Largest Inhibition Zone Research Articles

Synthesis, Characterization, and Antibacterial Potential of Poly(o-anisidine)/BaSO4 Nanocomposites with Enhanced Electrical Conductivity

The poly(o-anisidine)/BaSO4 nanocomposites were prepared by oxidative polymerization of o-anisidine monomer with BaSO4 filler for the potential antibacterial properties of the composite materials. To achieve the optimal and tunable properties of the nanocomposites, the ratio of BaSO4 filler was changed at the rates of 1%, 3%, 5%, 7%, and 10% with respect to matrix. Different analytical techniques, i.e., FTIR and UV-visible spectroscopy, were employed for functional identification and optical absorption of the poly(o-anisidine)/BaSO4 nanocomposites. The FTIR data revealed the significant interaction between POA and BaSO4, as well as the good absorption behavior of the UV-visible spectra. The conducting properties were controllable by varying the load percentage of the BaSO4 filler. Furthermore, different bacterial strains, i.e., Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive), were used to evaluate the antibacterial activity of the POA/BaSO4 nanocomposites. The largest zones of inhibition 0.8 and 0.9 mm were reached using 7% and 10% for Staphylococcus aureus and Pseudomonas aeruginosa, respectively.

Synthesis and Characterization of Antibacterial ZnO - Functionalized Polysulfone Membrane

Membrane technology is an emerging alternative in water treatment. This study aims to synthesize a filtration membrane made of polysulfone polymer with the addition of ZnO in order to enhanced the membrane antibacterial/antibiofouling property. The membrane was manufactured via Non-Induced Phase Separation (NIPS) phase inversion of the polymer casting solution. The composition of ZnO was varied into 0%, 0.5%, 1%, 2%, and 3%. The results of the membrane synthesis were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), pure water permeability test, and selectivity test with a turbid meter. The hydrophilic properties of the membrane were analysed by measuring the contact angle, and the antibacterial characteristics were analyzed by the disc diffusion test. Analysis by FTIR showed the presence of a sulfone functional group (S=O) derived from polysulfone polymer and a methyl functional group (C-H) derived from PEG. SEM analysis showed that each variation of the polysulfone membrane had an upper surface structure that was close to the honeycomb structure. The pure air permeability test shows that the membrane is porous and able to pass through pure air. Selectivity test with a turbid meter showed that the membrane is selective to the feed stream that passes through it. Analysis of contact angle measurements showed that the polysulfone membrane surface was hydrophilic. Antibacterial activity analysis showed that polysulfone membrane had antibacterial ability with the largest zone of inhibition with a value 1.8 mm on the membrane with the largest concentration of ZnO.

Characterization of Quercus acatissima extract conjugated with gold-nanourchin and its enhanced bacterial growth inhibition

In this study, the antimicrobial potential was confirmed from the plant extract of Quercus acatissima conjugated with gold-nanourchin (Qa-AuNu) against gram-negative and gram-positive bacteria. The plant extract has the ability to inhibit Escherichia coli (9 ± 0.4 mm) and Bacillus subtilis (8 ± 0.4 mm), however, the activity was considerably increased when the plant extract was conjugated with AuNu as 16 ± 0.4 mm and 13.5 ± 0.5 mm, respectively. Further, the Qa-AuNu was characterized by morphological and structural analyses. The size and shape of the Qa-AuNu were confirmed by FE-SEM, FE-TEM, and AFM as 60 nm in diameter and star-shaped with spike-like structure. EDX analysis clearly displayed the presence of Au elements in the sample. The XRD pattern confirmed the crystalline nature of the Qa-AuNu with three different peaks located at 38.2°, 44.3°, and 65.1° corresponding to the (111), (200), and (220) diffraction planes, respectively. In addition, FTIR results confirmed the functional group in Q. acatissima that is involved in the conjugation of AuNu. This result clearly confirmed that the bonding of AuNu with plant extract via chemical bond enhanced the antibacterial potential as indicated by the large zone of inhibition.

Factors Determining Effective Probiotic Activity: Evaluation of Survival and Antibacterial Activity of Selected Probiotic Products Using an "In Vitro" Study.

