Bicyclic peptides,a class of polypeptides with two loops within their structure,have emerged as powerful tools in the development of new peptide drugs.They have the potential to bind to challenged drug targets,with an...Bicyclic peptides,a class of polypeptides with two loops within their structure,have emerged as powerful tools in the development of new peptide drugs.They have the potential to bind to challenged drug targets,with antibody-like affinity and selectivity.Meanwhile,bicyclic peptides possess small molecule-like access to chemical synthesis,which is conducive to large-scale synthesis and screening.In the last five years,bicyclic peptide technology has been increasingly developed,and researchers have carried out a variety of studies to elucidate the potential functions of bicyclic peptides.With the continuous development of synthetic methods and the advances of new technology to build bicyclic peptide libraries,bicyclic peptides are now becoming widely used in the development of new drugs for various diseases.This perspective provides an overview of the structure types,synthesis and applications of bicyclic peptides in current drug development,and our own views on future challenges of bicyclic peptides.展开更多
From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were establish...From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were established as cyclo (Pro(1)-Phe-Leu-Ala(1)-Thr-Pro(2)-Ala(2)-Gly) (1), cyclo (Pro(1)-Ala-Phe-Trp-Asp-Pro(2)-Leu-Gly) (2), cyclo (Pro(1)-Ile-Gly-Pro(2)-Val-Ala(1)-Ala(2)-Tyr) (3) and cyclo ( Pro-OMet-Trp-Ile-Gly-Ala-Leu-Asp) (4) respectively by means of extensive spectral methods.展开更多
New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 fromCastaniopsis fissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-...New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 fromCastaniopsis fissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.展开更多
Chromatographic separation of the marine-derived bacterium Bacillus licheniformis resulted in the isolation of two new cyclic lipopeptides named ai-Cl6 surfactin （1） and ai-Cl4 surfactin （2）, together with iso-Cm5...Chromatographic separation of the marine-derived bacterium Bacillus licheniformis resulted in the isolation of two new cyclic lipopeptides named ai-Cl6 surfactin （1） and ai-Cl4 surfactin （2）, together with iso-Cm5 surfactin and iso-Cl6 surfactin. The structures of the new cyclic lipopeptides were determined through extensive spectroscopic analysis. The sequences of the amino acids in cyclic nucleus were established by the ESI-MS/MS fragmentation, which provided an efficient method to detect lipopeptides from bacterium extracts without senaration展开更多
Heterocycle-braced cyclic peptides have demonstrated enhanced metabolic stability,increased potency and selectivity.Here,we present a rapid synthesis method for constructing Trp(C7)-alkene(E)-crosslinked cyclic peptid...Heterocycle-braced cyclic peptides have demonstrated enhanced metabolic stability,increased potency and selectivity.Here,we present a rapid synthesis method for constructing Trp(C7)-alkene(E)-crosslinked cyclic peptides with potent anti-proliferative activities against cancer cells,through C-H alkenylation and macrolactamization.This report addresses critical challenges associated with the installation and removal of the directing group N-Piv,configuration selectivity of the olefin,and intramolecular cyclization.No-tably,this method exhibits mild reaction conditions,traceless removal of the directing group,and high configuration selectivity.展开更多
We report here the synthesis of cyclic peptides using benzotriazolyloxy-bis(pyrrolidino)-carbonium hexafluoro- phosphate(BBC)as a coupling reagent with high yield and speed even in low concentration compared with the ...We report here the synthesis of cyclic peptides using benzotriazolyloxy-bis(pyrrolidino)-carbonium hexafluoro- phosphate(BBC)as a coupling reagent with high yield and speed even in low concentration compared with the other usual coupling reagents.展开更多
