Inhibition Of Bacterial Activity Research Articles

Development and evaluation of novel taste-masking tilmicosin microcapsules containing octenylsuccinic anhydride modified starch and maltodextrin as wall materials

Tilmicosin (TMS) is an important antibiotic in veterinary medicine, but its extreme bitter taste limits its use. In this study, TMS was encapsulated in octenyl succinic anhydride modified starch/maltodextrin (HI-CAP/MD) composite capsules with a spray drying method. The TMS microcapsules (TMS-MC) exhibited good drug loading performance with drug loading (DL) and encapsulation efficiency (EE) of 9.90 ± 0.23 % and 98.03 ± 1.56 %, respectively. There was no significant change in particle diameter and zeta potential for the emulsion and redissolved TMS-MC. These results combined with FT-IR, TGA and DSC showed the crystalline shape and chemical structure of TMS did not change during the microencapsulation. In vitro release characterization in an acidic medium (pH 1.2) and an alkaline medium (phosphate buffered solution, pH 6.8) showed that TMS-MC can be rapidly released in vitro. The bitterness evaluation implied the bitterness of TMS was masked after microencapsulation. In vitro bacterial inhibition test showed the bacterial inhibitory activity of TMS was not reduced by the microencapsulation, but was much better than that of the commercially available tylosin (TLS). Therefore, HI-CAP/MD can effectively encapsulate TMS, mask the bitter taste and maintain a good bacterial inhibitory effect, making a new drug formulation with good development prospects.

New Arene and/or Heteroarene‐Linked 1,3,4‐Oxadiazoles: Synthesis of Potential Methicillin‐Resistant Staphylococcus aureus and Vancomycin‐Resistant Enterococcus Inhibitors

AbstractBacterial infections, particularly those associated with methicillin‐resistant Staphylococcus aureus (MRSA) and vancomycin‐resistant Enterococcus (VRE), threaten public health and economies, with rising antibiotic resistance resulting in more deaths yearly. In this study, we investigated the bacterial inhibitory activity of some new 1,3,4‐oxadiazoles prepared, in good yields, using a two‐step tandem protocol. Therefore, the appropriate N‐benzoylhydrazones were prepared first, then, without isolation, underwent oxidative‐cyclization in the presence of chloramine trihydrate. More 4‐acyloxyphenyl‐linked 1,3,4‐oxadiazoles were prepared by the pyridine‐mediated acylation of 2‐(4‐hydroxyphenyl)‐1,3,4‐oxadiazoles with the appropriate acyl chlorides. Some new products demonstrated good activity, particularly against S. aureus and Enterococcus faecalis strains. The 4‐(5‐(furan‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl)phenyl acetate showed comparable antibacterial activity to ciprofloxacin, with MIC/MBC values up to 3.6/7.2 µM against the previous strains. Moreover, it demonstrated good inhibitory activity against different MRSA and VRE strains when compared to linezolid. It had MIC/MBC values of 7.2/14.4 and 14.4/57.8 µM against MRSA and VRE strains, respectively.

Bacterial recognition and inhibition activities of an LRR-only protein in the Chinese mitten crab, Eriocheir sinensis

LRR-only protein (LRRop) is an important class of immune molecules that function as pattern recognition receptor in invertebrates, however, the bacterial inhibitory activity of this proteins remain largely unknown. Herein, a novel LRRop was cloned from Eriocheir sinensis and named as EsLRRop2. The EsLRRop2 consists of six LRR motifs and formed a horseshoe shape three-dimension structure. EsLRRop2 was mainly expressed in intestine and hepatopancreas. The transcripts of EsLRRop2 in the intestine and hepatopancreas were induced by Vibrio parahaemolyticus and Staphylococcus aureus, and displayed similar transcriptional profiles. The expression levels of EsLRRop2 responded more rapidly and highly to V. parahaemolyticus than S. aureus in the intestine and hepatopancreas. Although the basal expression level of EsLRRop2 in hemocytes was relatively low, its transcripts in hemocytes were significantly induced by V. parahaemolyticus and S. aureus. The recombinant proteins of EsLRRop2 (rEsLRRop2) displayed a wide range of binding spectrum against vibrios, including V. parahaemolyticus, V. alginolyticus, and V. harveryi. The rEsLRRop2 showed dose- and time-dependent inhibitory activity against V. parahaemolyticus and S. aureus, and it could agglutinate the two bacteria. Furthermore, the inhibitory activities of rEsLRRop2 against V. parahaemolyticus, V. alginolyticus, V. harveryi and S. aureus was slightly affected by pH and salinity, and the rEsLRRop2 displayed the strongest inhibitory activity against all the three vibrios when the salinity was 20 ‰ and pH was 8.0. Collectively, these results elucidate the bacterial binding and inhibitory activities of EsLRRop2, and provide theoretical foundations for the application of rEsLRRop2 in prevention and control of vibrio diseases in aquaculture.

