Antibacterial Activity Of Compounds Research Articles

Synthesis of Acetylene‐Functionalized Schiff base for Selective Detection of Al(III) and Exploring Its Antibacterial Properties via In Silico and In Vivo Approach

AbstractThe identification of perilous metal ions and the treatment of diseases induced by microorganisms are critical areas requiring attention. We report herein the design and development of an acetylene‐functionalized Schiff base compound 4, using a low‐cost and straightforward approach. This compound 4 exhibits dual functions in the detection of harmful metal ions, particularly Al(III), as well as in the prevention of disorders caused by bacteria, specifically Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis). It was well characterized through the utilization of diverse spectroscopic techniques, such as NMR (1H and 13C), FT‐IR, and mass spectrometry. Furthermore, the complete structure clarification of the Schiff base compound 4 was revealed through the utilization of X‐ray crystallography. The limit of detection (LOD) for Al(III) is 35.5 × 10−8 M, surpassing the WHO drinking water standard of 26.7 µM, underscoring the high sensitivity of compound 4. The antibacterial activity of compound 4 has also been effectively evaluated on Gram‐positive (S. aureus and B. subtilis) bacteria. Furthermore, compound 4 was docked to S. aureus and B. subtilis proteins, which represents outstanding outcomes with binding energies of −7.31 kcal/mol and −7.87 kcal/mol, respectively. The antibacterial activity of the compound 4 in both in vitro and docking studies suggests that it possesses the potential to serve as an antibacterial agent in the future.

Synthesis, characterization and antibacterial activity of hexasubstituted Coumarin-based Schiff base derivative of cyclophosphazene

This study focuses on synthesis and characterization of hexa-substituted coumarin based Schiff base derivative of cyclotriphosphazene (Compound 3). The antibacterial activity of Compound 3 was evaluated against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Pseudomonas aeruginosa (P. aeruginosa), and Klebsiella pneumoniae (K. pneumoniae) bacterial strains using minimum inhibitory concentration (MIC) and percentage-killing method. Compound 3 exhibited a lower MIC of 300 μg/mL against S. aureus than 500 μg/mL for P. aeruginosa and K. pneumoniae, indicating greater efficacy against Gram-positive bacteria. Percentage-killing data confirmed Compound 3 significant bactericidal activity against S. aureus across concentrations ranging from 100 to 500 μg/mL, comparable to ampicillin. In contrast, its efficacy against Gram-negative strains was lower, suggesting a more selective spectrum of activity. These findings suggest that Compound 3 shows promise as a potential antibacterial agent with preferential activity against Gram-positive bacteria, warranting further investigation into its mechanism of action and therapeutic potential.

Virtual screening of potential orally active anti-bacterial compounds of finger millet

Virtual screening of potential orally active anti-bacterial compounds of finger millet

Thiophene-Linked 1,2,4-Triazoles: Synthesis, Structural Insights and Antimicrobial and Chemotherapeutic Profiles.

The reaction of thiophene-2-carbohydrazide 1 or 5-bromothiophene-2-carbohydrazide 2 with various haloaryl isothiocyanates and subsequent cyclization by heating in aqueous sodium hydroxide yielded the corresponding 4-haloaryl-5-(thiophen-2-yl or 5-bromothiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 5a-e. The triazole derivatives 5a and 5b were reacted with different secondary amines and formaldehyde solution to yield the corresponding 2-aminomethyl-4-haloaryl-2,4-dihydro-3H-1,2,4-triazole-3-thiones 6a-e, 7a-e, 8, 9, 10a and 10b in good yields. The in vitro antimicrobial activity of compounds 5a-e, 6a-e, 7a-d, 8, 9, 10a and 10b was evaluated against a panel of standard pathogenic bacterial and fungal strains. Compounds 5a, 5b, 5e, 5f, 6a-e, 7a-d, 8, 9, 10a and 10b showed marked activity, particularly against the tested Gram-positive bacteria and the Gram-negative bacteria Escherichia coli, and all the tested compounds were almost inactive against all the tested fungal strains. In addition, compounds 5e, 6a-e, 7a-d and 10a exhibited potent anti-proliferative activity, particularly against HepG-2 and MCF-7 cancer cell lines (IC50 < 25 μM). A detailed structural insight study based on the single crystals of compounds 5a, 5b, 6a, 6d and 10a is also reported. Molecular docking studies of the highly active antibacterial compounds 5e, 6b, 6d, 7a and 7d showed a high affinity for DNA gyrase. Meanwhile, the potent anti-proliferative activity of compounds 6d, 6e and 7d may be attributed to their high affinity for cyclin-dependent kinase 2 (CDK2).

Syntheses, structures and biological activities of new pyridinyl lactones

Several novel lactones containing either a pyridin-3-yl or a pyridin-2-yl ring in their structure were synthesized: trans δ halolactones 6–8a,b (chloro‑, bromo‑ and iodo-), γ iodolactone 11b and isomeric γ hydroxylactones 9–10a,b. Their structures were confirmed by NMR, IR and HR-MS and additionally by single crystal X-ray diffraction for trans δ bromolactone 6a, trans δ chlorolactone 7b and γ hydroxylactone 10b. Spectral analyses were further supported by DFT calculations. In testing of the compounds for antibacterial activity, none of the lactones exhibited activity against several bacteria strains. However, all lactones exhibited significant cytotoxicity against normal eukaryotic murine fibroblast L929 and human gastric adenocarcinoma AGS cell lines with lactones possessing a pyridine-2-yl ring being more cytotoxic than their pyridine-3-yl counterparts.