This paper reports the determination of stability constants for complexes of Cd(Ⅱ)with Gly, Ala,Val,Asp,Gly—Asp,Asp Gly,Gly—Gly and Gly—Gly—Gly using both micro—pH—metric titra- tions and the application of con...This paper reports the determination of stability constants for complexes of Cd(Ⅱ)with Gly, Ala,Val,Asp,Gly—Asp,Asp Gly,Gly—Gly and Gly—Gly—Gly using both micro—pH—metric titra- tions and the application of convolution—deconvolution cyclic voltammetry at 25℃ and I=0.10 mol· dm^(-3)(KNO_3).Stability constants were calculated from pH—metric data using the SUPERQUAD com- puter program and cyclic voltammograms were collected,stored and manipulated using the EG and G CONDECON 300 software.A considerably larger ligand:metal ratio(e,g.50:1)was possible using voltammetry.Evaluation of results from the two techniques suggests that stability constants for the species[CdL_2]and[CdL_3]are reliable when calculated fromvoltammetry while those for[CdL]are more reliable when determined by pH-metric titration.展开更多
From Psammosilene tunicoides W. C. Wu et C. Y Wu, two cyclic octapeptides (namedpsammosilenins A and B) were isolated. Their structures were determined as cyclo(-Pro1-phe1-Pro2-Phe2-Phe3-Ala-Pro3-Leu-) and cyclo(-Pro...From Psammosilene tunicoides W. C. Wu et C. Y Wu, two cyclic octapeptides (namedpsammosilenins A and B) were isolated. Their structures were determined as cyclo(-Pro1-phe1-Pro2-Phe2-Phe3-Ala-Pro3-Leu-) and cyclo(-Pro1-Gly-Phe1-Val-Pro2-Phe2-Thr-Ile) by spectroscopicmethods.展开更多
The interaction between HIV-1 DNA and five cyclic peptides （CP1-CP5） was investigated using electrospray ionization mass spectrometry （ESI-MS）. It revealed that CP1 [c（Ala-Tyr-Leu-Ala-Gly）] and CP4 [c（Pro-D-Tyr...The interaction between HIV-1 DNA and five cyclic peptides （CP1-CP5） was investigated using electrospray ionization mass spectrometry （ESI-MS）. It revealed that CP1 [c（Ala-Tyr-Leu-Ala-Gly）] and CP4 [c（Pro-D-Tyr-Leu-D-Ala-Gly）] have the higher binding affinity with the duplex DNA among the five cyclic peptides.展开更多
Protein-protein interactions(PPIs) are recognized as attractive therapeutic targets. However targeting PPIs especially intracellular ones has been proven extremely difficult for conventional drug-like small molecules,...Protein-protein interactions(PPIs) are recognized as attractive therapeutic targets. However targeting PPIs especially intracellular ones has been proven extremely difficult for conventional drug-like small molecules, and biological drugs such as monoclonal antibodies have difficulty in reaching intracellular targets. Macrocyclic peptides are promising candidates of PPI regulators for their potential in combining high potency and biological stability together. Cell permeability of macrocyclic peptides may also be achieved by structural modifications or conjugation to a cell-penetrating sequence. Significant progress has been made in this research area in recent years. Important technology progress and recent examples of macrocyclic peptide PPI modulators are reviewed.展开更多
Objective:To find potential peptide inhibitors against the NS2B/NS3 protease of DENV which in turn,can inhibit the viral replication inside host cell.Methods:Cyclic peptides were designed having combination of positiv...Objective:To find potential peptide inhibitors against the NS2B/NS3 protease of DENV which in turn,can inhibit the viral replication inside host cell.Methods:Cyclic peptides were designed having combination of positively charged amino acids using ChemSketch software and were converted to 3D structures.DENV NS3 protein structure was retrieved from Protein Data Bank(PDB)using PDB Id:2FOM.DENV NS3 and cylic peptides were docked using MOE software after structural optimization.Results:Through molecular docking it was revealed that most of the peptides bound deeply in the binding pocket of DENV NS2B/NS3 protease an had interactions with catalytic triad.Peptide 2 successfully blocked the catalytic triad of NS2B/NS3 protease.Peptide 1,,4 and 6 also had potential interactions with active residues of the NS2B/NS3 protease while all other peptides were in close contact with the active sites of NS2B/NS3 protease thus,these peptides can serve as a potential drug candidate to stop viral replication.Conclusions:Thus.it can be concluded from the study that these peptides could serve as important inhibitors to inhibit the viral replication and need further in-vitro investigations to confirm their efficacy.展开更多