Characterisation of Tenebrio molitor Reared on Substrates Supplemented with Chestnut Shell.

Tenebrio molitor larvae represent a sustainable protein source for food and feed. The aim of this study was to evaluate the supplementation of chestnut shell, a by-product of the agro-industrial chain, in growth substrates for T. molitor larvae rearing. Seven-week-old larvae were reared on three different growth substrates: the control group (CTRL) was fed wheat bran, treatment group one was fed wheat bran supplemented with 12.5% w/w chestnut shell (TRT1), and treatment group two was fed wheat bran supplemented with 25% w/w chestnut shell (TRT2). Larval weight, substrate consumption, and mortality were recorded weekly. After 14 days, insect meals were produced for bromatological and colorimetric analysis, and bacterial inhibition activity assay using a microdilution method. The amino acid profile of insects was determined using quantitative nuclear magnetic resonance spectroscopy. Our results showed a lower feed conversion ratio and higher larval survival rate % in TRT2 compared to CTRL (p < 0.05). Proteins and lipids of TRT2 were higher than other groups (p < 0.05). Important differences were observed in the amino acid profile of TRT1 and TRT2 compared to CTRL (p < 0.05). TRT1 and TRT2 showed higher E. coli inhibitory activity than CTRL (p < 0.05). In conclusion, chestnut shell supplementation improved the survival and functional characteristics of larvae and likely impacted the insects' metabolism.

A novel endolysin from an Enterococcus faecalis phage and application

Enterococcus faecalis is the primary species detected in cases of secondary persistent infection resulting from root canal therapy failure. Due to the overuse of antibacterial agents, E. faecalis has developed resistance to these drugs, making it challenging to treat clinical diseases caused by E. faecalis infection. Therefore, there is an urgent need to explore new alternative drugs for treating E. faecalis infections. We aimed to clone and express the genes of phage endolysins, purify the recombinant proteins, and analyze their antibacterial activity, lysis profile, and ability to remove biofilm. The crude enzyme of phage endolysin pEF51 (0.715 mg/mL), derived from phage PEf771 infecting E. faecalis, exhibited superior bacterial inhibitory activity and a broader bactericidal spectrum than its parental phage PEf771. Furthermore, pEF51 demonstrated high efficacy in eliminating E. faecalis biofilm. Therapeutic results of the infected Sprague-Dawley (SD) rat model indicated that among 10 SD rats, only one developed a thoracic peritoneal abscess and splenic peritoneal abscess after 72 h of treatment with pEF51. This suggests that pEF51 could provide protection against E. faecalis infection in SD rats. Based on the 16S rDNA metagenomic data of the intestinal microbial community of SD rats, endolysin pEF51 exerted a certain influence on the diversity of intestinal microorganisms at the genus level. Thus, pEF51 may serve as a promising alternative to antibiotics in the management of E. faecalis infection.

Design, synthesis, and bioactivity evaluation of clindamycin derivatives against multidrug-resistant bacterial strains.

