Gram-positive Bacterial Strains Research Articles

Four new flavonoids from Sophora flavescens and their antibacterial activities

Three new flavanones sophoflavanone C (1), sophoflavanone D (2), sophoflavanone E (3), and one new flavanonol, sophoflavanone F (4), were isolated from the ethanol extract of the root bark of Sophora flavescens. The structures of these compounds were identified by UV spectroscopy, high-resolution electrospray ionisation mass spectrometry (HRESIMS), nuclear magnetic resonance spectroscopy (NMR), and comparison with previous reports. Additionally, the antibacterial activity of compounds 1–4 against eight bacterial strains, including four Gram-positive bacterial strains and four Gram-negative bacterial strains, was determined using the micro broth dilution method. Both isopentenyl flavones, sophoflavanone C (1) and sophoflavanone F (4) exhibited significant antibacterial activity against the Gram-positive bacterial strains.

Evaluation of the in Vitro Antibacterial Activity of Natural kinds of Multi-floral Honey Against Selected Gram-Positive and Gram-Negative Bacterial Strains

Evaluation of the in Vitro Antibacterial Activity of Natural kinds of Multi-floral Honey Against Selected Gram-Positive and Gram-Negative Bacterial Strains

Discovery of Novel Coumarin Pleuromutilin Derivatives as Potent Anti-MRSA Agents.

Treating methicillin-resistant Staphylococcus aureus (MRSA) infection remains one of the most difficult challenges in clinical practice, primarily due to the resistance of MRSA to multiple antibiotics. Therefore, there is an urgent need to develop novel antibiotics with high efficacy and low cross-resistance rates. In this study, a series of novel pleuromutilin derivatives with coumarin structures were synthesized and subsequently assessed for their biological activities. Most of these derivatives showed potent antimicrobial activity against drug-resistant Gram-positive bacterial strains. Compound 14b displayed particularly rapid bactericidal effects, slow resistance development, and low cytotoxicity. Moreover, it decreased bacterial loads in the lung, liver, kidney, spleen, and heart and exhibited better antibacterial efficacy (ED50 = 11.16 mg/kg) than tiamulin (ED50 = 28.93 mg/kg) in a mouse model of systemic MRSA infection. Both in vitro and in vivo analyses suggest that compound 14b is a promising agent for the treatment of MRSA infections.

Effect of silver ion and silicate group on the antibacterial and antifungal properties of nanosized hydroxyapatite

Hydroxyapatite is one of the most widely used materials in biomedical applications in reparative and regenerative medicine. Doping of nanosized hydroxyapatite improves its bioactive properties, and thus, the synthesis of different types of nanohydroxyapatite with antimicrobial activity is a perspective route of modern materials science. In this study, undoped hydroxyapatite (HAp), hydroxyapatite doped with silver (HAp with 0.1, 0.5 and 1 mol% Ag+ ions), and silicate-substituted hydroxyapatite doped with silver (Si-HAp with 0.1, 0.5 and 1 mol% Ag+ ions) nanoparticles (NPs) were synthesized by microwave-assisted hydrothermal technique and sintered at 450 °C. The structural properties and composition of obtained hydroxyapatite NPs were investigated using X-ray powder diffraction (XRPD), Fourier-transformed infrared spectroscopy (FT-IR), and Energy-dispersive X-ray spectroscopy (EDS). The morphology of synthesized nanosized powders was detected using the high-resolution transmission electron microscopy (HRTEM) technique. The results of XRPD for all synthesized nanosized powders confirmed the presence of hydroxyapatite crystal structure. The FT-IR spectra confirmed the presence of functional groups characteristic of the hydroxyapatite structure. The EDS analysis of obtained materials has shown the presence of Ca, P, O, Si, and Ag elements. Significant differences in size and morphology of the obtained particles were found using HRTEM. The particles have an elongated, rod-like shape with subtle differences. Moreover, HAp doped with 1 mol% Ag+ ions and Si-HAp doped with 1 mol% Ag+ ions nanosized powders showed antibacterial activity in comparison to pure hydroxyapatite both against gram-positive and gram-negative bacterial strains (Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis). These two types of hydroxyapatite NPs also demonstrated antifungal activity against reference strains of Candida albicans, Candida kruzei, and Candida tropicalis, with stronger activity observed for Si-HAp doped with silver.