There are many different probiotic products on the market. Are they all equally effective? What criteria should a probiotic formulation meet to provide the most benefit to the patient? The current research aims to evaluate the parameters that influence the effectiveness of market probiotic products. These properties are critical for restoring eubiosis in patients with drug-induced dysbiosis or other pathological conditions, which could be caused by stress, wrong eating. Methods: The disintegration time of probiotic capsules in hydrochloric acid was investigated using a disintegration testing device. The survival rate of probiotic preparations in hydrochloric acid at pH 2 and in a 0.4% bile solution was then evaluated. For this purpose, the number of bacteria before and after incubation in the respective solutions was determined using the plate method. Inhibition of gastrointestinal pathogens by the probiotic products was determined using the Strus bar graph method. The highest survival rate of probiotic bacteria at low pH is shown by preparations produced in the form of acid-resistant capsules. Conclusions: The most important factor determining the good survival of bacterial strains under conditions simulating the gastrointestinal tract is the type of capsule used for their production and storage. The best antimicrobial activity against most common human gastrointestinal pathogens such as Eschericha coli, Shigella, Salmonella spp., Clostridioides difficile (the largest inhibition zones) are shown by probiotic products with the greatest diversity of bacterial strains.

In vitro Effect of Alum on Microbes Associated with Foliar Phytoplasma Disease of Noni

Foliar phytoplasma disease of Noni (Morinda citrifolia) has a devastating socioeconomic impact on host crop species and a huge problem to farmers and scientists. Therefore, this study investigates the in vitro effect of alum on microorganisms associated with foliar phytoplasma disease (FPD) of Noni. Bacteria and fungi were isolated and identified by culture-dependent technique using standard microbiological procedures and susceptibility of species were evaluated by disc and agar well diffusion techniques and inhibition zones (IZs) were measured in millimeter (mm). The microbes identified were Bacillus subtilis, B. tequilensis, Brevundimonas vesicularis, B. cereus, Staphylococcus aureus and Serratia species as well as Aspergillus flavus, A. fumigatus, A. niger and Penicillium species. Relative abundance (%) of bacterial species occurred in the order; S. aureus > B. tequilensis > B. cereus and least being Br. vesicularis whereas fungi were A. fumigatus (75%), A. niger and A. flavus (50%) respectively and Penicillium (25%) species. Susceptibility test efficacy of Alum was concentration dependent with Serratia sp. as (6.0mm) and S. aureus (4.0mm) whilst A. flavus (36.0mm), A. fumigatus (32.5mm), Penicillium (30.2mm) and A. niger (30.0mm) at 5.0% Alum concentrations as the largest IZs respectively. The minimum inhibitory concentration (MIC) of Alum against all the microflora were < 2.0gm/mL except for S. aureus which portends a good future prospects in agronomy. However, the higher concentrations of Alum compared favourably with Ketoconazole (control) but showed wide disparity with Ofloxacin (control). This study, however, may proffer solutions for the prevention and management of FPD or foliar related diseases by periodic spraying or fumigation with Alum.

Rapid Assessment of Biological Activity of Ag-Based Antiviral Coatings for the Treatment of Textile Fabrics Used in Protective Equipment Against Coronavirus.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants have rapidly spread worldwide, causing coronavirus disease (COVID-19) with numerous infected cases and millions of deaths. Therefore, developing approaches to fight against COVID-19 is currently the most priority goal of the scientific community. As a sustainable solution to stop the spread of the virus, a green dip-coating method is utilized in the current work to prepare antiviral Ag-based coatings to treat cotton and synthetic fabrics, which are the base materials used in personal protective equipment such as gloves and gowns. Characterization results indicate the successful deposition of silver (Ag) and stabilizers on the cotton and polypropylene fiber surface, forming Ag coatings. The deposition of Ag and stabilizers on cotton and etched polypropylene (EPP) fabrics is dissimilar due to fiber surface behavior. The obtained results of biological tests reveal the excellent antibacterial property of treated fabrics with large zones of bacterial inhibition. Importantly, these treated fabrics exhibit an exceptional antiviral activity toward human coronavirus OC43 (hCoV-OC43), whose infection could be eliminated up to 99.8% when it was brought in contact with these fabrics after only a few tens of minutes. Moreover, the biological activity of treated fabrics is well maintained after a long period of up to 40 days of post-treatment.