Our research aims to reduce the bacterial resistance of clindamycin against Gram-positive bacteria and expand its range of bacterial susceptibility. First, we optimized the structure of clindamycin based on its structure-activity relationship. Second, we employed the fractional inhibitory concentration method to detect drugs suitable for combination with clindamycin derivatives. We then used a linker to connect the clindamycin derivatives with the identified combined therapy drugs. Finally, we tested antibacterial susceptibility testing and conducted in vitro bacterial inhibition activity assays to determine the compounds. with the highest efficacy. The results of our study show that we synthesized clindamycin propionate derivatives and clindamycin homo/heterodimer derivatives, which exhibited superior antibacterial activity compared to clindamycin and other antibiotics against both bacteria and fungi. In vitro bacteriostatic activity testing against four types of Gram-negative bacteria and one type of fungi revealed that all synthesized compounds had bacteriostatic effects at least 1000 times better than clindamycin and sulfonamides. The minimum inhibitory concentration (MIC) values for these compounds ranged from 0.25 to 0.0325 mM. Significantly, compound 5a demonstrated the most potent inhibitory activity against three distinct bacterial strains, displaying MIC values spanning from 0.0625 to 0.0325 mM. Furthermore, our calculations indicate that compound 5a is safe for cellular use. In conclusion, the synthesized compounds hold great promise in addressing bacterial antibiotic resistance.

PREPARING AND CHARACTERIZING SOME NEW DERIVATIVES OF ORGANIC CYCLIC COMPOUNDS DERIVED FROM SOME DRUGS AND STUDYING THEIR BIOLOGICAL

This study involved synthesis some of derivatives via that a Suzuki-Miyaura cross-coupling procedure was used in order to produce a wide variety of Baclofen derivatives. After beginning with the reaction of 4-methoxy carbonyl phenyl boronic acid by the use of the reflex method, the treatment of Baclofen with a number of other boronic acids was carried out. The subsequent stage was the incorporation of Pd(0)(PPh3)4, and lastly, once the reaction had reached a state of equilibrium,Ethyl Acetoacetate ( EtOAc) was incorporated into the mixture. Taking this action was necessary in order to finish the procedure. Using the thin layer chromatography (TLC)technique, the observation of the reaction was carried out in order to carry out the observation. In order to accomplish the job of characterizing all of the unique Baclofen derivatives that were discussed in the preceding paragraphs [1-6], the analytical procedures of Fourier Transform Infrared (FT-IR) , Proton nuclear magnetic resonance (1HNMR) ,Carbon-13 nuclear magnetic resonance (13C-NMR) , and C.H.N were used. Furthermore, a wide range of other physical characteristics, such as color, Rf, and mechanical capabilities, were investigated and appraised. The objective of the experiment was to determine whether or not the treatment was effective against two different types of bacteria according to the biological standards. One of the objectives of the experiment was to do this. There was one species of fungus, which was Candida albicans, and one of the bacteria was positive (Staphylococcus aureus). The other bacterium was negative (Escherichia coli), and there was one type of bacteria. Of the bacteria, two were found to be positive. Following the assessment of the compounds' bacterial inhibitory biological activity [1-6], it was shown that the derivatives had an exceptionally high degree of effectiveness at a certain concentration. An additional accomplishment was the successful completion of a molecular docking investigation of novel Baclofen derivatives. [1-6].

Antibacterial and antioxidant properties and phytochemical screening of Laurus nobilis L. extract from Ethiopia

Microbial resistance to antibiotics and the shortage of efficient antimicrobial agent has necessitated the search for a better antimicrobial agent from various sources. Plants secondary metabolites are the major sources for discovery of new bioactive chemical compounds. The objective of this study was to determine the antibacterial and antioxidant activities of Laurus nobilis leaf extract and its essential oil against human pathogenic microorganisms and to analyse its chemical composition. The leaf of L. nobilis (500 g) was air-dried, powdered and extracted using four different solvents. The crude extract and the essential oil were tested against four Gram-negative and two Gram-positive bacterial strains. The radical scavenging activity of the crud extract was examined using DPPH assay. Bacterial inhibition activity of the crude extract increased with increased concentration from 25 mg/mL to 200 mg/mL. The maximum inhibition zone was recorded against Enterococcus faecalis 13.33±1.52 mm, Escherichia coli 14.33±1.53 mm and Salmonella typhimurium 16.00±1.00 mm, respectively. MeOH extract (1000 µg/mL) showed superior radical scavenging property (0.02) than ascorbic acid (0.05). The analysis of the oil using GC-MS indicated the presence of 48 chemical substances accounting for 91.4 % of the total compositions. The finding of this study showed that bay leaf has considerable antimicrobial and antioxidant activities. Further evaluation of this plant is recommended with particular focus on the mechanisms of action of the antimicrobial substance.

