Good Antibacterial Activity Research Articles

A comparative study on stabilizing and releasing thymol by pre-formed V-type starch and β-cyclodextrin

Cyclodextrins (CD) are well known to form host-guest assemblies with hydrophobic compounds. As a structural homologue, starch-guest inclusion complexes (ICs) have become promising in the food, agriculture, and pharmaceutical industries due to their low cost and versatility. This study compared the stabilizing and releasing abilities for thymol of three kinds of pre-formed V-type starch (Water-V, Salt-V, and Alkali-V) and β-CD. The loading efficiency for thymol decreased in the order of Water-V > Alkali-V > CD > Salt-V when removing the free thymol. Water-V, β-CD, and their ICs had better thermal stability with maximum thermal decomposition temperatures over 320 °C. Under non-cold chain daily storage conditions for 4 d, the percentage of thymol released from starch/CD-thymol ICs was 14% (Water-V), 35% (Salt-V), 34% (Alkali-V), and 43% (CD). The Water-V made ICs had good sustained release properties and long-term antibacterial activity, which kept strawberries fresh for 6 d without decay.

Total Syntheses and Antibacterial Studies of Natural Isoflavones: Scandenone, Osajin, and 6,8-Diprenylgenistein.

Isoflavones are a class of natural products that exhibit a wide range of interesting biological properties, including antioxidant, hepatoprotective, antimicrobial, and anti-inflammatory activities. Scandenone (1), osajin (2), and 6,8-diprenylgenistein (3) are natural prenylated isoflavones that share the same polyphenol framework. In this research, the key intermediate 15 was used for the synthesis of the natural isoflavones 1-3, establishing a stereoselective synthetic method for both linear and angular pyran isoflavones. The antibacterial activities of 1-3 were also evaluated, and all of them displayed good antibacterial activity against Gram-positive bacteria. Among them, 2 was the most potent one against MRSA, with a MIC value of 2 μg/mL, and the SEM assay indicated that the bacterial cell membranes of both MRSA and E. faecalis could be disrupted by 2. These findings suggest that this type of isoflavone could serve as a lead for the development of novel antibacterial agents for the treatment of Gram-positive bacterial infections.

Synthesis and Biological Studies of New Temporin A Analogs Containing Unnatural Amino Acids in Position 7.

(1) Background: Antimicrobial resistance is growing at an extreme pace and has proven to be an urgent topic, for research into alternative treatments. Such a prospective possibility is hidden in antimicrobial peptides because of their low to no toxicity, effectiveness at low concentrations, and most importantly their ability to be used for multiple treatments. This work was focused on the study of the effect of the modification in position 7 of Temporin A on its biological activity; (2) Methods: The targeted peptides were synthesized using Fmoc/Ot-Bu SPPS. The antibacterial activity of the analogs was determined using the broth microdilution method and disk-diffusion method. In vitro tests were performed to determine the cytotoxicity, phototoxicity, and antiproliferative activity of the peptide analogs on a panel of tumor and normal cell lines; (3) Results: All analogs except DTCit showed good antibacterial activity, with DTDab having the best activity according to the disk-diffusion method. However, DTCit had an acceptable cytotoxicity, combined with good selectivity against the test MCF-7 cell line; (4) Conclusions: The obtained results revealed the importance of the basicity and length of the side chain at position 7 in the Temporin A sequence for both tested activities.

Syzygium aromaticum Bud Extracted Core–Shell Ag–Fe Bimetallic Nanoparticles: Phytotoxic, Antioxidant, Insecticidal, and Antibacterial Properties