Characterization of Serratia marcescens (OK482790)’ prodigiosin along with in vitro and in silico validation for its medicinal bioactivities

BackgroundMicrobial prodigiosin pigment has been proposed as a promising biomolecule having an antibacterial, immunosuppressive, antimalarial, antineoplastic, and anticancer activities. The good outcome originates from getting natural pigment, which has many medical applications.ResultsIn this investigation, prodigiosin (PG) was extracted, characterized by UV-visible spectroscopy, thin-layer chromatography, mass spectroscopy, Fourier-transform infrared spectroscopy, and tested in various medical applications as an antibacterial, antioxidant, antibiofilm, anticancer, and wound healing agent at different concentrations. Antibacterial activity of PG pigment was shown against both Gram-positive and Gram-negative bacterial strains. Enterococcus faecalis was the most severely impacted, with minimum inhibitory value of 3.9 µg/mL. The formed biofilm by Pseudomonas aeruginosa was suppressed by 58–2.50% at prodigiosin doses ranging from 1000 to 31.25 µg/mL, respectively. The half-maximal inhibitory concentration (IC50) of 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical was 74.18 ± 23.77 µg/mL. At 100 µg/mL concentration, OK482790 prodigiosin had no harmful effect on normal skin cells and exhibited mild wound healing properties. Additionally, molecular docking simulations confirmed the prodigiosin’s interactions with target proteins, including epidermal growth factor receptor tyrosine kinase (EGFR-TK, PDB ID: 1M17), peptide deformylase from E. faecalis (PDB ID: 2OS1), acidic fibroblast growth factor (FGF-1, PDB ID: 3K1X), PA14_16140 protein from P. aeruginosa (PDB ID: 8Q8O), and human peroxiredoxin 5 (PDB ID: 1HD2) for explaining the anticancer, antibacterial, wound healing, antibiofilm, and antioxidant activities, respectively. Prodigiosin had favorable binding affinities and putative modes of action across various therapeutic domains.ConclusionThis study pioneers the use of prodigiosin as a natural alternative to synthetic medicine since it fights germs, heals wounds, is antioxidant, and reduces biofilm formation.Clinical trial numberNot applicable.

A new antibacterial neo-clerodane diterpenoid and other constituents from Chasmantheradependens Hochst. (Menispermaceae) and their chemotaxonomic significance

The leaves, stems and fruits methanol extracts of Chasmanthera dependens were chemically investigated to afford one new neo-clerodane diterpenoid (1) along with seventeen known compounds including three diterpenoids (2–4), six triterpenoids (5–10), four steroids (11–14), one sesquiterpenoid (15), one lignan (16) and two phenolic acids (17 and 18). Structures were established by analysis of their spectroscopic and spectrometric data and in comparison with those reported from the literature. Except columbin (2), compounds are reported for the first time from the genus Chasmanthera. The extracts, fractions, and isolated compounds were subjected to in vitro antibacterial assays against three Gram-positive and three Gram-negative bacteria, using the broth microdilution method. The MeOH extract of the leaves and its fractions F1–F4 had significant (MIC = 93.8 μg/mL for F4) or moderate (187.5 ≤ MIC ≤ 375 μg/mL) activities against Pseudomonas aeruginosa. Chasmantherenolide (1) was moderately active (MIC = 75 μg/mL, 202.6 μM) against Gram-positive bacterial strains. Significant antibacterial activity (MIC = 9.4 μg/mL, 20.6 μM) was recorded for oleanolic acid (7) against Mycobacterium smegmatis. The chemotaxonomic significance of the isolated compounds was discussed.

