)acetate), 3b-2(ethane-1,2-diylbis(2-(4-chloro-2-methylphenoxy)acetate)) and 3c-2(ethane-1,2-diylbis(3,6-dichloro-2-methoxybenzoate)) significantly increased the efficacies and reduced volatilities, thus could be developed as potential novel postemergence herbicides.
研究领域:
植物学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
Pharmaceutics
·
2023
·Vol. 15
·期 7
·1874
·
IF 5.4
Heming Zhao,Liming Gong,Hao Wu,Chao Liu,Yanhong Liu,Congcong Xiao,Chenfei Liu,Liqing Chen,Mingji Jin,Zhonggao Gao,Youyan Guan,Wei Huang
Prostate cancer (PC) is one of the common malignant tumors of the male genitourinary system. Here, we constructed PTX@ZIF-8, which is a metal-organic-framework-encapsulated drug delivery nanoparticle with paclitaxel (PTX) as a model drug, and further modified the synthesized peptide dimer (Di-PEG2000-COOH) onto the surface of PTX@ZIF-8 to prepare a nanotargeted drug delivery system (Di-PEG@PTX@ZIF-8) for the treatment of prostate cancer. This study investigated the morphology, particle size distribution, zeta potential, drug loading, encapsulation rate, stability, in vitro release behavior, and cytotoxicity of this targeted drug delivery system, and explored the uptake of Di-PEG@PTX@ZIF-8 by human prostate cancer Lncap cells at the in vitro cellular level, as well as the proliferation inhibition and promotion of apoptosis of Lncap cells by the composite nanoparticles. The results suggest that Di-PEG@PTX@ZIF-8, as a zeolitic imidazolate frameworks-8-loaded paclitaxel nanoparticle, has promising potential for the treatment of prostate cancer, which may provide a novel strategy for the delivery system targeting prostate cancer.Keywords:metal-organic framework;paclitaxel;peptide dimer;prostate cancer
研究领域:
药学
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）