Today, there is the roar of sustainable material development around the globe. Green nanotechnology is one of the extensions of sustainability. Due to its sustainable approach, the green fabrication of nanoparticles has recently surpassed their classical synthesis in popularity. Among metal nanoparticles, contemporary findings have demonstrated that bimetallic nanoparticles possess more potential for different applications than monometallic nanoparticles due to the synergistic effects of the two metals. So, we are presenting facile, one-vessel, and one-step phyto-fabrication of Ag–Fe BMNPs using the bud extract of Syzygiumaromaticum. The synthesized nanoparticles were characterized by UV-VIS, XRD, EDX, FTIR, and SEM. The synthesized NPs and the extract underwent biological studies. The radical scavenging potential of the NPs and the extract was found to be 64% and 73%, and the insecticidal potential was found to be 80% and 100%, respectively. Similarly, the NPs and the extract both exhibited good antibacterial activity. The zone of inhibition using 100 mg/mL of extract and NPs was found to be 1 cm against all bacterial species, i.e., K. pneumonia, E. coli, and S. aureus. It was 1.5 cm, 1.3 cm, and 1 cm against K. pneumonia, E. coli, and S. aureus, respectively, showing that the antibacterial activity of the extract is higher than that of the NPs. So, this study unlocks the synthesis of Ag–Fe bimetallic nanoparticles using eco-safe, cost-effective, facile, and least-harmful green methodology with potential applications of both NPs and SA extract in medical and agricultural fields, a step towards sustainability.

Isolation of a Marker Olean-12-en-28-butanol Derivative from Viscum continuum E. Mey. Ex Sprague and the Evaluation of Its Antioxidant and Antimicrobial Potentials.

Viscum continuum E. Mey. Ex Sprague (Mistletoe) is a semi-parasitic plant that grows on the branches of other trees with reported numerous biological activities. This study was aimed at isolating a compound/s that will be used as a standard reference for quality control of South African-based commercialized mistletoe products and to further perform antioxidant and antimicrobial tests on the isolated compound. A dried sample of mistletoe was ground and extracted successively with hexane, dichloromethane (DCM), acetone and methanol using a serial exhaustive cold maceration procedure. The compound was isolated using column chromatography, and its chemical structure was elucidated using two-dimensional nuclear magnetic resonance (2D NMR) and ultrahigh-performance liquid chromatography-mass spectrometry (UPLC-MS). The antioxidant activity of the compound was determined using DPPH, hydrogen radical scavenging activity and reducing power assays, whereas antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) method. Subjection of the DCM extract to column chromatography resulted in the isolation of a compound elucidated as olean-12-en-28-butanol-1-one, 3-hydroxy-4,4,10, 14, 20-pentamethyl (D4). Both the DPPH, H2O2 radical scavenging activity and reducing power assays revealed a significant antioxidant potential of compound D4 with an IC50 of 0.701 mg/mL, lower than that of gallic acid (0.793 mg/mL) for the H2O2 radical scavenging assay. The results also indicated good antibacterial activity of D4 with an IC50 of 0.25 mg/mL, compared to ciprofloxacin with an IC50 of 0.0039 mg/mL, against two Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and three Gram-positive (Streptococcus pyogenes, Bacillus cereus and Staphylococcus aureus) bacteria. This study is the first to report on the isolation of the olean-12-en-28-butanol derivative from mistletoe of the South African ecotype.

Extraction and characterization of carotenoid pigments with antioxidant and antibacterial potential from marine yeast Rhodotorula sp. KSB1.

Pigments are coloring agents used widely in different industrial sectors. There is a demand for using natural pigments rather than synthetic dyes because of the health hazards caused by synthetic dyes. Many natural pigments have different medicinal activities which can contribute to the nutritional value of the product. This study was carried forward with marine yeasts which can produce pigments. A total of 4 marine yeast isolates were recovered from the mangrove area of Sundarbans, West Bengal, India. Among them, the isolate KSB1 produced 856µg/g total concentration of carotenoid pigment and the dry mass weight was 3.56g/L. The stability of the extracted pigments was checked using temperature, pH, UV light exposure time, and different saline conditions. The pigments were characterized using HPLC and FTIR analysis. All of the extracted pigments showed good antioxidant activity in DPPH, metal chelating, and reducing power assay. The pigments were also found to have good antibacterial activity against the bacterial pathogens Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. Carotenoid pigment from KSB1 was found to have maximum activity in all the pathogens. The cytogenotoxicity using onion roots and phytotoxicity analysis indicated that the pigments were non-toxic and safe for cells. Finally, the potential marine yeast was identified using 18s rRNA sequencing and identified as Rhodotorula sp. KSB1 (Accession no. MH782232).

