Objective:To evaluate in ritro antimicrobial activities of selected 58 ethno-medicinal plant extracts with a view to assess their therapeutic potential.Methods:A total of 58 traditional Chinese medicinal plants were c...Objective:To evaluate in ritro antimicrobial activities of selected 58 ethno-medicinal plant extracts with a view to assess their therapeutic potential.Methods:A total of 58 traditional Chinese medicinal plants were carefully selected based on the literature review and their traditional use.The antimicrobial activities of ethanol extracts of these medicinal plants were tested against fungi(Aspergillus funigaius),yeast(Candida albicans),gram-negative(Acirelobacter haumannii and Pseudornnruis aeruginosa)and gram-positive bacteria(Staphglococcus aureus).The activities were tested at three different concentrations of 1.00,0.10 and 0.01 mg/mL.The data was analysed using Gene data Screener program.Results:The measured antimicrobial activities indicated that out of the 58 plant extracts,15 extracts showed anti-fungal activity and 23 extracts exhibited anti-bacterial activity.Eight plant extracts have exhibited both anti-bacterial and anti-fungal activities.For instance,Eucommia ulmoides,Pohgonum cuspidcrtum,Poria cocas and Uncaria rhineophylla showed activity against both bacterial and fungal strains,indicating their broad spectrum of activity.Conclusions:The results revealed that the ethanol extracts of 30 plants out of the selected 58 possess significant antimicrobial activities.It is interesting to note that the findings from the current study are consistent with the traditional use.A clear correlation has also been found between the antimicrobial activity and the flavonoid content of the plant extracts which is in agreement with the literature.Hence.the results presented here can be used to guide the selection of potential plant species for the isolation and structure elucidation of novel antimicrobial compounds in order to establish the structure-activity relationship.This in turn is expected to lead the way to the discovery of novel antimicrobial agents for therapeutic use.展开更多
Objective:To study the morphology,biochemistry and bioactivity of the epidermal glands of the glandular morphotype of Christella parasitica(C.parasitica)(L.) H.Lev.Methods: Morphological studies on epidermal glands we...Objective:To study the morphology,biochemistry and bioactivity of the epidermal glands of the glandular morphotype of Christella parasitica(C.parasitica)(L.) H.Lev.Methods: Morphological studies on epidermal glands were earned out by using light microscope and scanning electron microscope.To prepare the extract,the shade-dried fronds of glandular morphotype were soaked in acetone.For antibacterial studies paper disc method was followed by using various pathogenic bacteria.Results:Detailed micromorphological,phytochemical and bioactivity studies on a medicinal fern C.parasitica(L.) H.Lev.showed its inlraspecific variation in antibacterial activity.The presence or absence of the epidermal glands was the key factor for antibacterial activity in the morphovariants of this species.The epidermal glands were orange-coloured,stalked and elongated ones of about 84.2μm×45μm,and distributed on the undersurface of cosla,coslules and veins in croziers,young and mature leaves.Frequency of glands varied from 15/cm on costa in mature leaves to 140/cm on costules in croziers.The acetone extract of the glands showed antibacterial activities and also toxic effect against mosquito larvae and tadpoles of frog.Preliminary phytochemical analysis and HPLC studies of the gland extract showed the presence of various kinds of terpenoids,alkaloids,tannins,saponins and flavonoids in it.Conclusions:The present study shows that epidermal glands of the glandular morphotype of C. parasitica(L.) H.Lev.have several bioactive compounds and such rare moiphovariant should be conserved in nature.The next step is to isolate the pure compounds and to screen the bioactivity of individual compounds of the epidermal glands.展开更多
