Agar-well Diffusion Technique Research Articles

Antifungal films for strawberry packaging using carbon quantum dots derived from lemon and onion juice via green hydrothermal method

Fungi are the prime concern since they cause post-harvest decay in fruits such as strawberries; the fungi motivate the need for new antifungal agents. Among all these nanoparticles, the carbon quantum dots (CQDs) show the most promising results for their use in food packaging applications. Lemon carbon quantum dots (LCQD), which is derived from lemon juice, and onion carbon quantum dots (OCQD), which is derived from onion juice, were synthesized using the one-step hydrothermal method. The synthesized materials were then characterized using a transmission electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, and ultraviolet-visible (UV-Vis) spectroscopy. LCQD and OCQD solutions were applied to fresh strawberries for the purpose of conducting studies on weight loss, decay, and shelf-life extension. The antifungal activity of both CQDs was assessed against Rhizopus sp., Penicillium sp., Candida albicans, Aspergillus sp., and Botrytis cinerea using the agar-well diffusion technique. The obtained average size was 4.33±1.67 nm for LCQDs and 3.34±1.72 nm for OCQDs. Strawberries packaged with OCQDs and LCQDs showed weight loss of 5.21%±1.03% and 8.14%±1.09% on the fourth day of observation, respectively, against 18.71%±2.2% by control. On the same day, the decay rate for OCQDs was 11%, 40% for LCQDs, and 96.65% for control. Both exhibited antifungal activity, with inhibition zones ranging from 12.6-44.5 mm for various fungi. OCQD exhibits higher activity packaging compared to LCQD due to their smaller size and superior antifungal activity against a variety of fungi.

Green Synthesis, Spectroscopic, Electrochemical and Antifungal Characteristics of Ni-doped CeO2 Nanoparticles

This study intended to synthesize Nickel-doped Cerium oxide (Ni-CeO2 NPs) nanoparticles using Pedalium Murex leaf extract. X-ray diffraction (XRD) was used to investigate the structure of the Ni-CeO2 NPs. The XRD measurements showed that the Ni-CeO2 NPs crystallized into the face-centered cubic system. The Ni(1%)-CeO2 and Ni(3%)-CeO2 NP’s crystallite sizes were between 47[Formula: see text]nm and 59[Formula: see text]nm. FTIR and Raman spectral studies were conducted to investigate the sample’s atomic vibrations and chemical bonding. Energy-dispersive X-ray study and field-emission scanning electron microscopy were performed to examine the surface texture and chemical assembly of the Ni-CeO2 NPs. UV–Vis DRS spectrum study was performed to ascertain the reflectance characteristics and bandgap of Ni-CeO2 NPs. The Ni(1%)-CeO2 and Ni(3%)-CeO2 NPs were found to have bandgaps of 2.73[Formula: see text]eV and 2.82[Formula: see text]eV, respectively. Electrochemical impedance spectroscopy and cyclic voltammetry were employed to explore the electrochemical nature of Ni-CeO2 NPs and their capacitive properties at various scanning rates. Using the agar well-diffusion technique, the antifungal activities of Ni-CeO2 NPs were assessed. The experimental findings illustrate the utility of Ni-CeO2 NPs for supercapacitor electrode material and healthcare applications.

Novel hybrid thiazoles, bis-thiazoles linked to azo-sulfamethoxazole: Synthesis, docking, and antimicrobial activity

The reaction of sulfamethoxazolehydrazonoyl chloride with thiosemicarbazones, bis-thiosemicarbazones, or 4-amino-3-mercapto-1,2,4-triazole in dioxane in the presence of triethylamine as a basic catalyst at reflux resulted in the regioselective synthesis of thiazoles and bis-thiazoles linked to azo-sulfamethoxazole as novel hybrid molecules. The structures of the new compounds were confirmed using a range of spectra. Each compound's antibacterial properties were evaluated using the agar well-diffusion technique, and most of them demonstrated significant potency. In silico investigations revealed that the described compounds had strong interactions with the binding sites of MurE ligase, tyrosyl-tRNA synthetase, and dihydropteroate synthase, demonstrating inhibitory activity.