Bio-computational modeling, POM analysis and molecular dynamic simulation for novel synthetic quinolone and benzo[d][1,3]oxazine candidates as antimicrobial inhibitors

The current study offers a metal-free, direct, and successful synthesis technique for a new series of quinolinone and benzo[d][1,3]oxazine, along with an assessment of their biological activities. Heteroannulation of anthranilic acid with carbonyl-containing chemicals (aroyl pyruvate, ethyl acetoacetatete, maleic anhydride, and ethyl cyanoacetate) resulted in the desired quinolones and benzo[d][1,3]oxazines. This technique introduces a number of fundamental breakthroughs in organic synthesis, including metal-free catalysts, smart reaction conditions with column purification, and a wide functional scope. Furthermore, the structure of the newly synthesized chemical series was investigated and validated using spectroscopic techniques. The synthesized series were evaluated for antibacterial (against gram-positive and gram-negative bacterial strains) and antifungal activity. The quinolone and benzo[d][1,3]oxazine candidates had remarkable antibacterial action. Furthermore, molecular docking investigations corroborated the biological studies using the Molecular Operating Environment and Petro Osiris Molinspiration (POM) experiments, which confirmed the activity of compounds 8, 15, and 17. Our studies on the cytotoxic activity of various chemicals have demonstrated that these compounds exhibit minimal toxicity. Specifically, when comparing the cytotoxic effects on human lung fibroblast (WI38) cells to those of Doxorubicin, a well-known chemotherapy agent, compounds 8, 15, and 17 showed weak cytotoxic effects on the normal WI38 cells. This indicates that these compounds may possess some level of selectivity and reduced toxicity towards normal cells, suggesting potential for further exploration as antibacterial agents with a safer profile for normal cells.

Exploring the Efficacy of pH-Responsive Vancomycin/Ag/ZIF-8 Nanoparticles Modified with Hyaluronic Acid for Enhanced Antibacterial Therapy and Wound Healing.

This study introduces a novel type of metal-organic framework material, specifically zeolitic imidazolate framework-8 (ZIF-8), that is integrated with silver nanoparticles and further enhanced by incorporating vancomycin (Van) to create a composite named as Van/Ag/ZIF-8. This composite demonstrates a potent and smart antimicrobial effect due to its ability for releasing silver ions and Van in a controlled manner, especially in the microacidic conditions surrounding bacterial cells. Furthermore, we used hyaluronic acid to modify Van/Ag/ZIF-8, resulting in a composite denoted as Van/Ag/ZIF-8@HA. This composite exhibits a significant inhibition effect against the proliferation of both Gram-negative (Escherichia coli 100%) and Gram-positive (Staphylococcus aureus 99.9%) resistant bacterial strains while exerting no adverse effects on animal cellular growth. These findings underscore its favorable biocompatibility profile. The experimental results show a combined antibacterial action against prevalent bacterial infections, which is supported by in vivo experiments using a skin wound model. This work confirms the composite's significant role in fighting pathogenic infections and aiding in healing skin wounds. The innovative strategy not only tackles the pressing issue of antibiotic-resistant bacterial infections but also marks a significant advancement in the areas of wound healing and medical research, offering a promising path for future investigations and therapeutic uses.

Rhodamine-B degradation, chromium removal and bactericidal potential of Cu–ZnO@ZrO2 nanoneedles fabricated via green route

Nanoparticles are being used for diverse environmental as well as biomedical applications due to their versatile features. In current work, a facile green synthesis route was employed for the fabrication of Cu–ZnO@ZrO2 nano-needles (NNs) using Momordica charantia (MC) stem extract and ZrO2 was used as a precursor along with CuCl2 and ZnCl2. UV–Vis and FTIR analysis confirmed the formation of Cu–ZnO@ZrO2 NNs. XRD studies confirmed orthorhombic geometry and FE-SEM images confirmed needle like structure of the prepared Cu–ZnO@ZrO2. Catalytic potential of the synthesized NNs was evaluated in terms of its efficiency towards degradation of rhodamine-B (Rh–B) dye. Degradation was achieved up to 98 % in 14 min in the presence of NNs. Conditions were optimized for the maximum removal of the dye using ascorbic acid (AA) as a reducing agent. Synthesized NNs sample was tested against another toxic pollutant i.e. Cr (VI) that was removed up to 65 % from aqueous medium. Promising antibacterial activity of the NNs was recorded against gram-positive and gram-negative bacterial strains. The results of the current study revealed promising features of NNs suggesting its use for the removal of microorganisms, organic and metallic pollutants. Authors would strongly suggest the fabrication of nanocomposites of same composition for the treatment of toxic pollutants in aqueous medium.