Objective:To examine the ethanol,aqueous,chloroform,benzene,acetone and petroleum ether extracts of Hemigraphis colorata(H.colorata) leaves and stem and Elephantopus scaber (E.scaber) leaves,root and flower for the pr...Objective:To examine the ethanol,aqueous,chloroform,benzene,acetone and petroleum ether extracts of Hemigraphis colorata(H.colorata) leaves and stem and Elephantopus scaber (E.scaber) leaves,root and flower for the presence of phyto-constituents and screened the antibacterial activity against the selected pathogens.Methods:The fresh materials were shade dried and powdered using the tissue blender.The dried and powered materials(50 g) were extracted successively with 200 mL of aqueous,acetone,benzene,chloroform,etganol.and petroleum ether by using Soxhlet extractor for 8 h at a temperature not exceeding the boiling point of the solvent.Aqueous,acetone,benzene,chloroform,ethanol.and petroleum ether extracts were prepared from powdered materials were used for preliminary phytnehemical and antimicrobial studies using standard methods.Results:The crude aqueous,acetone,benzene,chloroform, ethauol.and petroleum ether extracts E.scaber leaves,flower and root and H.colorata leaves and stem demonstrated that out of(5×6×12 = 360) tests for the presence or absence of the above compounds.188 tests gave positive results and the remaining 172 gave negative results. The results of the phvtochemical screening revealed that phenol(12/12).carbohydrates(9/12). steroids(8/12).saponins and coumarins(7/12).tannins(6/12),proteins(5/12).earboxylic acid and flavonoids(4/12).xanthoproteins(3/12) and alkaloids(2/12) presence in the crude aqueous, acetone,benzene,chloroform,ethanol.and petroleum ether extracts of H.colorata leaves and stem.The crude aqueous,acetone,benzene,chloroform,ethanol.and petroleum ether extracts E.scaber leaves,flower and root displayed the presence of phenol(18/18).tannin(17/18). carbohydrates(16/18).steroids(14/18),oarboxylic acid and coumarins(12/18).saponins(10/18), xanthoprotein(9/18).flavonoids(7/18).protein(4/18) and alkaloids(2/18).The root ethanolic extracts of E.scaber illustrated the highest zone of inhibition against three pathogens viz.. Staphylococcus aureus(S.aureus)(24 mm).Escherichia coli(E.coli)(16 mm) and Psemlomonas aeruginosa {P.aeruginosa)(13 mm).The chlorofrom extracts of E.scaber showed the highest zone of inhibition against Bacillus cereus(B.ceretus)(12 mm).The leaves ethanolic extracts of E.scaber demonstrated the highest zone of inhibition against three pathogens viz.,Enterococcus faecalis (E.faecalis)(18 mm).Proteus mirabilis(P.mirabilis)(17 mm).Salmonella Typhi(S.typhi)(14 mm) and Enterobacter sp.(11 mm) While the benzene extracts of H.colorata demonstrated maximum zone of inhibition against the pathogen Acinetobucter sp.(14 mm) and S.aureus (12 mm).Conclusions:It is hoped that this study would direct to the establishment of some compounds that could be used to invent new and more potent antimicrobial drugs of natural origin.展开更多
The tobacco Ralstonia Solanacearum were both cultured on nutrient agar plates and inoculated in seedling stage of tobacco, then treated with K1 and K2, two anti-bacterial agents, at a serial con-centrations to study t...The tobacco Ralstonia Solanacearum were both cultured on nutrient agar plates and inoculated in seedling stage of tobacco, then treated with K1 and K2, two anti-bacterial agents, at a serial con-centrations to study their inhibitory efficiency. The result indicated that K1 can inhibit R. Solanacearum growth entirely, at the concentration range from 1/50 to 1/5000. K2 can reach the same result at the concentration range from 1/50 to 1/50000. Compared with the control plates, K1, at the concentration 1/50000, had no significant differences, and the average number of colony per plate was 112-115. The immature tobacco shown wilt as soon as inoculated with R. Solanacearum, and recovered gradually after using K1, K2. The densities of microbial suspension, handled by K1, K2 within 10 hs, were both significantly lower than the controlled ones. The optical microscopy also shown that handled microbial body differed from the controlled, whose body was regular short, rod shape as opposed to the handled ones with irregular rod shape and damaged body. All the results indicated that K1 and K2 both had inhibitory effects on tobacco R. Solanacearum, and K2 was more efficient than K1.展开更多
Objective:To investigate the anti-biofilm and anti-bacterial activity of Junceella juncea(J.juncea)against biofilm forming pathogenic strains.Methods:Gorgonians were extraeted with methanol and analysed with fourier t...Objective:To investigate the anti-biofilm and anti-bacterial activity of Junceella juncea(J.juncea)against biofilm forming pathogenic strains.Methods:Gorgonians were extraeted with methanol and analysed with fourier transform infrared spectroscopy.Biofilm forming pathogens were identified by Congo red agar supplemented with sucrose.A quantitative spectrophotometric method was used to monitor in vitro biofilm reduction by microtitre plate assay.Anti-bacterial activity of methanolic gorgonian extract(MGE)was carried out by disc diffusion method followed by calculating the percentage of increase with