Continuous preparation and antibacterial mechanisms of biodegradable polylactic acid/nano-zinc oxide/additives antibacterial non-wovens

Biodegradable polylactic acid (PLA)/nano‑zinc oxide (ZnO)/additives non-woven slices were prepared by melt blending method. The effects of antibacterial agent nano-ZnO, antioxidant pentaerythrityl tetrakis-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate (1010), and chain extender multi-functional epoxy (ADR), on the melt flow rate, mechanical properties, thermal stabilities and micromorphology of the slices were investigated. The melt flow rate decreased from 26.94 g/10 min to 17.76 g/10 min, and the tensile strength increased from 10.518 MPa to 30.427 MPa with the increase of nano-ZnO and additives content. The slices were further spunbonded. The wettability and antibacterial properties of PLA/nano-ZnO/additives antibacterial non-wovens were studied, and the antibacterial action mechanism was clarified. The results showed that the biodegradable PLA/nano-ZnO/additives antibacterial non-wovens were prepared continuously successfully. The prepared non-woven fabrics exhibited good hydrophobicity and antibacterial properties. The mechanism study shows that zinc ion produced by nano-ZnO and photocatalytic reaction make the fabrics have good antibacterial activity at low nano-ZnO content. When nano-ZnO concentration reaches 1.5 wt%, the antibacterial rate against Escherichia coli and Staphylococcus aureus reaches 98.52 % and 98.13 %, respectively.

Exploring self-crosslinked hydrogel: Carboxymethyl chitosan and oxidized alginate for wound healing applications

This study reports the development and evaluation of self-healing hydrogel composed of carboxymethyl chitosan (CmCh) and oxidized alginate, with a focus on wound healing applications. Oxidized alginate was synthesized via metaperiodate oxidation and characterised. The hydrogels were formulated using Schiff base reactions with two weight ratios of oxidized alginate and CmCh, and their cross-linking mechanism was proposed. The developed hydrogels were characterised for their gelation, pH, self-healing capability, conductivity, and injectability. The optimized hydrogel was further evaluated for antibacterial activity, cytotoxicity, haemocompatibility, and in vitro wound healing studies. Results revealed that hydrogels with the lowest ratio of oxidized alginate to CmCh exhibited superior gelation, tensile strength, and injectability without needle clogging. Additionally, rapid self-healing of hydrogels was confirmed via Scanning Electron Microscope (SEM) analysis. The optimized hydrogel displayed good antibacterial activity against Staphylococcus aureus and Escherichia coli, alongside haemocompatibility. Additionally, in vivo studies demonstrated comparable wound healing efficacy to marketed formulations and significant improvement over control groups. These findings indicates the potential of self-healing hydrogels made up of oxidized alginate and CmCh for tissue engineering applications.

Solidago virgaurea L.: Chemical composition, antibacterial, and antileishmanial activity of essential oil from aerial part

Solidago virgaurea L. popularly called Goldenrod is a member of the Asteraceae family. S. virgaurea sample were obtained from Binsar, Almora (Indian state of Uttarakhand). The essential oil from the aerial part was distilled out using steam distillation, and GC and GC-MS were employed for analysis. A total of 27 constituents from aerial part were identified constituting 92.92% of total oil composition. The aerial parts of S. virgaurea were found to contain limonene (25.57%), α-humulene (12.19%), linalool oxide (8.65%), benzyl salicylate (6.40%), 1,4-cineole (6.22%) and humulene epoxide (II) (5.93%). The antibacterial activity of this essential oil was studied using disk diffusion and broth microdilution methods on five human pathogen bacteria and six plant pathogenic bacteria. There was moderate to good antibacterial activity in the oil sample extracted from the entire aerial portion of the plant. We did the antileishmanial activity of essential oils with Leishmania donovani (Dd8) promastigotes and intracellular amastigotes. EO was safer on the J774.A1 macrophages and lethal to promastigotes and intracellular amastigotes at different concentrations (10, 50, and 100 μg/ mL). These findings support the traditional uses of S. virgaurea and suggest its potential as a natural remedy for bacterial infections and leishmaniasis.