EVALUATION AND QUANTITATIVE ANALYSIS OF BIOACTIVE COMPOUNDS FROM CHAETOCEROUS CALCITRANS AGAINST HUMAN PATHOGENS

The distribution of secondary metabolites and pharmacologically dynamic complexes from marine microalgae has increased in the previous decade. The antibacterial metabolites lessons in the current search were taught by Chaetoceroscalcitrans. Methods :Chaetoceroscalcitrans(green algae) was chosen as the subject of the existing secondary metabolites study. The properties of pH, temperature, and salinity were tested to see if they aided in the growth of microalgae. Dissimilar solvent extracts of Chaetoceroscalcitrans were tested for antibacterial activity against Vibrio cholerae ,Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Salmonella sp.,Proteus sp., Streptococcus pyrogens, Staphylococcus aureus, Bacillus megaterium, and Bacillus subtilis. Result : The uppermost cell growth was detected during the 9th day of incubation when the medium was adjusted with pH of 9.0 in 30 ppt of salinity at 25C. Butanol + Isopropanol(1:1) crude extract of Chaetoceroscalcitrans had the largest zone of inhibition (13.4 mm) against Salmonella of all the solvents tested. . For the crude extract of Chaetoceroscalcitrans, GC-MS analysis revealed the presence of unique chemical compounds such as 3, 3, 5-Trimethylheptane (M.W. 142.2) and n-Hexadecane (M.W.226.2), respectively. Conclusion:These results show that the Butanol + Isopropanol (1:1) extract of Chaetoceroscalcitranshas significant antimicrobial activity and thus has great potential as a solvent for extracting bioactive compounds from natural sources for biomedical and pharmaceutical applications.

Peel-off Mask Formulation from Stem of Sempeng (Nepenthes gracilis) as Anti Acne Against Propionibacterium acnes Bacteria

Introduction: Stem of Sempeng (Nepenthes gracilis), which contain saponin and tannin has been known had antibacterial activity against Propionibacterium acnes that usually improve severe of acne. Acne is a skin disease characterized by chronic inflammation in the polisebasca that often occurs in adolescence. Aims and Objective: The aims of this research are to develop and test a peel-off mask prepared from stem of Sempeng extracts, which has antibacterial activity against Propionibacterium acnes. Materials and Methods: Stem of Sempeng was extracted with soxhletation method by ethanol 96%. The extract was formulated into peel-off mask with different extract concentration (0, 1, 5, 10, 15) %. Then the inhibition test of the extract and peel-off mask was measured against bacteria Propionibacterium acnes. The data analysis technique used in this study was to measure the zone diameter on a petri dish using a caliper with a millimeter (mm) unit and presented in tables and photos, the results of the inhibition zone measurement were compared with the classification of the response of the extract barrier to the growth of Clinical and Laboratory Standards Institute (CSLI) standard bacteria. Results: The result showed that the inhibition zone of the peel off mask preparation of sempeng stem extract in F1 and F2 formulations with extract concentrations of 1% and 5% are categorized as resistant, which means that the Propionibacterium acnes bacteria has a low level of sensitivity so that a large inhibition zone is not formed. Whereas in the F3 formulation with a concentration of 10% is categorized as an intermediate, which means in this concentration, the mask can inhibit the growth of the inhibition zone Propionibacterium acnes bacteria which is formed quite well, but in this category it will require repeated use or with high doses of use. Then in the F4 formulation with a concentration of 15%, it is categorized as susceptible, which means the mask have a good inhibitory resistance zone, this shows that the increase in high concentration, the greater the inhibition zone as well. Conclusion: The peel off mask from ethanol extract of Sempeng stem is able to inhibit the growth of Propionibacterium acnes bacteria. The peel mask preparation with concentration 1%, 5%, 10% and 15% forms a clear zone around the disc which means that this peel off mask formulation has activity to inhibits Propionibacterium acnes bacteria and is included in the category of susceptible interpretation according to the CLSI standard.