Fractionation of the Caspian sand goby epidermal exudates using membrane ultrafiltration and reversed-phase chromatography: an investigation on bioactivities.

Bioactive peptide-based drugs have gained exceeding attention as promising treatments for infectious and oxidative-stress-related diseases, are exacerbated by the advent and spread of various multidrug-resistant bacteria and industrial lifestyles. Fish skin mucus has been recognized as a potential source of bioactive peptides, providing the first line of fish defense against invading pathogens which are targeted here to be explored as a new source of biopharmaceutics. Peptide fractions were isolated from the epidermal exudates of Caspian sand goby, Neogobius fluviatilis pallasi, by solid-phase extraction (SPE), ultrafiltration, and reversed-phase chromatography. The resulting fractions were characterized for their antibacterial and antioxidant properties, and results showed that the molecular weight fraction < 5kDa represented the highest (p < 0.05) bacterial inhibition activity against Staphylococcus aureus and Bacillus subtilis as well as scavenging activity against DPPH and ABTS radicals. Overall, these results introduce the epidermal mucus of Caspian sand goby as a valuable source of bioactive compounds that can be considered new and efficient biopharmaceutics.

Antibacterial properties of the flower shaped nano-CuFe2O4@MoS2 composites

Pathogenic bacteria cause diseases that pose a considerable threat to global public health. Addressing this issue requires novel and effective antimicrobial agents. In this paper, CuFe2O4 was synthesized using FeCl3·6H2O and CuCl2·2H2O via solvothermal methods. Then, CuFe2O4@MoS2 composites were produced, using CuFe2O4 as the core, via a one-pot method. Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and vibrating sample magnetometry were used to systematically characterize the composites and to investigate the antibacterial properties of CuFe2O4@MoS2 against the Gram-negative bacterium Escherichia coli, the Gram-positive bacterium Staphylococcus aureus, and the white fungi Candida albicans and its inhibitory mechanism. Studies on bacterial inhibitory activity demonstrated that at a concentration of 200 μg/mL for 40 min, CuFe2O4@MoS2 inhibited 99.9%, 99.9%, and 99.4% of the three test bacteria. When compared with CuFe2O4 alone, the inhibitory efficacy of CuFe2O4@MoS2 composites increased significantly against the three test bacteria. The bacterial inhibition mechanism of the composite material entails the release of copper ions and oxidative stress, and CuFe2O4@MoS2 can destroy the bacterial cell wall, leading to the death of bacteria. Moreover, CuFe2O4@MoS2 can disrupt the bacterial cell wall, resulting in bacterial death. Furthermore, the material displays high biocompatibility. Therefore, the outstanding bacteriostatic characteristics of CuFe2O4@MoS2 could be used in various fields, including medicine.

A green-micro-synthesis of curcumin functionalized silver nanoparticles for bacteria inhibition and glucose sensor electrode modifier

A novel strategy for silver nanoparticles synthesis has been developed in a simple way. The method promotes green synthesis by using demineralized water as the primary solvent, sunlight as the energy source, and the small volume of the reaction. The silver nanoparticles were obtained by utilizing the autooxidation pathways of curcumin that was dissolved in ethanol. Interestingly, the volume of curcumin at the microliter level could produce AgNPs with good properties. The materials were characterized using UV–Visible spectrophotometer, Fourier Transform Infra-Red Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX), and Nano Particle Analyzer. The bacterial inhibition activity of silver nanoparticles (cAgNPs) was tested against Eschericia coli ATRCC6633 and Staphylococcus aureus ATRCC6633. This material showed good activity in inhibiting Gram-negative and Gram-positive bacteria compared to the control Ag + ion and curcumin. MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) test results exhibited a good performance of cAgNPs against E. coli ATRCC6633 and S. aureus ATRCC6633. Carbon paste electrode (CPE) modified with cAgNPs was used to detect glucose using Differential Pulse Voltammetry (DPV) technique. The cAgNPs were electrodeposited on CPE using cyclic voltammetry (CV) technique. The modified electrode showed promising results to be applied for glucose detection due to its good linearity and sensitivity. In addition, this work will give new insight into a sustainable method for producing silver nanomaterials that provide good bacteria inhibition and enhance the CPE performance to detect glucose.