Evaluation Of the Antifungal Activity of Cassia fistula (Linn) On Phytopathogenic Fungi Isolated from Citrus sinensis

Citrus sinensis is a prominent tropical fruit with nutritional and economic benefits for humans. However, it can also be plagued by fungal diseases, causing global economic and production reduction. The extensive application of synthetic fungicides in agricultural systems has posed increased toxicological risks to humans and ecosystems. However, the varying phytochemicals found in medicinal plants have enabled them to be regarded as safe and effective alternatives. However, few studies have evaluated the use of Cassia fistula extracts as potential bio-fungicides. This research purposed to evaluate the antifungal activity of Cassia fistula leaflet extracts against phytopathogenic fungi. Ethanol as well as aqueous extracts of Cassia fistula leaves were assessed for antifungal activity. The agar well-diffusion technique was implemented for in vitro screening, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of all different extracts against isolated fungal species of Aspergillus, Penicillium and Geotrichum. All fungal isolates identified from the spoiled oranges were Aspergillus flavus, Aspergillus fumigatus, Geotrichum sp. and Fusarium sp. Preliminary phytochemical screening exhibited the presence of carbohydrates, terpenoids, quinones and saponins in both ethanolic and aqueous extracts. At 1000 mg/ml, the aqueous and ethanolic extracts had the highest antifungal activity against A. flavus (40 mm) and Fusarium sp. (38 mm), respectively. Both extracts had no antifungal activity against A. fumigatus at 62.5 mg/ml but zones of inhibition were observed from the positive and negative controls of ketoconazole and DMSO, respectively. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were evaluated at 62.5 mg/ml and 250 mg/ml, respectively. This study’s findings demonstrated the antifungal potential of C. fistula leaf extracts as a bio-fungicidal agent against fungal invasion in plants.

Fractionation and identification of bioactive compounds from a salt marsh plant Sesuvium portulacastrum (L.) and its antioxidant activity

Sesuvium portulacastrum (L.) is a fast-growing herbaceous perennial and halophyte belonging to the family Aizoaceae. Bioactive compound identification from halophytes is more helpful for the drug development process. The present investigation was to fractionate and identify the bioactive compounds of leaf extracts from Sesuvium potrucastrulam and evaluate their antioxidant potential. The Soxhlet extraction method was used in this study, and column chromatography was done for the partial purification. The bactericidal activity of the fraction was determined using the agar-well diffusion technique, and the effective fraction was analysed by GC-MS. A hydrogen peroxide-reducing assay was carried out on the antioxidant activity of the elite fraction. Five active fractions were collected from the crude extract. Fraction (F3) exhibited promising antibacterial and antioxidant activity. GS-MS analysis suggested the active compounds of the elite fraction are n-Hexadecanoic acid (29.70%), oleic acid (8.08%), octadecatrienoic acid (8.01%), 2-methoxy-4-vinylphenol (6.65%), tertracosamethyl-cyclododecasiloxane (6.55%), and lineolic acid (4.68%).

Synthesis, Characterization of New Metal Complexes of Ligand [3-(4-hydroxyphenyl)-2-(3-(4-methoxybenzoyl) thio ureido)propanoicacid] (HMP ) and Study of the Biological Activity

A new ligand [3-(4-hydroxyphenyl)-2-(3-(4-methoxybenzoyl)thioureido)propanoic acid] (HMP) was synthesized by reaction of Tyrosine and, 4- methoxy benzoylisothiocyanate , and used for the synthesis of a series of new metalcomplexes cobalt(II) Nickel (II), Copper (II), Zinc(II) , Palladium(II), Cadmium (II), mercury (II). The mineral complexes were characterized by molar conductivity, elemental analyzes (C.H.N.S), and spectroscopic techniques: electronic spectral UV-Vis , infrared FT-IR , 1H- NMR, 13C-NMR and magnetic properties . The results confirmed that the ligand (HMP) behaves as a Bidentate and coordinates with the metal ion via the oxygen atom of the carboxyl group and an nitrogen atom of the amine group. The antimicrobial properties of all newly synthesized compounds were also demonstrated against the bacterial pathogenic organisms Escherichia coli (G-) and Staphylococcus aurous (G+) by the agar-well diffusion technique. These complexes are more effective against bacteria compared to the Amoxicillin antibiotic. The aim of this study describes the characterization and synthesis of the new ligand (HMP) derived from Tyrosine and its metal complexes with knowing their effect on selected bacteria.