Eco-Friendly Synthesis of ZnO Nanoparticles for Quinoline Dye Photodegradation and Antibacterial Applications Using Advanced Machine Learning Models

Community drinking water sources are increasingly contaminated by various point and non-point sources, with emerging organic contaminants and microbial strains posing health risks and disrupting ecosystems. This study explores the use of zinc oxide nanoparticles (ZnO-NPs) as a non-specific agent to address groundwater contamination and combat microbial resistance effectively. The ZnO-NPs were synthesized via a green chemistry approach, employing a sol-gel method with lemon peel aqueous extract. The catalyst was characterized using techniques including XRD, ATR-FTIR, SEM-EDAX, UV-DRS, BET, and Raman spectroscopy. ZnO-NPs were then tested for photodegradation of quinoline yellow dye (QY) under sunlight irradiation, as well as for their antibacterial and antioxidant properties. The ZnO-NP photocatalyst showed significant photoactivity, attributed to effective separation of photogenerated charge carriers. The efficiency of sunlight dye photodegradation was influenced by catalyst dosage (0.1–0.6 mg L−1), pH (3–11), and initial QY concentration (10–50 mg L−1). The study developed a first-order kinetic model for ZnO-NPs using the Langmuir–Hinshelwood equation, yielding kinetic constants of equilibrium adsorption and photodegradation of Kc = 6.632 × 10−2 L mg−1 and kH = 7.104 × 10−2 mg L−1 min−1, respectively. The results showed that ZnO-NPs were effective against Gram-positive bacterial strains and showed moderate antioxidant activity, suggesting their potential in wastewater disinfection to achieve sustainable development goals. A potential antibacterial mechanism of ZnO-NPs involving interactions with microbial cells is proposed. Additionally, Gaussian Process Regression (GPR) combined with an improved Lévy flight distribution (FDB-LFD) algorithm was used to model QY photodegradation by ZnO-NPs. The ARD-Exponential kernel function provided high accuracy, validated through residue analysis. Finally, an innovative MATLAB-based application was developed to integrate the GPR_FDB-LFD model and FDB-LFD algorithm, streamlining optimization for precise photodegradation rate predictions. The results obtained in this study show that the GPR and FDB-LFD approaches offer efficient and cost-effective methods for predicting dye photodegradation, saving both time and resources.

A potent moiety of (E)-5-(4-(5-chlorothiophene-2-carbonyl) piperazin-1-yl)-N'-(substituted methylene) benzofuran-2-carbohydrazide: Molecular docking, synthesis and antimicrobial evaluation