crude methanol(CM).Results:The presence of active functional group was exemplified by FT-IR spectroscopy.Dry,black,crystalline colonies confirm the production of extracellular polymeric substances responsible for biofilm formation in Congo red agar.MGE exhibited potential anti-biofilm activity against all tested bacterial strains.The anti-bacterial activity of methanolic extract was comparably higher in Salmonella typhii followed by Escherichia colt,Vibrio cholerae and Shigella flexneri.The overall percentage of increase was higher by 50.2%to CM.Conclusions:To conclude,anti-biofilm and anti-bacterial efficacy of J.juncea is impressive over biofilm producing pathogens and are good source for novel anti-bacterial compounds.展开更多
OBJECTIVE To establish a small compound library via a versatile synthetic route for the investigation of natural-inspiring compounds containing N-hydroxypyridones motif as potential anti-plasmodial,anti-bacterial and ...OBJECTIVE To establish a small compound library via a versatile synthetic route for the investigation of natural-inspiring compounds containing N-hydroxypyridones motif as potential anti-plasmodial,anti-bacterial and iron(Ⅱ)-chelating agents.METHODS An amidation/cyclization approach was adopted to synthesize a library of N-hydroxyquinolinones.The anti-plasmodial susceptibility of lab clone 3D7 P.falciparum was measured using aprotocol modified from the WHO microtest.The minimum bactericidal concentration(MBC)values were determined against Escherichia coli and Staphylococcus arueus.Nine compounds were selected to test their iron(Ⅱ)-chelating abilities.The iron(Ⅱ)-chelating ability was determined by measuring the absorbance of ferrozine-iron complex at 562 nm.RESULTS A new route for the facile synthesis of a library of N-hydroxyquinolinones based on one-pot palladium catalyzed C-N amidation/dehydrocyclizationsequence was implemented.Four compounds show anti-plasmodial activities with the range of 1.1-1.4μmol·L-1,50% chelation abilities of the nine selected compounds were shown to be 0.24-0.29mmol·L-1.CONCLUSION Alibrary of N-hydroxyquinolinones was synthesized via a novel synthetic route.The anti-plasmodial and anti-bacterial activities of these compounds were evaluated.Four compounds show potent anti-plasmodial activities Nine compounds were examined for their propensities to undergo iron chelation and these compounds were shown to be promising iron(Ⅱ)chelators as compared to EDTA.展开更多
Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis o...Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis of AgNPs using green tea(GT)extract and two of its components,(-)-epigallocatechin gallate(EGCG)and(+)-catechin(Ct)as capping/stabilizing agents,is reported.The synthesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli,along with anticancer activity against HeLa cells.After administering nanoparticles to the body,they come in contact with proteins and results in the formation of a protein corona;hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme(HEWL)as a carrier protein.Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs.The binding constant(Kb)was found to be higher for EGCG-AgNPs((2.309±0.018)×104 M-1)than for GT-AgNPs and Ct-AgNPs towards HEWL.EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect,but GT-AgNPs had no such observable effects.Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL.The key findings of this research included the synthesis of AgNPs using GT extract and its constituent polyphenols,and showed significant antibacterial,anticancer and protein-binding properties.The-OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis,which might offer new opportunities having implications for nanomedicine and nanodiagnostics.展开更多
Cranberry,the fruit of Vaccinium macrocarpon Aiton,is becoming popular all over the world,due to its pleasant taste,nutraceutical value and biological activities.For a long time,98%of its yield has been from America.S...Cranberry,the fruit of Vaccinium macrocarpon Aiton,is becoming popular all over the world,due to its pleasant taste,nutraceutical value and biological activities.For a long time,98%of its yield has been from America.Since being introduced to China as an import in recent decades,cranberry has become a rapid success in the food industry even with the high transportation cost.Recently,V.macrocarpon was cultivated in the Northeast of China,and the area of cultivation has increased dramatically.Therefore,it is important to systematically determine the useful compounds and their activity in this“Made-in-China”cranberry.In the present study,the content of total