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1.
The antifungal activity of polyvinylpyrrolidone (PVP)-stabilized quantum-sized silver nanoparticles (SNPs) against the growth of Candida albicans has been demonstrated in the present study. C. albicans is a known opportunistic human pathogen causing superficial and systemic infections. Research data carried out on C. albicans so far have shown unequivocally that it develops resistance against conventional antifungal drugs and that the infections it causes are difficult to cure with conventional antifungal agents. Hence, it is urgent to find newer materials for the treatment of infections caused by C. albicans that must be safe for the host. PVP-capped SNPs were synthesized, and its surface plasmon band was observed at 410 nm. The growth of C. albicans was markedly inhibited when the cells were incubated with SNP. The minimum inhibitory concentration (MIC) of SNP was determined as 70 ng/ml, and this value is relatively lower when compared with the conventionally used antifungal drugs such as amphotericin B (0.5 μg/ml), fluconazole (0.5 μg/ml), and ketoconazole (8 μg/ml). The viability of SNP-treated cells was checked by measuring the metabolic activity using XTT assay. Field emission scanning electron microscopic (FE-SEM) and transmission electron microscopic (TEM) analyses of the cells treated with SNP have lost the structural integrity to a greater extent.  相似文献   

2.
Abstract

Tunicamycin E (1), featuring a methyl substitution at C-10′, was isolated from marine-derived Streptomyces xinghaiensis SCSIO S15077 originated from the South China Sea sediment together with six known compounds, tunicamycin B (2), tunicamycin X (3), tunicamycin A (4), streptovirudin D2 (5), tunicamycin C (6), and tunicamycin C3 (7). The structure of compound 1 was elucidated by detailed spectroscopic data analyses. All the compounds exhibited strong to moderate antibacterial activity against Gram-positive bacteria Bacillus thuringiensis BT01 and B. thuringiensis W102 with MIC values ranging from 0.008 to 2 μg/mL. Moreover, compounds 17 exhibited moderate antifungal activity against Candida albicans ATCC 96901 and C. albicans CMCC (F) 98001 with MIC values ranging from 2 to 32 μg/mL. This is the first report that tunicamycins exhibit antimicrobial activities against B. thuringiensis, C. albicans CMCC (F) 98001 and a fluconazole resistant strain C. albicans ATCC 96901.  相似文献   

3.
The use..... of aqueous leaf extract of Lavandula × intermedia for biosynthesis of silver nanoparticles (AgNPs) is presented. The plant extract was obtained by boiling dried leaves and using the obtained filtrate for the synthesis of AgNPs. The study was conducted to investigate an ecofriendly approach to metal nanoparticle synthesis and to evaluate the antimicrobial potential of both the aqueous plant extract and resulting silver nanoparticles against different microbes using the disc diffusion method. The synthesis of silver nanoparticles was monitored using ultraviolet–visible (UV–v is) spectroscopy, which showed a localized surface plasmon resonance band at 411 nm and a shift of the band to higher wavenumber of 422 nm after 90 min of reaction. Powder X-ray diffraction analysis and transmission electron microscopy of the obtained AgNPs revealed their crystalline nature, with average size of 12.6 nm. Presence of elemental silver was further confirmed by energy-dispersive X-ray spectroscopy. Fourier-transform infrared spectroscopy confirmed presence of phytochemicals from Lavandula × intermedia leaf extract on the AgNPs. The AgNPs showed good antimicrobial activity with inhibition zone ranging from 10 to 23 mm; the largest inhibition zone (23 mm) occurred against Escherichia coli. Generally, the AgNPs displayed more antimicrobial activity against all investigated pathogens compared with Lavandula × intermedia leaf extract, and were also more active than streptomycin against Klebsiella oxytoca and E. coli at the same concentration. The silver nanoparticles showed prominent antimicrobial activity with a lowest minimum inhibitory concentration (MIC) value of 15 μg/mL against E. coli, K. oxytoca, and Candida albicans.  相似文献   