Biological activities and phytochemicals of five orangutan food plants from Wehea-Kelay Landscape

Several studies on the therapeutic potential of primate plant food species have been reported. However, research into the medicinal properties of orangutan plant foods is still in its early stages. The purpose of this research is to examine the phytochemical composition and biological activities of five orangutan food plants taken from the Wehea-Kelay Landscape: Aglaia elliptica, Croton argyratus, Artocarpus lanceifolius, Artocarpus odoratissimus, and Baccaurea macrocarpa. Phytochemicals analysis were conducted by color changes and colorimetry methods. To determine the antioxidant activity, DPPH free radical scavenging was used. The agar-well diffusion technique was used to assay the antimicrobial activity against four pathogenic microorganisms. The results showed that the plants contained alkaloids, flavonoids, tannins, and carbohydrates. The total flavonoid content of the plants varied from 64.91 to 95.87 mg CE/g extract, whereas the total phenolic content ranged from 76.93 to 115.58 mg GAE/g extract. The antimicrobial assay revealed that at specific concentrations, the plants samples were able to inhibit the tested microorganisms. The five plants inhibited DPPH free radicals with IC50 values ranging from 47.22 to 77.6 ppm. The findings of this study demonstrated that the five plants possess antioxidant activity as scientific evidence of therapeutic properties of orangutan food plants.

Impact of Diameter of Inhibition in Crowded Plates on the in vitro Inhibitory Strength of Potential Antibiotic-Producing Bacteria Isolated from Some Natural Habitats

Antimicrobial resistance is a global problem, and efforts to replace failing antibiotics are crucial. We investigated the impact of the diameter of inhibition (mm) in crowded plates of potential antibiotic-producing bacteria on their in-vitro inhibitory strength. Our previous research identified 12 potential antibiotic-producing bacteria from natural habitats and obtained their diameters of inhibition in preliminary crowded plates. The potential candidates were further challenged with some pathogenic microbes by the Agar-well diffusion technique to test their strength. The results showed that the diameter of inhibition of the potential antibiotic-producing isolates obtained at the crowded plate technique level was not a predictor of the potency of potential antibiotic-producing bacteria (rs = 0.52, P = 0.08). In summary, the selection of potent candidate microbes for the development of new antimicrobial compounds against multidrug-resistant pathogens cannot be determined based on the diameter of inhibition in a preliminary investigation using the crowded plate technique. Further studies involving complementary techniques are necessary to determine the best potential candidate organisms for the development of novel antimicrobial compounds.

Evaluation of Antibacterial Activity of Pineapple Fruit Bar Extract, treated with Sugar and Jaggery

The infections/diseases are caused by many antibiotic-resistant bacteria, virus, fungi and protozoan parasites. The discovery of the plant origin of antibiotic drugs has inevitably fostered the development of resistance in microorganisms. The variety of natural candidates of plant origin, many leaves and fruits have potent antibacterial activity. This study is aimed at determining the antibacterial activity of pineapple (Ananas comosus) fruit bar extracts used for the antibacterial activity was carried out by agar well-diffusion technique and the activity was measured by the zone of inhibition in diameter. The results of the study revealed that the various extracts of pineapple (P1, PS2 and PJ3) have potential activity against both gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli).

Complexation of some alkaline earth metals with bidentate uracil ligand: Synthesis, spectroscopic and antimicrobial analysis

ABSTRACT. Magnesium, calcium, strontium, and barium complexes of uracil were prepared in a 2:1 ligand to metal ratio to investigate the ligational character of the uracil (Ura). The modes of chelation were explained depending on elemental analyses, FT. IR, 1H–NMR spectra as well as scanning electron microscopy. Uracil has two donation sites either through N(3) and C(2)=O, or through N(3) and C(4)=O with the molecular formulas [M(Ura)2(H2O)2]Cl2 where M = Mg(II), Ca(II), Sr(II) and Ba(II) . The morphological surface and particle size of uracil metal complexes were determined using SEM and TEM. The thermal behaviors of the complexes were studied by the TGA (DTG) technique. The data obtained agreed well the proposed structures and showed that the complexes were finally decomposed to the corresponding metal oxide. The thermodynamic parameters are calculated from the thermal analysis curves using the Coats–Redfern and Horowitz–Metzger methods. The negative values of deduced the ordered structures of the prepared complexes compared to their starting reactants. Antibacterial activity of ligands and complexes is evaluated with two types of bacteria Staphylococcus aureus (gram‐positive) and Escherichia coli (gram‐negative) by the agar-well diffusion technique using DMSO as a solvent.
 