phenolics,anthocyanins,proanthocyanidins,sugars and organic acids was determined.Our results demonstrated that domestic cranberry is a rich source of phenolics,anthocyanins,proanthocyanidins,sugars and organic acids.Analysis of the chemical composition of an acidic ethanol extract by UPLC-QTOF-MS identified 21 compounds as well as the contents determination of catechin and cyanidin-3-O-glucoside using RPHPLC.Furthermore,cranberry extract was tested for its anti-bacterial activity against five clinically important pathogens,as well as its inhibitory effect on the proliferation and migration of cancer cells in vitro.Our results demonstrated that cranberry produced in Chinese cultivation areas is a rich source of bioactive compounds and exhibited in vitro anti-microbial and anti-tumor activities.Our work provides essential information about the quality of domestic cranberry and facilitates the development of related industries.展开更多
The anti-bacterial adhesion properties of TiO2-coated polymethyl methacrylate (PMMA) surfaces are investigated systematically. In detail, the adhesion of S. aureus (gram positive) and E. coli (gram negative) to ...The anti-bacterial adhesion properties of TiO2-coated polymethyl methacrylate (PMMA) surfaces are investigated systematically. In detail, the adhesion of S. aureus (gram positive) and E. coli (gram negative) to TiO2-coated and uncoated PMMA surfaces are performed by the plate counting method. Afterwards, the adhesion free energy of bacteria on both supporting materials is quantified using the thermodynamic approach of Lifshitz van der Waals and acid/base interactions. The superior anti-adhesion capability of TiO2-coated PMMA is demonstrated when compared to native PMMA, both experimentally and theoretically.展开更多
A research on the process of cotton fabric flame-re-tarding,anti-bacterial finishing and one-bath finish-ing of anti-bacterial and flame-retarding is discussed.The flame retardant agent was phosphorous-contained,and t...A research on the process of cotton fabric flame-re-tarding,anti-bacterial finishing and one-bath finish-ing of anti-bacterial and flame-retarding is discussed.The flame retardant agent was phosphorous-contained,and the bacteriostatic finishing agent named SFR-1 wassynthesized.The flame retardancy of the fabric finishedcan meet the DOC FF3-71 Children Sleepwear Stan-dard.Its bacterial inhibiting capacity can meet and ex-ceed the requirements of similar products展开更多
The regeneration of alveolar bone after tooth extraction is critical for the placement of dental implants.Developing a rigid porous scaffold with defect shape adaptability is of great importance but challenging for al...The regeneration of alveolar bone after tooth extraction is critical for the placement of dental implants.Developing a rigid porous scaffold with defect shape adaptability is of great importance but challenging for alveolar bone regeneration.Herein,we design and synthesize a biocompatible poly(L-glutamic acid)-g-poly(ε-caprolactone)(PLGA-g-PCL)porous shape memory(SM)polymer.The PLGA-g-PCL is then copolymerized with acryloyl chloride grafted poly(ω-pentadecalactone)(PPDLDA)having a higher phase transition temperature than shape recovery temperature to maintain stiffness after shape recovery to resist chewing force.The hybrid pol-ydopamine/silver/hydroxyapatite(PDA/Ag/HA)is coated to the surface of(PLGA-g-PCL)-PPDL scaffold to afford the anti-bacterial activity.The porous SM scaffold can be deformed into a compact size and administered into the socket cavity in a minimally invasive mode,and recover its original shape with a high stiffness at body tem-perature,fitting well in the socket defect.The SM scaffold exhibits robust antibacterial activity against Staphy-lococcus aureus(S.aureus).The porous microstructure and cytocompatibility of PLGA allow for the ingrowth and proliferation of stem cells,thus facilitating osteogenic differentiation.The micro-CT and histological analyses demonstrate that the scaffold boosts efficient new bone regeneration in the socket of rabbit mandibular first premolar.This porous shape memory self-adaptive stiffened polymer opens up a new avenue for alveolar bone regeneration.展开更多