Effects of propolis coating on antibacterial resistance of intrauterine devices

Intrauterine devices (IUDs) are widely used in preventing fertilization as contracepting devices. In market, they are produced as T-shaped polyethylene (or propylene) and metal (especially copper) composites. Although the metal component is utilized to provide antibacterial efficacy, prolonged implantation and the presence of a wide range of bacteria flora in the intrauterine environment make IUDs susceptible to bacterial contamination, biofilm formation, and unpleasant infection. In the presented study, the propolis, a natural anti-bacterial/-viral product used for different biomedical applications, coating strategy was applied comparatively in three different ways: coating directly on metal components, coating on polymeric material, and using carrying polymer. In addition, antibacterial activity against Gram-positive (Staphylococcus aureus, S. aureus) and Gram-negative (Escherichia coli, E. coli) bacterial strains were investigated by both dynamic bacterial culture (bacterial inhibition activity) and biofilm (biofilm formation resistance) tests. As a result of 48 h of dynamic bacterial culture; it was determined that the antibacterial inhibition efficiency depending on propolis concentration increased up to 99.5% and 98.5% for E. coli and S. aureus, respectively. In addition, the carrying polymer allows IUDs to cover surfaces more homogeneously, as well as improve antibacterial activity. Similarly; it was determined that biofilm formation resistance was improved by 44.33% for E. coli and by 45.99% for S. aureus with both the propolis concentration and the use of carrying polymer. As a result, it has been revealed that propolis will be classified as an alternative, promising, and effective coating agent for improving antibacterial properties and biofilm formation resistance of IUDs.

Design, synthesis, and bioactivity studies of chalcone derivatives containing [1,2,4]-triazole-[4,3-a]-pyridine

In this study, 30 chalcone derivatives containing [1,2,4]-triazole-[4,3-a]-pyridine were designed and synthesized. The results of antibacterial activity showed that EC50 values of N26 against Xoo, Pcb was 36.41, 38.53 μg/mL, respectively, which were better than those of thiodiazole copper, whose EC50 values were 60.62, 106.75 μg/mL, respectively. The bacterial inhibitory activity of N26 against Xoo was verified by SEM. Antibacterial mechanism between N26 and Xoo was preliminarily explored, the experimental results showed that when the drug concentration was 100 mg/L, N26 had a good cell membrane permeability of Xoo, and it can inhibit the production of EPS content and extracellular enzyme content to disrupt the integrity of the Xoo biofilms achieving the effect of inhibiting Xoo. At 200 mg/L, N26 can protect and inhibit the lesions of post-harvested potatoes in vivo. The activities of N1-N30 against TMV were determined with half leaf dry spot method. The EC50 values of the curative and protective activity of N22 was 77.64 and 81.55 μg/mL, respectively, which were superior to those of NNM (294.27, 175.88 μg/mL, respectively). MST experiments demonstrated that N22 (Kd = 0.0076 ± 0.0007 μmol/L) had a stronger binding ability with TMV-CP, which was much higher than that of NNM (Kd = 0.7372 ± 0.2138 μmol/L). Molecular docking results showed that N22 had a significantly higher affinity with TMV-CP than NNM.

A novel study of biological and structural analysis on Cissus quadrangularis fiber-reinforced CaO particulates epoxy composite for biomedical application

Natural fibers derived from renewable, environmentally sustainable sources are being considered for use as reinforcements in polymer composites. The current study focuses on the fabrication of composite materials using fiber extracted from the Cissus quadrangularis (CQ) natural plant as reinforcement, an epoxy polymer as a matrix, and calcium oxide (CaO) nanoparticles as filler material, with the weight ratio of Cissus quadrangularis fiber (CQF) and CaO filler materials are varied to quantify the biological and structural effects of CQF composite. X-ray diffraction (XRD) results demonstrate a 58% amorphous zone in this composite, while Fourier transforms infrared spectroscopy (FTIR) examination revealed the hydrophobic nature, chemical bonding, and cellulose content. Because of the increased amount of chopped CQF loading in this composite, the mechanical qualities result in an average of 23% better tensile strength. Scanning electron microscopic (SEM) analysis was used to analyze the failure analysis for fiber interaction with matrix, filler, and fiber pullouts under mechanical stress. The antibacterial research revealed that this CQF composite exhibits bacterial inhibitory activity suitable for biomedical applications.