4.
Green fabrication has become a safe approach for producing nanoparticles. Plant-based biogenic synthesis of silver nanoparticles (AgNPs) has emerged as a possible alternative to traditional chemical production. In this paper, we provide a low-cost, green synthesis of AgNPs utilizing using Kei-apple (Dovyalis caffra) fruit extract. Ultraviolet–visible (UV–Vis) spectroscopy, Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Scanning-Electron Microscope (SEM), and Dynamic Light Scattering (DLS) analyses were used to characterize green produced AgNPs. The formation of AgNPs was shown to have a surface resonance peak of 415 nm in UV–visible spectra, and FTIR spectra verified the participation of biological molecules in Synthesis of AgNPs. The TEM revealed that the biosynthesized AgNPs were mostly spherical in form, with size range of 12–53 nm. XRD diffractogram was used to demonstrate the face cubic centre (fcc) character of AgNPs. Excellent anticancer activity of AgNPs was recorded where more than 80% of Prostate Cancer (PC-3) cell lines was inhibited by 100–150 µg/mL of AgNPs, while 38% only was recorded using AgNO3 and 55.62% was recorded D. caffra fruit extract at 150 µg/mL. Destructions of PC-3 cell was observed as a result of exposed to AgNPs, followed by D. caffra fruit extract, while minor alterations were recorded as exposed to AgNO3. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging using AgNPs was three fold using fruit extract at 100 µg/mL indicating good antioxidant activity. Excellent inhibitory activity of AgNPs was recorded against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus with inhibition diameter zone 28.22 ± 0.25 mm, 23.21 ± 0.35 mm, 27.25 ± 0.03 mm, 28.40 ± 0.15 mm, 29.23 ± 0.44 mm, and 9.52 ± 0.5 mm, respectively compared with AgNO3. D. caffra fruits considered a promising and safe source for fabrication of AgNPs with multi-biological functions.  相似文献   

5.
Two rare polyketides, named as janthinopolyenemycins A (1) and B (2), were isolated from a co-culture of two marine-sourced bacteria Janthinobacterium spp. ZZ145 and ZZ148. Their structures were established by a combination of extensive NMR spectroscopic analyses, HRESIMS data, and ECD calculation. Both janthinopolyenemycins A and B showed activity in inhibiting the growth of Candida albicans with a MIC value of 15.6?μg/mL and a MBC value of 31. 25?μg/mL.  相似文献   

6.
Seven novel naphthalen-1-ylmethyl substituted silver N-heterocyclic carbene (Ag–NHC) complexes (1–7) were synthesized by the interaction of benzimidazolium salts with silver carbonate in dry dichloromethane at room temperature and characterized by means of spectroscopic methods and elemental analysis techniques. The Ag–NHC compounds were tested for their in vitro antibacterial and antifungal activity against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Candida albicans and Candida tropicalis and showed high antimicrobial activities. The synthesized complexes, in particular, demonstrated better results against both fungi and gram-positive bacteria.  相似文献   

7.
In the past years, use of plant sources for the biosynthesis of nanoparticles has become very important. Gold nanoparticles with unique biological properties are one of these materials which are being investigated extensively. In the present study, the aqueous extract of Pistacia vera hull was utilized to fabrication of gold nanoparticles (AuNPs@PV) in a facile, environmentally friendly, and affordable way. Then the anticancer, antifungal, antibacterial, and photocatalytic potentials of AuNPs@PV were also investigated. The results of various techniques applied, including XRD, UV–vis, TEM, FT-IR, EDS, and FESEM showed the biological reduction of Au3+ ions to Au0. Antibacterial studies were performed on a wide range of bacteria including seven strains of ATCC and seven strains of drug-resistant pathogens. According to the findings of this research, it seems that biosynthesized gold nanoparticles had good antibacterial activity against ATCC and drug-resistant strains of bacteria. The MIC values of E. coli, S. aureus, P. mirabilis, P. aeruginosa, E. faecalis, K. pneumonia, A. baumannii were 34.37, 4.2, 8.59, 4.29, 0.5, 34.37, and 8.59 μg/mL, respectively. The result of the antifungal investigation showed that two pathogenic fungi, Candida albicans (IFRC1873) and Candida albicans (IFRC1874) were susceptible to AuNPs@PV with MIC values of 550 and 137 μg/mL, respectively. Furthermore, AuNPs@PV revealed noteworthy anticancer efficacy against AGS-3 and MCF-7 cell lines with IC50 values of 58.31 and 148.1 μg/mL, respectively. The results of the cytotoxicity effect of AuNPs@PV on BEAS-2B as a normal cell line indicated the selectivity of AuNPs@PV on cancerous cells. Furthermore, the fabricated AuNPs@PV under UV irradiation exhibited significant potential in the decolorization of methylene orange (MO) with a percent decolorization of 91.5 % after 20 min. Therefore, it can be concluded that biosynthesized gold nanoparticles as a photocatalyst, anti-bacterial, antifungal, and anti-cancer agents have potential applications in the fields of environment and biology.  相似文献   