Pickering emulsions stabilized by essential oil-tannin-chitosan particles: Microstructure, stability, antibacterial activity, and antioxidant activity

In this study, four different types of essential oil monomer and tannic acid were used to prepare different kinds of essential oil-tannin particles. As well as encapsulating the chemically labile essential oils, these particles could also be used as Pickering emulsifiers to prepare oil-in-water emulsions. These emulsions were co-stabilized using the essential oil-tannin particles in combination with chitosan. The resulting Pickering emulsions were shown to have good storage stability, viscoelastic properties, antioxidant activity, and antibacterial activity. The emulsions co-stabilized by cinnamaldehyde-tannin and chitosan had the smallest particle size and largest shear viscosity, shear modulus, and physical stability. An in vitro digestion study showed that the cinnamaldehyde encapsulated within these emulsions also had a relatively high bioaccessibility. Considerable differences were observed in the stabilities of emulsions prepared with different oil phase volume fractions. The more concentrated emulsions did not exhibit phase separation after 30 days storage, which was attributed to the fact that the close packing of the oil droplets prevented their movement. This study shows that essential oil-polyphenol particles can be used as multifunctional ingredients, such as antioxidants, antimicrobial agents, and emulsifiers.

Green synthesis of copper and iron nanoparticles from extracts of eucalyptus with their antimicrobial activities

Eco-friendly iron and copper nanoparticles were synthesized using masquerade and eucalyptus leaves extract as a reducing and stabilizing agents. Iron chloride heptahydrate (FeCl2.7H2O) and Copper sulphatepenta hydrate (CuSO4.5H2O) as metal precursors. It was characterized using UV visible, FTIR, XRD and SEM analysis. The UV result shows the highest peaks at 500 and 600 nm for iron and copper respectively. This is due to the surface plasma vibration of the phytochemical constituents present in the extract. FTIR shows presence of alkanoids and triterpenes, SEM shows the spherical granular with no well-defined morphology and mono dispersed structures for iron and copper nanoparticles respectively. It shows good antibacterial activity when tested against Escherichia-coli and Pseudomonas auredinosa (gram- negative), Staphylococcus aureus and Klebsella pneumonia (gram-positive).

In vitro Antibacterial, ADME and Toxicity Screening of Newly Synthesized 4-(Substituted phenyl)-2-(2-chloroquinolin-3-yl)thiazoles

A series of novel thiazole (Va-o) compounds were synthesized following multi-step synthetic process. Using analytical methods like nuclear magnetic resonance, mass spectrometry and FTIR, the elucidation of the structure of the synthesized compounds was performed. All the 15 novel thiazoles were assessed for their antibacterial activity. The synthesized thiazoles were examined for inhibitory antibacterial activity against a panel Gram-positive strain viz. Staphylococcus aureus (NCTC 65710), Streptococcus pyogenes (MTCC-442), Bacillus subtilis (NCIM 2250) and Gram-negative bacteria Pseudomonas aeruginosa (NCTC 10662) and Escherichia coli (NCTC 10418) by agar well diffusion technique. It was observed that some of the compounds, particularly those having substitution groups like chloro, fluoro and bromo in the phenyl ring bonded to thiazole nucleus, had moderate to good antibacterial activity. Quinoline clubbed thiazoles compounds Vk, Vl, Vn and Vo showed significant antibacterial against all bacterial strains having values of minimum inhibitory concentration (MIC) from 12.5 to 25 µg/mL. The results of antimicrobial investigation suggest that 2-chloroquinoline incorporated thiazole scaffold appears to more promising for developing potent antibacterial agents. Genome gyrase docking experiments (PDB ID: 1KZN) revealed a favourable binding relationship similar to that of the pre-occupied ligand clorobiocin. The study also provides in silico ADME and toxicity studies evaluation which revealed that compounds are impartially compatible and were devoid of potential toxicity except the hepatotoxicity.