In current electronic information era,the complex application circumstance of 5G devices pursues the exploration of multi-functional electromagnetic wave(EMW)absorbent materials and it has become the crucial focus in ...In current electronic information era,the complex application circumstance of 5G devices pursues the exploration of multi-functional electromagnetic wave(EMW)absorbent materials and it has become the crucial focus in industrial development.A two-dimensional(2D)graphite nanosheet decorated by nickel nanocapsules(2D graphite/Ni@C nanocomposite)was fabricated to possess the EMW absorption and the Escherichia coli(E.coli)anti-bacterial performance simultaneously.By adjusting the filling ratio and injecting nitrogen doping,the value of minimum reflection loss is−36.08 dB and the effective absorption bandwidth reaches to 5.12 GHz(from 11.4 to 16.52 GHz)with the mass ratio of 30 wt%and the absorber thickness of 2 mm.This 2D nanocomposite simultaneously gets an excellent anti-bacterial function expressing an E.coli anti-bacterial rate of 92%during 24 h which is significantly correlated to the interaction between the nanostructure of the 2D nanographite and the nickel ion released from Ni@C nanocapsules.This work provides a new approach to develop a promising 2D anti-bacterial EMW absorber.展开更多
基金funded by the University of Western Sydney and the Fundacion MEDINAa public-private partnership of Merck Sharp&Dohme de Espana S.A./Universidad de Granada/Junta de Andalucia
文摘Objective:To evaluate in ritro antimicrobial activities of selected 58 ethno-medicinal plant extracts with a view to assess their therapeutic potential.Methods:A total of 58 traditional Chinese medicinal plants were carefully selected based on the literature review and their traditional use.The antimicrobial activities of ethanol extracts of these medicinal plants were tested against fungi(Aspergillus funigaius),yeast(Candida albicans),gram-negative(Acirelobacter haumannii and Pseudornnruis aeruginosa)and gram-positive bacteria(Staphglococcus aureus).The activities were tested at three different concentrations of 1.00,0.10 and 0.01 mg/mL.The data was analysed using Gene data Screener program.Results:The measured antimicrobial activities indicated that out of the 58 plant extracts,15 extracts showed anti-fungal activity and 23 extracts exhibited anti-bacterial activity.Eight plant extracts have exhibited both anti-bacterial and anti-fungal activities.For instance,Eucommia ulmoides,Pohgonum cuspidcrtum,Poria cocas and Uncaria rhineophylla showed activity against both bacterial and fungal strains,indicating their broad spectrum of activity.Conclusions:The results revealed that the ethanol extracts of 30 plants out of the selected 58 possess significant antimicrobial activities.It is interesting to note that the findings from the current study are consistent with the traditional use.A clear correlation has also been found between the antimicrobial activity and the flavonoid content of the plant extracts which is in agreement with the literature.Hence.the results presented here can be used to guide the selection of potential plant species for the isolation and structure elucidation of novel antimicrobial compounds in order to establish the structure-activity relationship.This in turn is expected to lead the way to the discovery of novel antimicrobial agents for therapeutic use.
文摘Objective:To study the morphology,biochemistry and bioactivity of the epidermal glands of the glandular morphotype of Christella parasitica(C.parasitica)(L.) H.Lev.Methods: Morphological studies on epidermal glands were earned out by using light microscope and scanning electron microscope.To prepare the extract,the shade-dried fronds of glandular morphotype were soaked in acetone.For antibacterial studies paper disc method was followed by using various pathogenic bacteria.Results:Detailed micromorphological,phytochemical and bioactivity studies on a medicinal fern C.parasitica(L.) H.Lev.showed its inlraspecific variation in antibacterial activity.The presence or absence of the epidermal glands was the key factor for antibacterial activity in the morphovariants of this species.The epidermal glands were orange-coloured,stalked and elongated ones of about 84.2μm×45μm,and distributed on the undersurface of cosla,coslules and veins in croziers,young and mature leaves.Frequency of glands varied from 15/cm on costa in mature leaves to 140/cm on costules in croziers.The acetone extract of the glands showed antibacterial activities and also toxic effect against mosquito larvae and tadpoles of frog.Preliminary phytochemical analysis and HPLC studies of the gland extract showed the presence of various kinds of terpenoids,alkaloids,tannins,saponins and flavonoids in it.Conclusions:The present study shows that epidermal glands of the glandular morphotype of C. parasitica(L.) H.Lev.have several bioactive compounds and such rare moiphovariant should be conserved in nature.The next step is to isolate the pure compounds and to screen the bioactivity of individual compounds of the epidermal glands.