8.
The enhanced thermal and antimicrobial activity of silver nanoparticles prompts their uses in many medical devices. Mesua ferrea L. seed oil based antimicrobial biocompatible hyperbranched and linear polyurethane/Ag nanocomposites have been prepared in dimethylformamide without using any extra reducing agent. Formation of the stable and well-dispersed Ag nanoparticles was confirmed by ultra violet, X-ray diffractometeric, transmission electron microscopic and Fourier transform infra-red spectroscopic analyses. The enhancement of properties like thermal stability by (46-53)°C and 42 °C, tensile strength to ∼170% and ∼180% for hyperbranched and linear polyurethanes respectively was observed by the formation of nanocomposites. The cytocompatibility test based on the inhibition of RBC hemolysis showed that the materials lack cytotoxicity. The nanocomposites showed biodegradability as conferred from the bacterial degradation. Dose dependent excellent antibacterial activity of the nanocomposites against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria and antifouling activity against Candida albicans was observed.  相似文献   

9.
《Analytical letters》2012,45(7):1180-1189
The green synthesis of silver nanoparticles using an aqueous extract of Ferocactus echidne(a member of the cactus family) as a reducing agent is reported. It is simple, efficient, rapid, and ecologically friendly compared to chemical-mediated methods. Ferocactus echidne is a plant of high medicinal value and rich in polyphenolic antioxidants. The extraction is simple and the product rapidly reduces silver ions without involvement of any external chemical agent. The reduction of silver nanoparticles was characterized by ultraviolet-visible spectrometry as a function of time and concentration. The results show that Ferocactus echidne reduces silver ions within 6 h depending upon the concentration. Further increases in reaction time may result in a blue shift, indicating an increase in particle size, whereas concentration had a minor effect on the particle size. The structure of synthesized nanoparticles was investigated by infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The infrared spectra indicated the association of organic materials with silver nanoparticles to serve as capping agents. Scanning electron micrographs showed that synthesized silver nanoparticles were nearly uniform and elliptical in shape with diameters of 20 to 60 nm. X-ray diffraction confirmed the formation of silver nanoparticles with an approximate 20 nm particle size calculated using the Debye-Scherer equation. Biological tests revealed that the silver nanoparticles were active against gram positive and negative bacteria( Escherichia coli and Staphylococcus aureus) and fungi (Candida albicans), indicating their broad spectrum antibiotic and antifungal abilities.  相似文献   

10.
Abstract

This study was designed to establish the most effective solvent/technique for extracting antioxidant phytoconstituents from leaves and flower buds of Inula viscosa (L.) Aiton (Asteraceae) grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. The antioxidant potential was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. I. viscosa leaf and flower bud extracts displayed the strongest effect in the DPPH test, being the Soxhlet ethanol the most active ones (IC50 = 54.24?±?0.21?μg/mL and 39.77?±?0.23?μg/mL); thus, they were selected for further investigations. The antimicrobial efficacy of the Soxhlet ethanol extracts against ATCC and food isolates strains was assayed; the leaf extract showed the best activity, and Candida albicans was the most sensitive strain (MIC = 125?µg/mL). The extracts resulted non-toxic against Artemia salina. Among the phenolics characterised by HPLC-PDA-ESI-MS, hispidulin hexoside, patuletin and spinacetin were identified for the first time.  相似文献   

11.
Candida albicans is an important opportunistic fungal pathogen capable of provoking infection in humans. In the present study, we evaluated the antifungal effect of 23 ester derivatives of the cinnamic and benzoic acids against 3 C. albicans strains (ATCC-76645, LM-106 and LM-23), as well as discuss their Structure–Activity Relationship (SAR). The antifungal assay results revealed that the screened compounds exhibited different levels of activity depending on structural variation. Among the ester analogues, methyl caffeate (5) and methyl 2-nitrocinnamate (10) were the analogues that presented the best antifungal effect against all C. albicans strains, presenting the same MIC values (MIC = 128 μg/mL), followed by methyl biphenyl-2-carboxylate (21) (MIC = 128, 128 and 256 μg/mL for C. albicans LM-106, LM-23, and ATCC-76645, respectively). Our results suggest that certain molecular characteristics are important for the antifungal action.  相似文献   