Electrochemical Modification of Metronidazole and its Application as Antibacterial and Potential Drug Agent

Background: Drug resistance poses a threat to global health given the disturbing rate at which microbiological illnesses are rising and the widespread use of antibiotics. While naturally occurring antibiotics reduce the likelihood of bacterial resistance, recognized drugs can develop the same properties when structurally modified. Metronidazole has been targeted to achieve this feat. Objective: The purpose of this work is to enable the structural modification of metronidazole by means of electric current, using inexpensive, easily accessible magnesium ribbon as electrodes in order to produce a novel, effective antibiotic. Method: With magnesium ribbon electrodes, metronidazole is modified electrochemically, in an undivided cell system. Ultraviolet-visible (UV-Vis), Fourier Transform Infrared (FTIR), and Gas Chromatography-Mass Spectrometry (GC-MS) were used to characterize the product. Antibacterial activity was evaluated using the agar well diffusion method and Wistar rats were used for in vivo toxicity assessment. Result: 2-Methyl-1-vinyl-1H-imidazol-5-amine showed good antibacterial activities compared to the standard nitrofurantoin and toxicity evaluations using Wistar rats revealed that the product might induce dose-dependent variations in kidney function biomarkers, with doses of 100 mg/kg and below. However, when the compound was administered orally, there was no significant effect on liver function, even at a dose of 1000 mg/kg. Conclusion: These results point to the modified metronidazole's potential as a potent antibiotic with controllable toxicity, indicating that additional research into its pharmacological uses is necessary.

Unlocking the Potential of Trans-Himalayan High-Altitude Seabuckthorn (Hippophae rhamnoides) Plants in the Green Synthesis of Silver Nanoparticles Against Drug-Resistant Foodborne Pathogens: A Step Towards Sustainable Food Safety Goals

Controlling foodborne pathogens is challenging due to the new emergence of antimicrobial resistance to conventional antimicrobials. Therefore, new alternative antimicrobials need to be developed to control foodborne pathogens and avoid microbial resistance. Furthermore, the potential of trans-Himalayan high-altitude seabuckthorn (Hippophae rhamnoides ) plants has not been explored much for the synthesis of silver nanoparticles having antibacterial properties. Hence, this study investigated the development of long-term stable silver nanomaterials using the aqueous extract of seabuckthorn leaves through a green-synthesis approach and evaluated their antibacterial efficacy. These synthesized nanomaterials were characterized along with their stability using UV spectrometry for lambda max ([Formula: see text]) characteristics. Further, the nanoparticles were evaluated for zeta potential (mV), polydispersity index, particle size distribution (nm), electrophoretic mobility ([Formula: see text]mcm/Vs) and conductivity (mS/cm). The seabuckthorn silver nanoparticles are of 260[Formula: see text]nm size and stable (−15[Formula: see text]mV zeta potential) with good antioxidant and antibacterial properties against two typical food pathogens, e.g., Escherichia coli (MTCC 3222) and Salmonella typhimurium (MTCC 3224). Hence, this study developed an eco-friendly, rapid, low-cost green synthesis method for the development of seabuckthorn-coated, stable silver nanoparticles with good antibacterial activity against foodborne pathogens.

New Amino Acids Naphthalene Scaffolds as Potent Antimicrobial Agents: In Vitro Assay and In Silico Molecular Docking Study