文摘Objective:To examine the ethanol,aqueous,chloroform,benzene,acetone and petroleum ether extracts of Hemigraphis colorata(H.colorata) leaves and stem and Elephantopus scaber (E.scaber) leaves,root and flower for the presence of phyto-constituents and screened the antibacterial activity against the selected pathogens.Methods:The fresh materials were shade dried and powdered using the tissue blender.The dried and powered materials(50 g) were extracted successively with 200 mL of aqueous,acetone,benzene,chloroform,etganol.and petroleum ether by using Soxhlet extractor for 8 h at a temperature not exceeding the boiling point of the solvent.Aqueous,acetone,benzene,chloroform,ethanol.and petroleum ether extracts were prepared from powdered materials were used for preliminary phytnehemical and antimicrobial studies using standard methods.Results:The crude aqueous,acetone,benzene,chloroform, ethauol.and petroleum ether extracts E.scaber leaves,flower and root and H.colorata leaves and stem demonstrated that out of(5×6×12 = 360) tests for the presence or absence of the above compounds.188 tests gave positive results and the remaining 172 gave negative results. The results of the phvtochemical screening revealed that phenol(12/12).carbohydrates(9/12). steroids(8/12).saponins and coumarins(7/12).tannins(6/12),proteins(5/12).earboxylic acid and flavonoids(4/12).xanthoproteins(3/12) and alkaloids(2/12) presence in the crude aqueous, acetone,benzene,chloroform,ethanol.and petroleum ether extracts of H.colorata leaves and stem.The crude aqueous,acetone,benzene,chloroform,ethanol.and petroleum ether extracts E.scaber leaves,flower and root displayed the presence of phenol(18/18).tannin(17/18). carbohydrates(16/18).steroids(14/18),oarboxylic acid and coumarins(12/18).saponins(10/18), xanthoprotein(9/18).flavonoids(7/18).protein(4/18) and alkaloids(2/18).The root ethanolic extracts of E.scaber illustrated the highest zone of inhibition against three pathogens viz.. Staphylococcus aureus(S.aureus)(24 mm).Escherichia coli(E.coli)(16 mm) and Psemlomonas aeruginosa {P.aeruginosa)(13 mm).The chlorofrom extracts of E.scaber showed the highest zone of inhibition against Bacillus cereus(B.ceretus)(12 mm).The leaves ethanolic extracts of E.scaber demonstrated the highest zone of inhibition against three pathogens viz.,Enterococcus faecalis (E.faecalis)(18 mm).Proteus mirabilis(P.mirabilis)(17 mm).Salmonella Typhi(S.typhi)(14 mm) and Enterobacter sp.(11 mm) While the benzene extracts of H.colorata demonstrated maximum zone of inhibition against the pathogen Acinetobucter sp.(14 mm) and S.aureus (12 mm).Conclusions:It is hoped that this study would direct to the establishment of some compounds that could be used to invent new and more potent antimicrobial drugs of natural origin.
文摘The tobacco Ralstonia Solanacearum were both cultured on nutrient agar plates and inoculated in seedling stage of tobacco, then treated with K1 and K2, two anti-bacterial agents, at a serial con-centrations to study their inhibitory efficiency. The result indicated that K1 can inhibit R. Solanacearum growth entirely, at the concentration range from 1/50 to 1/5000. K2 can reach the same result at the concentration range from 1/50 to 1/50000. Compared with the control plates, K1, at the concentration 1/50000, had no significant differences, and the average number of colony per plate was 112-115. The immature tobacco shown wilt as soon as inoculated with R. Solanacearum, and recovered gradually after using K1, K2. The densities of microbial suspension, handled by K1, K2 within 10 hs, were both significantly lower than the controlled ones. The optical microscopy also shown that handled microbial body differed from the controlled, whose body was regular short, rod shape as opposed to the handled ones with irregular rod shape and damaged body. All the results indicated that K1 and K2 both had inhibitory effects on tobacco R. Solanacearum, and K2 was more efficient than K1.
基金Supported by DST-NRDMS,Government of India(grant No.041594/F3/2008/dt.08.12.2010)
文摘Objective:To investigate the anti-biofilm and anti-bacterial activity of Junceella juncea(J.juncea)against biofilm forming pathogenic strains.Methods:Gorgonians were extraeted with methanol and analysed with fourier transform infrared spectroscopy.Biofilm forming pathogens were identified by Congo red agar supplemented with sucrose.A quantitative spectrophotometric method was used to monitor in vitro biofilm reduction by microtitre plate assay.Anti-bacterial activity of methanolic gorgonian extract(MGE)was carried out by disc diffusion method followed by calculating the percentage of increase with crude methanol(CM).Results:The presence of active functional group was exemplified by FT-IR spectroscopy.Dry,black,crystalline colonies confirm the production of extracellular polymeric substances responsible for biofilm formation in Congo red agar.MGE exhibited potential anti-biofilm activity against all tested bacterial strains.The anti-bacterial activity of methanolic extract was comparably higher in Salmonella typhii followed by Escherichia colt,Vibrio cholerae and Shigella flexneri.The overall percentage of increase was higher by 50.2%to CM.Conclusions:To conclude,anti-biofilm and anti-bacterial efficacy of J.juncea is impressive over biofilm producing pathogens and are good source for novel anti-bacterial compounds.