 KEY WORDS: Uracil, Coordination compounds, Non-isothermal kinetic parameters, Elemental analysis, Spectral studies, Biological efficiency
 Bull. Chem. Soc. Ethiop. 2023, 37(4), 945-957. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i4.11

Assessment of Antibacterial Properties of Jatropha tanjorensis

Aim: This study aimed at evaluating the Phytochemical and antibacterial properties of Jatropha tanjorensis against selected test bacteria.
 Methods: The antibacterial properties were tested using the agar-well diffusion technique. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts were also determined. Phytochemical analysis of the hot and cold extracts revealed presence of flavonoids, glycosides, phenols, saponins, anthraquinones and tannis.
 Results: Results obtained revealed that the cold extracts were more effective than the hot extracts. Cold extracts of Jatropha tanjorensis leaf has antibacterial activity against E. coli and S. aureus. Hot extracts of Jatropha tanjorensis stem has very little antibacterial activity against S. marcescens at low concentrations with no MBC. Cold extract of Jatropha tanjorensis leaf was bactericidal for S. aureus at 250 mg/ml. Salmonella sp., E. coli, Pseudomonas sp., S. pyogenes, Serratia marcescens and Serratia marcescens were resistant to HE of Jatropha tanjorensis leaf and stem respectively.
 Conclusion: This study shows that there are phytochemicals present in Jatropha tanjorensis. The plant shows antibacterial properties against some bacteria, namely: Serratia marcescens, Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli, indicating that they can be used as antimicrobials.

Antibacterial and Anticandidal Activity of Ethanolic Extract of Immature Flower Buds of Syzygium aromaticum

Microbial resistance to antibiotics has been raised over time, creating a serious burden and an issue that requires a quick response. As a result, interest has shifted to medicinal plants as natural, effective, and cost-efficient alternatives. The goal of this study was to assess the antibacterial and antifungal activities of the dried buds of the clove’s flowers, which were extracted in 250 ml of ethanol using the Soxhlet apparatus. Subsequently, DMSO stock solutions were utilized to create concentrations of 100, 50, 25, 12.5, 6.25, and ultimately 3.125 mg/ml. Following that, the agar-well diffusion technique was utilized for the evaluation of the antibacterial activities of the clove extract against gram-positive bacteria (Staphylococcus aureus and Group A Streptococcus bacteria) and gram-negative bacteria (Escherichia coli), as well as Candida albicans, isolated and identified through the pediatric hospital's medical laboratory west of Gaza city. Lastly, the results of this study clearly showed that the ethanolic extract of dried immature flower buds of clove has anti-S. aureus and anti-group A Streptococcus effects, as well as for the C. albicans used in the present study, with the exception of E. coli, which demonstrated resistance to the plant extract at all concentrations tested. While the lowest concentrations that showed anti-bacterial activity were revealed to be 12.5 and 25 mg/ml for anti-S. aureus and anti-group A Streptococcus, respectively, with inhibition zone diameters of 2 and 1 mm, on the other hand, 25 mg/ml with a 2 mm inhibition zone was determined to have the lowest concentration that had anti-C. albicans activity. This study concluded that cloves can be employed as a plant with anti-bacterial and anti-fungal characteristics, but additional research is required.