The Antarctic fungus Cadophora malorum produces previously undescribed cyclic heptapeptides(cadophorin A and B)containing an anthranilic acid residue.The planar structure of these peptides was determined by high-resol...The Antarctic fungus Cadophora malorum produces previously undescribed cyclic heptapeptides(cadophorin A and B)containing an anthranilic acid residue.The planar structure of these peptides was determined by high-resolution mass spectrometry combined with extensive 1D and 2D NMR spectroscopy.The absolute configuration of the amino acids was determined by Marfey’s method,with HPLC analysis of FDVA(Nα-(2,4-dinitro-5-fluorphenyl)-l-valinamide)derivatives making use of a PFP column.Remarkably,cadophorin 2 possesses both the uncommon d-Ile and d-allo-Ile in its structure.The peptides have metal binding properties as shown by LCMS with post column addition of metal salt solutions.These results were supported by DFT calculations.展开更多
In biological controls using <em>Bacillus</em> spp., cyclic lipopeptides play a role as elicitors to induce disease resistance on various host plants. However, it is still unclear the specificity between c...In biological controls using <em>Bacillus</em> spp., cyclic lipopeptides play a role as elicitors to induce disease resistance on various host plants. However, it is still unclear the specificity between cyclic lipopeptides and host plants to induce disease resistance. In this study, we aimed to clarify the specificity to induce disease resistance among cyclic lipopeptides on various host plants. Our data clearly showed both cyclic lipopeptides conferred disease suppression on most of host plants, but at different range of cyclic lipopeptide concentration. Our findings contribute to understanding the complex on the specificity of cyclic lipopeptide derived induced disease resistance.展开更多
P-113 is a fragment of natural occurring peptide Histatin 5 found in human saliva. This peptide exhibited broad spectrum of antibacterial and antifungal biological activities. In this study, bifunctional P-113 peptide...P-113 is a fragment of natural occurring peptide Histatin 5 found in human saliva. This peptide exhibited broad spectrum of antibacterial and antifungal biological activities. In this study, bifunctional P-113 peptides 2–5 were designed as Sortase A substrates and synthesized by solid support peptide synthesis,where the N-terminus were equipped with glycine and its analogues, and C-terminus were extended with LPETGGS, respectively. Under Sortase A catalyzed condition, head to tail cyclization products 7–10were afforded in yields from 76% to 93%. The conformation insights of linear peptides 2–5 and cyclic analogues 7–10 in aqueous buffers and in trifluroethanol（TFE） analyzed by circular dichroism（CD）suggested that a-helix structures were produced progressively in hydrophobic environment independent of the cyclization, which displayed the similar behavior as parent peptide P-113.展开更多
Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynam...Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynamic size and slower degradation.It is key to develop facile methods to large-scale synthesis of polymer rings with tunable compositions and microstructures.Recent progresses in large-scale synthesis of polymer rings against single-chain dynamic nanoparticles,and the example applications in synchronous enhancing toughness and strength of polymer nanocomposites are summarized.Once there is the breakthrough in rational design and effective large-scale synthesis of polymer rings and their functional derivatives,a family of cyclic functional hybrids would be available,thus providing a new paradigm in developing polymer science and engineering.展开更多
The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batte...The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).展开更多
The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidom...The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidomics and bioinformatics were used to screen flavor peptides from Inner Mongolian cheese and further assess their antioxidant and angiotensin I-converting enzyme(ACE)inhibitory properties.According to sensory data,YH8 and IL7 had detectable bitter tastes with low thresholds of 0.03 and 0.06 mmol/L,respectively.With an umami threshold range of 0.24‒0.81 mmol/L,VQ6,FK13,HP13 and QT14 exhibited a range of flavors dominated by umami,including sweet,bitter,salty,sour and kokumi.Antioxidant activity wise,YH8,VQ6,HP13 and QT14 were well represented.The above-mentioned peptides all had some ACE inhibitory effect.The bitter peptide IL7(IC_(50)=0.08 mmol/L)had the highest level of ACE inhibitory activity,followed by YH8(IC_(50)=0.33 mmol/L).These multi-functional peptides,which have been assessed for bioactive and taste features in Inner Mongolian cheese,may have positive impacts on health and harmonize the cheese’s overall flavor.These results suggest that some flavor peptides produced in fermented foods might be with bioactivities while providing a basis for the exploration and application of multi-functional peptides.展开更多
Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environme...Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.展开更多
The microbial-induced calcite precipitation(MICP)technique has been developed as a sustainable methodology for the improvement of the engineering characteristics of sandy soils.However,the efficiency of MICP-treated s...The microbial-induced calcite precipitation(MICP)technique has been developed as a sustainable methodology for the improvement of the engineering characteristics of sandy soils.However,the efficiency of MICP-treated sand has not been well established in the literature considering cyclic loading under undrained conditions.Furthermore,the efficacy of different bacterial strains in enhancing the cyclic properties of MICP-treated sand has not been sufficiently documented.Moreover,the effect of wetting-drying(WD)cycles on the cyclic characteristics of MICP-treated sand is not readily available,which may contribute to the limited adoption of MICP treatment in field applications.In this study,strain-controlled consolidated undrained(CU)cyclic triaxial testing was conducted to evaluate the effects of MICP treatment on standard Ennore sand from India with two bacterial strains:Sporosarcina pasteurii and Bacillus subtilis.The treatment durations of 7 d and 14 d were considered,with an interval of 12 h between treatments.The cyclic characteristics,such as the shear modulus and damping ratio,of the MICP-treated sand with the different bacterial strains have been estimated and compared.Furthermore,the effect of WD cycles on the cyclic characteristics of MICP-treated sand has been evaluated considering 5–15 cycles and aging of samples up to three months.The findings of this study may be helpful in assessing the cyclic characteristics of MICP-treated sand,considering the influence of different bacterial strains,treatment duration,and WD cycles.展开更多
文摘Bicyclic peptides,a class of polypeptides with two loops within their structure,have emerged as powerful tools in the development of new peptide drugs.They have the potential to bind to challenged drug targets,with antibody-like affinity and selectivity.Meanwhile,bicyclic peptides possess small molecule-like access to chemical synthesis,which is conducive to large-scale synthesis and screening.In the last five years,bicyclic peptide technology has been increasingly developed,and researchers have carried out a variety of studies to elucidate the potential functions of bicyclic peptides.With the continuous development of synthetic methods and the advances of new technology to build bicyclic peptide libraries,bicyclic peptides are now becoming widely used in the development of new drugs for various diseases.This perspective provides an overview of the structure types,synthesis and applications of bicyclic peptides in current drug development,and our own views on future challenges of bicyclic peptides.
文摘From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were established as cyclo (Pro(1)-Phe-Leu-Ala(1)-Thr-Pro(2)-Ala(2)-Gly) (1), cyclo (Pro(1)-Ala-Phe-Trp-Asp-Pro(2)-Leu-Gly) (2), cyclo (Pro(1)-Ile-Gly-Pro(2)-Val-Ala(1)-Ala(2)-Tyr) (3) and cyclo ( Pro-OMet-Trp-Ile-Gly-Ala-Leu-Asp) (4) respectively by means of extensive spectral methods.
基金This work was supported by the National Natural Science Foundation of China(0072058)863 Foundation of China(2003AA624010)+2 种基金the National Natural Science Foundation of Guangdong Province,China(021732,2003A 3050401)a strategic grant at City University of Hong Kong(7000650)E.B.G.J.acknowledges the Royal Society,U.K.and City University of Hong Kong for the award of the Kan Tong Po Visiting Professorship.
文摘New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 fromCastaniopsis fissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.