12.
Silver nanoparticles (AgNPs) were synthesised using Kalopanax septemlobus plant leaf extracts. UV-visible spectrophotometric, Fourier-transform infrared, electron dispersive X-ray spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses confirmed synthesis of AgNPs. TEM micrographs revealed presence of well-dispersed AgNPs predominantly of small size and different shapes with an average particle size of 30.8 nm. Antimicrobial susceptibility tests of AgNP treatments revealed variability in sensitivity of bacteria Bacillus cereus and Saccharophagus degradans under study. Minimum inhibitory concentration (MIC) values of the AgNPs for B. cereus and S. degradans were found to be 30 and 10 μg/mL, respectively. The mixed culture of B. cereus and S. degradans treated with AgNPs at 10 μg/mL showed increase in growth with time, suggesting survival of bacteria in liquid media. The plating of mixed culture before AgNP treatment showed presence of both bacteria, but 24-h-old mixed culture treated with AgNPs at the concentration of 10 μg/mL showed presence of B. cereus colonies. SEM micrographs revealed damage to S. degradans cells but no effect on B. cereus cells after AgNP treatment. Confocal microscopic observations of AgNP-treated mixed cultures by Nile blue A staining indicated intact polyhydroxyalkanoates producing flourescent cells of B. cereus but damage and deformities in S. degradans cells. This study suggests that AgNPs can selectively inhibit growth of S. degradans and retain B. cereus at MIC of S. degradans. This report is a case study for selective inhibition of one bacteria and growth of the other in a culture using plant-synthesized silver nanoparticles.  相似文献   

13.
One new indole diterpenoid, drechmerin I (1), was isolated from the fermentation broth of Drechmeria sp. isolated from the root of Panax notoginseng. Its structure was elucidated based on 1 D and 2 D nuclear magnetic resonance (NMR), high resolution electrospray ionization mass spectrum (HRESIMS), and electronic circular dichroism (ECD) spectroscopic analyses as well as TD DFT calculations of ECD spectra. Drechmerin I (1) was assayed for its antimicrobial activity against Candida albicans, Staphylococcus aureus, Bacillus cereus, B. subtillis, Pseudomonas aeruginosa, and Klebsiella pneumonia, respectively. Drechmerin I (1) showed antimicrobial activities against B. subtillis with an MIC value of 200 μg/mL. The interaction of S. aureus peptide deformylase with drechmerin I (1) was investigated by molecular docking.  相似文献   

14.
Citridones E-G (1-3), three new phenylpyridone derivatives together with two known curvularins (4 and 5) were isolated from the solid culture of the endophytic fungus Penicillium sumatrense GZWMJZ-313 in Garcinia multiflora. The structures of new compounds were determined in the light of spectroscopic data,X-ray and ECD calculation. Compounds 1 and 3 are racemates, while compound 2 is optically pure.Compounds 1 and 4 showed antibacterial and antifungal activities against Staphylococcus aureus,Pseudomonas aeruginosa, Clostridium perfringens, Escherichia coli and Candida albicans with MIC values ranging from 8 μg/mL to 64 μg/mL.  相似文献   

15.
The antimicrobial effects of the cold plasma for the dental pathogenic microorganism propose a promising approach to the Denture Stomatitis (DS) treatment. However, it is crucial to understand that the complexity of the biofilm microenvironment may compromise the efficiency of the therapy. As one of the major issue for DS, Candida albicans biofilms (ATCC10231) formed on denture base resins were treated by cold Ar/O2 (2 %) plasma jet. Spatial viability of the biofilms was investigated with confocal scanning laser microscopy through evaluating their inside cross-section properties. Results showed Candida albicans biofilms with thickness of ~100 µm was completely inactivated by 8 min plasma treatment. Morphology change of the fungi was also observed by the scanning electron microscopy. Drug susceptibilities, the sessile minimum inhibitory concentration (SMIC50) of the biofilm for amphotericin B and fluconazole were decreased from >32 and >256 µg/mL to 8 and 64 µg/mL after 1 min’s plasma treatment, respectively. The reactive species produced from plasma were monitored by optical emission spectroscopy. The successfully inactivation of Candida albicans biofilms and the significant enhancement of its drug susceptibilities induced by the plasma released reactive species propose a promising strategy for the treatment of DS caused by drug-resistant Candida albicans biofilms.  相似文献   

16.
In this study a series of new mannich bases were synthesized and characterized by elemental and spectral (IR, 1H NMR, 13C NMR) studies. All the synthesized compounds were evaluated for their antimicrobial activity by broth dilution method against two Gram negative strains (Escherichia coli and Pseudomonas aeruginosa), two Gram positive strains (Bacillus subtilis and Staphylococcus aureus) and fungal strain (Candida albicans and Aspergillus niger). Preliminary pharmacological evaluation revealed that the compounds (3f, 3i, 3j, and 3k) showed good activity against these strains. The result demonstrates the potential and importance of developing new mannich bases which would be effective against resistant bacterial and fungal strain.  相似文献   