AbstractThe development of innovative antifungal medications to address the issues of indiscriminate antifungal use contributes to certain antifungal drug resistance. To tackle this issue, we have designed and synthesized novel amino acids naphthalene scaffolds (6 a–6 i) (Scheme 1) by acid amine coupling between compound 5 and various amino acids. Moreover, we evaluated the antifungal, anti‐bacterial and antimalarial activities of synthesized derivatives. Among them, compounds Met (6 a), Phe (6 c), Lys (6 d), Ser (6 f), and Tyr (6 i) expressed excellent antifungal activity at a minimum inhibitory concentration (MIC) value of 250 μg/mL against Candida albicans compared to standard drug griseofulvin (500 μg/mL). The antibacterial assay results showed that compound Met (6 a) exhibited effective antibacterial activity at MIC value at 50 and 62.5 μg/mL against Streptococcus pyogenes and Pseudomonas aeruginosa respectively, and compound Trp (6 g) showed very good antibacterial activity at MIC 62.5 μg/mL against Staphylococcus aureus. The antimalarial activity of synthesized compoundsVal (6 b) and Lys (6 d) showed moderately active with mean IC50 of 0.69 and 0.47 μg/mL, respectively compared with standard drug quinine (IC50=0.26 μg/mL). Also, a molecular docking study was performed to demonstrate the binding energy of synthesized scaffoldswith effective interaction with various proteins. The compound Met (6 a) showed that the highest binding affinity (binding energy: −7.1 kcal/mol) which interacted more effectively with VAL 120 (2.90 Å).

Effectiveness of Graptophyllum pictum L. Griff Extract as a Complementary Therapy for Peri-Implantitis: An In Vitro and In Silico Study

Background: Dental peri-implantitis is an inflammation that occurs in the peri-implant soft tissue and is accompanied by bone resorption, decreased osseointegration, and pockets. Graptophyllum pictum L. Griff extract may act as complementary therapy for peri-implantitis. Objectives: To investigate the effectiveness of G. pictum L. Griff extract as a complementary therapy for peri-implantitis. Materials and Methods: A phytochemical test was performed to determine the active compounds using each compound's reagents. Antioxidant assay to examine the antioxidant activity compared with vitamin C. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests were used to investigate the antibacterial activity of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn), and Provotella intermedia (Pi) as peri-implantitis-related bacteria. Molecular docking is an in-silico test to visualize the interaction of G. pictum L. Griff molecules with targeted proteins using several software programs and databases. This study was analyzed by parametric and non-parametric variance analysis and continued with a post-hoc test. Results: G. pictum L. Griff extract contained flavonoids, alkaloids, saponins, tannins, steroids, and terpenoids. The antibacterial effect of G. pictum L. Griff can inhibit the growth of dental peri-implantitis-related bacteria such as Aa, Pg, Pi, and Fn with a minimum 25% extract concentration. In silico, the interaction of ethylcholest and proteins shows possible pharmalogical effects such as anti-inflammatory, antibacterial, and antioxidant activity. Conclusion: G. pictum L. Griff extract possesses good antibacterial, antioxidant, and anti-inflammatory activity that may be effective for dental peri-implantitis complementary therapy as documented in silico and in vitro.

In Situ Fabrication of Silver Nanoparticle-Decorated Polymeric Vesicles for Antibacterial Applications.

Silver/polymeric vesicle composite nanoparticles with good antibacterial properties were fabricated in this study. Silver nanoparticles (AgNPs) were prepared in situ on cross-linked vesicle membranes through the reduction of silver nitrate (AgNO3) using polyvinylpyrrolidone (PVP) via coordination bonding between the Ag+ ions and the nitrogen atoms on the vesicles. X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis), and transmission electron microscopy (TEM) analyses confirmed the formation of AgNPs on the vesicles. The antibacterial test demonstrated good antibacterial activity against both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) for the produced AgNP-decorated vesicles. The minimum inhibitory concentration (MIC) values of the AgNP-decorated vesicles for E. coli and S. aureus were 8.4 and 9.6 μg/mL, respectively. Cell viability analysis on the A549 cells indicated that the toxicity was low when the AgNP concentrations did not exceed the MIC values, and the wound healing test confirmed the good antibacterial properties of the AgNP-decorated vesicles.