Formulation and Evaluation of Antimicrobial Ointment from Acacia auriculiformis Leaves Extract

The current experiment aims to create and test an ointment with an ethanolic extract from Acacia auriculiformis for antimicrobial action. The soxhalation procedure was used to create the ethanolic extract. After producing the ointment base, five batches of ointments were created by incorporating the extract into the base. Physical and chemical properties of each formulation, including color, flavor, pH, spreadability, consistency, solubility, and washability, were assessed. The formulation’s stability at different temperature conditions was also assessed, and the results show that neither its irritancy nor its spreadability has changed. F5 was discovered to be the ideal formulation among the ointment batches. It has a larger zone of inhibition over both gram-positive and gram-negative bacteria.

Nano-Green Betel Leaf Extracts (Piper betle L.) Inhibits the Growth of Streptococcus mutans and Staphylococcus aureus

Abstract: Streptococcus mutans is a type of bacterium that initiates plaque formation on the tooth surface causing tooth decay, meanwhile, Staphylococcus aureus causes pyogenic infections such as abscesses to necrosis. Green betel leaf (Piper betle L.) contains secondary meta-bolites that have the potential as antibacterial. This study aimed to investigate the effectiveness of green betel leaf extract (Piper betle L.) in micro and nano sizes against Streptococcus mutans and Staphylococcus aureus. This was an experimental and laboratory study with a post-test-only design. The results showed that nano-green betel leaf extracts had antibacterial activity against Streptococcus mutans and Staphylococcus aureus. Green betel leaf extract had a much larger inhibition zone against Staphylococcus aureus rather than against Streptococcus mutans in all groups (p<0.05), with inhibitory diameters of 13,883±1.1496 mm (micro 10%), 16,767± 1.8779 mm (micro 30%), and 18.667±3.148 mm (nano), respectively. A stable increase in antibacterial activity was derived from micro-green betel leaf extracts (Piper betle L.) concentrations of 10%, 30%, and nanoparticle size. In conclusion, nano-green betel leaf extract (Piper betle L.) showed better antibacterial effectiveness than micro-sizes in inhibiting Streptococcus mutans and Staphylococcus aureus bacteria.Keywords: Piper betle L.; nanoparticles; antibacterial; Streptococcus mutans; Staphylococcus aureus

Synthesis, Electrochemical and Antibacterial Studies of hexa-aza-macrocyclic Complexes of Ni(II) and Cu(II) Ions

Due to their distinct structural, electrical, and electrochemical properties, macrocyclic complexes have been recognized as potential models in a variety of areas, including electrocatalysis, biology, and medicine. In this study, two hexa-aza-macrocyclic complexes of Ni(II) and Cu(II) transition metals (denoted as [NiL] and [CuL]) were synthesized via template procedure. Based on the results of multiple spectroscopic characterization, a distorted octahedral geometry was proposed for both the complexes. The electrochemical results showed that the macrocyclic framework can stabilize the unusual oxidation states of Ni(II) and Cu(II) transition metal ions, as evidenced by the corresponding quasi-reversible Ni(II)/(III) and Cu(II)/(III) redox couples. Additionally, both the complexes were found to be promising antibacterial agents against the B. subtilis, S. aureus, P. aeruginosa, and E. coli pathogens. The Cu(II) complex had the largest inhibition zone (22[Formula: see text]mm) against B. subtilis, while the Ni(II) complex had the smallest (15[Formula: see text]mm).

Development of poly(vinylidene fluoride) graft random copolymer membrane for antifouling and antimicrobial applications

Biocidal and anti-fouling properties in the same polymeric membranes are important in biomedical field for their capability to protect serious infection and filtration of biological molecules. For this purpose we report random graft copolymer of poly(vinylidene fluoride) (PVDF-graft-poly(tBAEMA-ran-OEGMA, PVBO) membranes showing both antifouling and antibacterial activity. The PVBO copolymer is synthesised using ATRP technique and the polymer membranes are produced by breath figure (PVBO-1) and phase inversion (PVBO-2) techniques. The former shows well-developed hexagonal pores (diameter 15 ± 3.5 nm), and good hydrophilicity (contact angle 41.3°). PVBO-1 membrane exhibits good antifouling property for both lysozyme and BSA solutions. Antimicrobial activity measured from agar diffusion method indicates that PVBO-1 shows a large zone of inhibition in case of gram-negative E coli and gram-positive S. aureus bacteria, whereas PVBO-2 and its HCl treated state (PVBO-3) membranes exhibit only a moderate zone of inhibition. The MBC and MIC values indicate that the synthesized membranes are bactericidal in nature and not bacteriostatic. Live and dead cell assay indicates that PVBO-1 can significantly inhibit growth of bacteria even at high bacteria concentration confirming high antimicrobial activity. MTT assay suggests PVBO-1 is non-cytotoxic to mammalian cells and co-culturing activity result suggests high cellular selectivity of PVBO-1.