In this paper, we report new hybrid molecules of (E)-5-(4-(5-chlorothiophene-2-carbonyl) piperazin-1-yl)-N'-(substituted methylene) benzofuran-2-carbohydrazide (10a-10r) as an anti-microbial agent. The synthesized compounds have been characterized by FT-IR, Mass, 1H and 13C NMR spectroscopic techniques and were evaluated on gram-positive (S. aureus and S. pyogenes), gram-negative (E. coli and P. aeruginosa) bacterial strain and fungal (C. albicans and A. Niger) strains by the broth dilution method. The compounds exhibited significant antibacterial and antifungal activities, out of which compounds 10b and 10o, having MIC 62.5 μg/mL, showed the best activity against gram-positive bacterial strain S. aureus. Furthermore, compounds 10e, 10j, and 10m, having MIC 62.5 μg/mL, showed the best activity against the gram-negative bacterial strain E. coli. In contrast, compounds 10g and 10n, having MIC 62.5 μg/mL, showed the best activity against gram-negative bacterial strain P. aeruginosa. Out of the series, compounds 10h and 10l have been found to possess better inhibitory activity with MIC 250 μg/mL, compared to standard drug Griseofulvin (MIC 500 μg/mL) against anti-fungal strain C. albicans. Additionally, the compounds were docked in DNA gyrase enzyme of gram-positive and gram-negative bacteria and also C. albicans fungal. Compounds 10h and 10l were docked with the CYP51 of C. albicans (PDB: 5V5Z), revealing that the benzyl ring of the carbohydrazide Schiff base formed a potent π-π stacking interaction with the Hem601 complex. Additionally, the carbonyl part of the amide functional group connecting the piperazine and thiophene rings was found to interact with His377 through a hydrogen bond, which is considered a significant interaction. The compounds are also checked for their drug-likeness property using Lipinski rule. On the basis of these findings, we can conclude that (E)-5-(4-(5-chlorothiophene-2-carbonyl) piperazin-1-yl)-N'-(substituted methylene) benzofuran-2-carbohydrazide is a potent antimicrobial agent against a variety of bacterial and fungal species.

Green Synthesis of Nanoparticle-Loaded Bacterial Cellulose Membranes with Antibacterial Properties

The current work proposes the development of composite membranes based on bacterial cellulose (BC) loaded with silver (Ag) and zinc oxide (ZnO) nanostructures by in situ impregnation. The research involves the production and purification of BC, followed by its loading with different types of phases with the help of different precipitating solutions, turmeric extract (green synthesis) and ammonia (classic route). Additionally, the combination of both antibacterial agents into a single BC matrix to valorise the benefits of each, proposing a novel BC-Ag-ZnO composite with distinct characteristics, was explored. Overall, the synthesis was marked by colour changes from the light beige of the BC membrane to dark brown, dark orange and dark green for BC-Ag, BC-ZnO and BC-Ag-ZnO samples, which is proof of successful composites formation. The results proved that the antibacterial phases are attached as nanoparticles or nanosheets on BC fibres, with Ag being in a crystalline state, while ZnO showed a rather amorphous structure. Regarding the antibacterial efficiency, the BC-ZnO composite obtained by employing two precipitating solutions turned out to be the best material against both tested Gram-negative and Gram-positive bacterial strains.

Synthesis, Characterization and Antibacterial Activity Evaluation of CuO NPs and B-CuO NPs Obtained from Livistona Chinensis Leaf Extract.

Nanoparticles (NPs) exhibit fascinating size-dependent chemical and physical characteristics that make them useful for a variety of applications. The present paper reports the green synthesis of CuO NPs and B-doped CuO NPs (B-CuO NPs) from Livistona chinensis leaf extract. Not much work has been reported on the use of the plant extract for the fabrication of NPs, particularly those of Cu and its doped counterparts. Various spectroscopic techniques were used to characterize the synthesized NPs. In the FT-IR spectra, peaks obtained at 504 cm-1 to 600 cm-1 were due to Cu-O vibrations. The energy dispersive X-ray analysis (EDX) spectra confirmed the CuO NPs' composition and B's presence inside the NPs. The peak pattern in the X-ray diffraction (XRD) spectrum confirmed the crystalline and monoclinic phases of the NPs. The average crystalline size of CuO NPs and B-CuO NPs was 19.56 nm and 17.30 nm respectively. The CuO and B-CuO NPs were tested against three Gram-positive bacterial strains namely Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus and three Gram-negative Escherichia coli, Salmonella abony, and Pseudomonas aeruginosa through Agar well diffusion method and it was found that CuO NPs showed higher activity than B-CuO NPs. Gentamicin was used as the positive control. The antibacterial activity may be due to the cell wall disruption by induction of innate and adaptive host immune response, generating toxic reactive oxygen species (ROS), and stimulating intracellular effects.