17.
Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), β-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 μg/mL, a scavenging capacity SC50 of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC50 of 146 ± 20 µg/mL.  相似文献   

18.
Silver is known for its antimicrobial effects and silver nanoparticles are gaining their importance due to their antimicrobial activities. The aims of the current study were to use plant extract for the biosynthesis of silver nanoparticles and to evaluate their antibacterial and antioxidant activity in vitro. The results indicated that silver nanoparticles (AgNPs) can be synthesized in a simple method using Chenopodium murale leaf extract. The TEM analysis showed that the sizes of the synthesized AgNps ranged from 30 to 50 nm. The essential oil of C. murale leaf extract was formed mainly of α-Terpinene, (Z)-Ascaridole and cis-Ascaridole. The total phenolic compounds and total flavonides were higher in AgNPs-containing plant extract compared to the plant extract. AgNPs-containing leaf extract showed a higher antioxidant and antimicrobial activity compared to C. murale leaf extract alone or silver nitrate. It could be concluded that C. murale leaf extract can be used effectively in the production of potential antioxidant and antimicrobial AgNPs for commercial application.  相似文献   

19.
Six unknown cyathane diterpenes, named cyathinins A – E, and 10-hydroxyerinacine S, were isolated from Cyathus subglobisporus BCC44381 along with six known compounds, striatoid C, striatin C, striatals A, C, D, and glochidone. The chemical structures were determined by means of high resolution mass spectrometry (HRESI-MS) and nuclear magnetic resonance (NMR) spectroscopy. The absolute configurations were confirmed by X-ray diffraction analysis. The isolated active compounds exhibited antimalarial against Plasmodium falciparum (IC50 0.88–7.51?μM), antibacterial activities against Mycobacterium tuberculosis (MIC 25–50?μg/mL), Gram-positive bacteria of Bacillus cereus and Enterococcus faecium (MIC 0.78–50?μg/mL) and Gram-negative bacteria of Escherichia coli, Acinetobacter baumannii and Klebsiella pneumoniae in a presence of phenylalanine-arginine β-naphthylamide (MIC 3.13–50?μg/mL), antifungal activity against Candida albicans (IC50 8.6–80.3?μM) activities, and cytotoxic activity against both cancerous (MCF-7, KB, NCI-H187, IC50 0.36–28.32?μM) and non-cancerous (Vero, IC50 0.13–91.50?μM) cells.  相似文献   

20.
Numerous species of Allium genus have been used in the traditional medicine based on their vast biological effects, e.g., antimicrobial, digestion stimulant, anti-sclerotic, soothing, antiradical or wound healing properties. In this work, unpolar and polar extracts from two lesser-investigated species of Allium growing in Kazakhstan, Allium galanthum Kar. & Kir. (AG) and A. turkestanicum Regel. (AT), were studied for their composition and biological effects. In the HPLC-ESI-QTOF-MS/MS analyses of water and alcoholic extracts simple organic acids, flavonoids and their glycosides were found to be the best represented group of secondary metabolites. On the other hand, in the GC-MS analysis diethyl ether, extracts were found to be rich sources of straight-chain hydrocarbons and their alcohols, fatty acids and sterols. The antimicrobial activity assessment showed a lower activity of polar extracts, however, the diethyl ether extract from AT bulbs and AG chives showed the strongest activity against Bacillus subtilis ATCC 6633, B. cereus ATCC 10876, some species of Staphylococcus (S. aureus ATCC 25923 and S. epidermidis ATCC 12228) and all tested Candida species (Candida albicans ATCC 2091, Candida albicans ATCC 10231, Candida glabrata ATCC 90030, Candida krusei ATCC 14243 and Candida parapsilosis ATCC 22019) with a minimum inhibitory concentration of 0.125–0.5 mg/mL. The highest antiradical capacity exhibited diethyl ether extracts from AG bulbs (IC50 = 19274.78 ± 92.11 mg Trolox eq/g of dried extract) in DPPH assay. In ABTS scavenging assay, the highest value of mg Trolox equivalents, 50.85 ± 2.90 was calculated for diethyl ether extract from AT bulbs. The same extract showed the highest inhibition of mushroom tyrosinase (82.65 ± 1.28% of enzyme activity), whereas AG bulb ether extract was the most efficient murine tyrosinase inhibitor (54% of the enzyme activity). The performed tests confirm possible cosmeceutical applications of these plants.  相似文献   

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