基金Grants from COMRA(Grant No.DY125-15-T-01 and SOA(Grant No.2010319123366025-4)National High Technology Development Project(863 Project,Grant No.2011AA10A202-2)National Key Technologies R&D Program(Grant No.2011BAE06B04)
文摘Chromatographic separation of the marine-derived bacterium Bacillus licheniformis resulted in the isolation of two new cyclic lipopeptides named ai-Cl6 surfactin （1） and ai-Cl4 surfactin （2）, together with iso-Cm5 surfactin and iso-Cl6 surfactin. The structures of the new cyclic lipopeptides were determined through extensive spectroscopic analysis. The sequences of the amino acids in cyclic nucleus were established by the ESI-MS/MS fragmentation, which provided an efficient method to detect lipopeptides from bacterium extracts without senaration
基金the National Key R&D Program of China(No.2022YFA1302900 to H.Liu)National Natural Science Foundation of China(Nos.82130105,22337003,82121005 to H.Liu+2 种基金and Nos.22177124,82322063 to J.Wang)Program of Shang-hai Academic Research Leader(No.23XD1460300 to J.Wang)the Lingang Laboratory(No.LG-GG-202204-02 to J.Wang)for supporting this work.We would like to acknowledge Shanghai Highline Therapeutics.
文摘Heterocycle-braced cyclic peptides have demonstrated enhanced metabolic stability,increased potency and selectivity.Here,we present a rapid synthesis method for constructing Trp(C7)-alkene(E)-crosslinked cyclic peptides with potent anti-proliferative activities against cancer cells,through C-H alkenylation and macrolactamization.This report addresses critical challenges associated with the installation and removal of the directing group N-Piv,configuration selectivity of the olefin,and intramolecular cyclization.No-tably,this method exhibits mild reaction conditions,traceless removal of the directing group,and high configuration selectivity.
基金This work was supported by State Key Laboratory of Bio-organic and Natural products Chemistry.
文摘We report here the synthesis of cyclic peptides using benzotriazolyloxy-bis(pyrrolidino)-carbonium hexafluoro- phosphate(BBC)as a coupling reagent with high yield and speed even in low concentration compared with the other usual coupling reagents.
文摘This paper reports the determination of stability constants for complexes of Cd(Ⅱ)with Gly, Ala,Val,Asp,Gly—Asp,Asp Gly,Gly—Gly and Gly—Gly—Gly using both micro—pH—metric titra- tions and the application of convolution—deconvolution cyclic voltammetry at 25℃ and I=0.10 mol· dm^(-3)(KNO_3).Stability constants were calculated from pH—metric data using the SUPERQUAD com- puter program and cyclic voltammograms were collected,stored and manipulated using the EG and G CONDECON 300 software.A considerably larger ligand:metal ratio(e,g.50:1)was possible using voltammetry.Evaluation of results from the two techniques suggests that stability constants for the species[CdL_2]and[CdL_3]are reliable when calculated fromvoltammetry while those for[CdL]are more reliable when determined by pH-metric titration.
文摘From Psammosilene tunicoides W. C. Wu et C. Y Wu, two cyclic octapeptides (namedpsammosilenins A and B) were isolated. Their structures were determined as cyclo(-Pro1-phe1-Pro2-Phe2-Phe3-Ala-Pro3-Leu-) and cyclo(-Pro1-Gly-Phe1-Val-Pro2-Phe2-Thr-Ile) by spectroscopicmethods.
基金Project supported by the Research Fund for the Doctoral Program of Higher Education.
文摘The interaction between HIV-1 DNA and five cyclic peptides （CP1-CP5） was investigated using electrospray ionization mass spectrometry （ESI-MS）. It revealed that CP1 [c（Ala-Tyr-Leu-Ala-Gly）] and CP4 [c（Pro-D-Tyr-Leu-D-Ala-Gly）] have the higher binding affinity with the duplex DNA among the five cyclic peptides.