Pillar[5]arene stabilized gold nanoparticles for the enhanced light-triggered nitric oxide release with antibacterial and antibiofilm activities

The reactivity of guests confined in well-defined host cavities act significantly different from that in bulk systems. In this work, pillar[5]arene not only works as a stabilizer for the fabrication of gold nanoparticles, but also act as an accelerator for the enhanced photo-triggered release of gaseous nitric oxide (NO) from encapsulated NO donor. The host–guest complex can dramatically improve the photoactivity of loaded guest molecule to generate antibacterial NO molecules through the confinement effect of pillar[5]arene cavity. The synergistic photo-triggered localized NO release and photo-thermal effect of host–guest complex demonstrated impressive antibacterial behaviors against Gram-negative bacterial strain Escherichia coli, Gram-positive bacterial strain Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. Moreover, this biocompatible photo-responsive complex can also inhibit bacterial biofilm formation and disrupt the pre-existing biofilms.

Biodegradable films incorporating Malaysian stingless bee propolis: Development, characterization, and potential for food packaging

Three different Malaysian stingless bee propolis samples were examined using the ethanolic extraction method for total flavonoid (TFC) and phenolic content (TPC), antioxidant, and antibacterial activities. Additionally, the biodegradable films were developed and characterized, this study also aims to enhance the functional qualities for possible use in active food packaging by combining corn starch (CS) with propolis extract (PE). The propolis samples were extracted with 70 % ethanol and analysed through a UV–VIS spectrophotometer for determination of antioxidant, TPC, and TFC. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used as scavenging test for free radicals, while Folin-Ciocalteu and aluminium chloride (AlCl3) were used to measure total flavonoid and phenolic contents. The data presented in this study showed significant differences in TPC and TFC identified in each sample ranged from 31.95 to 59.48 mg/mL GAE and 53.88 to 59.49 mg/mL RE, respectively. The findings also showed significant differences in the antibacterial activities of Malaysian stingless bee propolis, especially against Gram-positive bacterial strains. In comparison to the control treatments, the ethanolic propolis extract treatments also improved the film's physiochemical and antibacterial qualities. The incorporation of PE into CS resulted in decreased moisture content of the films from 17.20 % to 14.39 %, whereas the solubility significantly decreased from 17.44 % to 12.14 %. The weight of CS and PE film lowered significantly after 14 days and the weight loss percentage also demonstrated that bioplastic degradation occurred. The propolis extract was able to prevent the growth of foodborne bacteria since the present data revealed that the microbial count was significantly lower than control groups by displaying an acceptable limit of aerobic plate count for red meat products, which is lower than 6 log CFU/g. Propolis from Malaysian stingless bees may offer a viable substitute for synthetic additives in biodegradable food packaging films. Its antimicrobial and antioxidant properties support its application for sustainable food preservation.

Engineering of self-assembled silver-peptide colloidal nanohybrids with enhanced biocompatibility and antibacterial activity

Several bacterial strains have developed resistance against commercial antibiotics, and interestingly, supramolecular nanomaterials have shown considerable advantages for antibacterial applications. However, the main challenges in adopting nanotechnology for antibacterial studies are random aggregation, compromised toxicity, multi-step preparation approaches, and unclear structure-function properties. Herein, we designed the amphiphilic tripeptide that acts as a reducing and capping agent for silver metal to form silver-peptide colloidal nanohybrids with the mild assistance of UV light (254 nm) through the photochemical reduction method. The nanohybrids are characterized by different spectroscopic and microscopic techniques, and non-covalent molecular interactions between metal and peptide building blocks confirm their central role in the formation of nanohybrids. The tripeptide is biocompatible and can reduce the toxicity of silver ions (Ag+) by reducing to Ag0. These colloidal nanohybrids showed antibacterial activity against gram-negative and gram-positive bacterial strains, and the possible mechanism of killing bacterial cells could be membrane disruption. This synthetic strategy is facile and green, which helps avoid using toxic chemicals or reagents and complicated methods for colloidal nanohybrid preparation for biomedical applications.