Natural Rubber (NR) Latex Films with Antimicrobial Properties for Stethoscope Diaphragm Covers.

Systematic disinfection of the stethoscope diaphragm is required to ensure that it does not act as a vector for cross-transmission of health-related diseases. Thus, an antimicrobial latex film could be used as a cover to inhibit pathogenic bacteria from growing on its surface. The aim of this work is to determine the antimicrobial activity and mechanical properties of antimicrobial natural rubber (NR) latex films with different types of antimicrobial agents (mangosteen peel powder (MPP), zinc oxide nanoparticles (ZnO NP), and povidone-iodine (PVP-I)). The antimicrobial loading was varied from 0.5, to 1.0, and 2.0 phr to monitor the effective inhibition of Gram-negative bacteria and fungi growth. For MPP and PVP-I antimicrobial agents, a loading of 2.0 phr showed good antimicrobial efficacy with the largest zone of inhibition. Simultaneously, ZnO NP demonstrated excellent antimicrobial activity at low concentrations. The addition of antimicrobial agents shows a comparable effect on the mechanical properties of NR latex films. In comparison to control NR latex film (29.41 MPa, 48.49 N/mm), antimicrobial-filled films have significantly greater tensile and tear strengths (MPP (33.84 MPa, 65.21 N/mm), ZnO NP (31.79 MPa, 52.77 N/mm), and PVP-I (33.25 MPa, 50.75 N/mm). In conclusion, the addition of antimicrobial agents, particularly ZnO NP, can be a better choice for NR latex films because they will serve as both an activator and an antimicrobial. In a clinical context, with regard to frequently used medical equipment such as a stethoscope, such an approach offers significant promise to aid infection control.

Optimization relation between antimicrobial activities and extraction of clove flowers using artificial neural network model.

Background Artificial neural network (ANN) is an optimization method which is able to interact the input data and predict the best outputs. The ANN model determines the important factors affection the process. This could allow maximization of the process outputs. Objective There was only very limited publication on use of ANN for optimization of the bioprocess. This was a trial to use the model to optimize an extraction process and relate the extraction to the antimicrobial activities. Methods An artificial neural network as model was tested to optimize the extraction for clove flowers and relate it to the antimicrobial activities of the extracts. ANN model was constructed as by multilayer perception (MPL) with six input, two hidden layer and one output layer. The mean for the inhibition zone was 1.5 cm so the data categorized into two sets. Large inhibition zone > 1.5 - 2.3 cm and intermediate or small inhibition zone < 0.7-1.5 cm. The antimicrobial activities were tested against 20 microbial strains including 16 bacteria and 4 fungi. Six extraction method were performed and the resulted extracts were examined for their antimicrobial activities against 20 microbial strains which resulted in 120 readings. The statistical calculations for the model outputs were performed. The inhibition zones were taken as preliminary results for the model however the MIC was determined. Results The model shows an excellent performance with overall accurate prediction 86.6 %. According to the outputs from the model, the most important factor was the use of hot water as solvent for extraction. Calculation of the importance found the hot water important by about 100%. All statistical parameters like AUC, accumulation gain curve and lift chart for the model suggested that the model has an acceptable prediction efficiency. The AUC value was 0.91. GC-Mass was used to identify the most active constituent, it most cases 24 eugenol was identified as active ingredients and some other phenolic compounds. Conclusion According to the results and the statistical calculation for accuracy of the model it was apparent that the model can used successfully to predict and optimized the data for the extraction process. This could incite the ability of these models to be applied on similar processes. The model was efficient in prediction and determination the effective factors.