基金The project supported by the Agency for Science Technology and Research(A*STAR)(JCO-10/03/FG/06/02)
文摘OBJECTIVE To establish a small compound library via a versatile synthetic route for the investigation of natural-inspiring compounds containing N-hydroxypyridones motif as potential anti-plasmodial,anti-bacterial and iron(Ⅱ)-chelating agents.METHODS An amidation/cyclization approach was adopted to synthesize a library of N-hydroxyquinolinones.The anti-plasmodial susceptibility of lab clone 3D7 P.falciparum was measured using aprotocol modified from the WHO microtest.The minimum bactericidal concentration(MBC)values were determined against Escherichia coli and Staphylococcus arueus.Nine compounds were selected to test their iron(Ⅱ)-chelating abilities.The iron(Ⅱ)-chelating ability was determined by measuring the absorbance of ferrozine-iron complex at 562 nm.RESULTS A new route for the facile synthesis of a library of N-hydroxyquinolinones based on one-pot palladium catalyzed C-N amidation/dehydrocyclizationsequence was implemented.Four compounds show anti-plasmodial activities with the range of 1.1-1.4μmol·L-1,50% chelation abilities of the nine selected compounds were shown to be 0.24-0.29mmol·L-1.CONCLUSION Alibrary of N-hydroxyquinolinones was synthesized via a novel synthetic route.The anti-plasmodial and anti-bacterial activities of these compounds were evaluated.Four compounds show potent anti-plasmodial activities Nine compounds were examined for their propensities to undergo iron chelation and these compounds were shown to be promising iron(Ⅱ)chelators as compared to EDTA.
基金the Science and Engineering Research Board(ECR File No.ECR/2016/000159 and CRG File No.CRG/2019/000852),Government of India,for funding this work。
文摘Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis of AgNPs using green tea(GT)extract and two of its components,(-)-epigallocatechin gallate(EGCG)and(+)-catechin(Ct)as capping/stabilizing agents,is reported.The synthesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli,along with anticancer activity against HeLa cells.After administering nanoparticles to the body,they come in contact with proteins and results in the formation of a protein corona;hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme(HEWL)as a carrier protein.Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs.The binding constant(Kb)was found to be higher for EGCG-AgNPs((2.309±0.018)×104 M-1)than for GT-AgNPs and Ct-AgNPs towards HEWL.EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect,but GT-AgNPs had no such observable effects.Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL.The key findings of this research included the synthesis of AgNPs using GT extract and its constituent polyphenols,and showed significant antibacterial,anticancer and protein-binding properties.The-OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis,which might offer new opportunities having implications for nanomedicine and nanodiagnostics.
基金This study was financially supported by“Liaoning Provincial Engineering Platform of the Development and Utilization of Endangered and Geo-authentic Medicinal Herbs”and“Propagation of Cranberry and the Establishment of Germplasm Resource Nursery(YZ2018ZR01)”.
文摘Cranberry,the fruit of Vaccinium macrocarpon Aiton,is becoming popular all over the world,due to its pleasant taste,nutraceutical value and biological activities.For a long time,98%of its yield has been from America.Since being introduced to China as an import in recent decades,cranberry has become a rapid success in the food industry even with the high transportation cost.Recently,V.macrocarpon was cultivated in the Northeast of China,and the area of cultivation has increased dramatically.Therefore,it is important to systematically determine the useful compounds and their activity in this“Made-in-China”cranberry.In the present study,the content of total phenolics,anthocyanins,proanthocyanidins,sugars and organic acids was determined.Our results demonstrated that domestic cranberry is a rich source of phenolics,anthocyanins,proanthocyanidins,sugars and organic acids.Analysis of the chemical composition of an acidic ethanol extract by UPLC-QTOF-MS identified 21 compounds as well as the contents determination of catechin and cyanidin-3-O-glucoside using RPHPLC.Furthermore,cranberry extract was tested for its anti-bacterial activity against five clinically important pathogens,as well as its inhibitory effect on the proliferation and migration of cancer cells in vitro.Our results demonstrated that cranberry produced in Chinese cultivation areas is a rich source of bioactive compounds and exhibited in vitro anti-microbial and anti-tumor activities.Our work provides essential information about the quality of domestic cranberry and facilitates the development of related industries.