Green biosynthesis of stable silver nanoparticles bound with macaranga indica plant extracts for the purification of drinking water

Plant-assisted green biosynthesis of silver nanoparticles (NPs) has become the most powerful technique to prepare stable NPs. Macaranga indica is a medicinal plant widely available in the western ghats. It has verities of medical properties like antibacterial, antioxidant, antidiabetic, cytotoxicity, and antidysentery and is commonly used in the traditional medicine system. This plant also contains polyphenols, flavonoids, and other plant constituents. Here, in this study, macaranga indicia leaf extract is used as a capping agent for the synthesis of silver NPs by using the microwave irradiation technique. Synthesized NPs are characterized by using Uv-Vis Spectra, XRD, EDX, FESEM, and FTIR. Interpretation of characterization data reveals that synthesized NPs are in a spherical shape, monodispersed, and have particles the size of ~15-20 nm. These bicapped silver NPs have shown potential thermotolerant bacterial inhibition activity and are also efficient in methylene blue dye removal and hence can be used in the purification process of drinking water at its source.

Characterization and exploration of biological properties of phycobiliproteins purified from Thai karstic cave cyanobacterium Nostoc sp. SW02

Phycobiliproteins are colored water-soluble proteins found in cyanobacteria with potential applications in food and pharmaceuticals. Phycobiliproteins extracted from the Thai karstic cave cyanobacterium Nostoc sp. strain SW02 were purified, and their biological properties were characterized. Scale-up cultivation for 12 days revealed that maximum biomass and phycobiliproteins producing yield were 1.53 g/L and 31.92%, respectively. After purification, phycoerythrin was obtained as the principal component of phycobiliproteins, with a purity index up to 2.62, sufficient to be considered food and cosmetic grade. Native and SDS-PAGE analysis displayed that purified phycoerythrin and phycocyanin contained the αβ-subunits in hexamer form. Purified phycobiliproteins had a more stable structure and functionality in pH range 5.0–7.0, were resistant to strong oxidizers, and could withstand temperatures up to 60 °C. They also exhibited DPPH scavenging capabilities comparable to standard ascorbic acid. Pathogenic bacterial inhibition (MIC 250 μg/mL) and anticancer activity against the human HeLa cancer cell line (IC50 140 μg/mL) were also observed. With these prospective characteristics, phycobiliproteins obtained from Nostoc sp. SW02 have biotechnological value for biomedical research and also as a natural colorant for food and cosmetic applications.

Secretory Expression and Application of Antilipopolysaccharide Factor 3 in Chlamydomonas reinhardtii.

Anti-lipopolysaccharide factor is a class of antimicrobial peptides with lipopolysaccharide-binding structural domains, which has a broad antimicrobial spectrum, high antimicrobial activities, and broad application prospects in terms of the aquaculture industry. However, the low yield of natural antimicrobial peptides and their poor expression activity in bacteria and yeast have hindered their exploration and utilization. Therefore, in this study, the extracellular expression system of Chlamydomonas reinhardtii, by fusing the target gene with the signal peptide, was used to express anti-lipopolysaccharide factor 3 (ALFPm3) from Penaeus monodon in order to obtain highly active ALFPm3. Transgenic C. reinhardtii T-JiA2, T-JiA3, T-JiA5, and T-JiA6, were verified using DNA-PCR, RT-PCR, and immunoblot. Additionally, the IBP1-ALFPm3 fusion protein could be detected not only within the cells but also in the culture supernatant. Moreover, the extracellular secretion containing ALFPm3 was collected from algal cultures, and then its bacterial inhibitory activity was analyzed. The results showed that the extracts from T-JiA3 had an inhibition rate of 97% against four common aquaculture pathogenic bacteria, including Vibrio harveyi, Vibrio anguillarum, Vibrio alginolyticus, and Vibrio parahaemolyticus. The highest inhibition rate of 116.18% was observed in the test against V. anguillarum. Finally, the minimum inhibition concentration (MIC) of the extracts from T-JiA3 to V. harveyi, V. anguillarum, V. alginolyticus, and V. parahaemolyticus were 0.11 μg/μL, 0.088 μg/μL, 0.11 μg/μL, and 0.011 μg/μL, respectively. This study supports the foundation of the expression of highly active anti-lipopolysaccharide factors using the extracellular expression system in C. reinhardtii, providing new ideas for the expression of highly active antimicrobial peptides.