Bio-Environmental preparation of chitosan nanoparticle using Bacillus subtilis and their biomedical activity

The aim of this study was to study the biomedical activity (antibacterial, antibiofilm, and antioxidant activity) and Characterization of Chitosan NPs synthesized by B. subtilis. Different types of bacterial strains(Z1-Z25) were screened for biosynthesis of chitosan NPs, Isolate (Z2) was selected as efficient isolate based on color change and antibacterial activity against the pathogenic bacteria, and it was diagnosed as Bacillus subtilis, depending on the morphology, microscopic examination and VITEK2 compact system. The characterization of biogenic chitosan NPs was achieved, using: UV visible spectrophotometry was used to describe the synthesis of chitosan NPs by B. subtilis, with an absorption peak at 280nm wavelength. SEM analysis showed the spherical, homogenous with average sizes from 29-51nm. The elemental analyses of biogenic chitosan with EDS showed 33.31% carbon, 10.24 % nitrogen, 50.55% oxygen, 5.34% phosphate and 0.55% chloride. The size and structurer of biogenic chitosan NPs was measured using XRD that appeared at 20°-26°’ AFM analysis showed the average diameter of the biogenic chitosan NPs was 47. 18. The antibacterial activity was studied for biogenic chitosan against pathogenic bacteria (P.aeruginosa, S. aureus, K. pneumonia, E.coli, and P. mirabilis). Biogenic chitosan NPs with deferent concentration (100, 200, 400ug/ml) showed inhibition against all tested bacteria and largest inhibition zone against S. aureus(26mm) with concentration 400 μg/ml. Biogenic chitosan expressed high significant antibiofilm activity with increasing concentration of chitosan NPs. DPPH reducing activity of nanoparticles which increased with increase concentration of biogenic chitosan NPs.

Potential for Antibacterial Activity of Chitosan-Polyvinyl Alcohol Membrane Loaded with Green Grass Jelly Leaf and Moringa Leaf Extract as a Wound Dressing

Chitosan is a natural polymer that can be used as wound dressing material; however, it has rigid and brittle properties. A combination of chitosan and polyvinyl alcohol (PVA) is expected to allow improvement of chitosan’s mechanical properties. Green grass jelly leaf (Cyclea barbarta M.) and moringa leaf (Moringa oleifera L.) have antibacterial compounds that can be added to the chitosan-PVA composite membrane. The purpose of the research was to develop and characterize the chitosan-PVA composite membrane with the addition of green grass jelly leaf and moringa leaf extracts to enhance the antibacterial activity of the membranes that have potential as a wound dressing. Both extracts with various composition volumes (75:25, 50:50, and 25:75) were tested for antibacterial activities against S. aureus and E. coli. Chitosan-PVA composite membrane with the volume ratios of 5:5, 6:4, and 7:3 was added with extract with the highest antibacterial activity. The composites were characterized for density, water vapor permeability, tensile strength, elongation, Fourier Transform Infrared spectroscopy, and Scanning Electron Microscope. The most significant inhibition zone was shown by an extract ratio of 50:50 against S. aureus and E. coli, 13.00±1.17 mm and 7.00±0.17 mm, respectively. Composite membrane with the addition of extract had a larger inhibition zone against S. aureus (9.75±0.75 mm) and E. coli (7.50±0.65 mm) than without extract. Chitosan-PVA(5:5)+extract membrane showed excellent density and water vapor permeability compared to other membrane ratio compositions. Mechanically, the addition of extract decreased the tensile strength and elongation of the membranes; however, it still complied with the medical material standard criteria. The characterization for functional groups showed that chitosan-PVA+extract generated the N-H group peak with two wavenumbers expressed as overlapping amides with amines and protonated amines. The SEM analysis showed that the addition of extract was not distributed homogeneously on the membrane surface.

The influence concentration gel agent propolis combination of mulberry leaf on the growth of the bacteria Propionibacterium acnes

This research was carried out with the aim of determining the inhibitory power of the combination gel of propolis extract and mulberry leaf extract against Propionibacterium acnes bacteria and determining the concentration of propolis extract that provided the greatest inhibitory power against the test bacteria. The research method includes the extraction of mulberry leaves by maceration using 70% ethanol as a solvent and the propolis extract used is a ready-to-use extract. The formulations were designed with various concentrations of propolis (0.5%, 1%, 1.5%) and 0.5% mulberry leaf concentration. Testing the antimicrobial activity of propolis extract in combination with mulberry extract in gel preparations against the growth of Propionibacterium acnes bacteria was carried out using the agar diffusion method. The results showed that the average diameter of the inhibition area at 0.5% concentration was 36.87 mm, at 1% concentration was 44.557 mm and at 1.5% concentration was 45.97 mm, positive control was 49.21 mm. Based on the data obtained, it is concluded that the gel formula with a propolis concentration of 1.5% is the preparation with the largest zone of inhibition.