基金Supported by the Program for Changjiang Scholars and Innovative Research Team in University (PCSIR0818)Health Ministry Foundation of China (WKJ2005-2-003)Natural Science Foundation of Fujian Province (2008H0089 and 2009J01025)
文摘The anti-bacterial adhesion properties of TiO2-coated polymethyl methacrylate (PMMA) surfaces are investigated systematically. In detail, the adhesion of S. aureus (gram positive) and E. coli (gram negative) to TiO2-coated and uncoated PMMA surfaces are performed by the plate counting method. Afterwards, the adhesion free energy of bacteria on both supporting materials is quantified using the thermodynamic approach of Lifshitz van der Waals and acid/base interactions. The superior anti-adhesion capability of TiO2-coated PMMA is demonstrated when compared to native PMMA, both experimentally and theoretically.
基金The project serial number 92B0716Shanghai Natural Science Foundation
文摘A research on the process of cotton fabric flame-re-tarding,anti-bacterial finishing and one-bath finish-ing of anti-bacterial and flame-retarding is discussed.The flame retardant agent was phosphorous-contained,and the bacteriostatic finishing agent named SFR-1 wassynthesized.The flame retardancy of the fabric finishedcan meet the DOC FF3-71 Children Sleepwear Stan-dard.Its bacterial inhibiting capacity can meet and ex-ceed the requirements of similar products
基金National Natural Science Foundation of China(No.52173131,51773113).
文摘The regeneration of alveolar bone after tooth extraction is critical for the placement of dental implants.Developing a rigid porous scaffold with defect shape adaptability is of great importance but challenging for alveolar bone regeneration.Herein,we design and synthesize a biocompatible poly(L-glutamic acid)-g-poly(ε-caprolactone)(PLGA-g-PCL)porous shape memory(SM)polymer.The PLGA-g-PCL is then copolymerized with acryloyl chloride grafted poly(ω-pentadecalactone)(PPDLDA)having a higher phase transition temperature than shape recovery temperature to maintain stiffness after shape recovery to resist chewing force.The hybrid pol-ydopamine/silver/hydroxyapatite(PDA/Ag/HA)is coated to the surface of(PLGA-g-PCL)-PPDL scaffold to afford the anti-bacterial activity.The porous SM scaffold can be deformed into a compact size and administered into the socket cavity in a minimally invasive mode,and recover its original shape with a high stiffness at body tem-perature,fitting well in the socket defect.The SM scaffold exhibits robust antibacterial activity against Staphy-lococcus aureus(S.aureus).The porous microstructure and cytocompatibility of PLGA allow for the ingrowth and proliferation of stem cells,thus facilitating osteogenic differentiation.The micro-CT and histological analyses demonstrate that the scaffold boosts efficient new bone regeneration in the socket of rabbit mandibular first premolar.This porous shape memory self-adaptive stiffened polymer opens up a new avenue for alveolar bone regeneration.
基金This work was supported by the National Natural Science Foundation of China(Nos.51871219,52071324,52031014 and U1908220)the National Key R&D Program of China(Nos.2022YFB3504804 and 2021YFC2202402)the Bintech‐IMR R&D Program(GYY‐JSBU‐2022-007).
文摘In current electronic information era,the complex application circumstance of 5G devices pursues the exploration of multi-functional electromagnetic wave(EMW)absorbent materials and it has become the crucial focus in industrial development.A two-dimensional(2D)graphite nanosheet decorated by nickel nanocapsules(2D graphite/Ni@C nanocomposite)was fabricated to possess the EMW absorption and the Escherichia coli(E.coli)anti-bacterial performance simultaneously.By adjusting the filling ratio and injecting nitrogen doping,the value of minimum reflection loss is−36.08 dB and the effective absorption bandwidth reaches to 5.12 GHz(from 11.4 to 16.52 GHz)with the mass ratio of 30 wt%and the absorber thickness of 2 mm.This 2D nanocomposite simultaneously gets an excellent anti-bacterial function expressing an E.coli anti-bacterial rate of 92%during 24 h which is significantly correlated to the interaction between the nanostructure of the 2D nanographite and the nickel ion released from Ni@C nanocapsules.This work provides a new approach to develop a promising 2D anti-bacterial EMW absorber.