Design, synthesis and biological activity of novel chalcone derivatives containing indole

In this study, 24 chalcone derivatives containing indole were designed and synthesized. Some of the target compounds exhibited significant antiviral and antibacterial effects. The results of EC50 test against tobacco mosaic virus showed that the EC50 value of curative activity of D11 was 107.4 μg/mL, which was better than the commercial drug ningnanmycin 311.5 μg/mL, and the EC50 value of protective activity of D16 was 106.6 μg/mL, which was superior to ningnanmycin 205.4 μg/mL, the inactivated activity of D11 was comparable to that of ningnanmycin. Microscale thermophoresis experiments demonstrated D11 (Kd = 0.0030 ± 0.0014 μmol/L) had a stronger binding ability with tobacco mosaic virus capsid protein (TMV-CP), which was much higher than that of ningnanmycin (Kd = 2.6062 ± 1.1767 μmol/L). Molecular docking results showed D11 had a significantly higher affinity with TMV protein than ningnanmycin. In addition, the malondialdehyde (MDA), peroxidase (POD), succinate dehydrogenase content (SDH) assay showed D11 could improve the disease resistance of tobacco. The results of bacterial inhibition activity showed that the EC50 value of D23 against Xoo was 50.3 μg/mL, which was better than the commercial drugs thiodiazole copper (79.8 μg/mL) and bismerthiazol (106.2 μg/mL), the bacterial inhibition activity of D23 was verified by scanning electron microscopy.

Effect of modified zinc oxide nanoparticles on enhancement of mechanical, thermal and antibacterial properties of disinfectant natural rubber latex foams

Natural rubber latex foams (NRLF) filled with unmodified zinc oxide (ZnO) and modified ZnO nanoparticles (ZnOnp) through the chemical coating on the calcium carbonate (CaCO3) are manufactured. This aimed to develop the mechanical, thermal, antibacterial properties of the NRLF for creating new innovative products and turn the NRLF to be the disinfectant NRLF. Various specific properties were considered, particularly the structure of modified ZnOnp and the antimicrobial activity of foams. It was found that the use of ZnOnp-coated CaCO3 at a ratio of 90:10 (ZnOnp-Ca10) indicated the highest of reinforcement efficiency, crosslink density based on the observed Mooney-Rivlin, and thermal stability. This related to the smaller particles, surface contacting area to the rubber chains, and shorter band gap in the activated states relative to the ZnO and unmodified ZnOnp. This NRLF had also the highest % inhibition of bacterial activity within 1 h by killing 94.01% of gram-native E.Coli bacteria. Relating the indication of the inhibition zone, NRLF filled with ZnOnp-Ca10 also showed strong efficiency for prohibiting the E.Coli and gram-positive S.Aureus bacteria. This affirmed the achievement of the disinfectant NRLF by using less ZnO purity in the foam which can support the preparation of other end rubber foam products.

Effects of Mangosteen Peel Extract Encapsulated By Maltodextrin On Antibacterial Activities of Escherichia coli

Mangosteen peel extract contains good antibacterial compounds and is thought to be better when microencapsulated is formed. This study aimed to determine the effects of formulation of mangosteen peel ethanol extract associated to maltodextrin on activities of Escherichia coli. It was conducted by disk diffusion method according to Kirby-Bauer test in Mueller Hinton Agar (MHA) using three different concentrations namely: 100, 75, and 50 (%). Each formulation was tested as many as 10 µL disk -1 consisted of each treatment. The employed maltodextrin was obtained by enzymatic processing of arenga starch. Nine formulations were tested by measuring their bacterial inhibition activity in a Mueller Hinton Agar (MHA) medium. The results showed that the effects of formulation between mangosteen peel ethanol extract and maltodextrin had the significant effect (P&lt;0.05) on the antibacterial activities of Escherichia coli. It had been shown the ability to actively inhibit the bacterial growth at medium levels.