Preliminary Antibacterial Screening of the Whole Stem of Rothmannia whitfieldii

Aim: To assess the antibacterial activity of the crude ethanolic and water extracts of the stem of Rothmannia whitfieldii on clinically isolated and typed pathogenic bacterial strains.
 Study Design: This experiment was performed in duplicates under aseptic condition.
 Place and Duration of Study: Department of Microbiology, University of Nigeria, Nsukka, Enugu State, Nigeria between April 2005 to August, 2005.
 Methodology: Whole dried stem specimen of Rothmannia whitfieldii was extracted by maceration and screened for antibacterial activity using agar well-diffusion technique. Five typed bacterial strains namely, Staphylococcus aureus (ATCC 12600), Pseudomonas aeruginosa (ATCC 10145), Escherichia coli (ATCC 11775), Salmonella kintambo (SSRL 113) and Bacillus subtilis (ATCC 6051), and six locally isolated clinical strains (Escherichia coli, Salmonella typhi, P. aeruginosa, S. aureus and two Proteus species designated as Proteus I and Proteus II), were tested for susceptibility to the plant extract.
 Results: Phytochemical analysis revealed the presence of flavonoids, saponnins, tannins, carbohydrates and steroidal aglycone. Alkaloid was present in trace amount only in the ethanolic extract. The ethanolic extract exhibited a wider spectrum of activity, being effective against 81.8% of the test organisms compared with the cold-water extract (54.5%) or hot water extracts (27.3%). The minimum inhibitory concentrations (MICs) varied not only with the test organisms but also with the various extracts of the plant.
 Conclusion: All the extracts had bacteriostatic activity on the susceptible organisms and none was bactericidal. The screening test results authenticate the folkloric claims that Rothmannia whitfieldii is medicinal against gastrointestinal diseases and aid in wound healing.

Evaluation of Hydrogen peroxide Scavenging and Antibacterial activity of successive extracts of Luisia tenuifolia Blume against skin and wound infections

Skin and wound infections might trigger severe secondary complications when left untreated. A proper balance between reactive oxygen species generation and antioxidant formation is necessary to achieve redox haemostasis. Luisia tenuifolia Blume (Orchidaceae) has been traditionally applied on cuts, boils and wounds in regions of Western Ghats. The present study was aimed to validate the antioxidant and antibacterial effect of the whole plants of Luisia tenuifolia against five pathogenic bacteria often responsible for skin and wound infections The whole plants of L.tenuifolia, after drying under shade, was pulverised, successively extracted with solvents of different polarity and evaporated to dryness. The hydrogen peroxide scavenging potential of all the four extracts was determined by H2O2 assay. The agar-well diffusion technique was employed for the preliminary screening of antibacterial activity. Further, the minimum inhibitory concentration was determined by broth-dilution assay. Among the four extracts, the ethanol extract of L. tenuifolia exhibited a strong antioxidant activity with an IC50 value of 42.61μg/mL compared to the standard Ascorbic acid (IC50 value of 21.56μg/mL). Moreover, the n-hexane extract was found to be more effective against Staphylococcus aureus whereas the ethanol extract exhibited highest antibacterial effect on Streptococcus oralis, Pseudomonas aeruginosa, Aeromonas hydrophila and Escherichia coli. Furthermore, the ethanol extract was found to be a promising antibacterial candidate with an MIC value of 0.312μg/mL against S.oralis and A.hydrophila. Thus the current study validate the antioxidant and antibacterial potential of L. tenuifolia whole plant extracts and further studies were aimed at identification of active components responsible for the activity.

A New DNA-Mediated Antibacterial Agent Magnetic (Fe3O4) Nanoparticles with Gold and Silver Functionalization

By using a hydrothermal process, magnetite (Fe3O4) nanoparticles with gold and silver caps (Au, Ag) were created, and their antibacterial activity was tested against S. aureus and E. coli .By using X-ray diffraction (XRD) and Scanning electron microscopy (SEM), the functionalized nanoparticles were evaluated. The functionalized Fe3O4-Au had an average size of (8-22) nm, whereas the Fe3O4-Ag had an average size in the range of (4-16) nm. At room temperature, the Fe3O4-Au @ Fe3O4-Ag displayed superparamagnetic and strong saturation magnetization. Using the agar well-diffusion technique, the antibacterial activity of the Fe3O4-Au and Fe3O4-Ag was assessed against Escherichia coli and Staphylococcus aureus. The release technique was used to track alterations in the morphology of the microorganisms under investigation. The outcomes demonstrated the effectiveness of magnetic (Fe3O4) nanoparticles functionalized with gold and silver as a new DNA-mediated antibacterial agent. By breaking through the bacterial membrane's cytoplasm and nucleic acid, Fe3O4-Au @ Fe3O4-Ag nanoparticles were shown to kill bacteria by causing cell-wall integrity to be lost, increased cell wall permeability and damage to nucleic acids.