Investigating antibacterial and anti-inflammatory properties of synthetic curcuminoids.

The concept of intratumoral microbiota is gaining attention in current research. Tumor-associated microbiota can activate oncogenic signaling pathways such as NF-κB, thereby promoting tumor development and progression. Numerous studies have demonstrated that curcumin and its analogs possess strong antitumor effects by targeting the NF-κB signaling pathway, along with potent antibacterial properties. In this study, we tested the antibacterial activity of two curcuminoids, Py-cPen and V-cPen, against the Gram-negative bacterial strains Pseudomonas aeruginosa and Escherichia coli and the Gram-positive bacterial strain Streptococcus aureus using in vitro assays and fluorescent microscopy. We observed that both Py-cPen and V-cPen reduced NF-κB activation upon lipopolysacharide (LPS) challenge in cell assays. In addition, our findings indicate that Py-cPen and V-cPen interact with LPS, as demonstrated by transmission electron microscopy and confirmed using in silico analyses, thereby modulating LPS activity. Overall, our data indicate that Py-cPen and V-cPen exhibit strong antibacterial and antiinflammatory properties, suggesting their potential as candidates for new multitarget therapeutic strategies.

Investigation of antibacterial and anticancer activities of biosynthesized metal-doped and undoped zinc oxide nanoparticles.

Over the past 10 years, nanotechnology has emerged as a very promising technique for a wide range of biomedical applications. Green synthesized metal and metal oxide nanoparticles (NPs) are cheap, easy to produce in large quantities, and safe for the environment. Currently, efforts are being made to dope ZnO in order to improve its optical, electrical, and ferromagnetic qualities as well as its crystallographic quality. Actually, doping is one of the simplest methods for enhancing an NP's physicochemical characteristics because it involves introducing impure ions into the crystal lattice of the particle. In this study, the biosynthesis of zinc oxide NPs (ZnONPs) and metal-doped (Mg2+ and Ag+) ZnONPs was carried out by using aqueous and water-alcoholic extracts of Cynara scolymus L. leaves, Carthamus tinctorius L. flowers, and Rheum ribes L. (RrL) plant, which are rich in phytochemical content. Plant extracts act as a natural reducing, capping, and stabilizing agent in the production. The produced NPs were characterized using a variety of methods, such as ultraviolet-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The produced metal-doped and undoped ZnONPs exhibited characteristic absorption peaks between 365 and 383nm due to their surface plasmon resonance bands. SEM analysis revealed that the NPs were oval, nearly spherical, and spherical. In the FTIR spectra, the Zn-O bonding peak ranges from 400 to 700cm-1. The peaks obtained in the range of 407-562cm-1 clearly represent the Zn-O bond. In addition, the FTIR results showed that there were notable amounts of phenol and flavonoid compounds in both the prepared extract and ZnONPs. According to DLS analysis results, the size distribution of produced NPs is between 120 and 786nm. The antibacterial properties of green produced NPs on Gram-positive (Staphylococcus aureus RN4220) and Gram-negative (Escherichia coli DH10B) bacterial strains were investigated by agar well diffusion method. In studies investigating the anticancer activities of biosynthesized NPs, mouse fibroblast cells (L929) were used as healthy cells and human cervical cancer cells (HeLa) were used as cancer cells. Only the produced Ag-ZnONPs showed potent dose-dependent antibacterial activity (at concentrations higher than 100µg/mL) against Gram-positive and Gram-negative bacteria. RrL-ZnONP-600 and RrL-ZnONP-800 NPs produced with water-ethanol extract of RrL plant and calcined at 600 and 800°C were effective at high concentrations in healthy cells and at low concentrations in HeLa cancer cells, showing that they have the potential to be anticancer agents. The study's findings highlight the potential of green synthesis techniques in the production of medicinal nanomaterials for the treatment of cancer and other biological uses.