基金supported by Principle Training Program of Education Department of Sichuan Province (No. 18CZ0042)Fundamental Research Fund of Chengdu University (No. 2081916027)Undergraduate Innovation Programm of Chengdu University (Nos. CDU_CX_2018250, CDU_CX_2018251)
文摘Protein-protein interactions(PPIs) are recognized as attractive therapeutic targets. However targeting PPIs especially intracellular ones has been proven extremely difficult for conventional drug-like small molecules, and biological drugs such as monoclonal antibodies have difficulty in reaching intracellular targets. Macrocyclic peptides are promising candidates of PPI regulators for their potential in combining high potency and biological stability together. Cell permeability of macrocyclic peptides may also be achieved by structural modifications or conjugation to a cell-penetrating sequence. Significant progress has been made in this research area in recent years. Important technology progress and recent examples of macrocyclic peptide PPI modulators are reviewed.
文摘Objective:To find potential peptide inhibitors against the NS2B/NS3 protease of DENV which in turn,can inhibit the viral replication inside host cell.Methods:Cyclic peptides were designed having combination of positively charged amino acids using ChemSketch software and were converted to 3D structures.DENV NS3 protein structure was retrieved from Protein Data Bank(PDB)using PDB Id:2FOM.DENV NS3 and cylic peptides were docked using MOE software after structural optimization.Results:Through molecular docking it was revealed that most of the peptides bound deeply in the binding pocket of DENV NS2B/NS3 protease an had interactions with catalytic triad.Peptide 2 successfully blocked the catalytic triad of NS2B/NS3 protease.Peptide 1,,4 and 6 also had potential interactions with active residues of the NS2B/NS3 protease while all other peptides were in close contact with the active sites of NS2B/NS3 protease thus,these peptides can serve as a potential drug candidate to stop viral replication.Conclusions:Thus.it can be concluded from the study that these peptides could serve as important inhibitors to inhibit the viral replication and need further in-vitro investigations to confirm their efficacy.
基金Universidad de Buenos Aires[UBACYT 2018-100246,PDE-48-2020],CONICET[PIP 11220200101898]and ANPCyT[PICT 2018-0930,PICT E 2018-0031]for partial financial support.
文摘The Antarctic fungus Cadophora malorum produces previously undescribed cyclic heptapeptides(cadophorin A and B)containing an anthranilic acid residue.The planar structure of these peptides was determined by high-resolution mass spectrometry combined with extensive 1D and 2D NMR spectroscopy.The absolute configuration of the amino acids was determined by Marfey’s method,with HPLC analysis of FDVA(Nα-(2,4-dinitro-5-fluorphenyl)-l-valinamide)derivatives making use of a PFP column.Remarkably,cadophorin 2 possesses both the uncommon d-Ile and d-allo-Ile in its structure.The peptides have metal binding properties as shown by LCMS with post column addition of metal salt solutions.These results were supported by DFT calculations.
文摘In biological controls using <em>Bacillus</em> spp., cyclic lipopeptides play a role as elicitors to induce disease resistance on various host plants. However, it is still unclear the specificity between cyclic lipopeptides and host plants to induce disease resistance. In this study, we aimed to clarify the specificity to induce disease resistance among cyclic lipopeptides on various host plants. Our data clearly showed both cyclic lipopeptides conferred disease suppression on most of host plants, but at different range of cyclic lipopeptide concentration. Our findings contribute to understanding the complex on the specificity of cyclic lipopeptide derived induced disease resistance.
基金supported by the National Natural Science Foundation of China(No.21472070)the Project for Jiangsu Scientific and Technological Innovation Team+2 种基金Fund for Jiangsu Distinguished Professorship ProgramProject Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,the 111 Project(No.111-2-06)the Jiangsu province“Collaborative Innovation Center for Advanced Industrial Fermentation”industry development program
文摘P-113 is a fragment of natural occurring peptide Histatin 5 found in human saliva. This peptide exhibited broad spectrum of antibacterial and antifungal biological activities. In this study, bifunctional P-113 peptides 2–5 were designed as Sortase A substrates and synthesized by solid support peptide synthesis,where the N-terminus were equipped with glycine and its analogues, and C-terminus were extended with LPETGGS, respectively. Under Sortase A catalyzed condition, head to tail cyclization products 7–10were afforded in yields from 76% to 93%. The conformation insights of linear peptides 2–5 and cyclic analogues 7–10 in aqueous buffers and in trifluroethanol（TFE） analyzed by circular dichroism（CD）suggested that a-helix structures were produced progressively in hydrophobic environment independent of the cyclization, which displayed the similar behavior as parent peptide P-113.