Comparative Evaluation of Antimicrobial Effects of Herbal Extracts Incorporated in Dentifrices among Adults: An In-vitro Study and a Double Blinded Randomized Control Trial

Introduction: A positive correlation has been observed between Streptococcus mutans, Candida albicans and periodontal diseases. Several substances including synthetic chemicals and natural agents have shown promising antimicrobial activity against the S. mutans- C. albicans complex. Extracts of Aloe Vera, Triphala, Tulsi, Pomegranate, and Acacia catechu have established therapeutic effects in medicine. The aim of the study was to evaluate the antimicrobial activity and the Minimum Inhibitory Concentration (MIC) of five herbal extracts in-vitro and to compare the antibacterial effects of 5 dentifrices containing the herbal extracts and a commercially available dentifrice on the plaque sample counts of S. mutans and C. albicans in-vivo
 Methodology: Extracts were obtained using a standardized method. Minimum inhibitory concentration was calculated for the test microorganisms using modified agar-well diffusion and macro broth dilution technique and the inhibition zone diameters were calculated. Dentifrices containing the extracts were formulated and the in vivo antimicrobial activity was evaluated by studying the CFU count from plaque samples of 420 participants. 
 Results: Highest antimicrobial activity against S Mutans and C albicans was shown by Acacia catechu and Tulsi respectively and least was by pomegranate. Mean reduction in microbial counts (CFU/ml) by inoculating nutrient broth from baseline to 60 days was highest in Acacia catechu and Triphala for S Mutans and C albicans respectively. All herbal extracts performed better than the commercially available toothpaste.
 Conclusion: Dentifrices with herbal extracts of Aloe Vera, Triphala, Tulsi, Pomegranate, and Acacia catechu could serve as an alternative to commercially available dentifrices for treating oral diseases whose causative organisms are S. mutans and C. albicans.

Evaluation of the antibacterial properties of the extracts and fractions of Ipomoea triloba l. (Convolvulaceae) on selected enteric diarrheagenic bacteria

Diarrhoea is a leading killer of young children accounting for approximately 8% of all deaths among children ˂ 5 years worldwide and causes neonatal mortality and hospitalization in geriatrics. Ipomoea triloba L. has been claimed to have antidiarrheal properties. This study evaluated antibacterial properties of the ethanol / aqueous extracts and fractions of I. triloba on diarrheagenic bacteria to validate its use in trado-medical treatment of diarrhoea. Aqueous and ethanol extracts of pulverized I. triloba were prepared by cold maceration and phytochemical screening was performed using standard procedures. Diarrheagenic bacteria were isolated from twenty (20) composite diarrhoeal stool samples by community bioprospecting using appropriate selective and differential media. In vitro antibacterial activity of extracts and fractions of I. triloba was determined by the modified agar-well diffusion technique, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined by reference standard agar-dilution technique (ADT) after re-incubation of MIC samples at 37o C for 24 h. A total of 74 isolates, belonging to six genera, were identified with their numbers and percentages of occurrence as follows: Escherichia coli, 26 (35.1%), Staphylococcus aureus, 4 (5.4 %), Pseudomonas aeruginosa, 9 (12.2%), Shigella dysenteriae, 18 (24.3%), Salmonella typhi, 8 (10.8%) and Vibrio cholera, 9 (12.2%). Flavonoids, saponins, terpenes, carbohydrates and steroids were detected in both extracts. Ethanol extracts (≥30 mm) showed more potent broad-spectrum antibacterial activity than aqueous extract (≥18 mm). The MIC and MBC values ranged from 250 to 500 mg/mL and 500 to 1000 mg/mL respectively, thus establishing a time-dependent bactericidal mode of antibacterial activity. The best antibacterial activity was elicited by dichloromethane fraction. From the study, I. triloba possesses antibacterial potentials and may be exploited in the chemotherapy of bacterial diarrhoea.