Antibacterial Test and Isolation of Xanthones from Pericarps Mangosteen (Garcinia mangostana L.) using Calcium Oxide (CaO) as a Vacuum Liquid Chromatography (VLC) Stationary Phase

Xanthones are one of the biggest classes of compounds in natural product chemistry. Xanthones have been isolated from pericarp mangosteen (Garcinia mangostana L.) and then purified with VLC using calcium oxide (CaO) as the stationary phase and eluted using n-hexane: EtOAc of increasing polarity. Extraction of the pericarp mangosteen using the maceration method with acetone as the solvent. The isolation of xanthones was carried out through various chromatography techniques, such as vacuum liquid chromatography (VLC), gravitational column chromatography (GCC), and thin layer chromatography (TLC). The molecular structure of the compound was identified based on spectroscopy data, including IR, 1D NMR (1H and 13C), and 2D NMR (HSQC and HMBC). Based on the analysis of spectrum data, the isolated compound is ɑ-mangostin. The acetone extract and ɑ-mangostin were also examined for antibacterial activity against Gram positive (+) Staphylococcus aureus (S. aureus) ATCC 25923 and Gram negative (-) Escherichia coli (E. coli) ATCC 25922. The largest inhibition zone was shown by ɑ-mangostin against S. aureus (12.16 mm) more than E. coli (12 mm).

ANTIBACTERIAL ACTIVITY OF KERSEN LEAF EXTRACT (MUNTINGIA CALABURA L) AGAINST STAPHYLOCOCCUS AUREUS

Kersen (Muntingia calabura) is a shady plant that is usually used as a shade. Cherry leaves contain several secondary metabolites such as flavonoid, tannin and terpenoid. Flavonoid can inhibit bacterial growth by denaturing proteins and damaging cell membranes and dissolving fats contained in cell walls. According to the World Health Organization as many as 25 million deaths worldwide in 2011, one third were caused by infectious diseases. One of the most common infectious diseases caused by the bacterium Staphyloccus aureus. The purpose of this study was to see whether the 96% ethanol extract of cherry leaves had antibacterial activity against Staphylococcus aureus. The concentration of the extract used was 15%, 30%, 45% and 60%. From the test results, it can be concluded that the largest inhibition zone diameter is at a concentration of 60% with an inhibition zone diameter of 6.78 mm and the smallest at a concentration of 30%, which is 0.42 mm. Concentration of 45% has (weak) activity inhibiting bacterial growth with an inhibition zone of 2.13 mm, while at a concentration of 15% it has no activity in the inhibition zone of bacterial growth.

The effect of pulp type on the performance of microfibrillar lignocellulosic bismuth-based active packaging material

AbstractThe study aims to investigate the effect of the different lignocellulosic pulp on the composite properties for active packaging application. Microfibrillated cellulose from bleached and unbleached Kraft and thermomechanical pulp (TMP) having different cellulose, hemicellulose, lignin, and extractive content were used as the matrix phase with antimicrobial bis-phosphinato bismuth complex as the dispersed phase. The Kraft pulp has thinner fibres as observed in the SEM images and have higher aspect ratio (EMT 109–157) compared to TMP (EMT 43–51). So, it is more easily fibrillated resulting in a strong close network and therefore resulting in low water vapor transmission rate (WVTR) and high tensile index (20–91 g/m2.day and 59–78 Nm/g respectively) compared to the TMP ones (153–261 g/m2.day and 35–43 Nm/g respectively). While the physical dimension of the fibres controls the mechanical and barrier properties, the leaching and antibacterial performance is related to the bonding of the complex with the matrix. The high hydrophilicity of the bleached kraft pulp results in a weak bond with the hydrophobic bismuth complex, easing its release to kill the surrounding microbial population and thus resulting in larger zones of inhibition against both Gram-positive and Gram-negative bacteria. Therefore, bleached kraft pulp was found to be the most suitable with promising barrier, mechanical and antibacterial properties.