基金Supported by the National Natural Science Foundation of China(Nos.52293472,22473096 and 22471164)。
文摘Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynamic size and slower degradation.It is key to develop facile methods to large-scale synthesis of polymer rings with tunable compositions and microstructures.Recent progresses in large-scale synthesis of polymer rings against single-chain dynamic nanoparticles,and the example applications in synchronous enhancing toughness and strength of polymer nanocomposites are summarized.Once there is the breakthrough in rational design and effective large-scale synthesis of polymer rings and their functional derivatives,a family of cyclic functional hybrids would be available,thus providing a new paradigm in developing polymer science and engineering.
基金supported by the Low-Cost Long-Life Batteries program,China(No.WL-24-08-01)the National Natural Science Foundation of China(No.22279007)。
文摘The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).
基金supported by the central government and guides local funds for science and technology development(2022ZY0109).
文摘The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidomics and bioinformatics were used to screen flavor peptides from Inner Mongolian cheese and further assess their antioxidant and angiotensin I-converting enzyme(ACE)inhibitory properties.According to sensory data,YH8 and IL7 had detectable bitter tastes with low thresholds of 0.03 and 0.06 mmol/L,respectively.With an umami threshold range of 0.24‒0.81 mmol/L,VQ6,FK13,HP13 and QT14 exhibited a range of flavors dominated by umami,including sweet,bitter,salty,sour and kokumi.Antioxidant activity wise,YH8,VQ6,HP13 and QT14 were well represented.The above-mentioned peptides all had some ACE inhibitory effect.The bitter peptide IL7(IC_(50)=0.08 mmol/L)had the highest level of ACE inhibitory activity,followed by YH8(IC_(50)=0.33 mmol/L).These multi-functional peptides,which have been assessed for bioactive and taste features in Inner Mongolian cheese,may have positive impacts on health and harmonize the cheese’s overall flavor.These results suggest that some flavor peptides produced in fermented foods might be with bioactivities while providing a basis for the exploration and application of multi-functional peptides.
基金supported by the Shanghai 3-year Public Health Action Plan(grant number:GWVI-11.1-39).
文摘Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.
基金the financial support provided by the Ministry of Education(MoE),Government of IndiaThe second author acknowledges Coal India Limited for providing financial assistance for the research(Project No.CIL/R&D/01/73/2021).
文摘The microbial-induced calcite precipitation(MICP)technique has been developed as a sustainable methodology for the improvement of the engineering characteristics of sandy soils.However,the efficiency of MICP-treated sand has not been well established in the literature considering cyclic loading under undrained conditions.Furthermore,the efficacy of different bacterial strains in enhancing the cyclic properties of MICP-treated sand has not been sufficiently documented.Moreover,the effect of wetting-drying(WD)cycles on the cyclic characteristics of MICP-treated sand is not readily available,which may contribute to the limited adoption of MICP treatment in field applications.In this study,strain-controlled consolidated undrained(CU)cyclic triaxial testing was conducted to evaluate the effects of MICP treatment on standard Ennore sand from India with two bacterial strains:Sporosarcina pasteurii and Bacillus subtilis.The treatment durations of 7 d and 14 d were considered,with an interval of 12 h between treatments.The cyclic characteristics,such as the shear modulus and damping ratio,of the MICP-treated sand with the different bacterial strains have been estimated and compared.Furthermore,the effect of WD cycles on the cyclic characteristics of MICP-treated sand has been evaluated considering 5–15 cycles and aging of samples up to three months.The findings of this study may be helpful in assessing the cyclic characteristics of MICP-treated sand,considering the influence of different bacterial strains,treatment duration,and WD cycles.