Chemical Characterization and Evaluation of the Antimicrobial Activity of Extracts from Two Cultivars of Cannabis sativa L. (Tisza and Kompolti) Grown in Sardinia

The present work was aimed at the chemical characterization and antimicrobial activity of some extracts of aerial parts (essential oils from leaves and inflorescences and resins from inflorescences) of two legal hemp (Cannabis sativa) varieties, Tisza and Kompolti, grown in Sardinia. Chemical characterization was carried out by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS) techniques. The main constituent was myrcene (11.75% in Tisza and 18.21% in Kompolti); delta-9-tetrahydrocannabinol (THC) was not found, while cannabidiol was present up to 0.36% in Tisza and up to 2.80% in Kompolti. The antimicrobial activity of these extracts against a panel of microorganisms was also determined via minimum inhibitory concentration (M.I.C.) determination. While the results showed minor or negligible antimicrobial activity of the extracts against the Gram+ and Candida strains (M.I.C. values equal to or greater than 4 mg/mL), good antibacterial activity (especially of resins) was recorded against S. aureus (M.I.C. 0.015–0.031 mg/mL); no substantial differences were detected between the chemical compositions of the two Cannabis varieties.

Application of Novel Ruthenium (II) Polypyridyl Complexes as Robust DNA Probes, Optical Material and Antimicrobials-An Experimental and DFT Approach.

The nature of the interaction of DNA with heteroleptic Ruthenium (II) Polypyridyl complexes of the type [Ru (A)2TPIP]2+, where TPIP = 2-(1-p-tolyl-1H pyrazol-4 -yl)-1H-imidazo [4, 5-f[1. 10] phenanthroline and A = 1,10 phenanthroline (1),4,4'-dimethyl-1,10-ortho Phenanthroline (2),2,2' - bipyridine(3) and 4, 4' dimethyl 2, 2'- bipyridine (4), has been investigated by experimentaland molecular docking approaches. The order of the DNA binding affinities of the synthesised complexes is 1 > 2 > 3 > 4. The findings imply that the unsubstitutedcomplex has a better affinity to bind with DNA than the substituted (dmp and dmb) emphasizing the significance of the auxiliary ligand. Additionally, as the medium's ionic strength drops, the DNA/Ru ratio rises, or when water is displaced by glycerol, the intercalation of complexes into DNA increases. DFT calculations at the B3LYP/LANL2MBlevel was used for molecular geometry (Ground State) and electronic characteristic calculations. The HOMO-LUMO gap of the Ru [II]complex is less than the intercalator and hence kinetically labile. Among the complexes, the bpy complex has shown utmost non-linear optical properties (α = -153.9099 10-24esuand β = 3.8498 10-30esu). The docking study shows the significance of the Metal-intercalator's shorter length may increase DNA binding affinity. This study divulges that the Ruthenium (II) polypyridyl complexes bind to DNA preponderantly by intercalation supporting Viscosity studies. All the complexes have a considerable attraction for guanine. The standarddiskdiffusion method reveals that complexes (1,2,3 and 4) have good antibacterial activity.

Multifunctional antibacterial enhanced amoxicillin carbon nanodots for the detection of Hg (II) and methanol in edible alcohol

Amoxicillin was used as the sole precursor to rapidly synthesize amoxicillin carbon nanodots via a one-step microwave method. The diameter of the amoxicillin carbon nanodots was concentrated at 1.8 ± 0.6 nm, with fluorescence excitation-dependent characteristics. After characterization, the carbon nanodots retained some of the amoxicillin structure, exhibiting low biological toxicity and good antibacterial activity. Due to the formation of the carbon dots structure, the hydrophilicity and water solubility of the amoxicillin carbon nanodots improved. An antibacterial plate experiment further showed that the antibacterial performance of the amoxicillin carbon nanodots was higher than that of the original amoxicillin. The amoxicillin carbon nanodots could quickly and conveniently detect Hg2+ via changes in their fluorescence intensity. Moreover, several aliphatic alcohols could be distinguished and quantified based on the fluorescence intensity increase of the amoxicillin carbon nanodots. Most importantly, the amoxicillin carbon nanodots quickly identified and quantified methanol mixed in edible alcohol. These multifunctional amoxicillin carbon nanodots have broad application prospects in antibiosis, toxic Hg2+ detection, and identification and detection of several aliphatic alcohols, especially the microfluorometric determination of methanol in edible alcoholic beverages.