Biofabricated silver nanoparticles from Calotropis procera: A potential antimicrobial solution against pathogenic bacteria

Calotropis procera has the potential as a traditional medicinal plant that offers a diverse array of healing treatments. It was used in conventional medicine to remedy several ailments, including diarrhea and snakebites. This study examines the antibacterial properties of silver nanoparticles derived from the floral and latex components of C. procera. The nanoparticles were tested for their effectiveness against Gram-negative and Gram-positive bacterial strains. For characterization, the synthesized nanoparticles underwent thorough analysis using UV spectroscopy, fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). After the reduction process, the FTIR analysis revealed that some functional biomolecules found in plants form a coating on the nanoparticles, serving as organic agents that stabilize the nanoparticles. The size of nanoparticles analyzed with SEM falls in the 30 to 130 nm range. Furthermore, the synthesized silver nanoparticles were tested as antimicrobial agents against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa, well-known microorganisms that can produce ulceration phases and severe health consequences. After a comprehensive examination, it was found that the silver nanoparticles have significant antibacterial effectiveness, particularly against S. aureus, a primary bacterium responsible for causing different ailments. The remarkable antibacterial efficacy of the silver nanoparticles synthesized in an environment-friendly manner underscores its potential applications in combating the evolution of antibiotic-resistant strains.

Facile modification of TiO2 as S-Scheme multifunctional materials for environmental protection and energy-storage applications

This paper reports a simple one-step modification of commercial TiO2 with a conducting polytrimethoxyslilypropyl aniline (PTMSPA, a polyaniline derivative having silyl networks) to have multi-functional (photocatalytic, optical, pseudocapacitive, hydrophobic, porous, antibacterial, and electromagnetic interference shielding (EMI)) properties and demonstrates associated applications. We present the S-Scheme heterojunction (SHJ) formation between TiO2 and PTMSPA through band position alignments and designate the resultant TiO2 - TiO2- based SHJ multifunctional materials as MF-TSSM. The internal electric field that is generated at the interface facilitates the transportation of the photogenerated electron transfer . The XRD pattern of MF-TSSM exhibits mainly the peaks of anatase TiO2. The TEM image of MF-TSSM indicates that the TiO2 particles are spherical in shape with sizes showing variations in diameters ranging from 60 nm to 250 nm depending on the experimental conditions of preparation and TiO2 particles are homogeneously distributed within the PTMSPA matrix. The optical energy band gap of MF-TSSM is 1.60 eV, a much lower value than PTMSPA (3.02 eV), suggesting that the composite formation between TiO2 and PTMSPA. The contact angle of MF-TSSM is significantly increased to 47.1 ° from 8.0 of TiO2, informing the increase of hydrophobic characteristics. The rate constant (k) for methylene blue photodegradation was 0.030 min-1, and 0.010 min-1 for MF-TSSM and pristine TiO2, respectively, The MF-TSSM composite exhibits a higher specific capacitance value (28.7 F/g) than TMSPA (21.1 F/g). At a frequency of 0.42 THz, MF-TSSM and PTMSPA exhibit return loss features indicating good EMI shielding performance. The MF-TSSM has been tested against two different Gram-positive and Gram-negative bacterial strains. The nanoparticles were evaluated at doses of 10, 20, 40, and 80 µg/ml. The results indicated that Klebsiella pneumoniae demonstrated a greater zone of inhibition, ranging from 9 mm at 10 µg/ml to 23 mm at 80 µg/ml, indicating increased susceptibility. Pseudomonas aeruginosa exhibited reduced inhibition zones, ranging from 10 mm at 10 µg/ml to 14 mm at 80 µg/ml, indicating increased resistance. The excellent effectiveness of MF-TSSM against various Gram-positive and Gram-negative pathogenic bacteria is explained by the interaction between reactive oxygen species and the cellular components of the bacteria as well the electrostatic interaction arising between positive charges in TMSPA and negative charges in the cell components, resulting in notable cytotoxicity and damage to the bacterial cells. The research underscores the capability of these modified TiO₂ nanoparticles in addressing bacterial infections, with efficiency differing by bacterial strain.