Phytochemical and antimicrobial studies of Markhamia platycalyx (Baker) Sprague leaf

Purpose: To isolate new antimicrobial agents from the leaves of Markhamia platycalyx (Baker) Sprague and assess their phytochemical characteristics and antimicrobial activity. Methods: Different chromatographic and spectroscopic techniques (NMR and ESI-MS) were applied for the identification of antimicrobial compounds. Agar-well diffusion technique was used for determination of antimicrobial activity. Anti-HCV effects were investigated using VITROS Anti-HCV assay. Results: Eighteen compounds were isolated for the first time from this genus. These were phytol, noctacosanoic acid (OCTA), tormentic acid and β-sitosterol-3-O-(6'-O-heptadecanoyl)-β-Dglucopyranoside. The other compounds were β-sitosterol, ursolic acid (URSA), oleanolic acids, pomolic acid (POMA), 2-epi-tormentic and β-sitosterol-3-O-β-D-glucopyranoside. However, stigmasterol and acteoside, which were seen in previous studies, were also present. Total ethanol extract (TEE) was the most effective against Escherichia coli, with the lowest minimum inhibitory concentration (MIC) of 1.0 μg/mL. Acteoside, URSA and 2-epi-tormentic acid showed the highest antibacterial effect on Pseudomonas aeruginosa while 2-epi-tormentic acid and acteoside produced the least MIC on Candida glabrata. These effects were superior to those produced by standard antibiotics. However, 2-epitormentic acid and β-sitosterol-3-O-β-D-glucopyranoside had no anti-HCV effects. Conclusion: Due to the good antimicrobial properties of Markhamia platycalyx, it is a potential source of new antimicrobial drugs.

Structural, Morphological and Antimicrobial Study of ZnO/Ag Nanoparticles

Metal oxide nanoparticles gain attention in the field of biomedical applications because of their unique physico-chemical properties and emerging out as an alternative to antibiotics. The major cause of most of the human diseases is the bacterial infection. However, antibiotics used in the cure show other complications to human health. Therefore, the purpose of the present work is to investigate the antibacterial properties of ZnO/Ag nanoparticles on the test bacterial strains, Escherichia coli (E. coli). ZnO/Ag nanoparticles are synthesized using surfactant mediated route in a single step and double step procedure. Here, CTAB and hydrazine hydrate used as a surfactant and reducing agents respectively. The synthesized nanoparticles are characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy for structure, morphology and compositional properties. The antibacterial activities of these nanoparticles are also studied using the agar-well diffusion technique. The result analysis shows that synthesized nanopaticles are spherical in shape, having particles of the size 6 nm and 13 nm in the desired elemental composition. ZnO/Ag nanoparticles possessed a strong antibacterial effect against E. coli. This study signifies that ZnO/Ag metal oxide nanoparticles exhibit stronger antimicrobial activity against pathogen bacteria E. coli which may works effectively on the antibacterial and antifungal infections.

Determination the Fatty Acid Composition of the Rumex patientia L. Leaves and in vitro Antimicrobial Activity of their Different Extracts

Rumex patientia L. is from Polygonaceae family and there are 25 species of it in Turkey. Rumex patientia L. has antifebrile, laxative, diuretic, and pain killer properties. In this study, the extraction of the Rumex patientia L. leaf were done and determination the fat content and fatty acid composition by using GC device and to determinate in vitro antimicrobial activity of their different extracts were aimed. On the purpose of detection of antimicrobial activity; Rumex patientia L. leaf was extracted with ethanol, methanol, acetone, petroleum ether and water. Rumex patientia L. leaves was tested their different extracts using Bacillus subtilis, Bacillus cereus, Escherichia coli, Pseudomonas aeroginosa, Pasteurella multocida, Yersinia enterocolitica, Klebsiella pneumoniae, Staphylococcus aureus bacteria and Candida albicans yeast by agar-well diffusion technique. As a result of the study, 26 fatty acid components were detected on Rumex patientia L. leaf. In addition, among obtained extracts the highest antimicrobial activity was formed by methyl alcohol extract on K. pneumoniae bacteria (32mm).