New secondary metabolites produced by an engineered strain Streptomyces sp. XZQH13OEΔastC

Two previously undescribed alkaloids (1–2), five known alkaloids (3–7) and five cyclodipeptides (8–12) were obtained from an ansatrienin-producing mutant strain Streptomyces sp. XZQH13OEΔ astC. Their structures were elucidated by analysis of the 1D, 2D NMR and ESI HRMS data and by comparison with the reported data. The antibacterial activities of compounds 1–12 were evaluated.

Isolation and Identification of the Antibacterial Compounds Produced by Maillard Reaction of Xylose with Phenylalanine or Proline.

Maillard reaction products (MRPs) of xylose with phenylalanine and xylose with proline exhibit high antibacterial activity. However, the active antibacterial compounds in MRPs have not yet been identified or isolated. This study aimed to isolate the active compounds in the two antibacterial MRPs. The organic layer of the MRP solution was separated and purified using silica gel chromatography and high-performance liquid chromatography. The chemical structures of the isolated compounds were determined by mass spectrometry and nuclear magnetic resonance spectroscopy. The compounds inhibited the growth of Bacillus cereus and Salmonella Typhimurium at 25 °C for 7 days at a concentration of 0.25 mM. Furthermore, the isolated compounds inhibited the growth of naturally occurring microflora of lettuce and chicken thighs at 25 °C for 2 days at a concentration of 0.5-1.0 mM. The antibacterial compounds found in MRPs demonstrated a wide range of effectiveness and indicated their potential as alternative preservatives.

Inhibition of Monilinia fructicola sporulation and pathogenicity through eucalyptol-mediated targeting of MfCat2 by Streptomyces lincolnensis strain JCP1-7.

Peach brown rot, attributed to Monilinia fructicola, presents a significant threat to postharvest peach cultivation, causing losses of up to 80%. With an increasing number of countries, spearheaded by the European Union, imposing bans on chemical agents in fruit production, there is a growing interest in mining highly active antibacterial compounds from biological control strains for postharvest disease management. In this study, we highlight the unique ability of Streptomyces lincolnensis strain JCP1-7 to inhibit M. fructicola sporulation, despite its limited antimicrobial efficacy. Through GC-MS analysis, eucalyptol was identified as the key compound. Fumigation of diseased fruits with eucalyptol at a concentration of 0.0335 μg cm-3 demonstrated an invivo inhibition rate against M. fructicola of 93.13%, completely suppressing spore formation. Transcriptome analysis revealed the impact of eucalyptol on multiple pathogenesis-related pathways, particularly through the inhibition of catalase 2 (Cat2) expression. Experiments with a MfCat2 knockout strain (ΔMfCat2) showed reduced pathogenicity and sensitivity to JCP1-7 and eucalyptol, suggesting MfCat2 as a potential target of JCP1-7 and eucalyptol against M. fructicola. Our findings elucidate that eucalyptol produced by S. lincolnensis JCP1-7 inhibits M. fructicola sporulation by regulating MfCat2, thereby effectively reducing postharvest peach brown rot occurrence. The use of fumigation of eucalyptol offers insights into peach brown rot management on a large scale, thus making a significant contribution to agricultural research.

Antibacterial activity and mechanism of luteolin isolated from Lophatherum gracile Brongn. against multidrug-resistant Escherichia coli.

Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.

Antibacterial Activities of Agaricus bisporus Extracts and Their Synergistic Effects with the Antistaphylococcal Drug AFN-1252.

Agaricus bisporus, commonly known as the button mushroom, has attracted attention for its biological properties, including antimicrobial activities. Here, we evaluated the efficacy of ethanolic and acetonic extracts from white and brown A. bisporus against different bacterial strains, including antibiotic-resistant strains. Bioautography and principal component analysis identified the most active antibacterial compounds for each of the tested bacteria and indicated the main markers responsible for the strain-specific effects. In addition, the mushroom extracts demonstrated a synergistic impact when combined with the antistaphylococcal antibiotic AFN-1252.

Soulaxanthone, a new xanthone derivative from Calophyllum soulattri

In search for new metabolites from the stem bark of Calophyllum soulattri and Calophyllum gracilentum, led to the isolation of a new xanthone, soulaxanthone (1), along with four other known metabolites, euxanthone (2), calopolyanolide E (3), calanolide E (4) and friedelin (5). The structures of these compounds were identified and elucidated using spectroscopic techniques such as 1H NMR,13C NMR, COSY, DEPT, HSQC, HMBC, MS and FTIR. The antibacterial activities of compounds 1–5, as well as the extracts, were tested against five bacterial strains. Soulaxanthone (1) exhibited moderate activity against Pseudomonas aeruginosa with an MIC value of 25 µg/mL. Hexane (non-polar) extract from both plants exhibited moderate activity against Enterobacter cloacae (MIC = 250 µg/mL). Calopolyanolide E (3) and friedelin (5) showed bactericidal activity against Enterobacter cloacae (MBC = 50 µg/mL), thus the compounds have the potential to serve as a new lead for developing effective antibacterial medication.

Antibacterial activity and bioactive compounds of a marine macroalgae endophytic fungi, Hypoxylon monticulosum

Antibacterial activity and bioactive compounds of a marine macroalgae endophytic fungi, Hypoxylon monticulosum

Uji Efektivitas Daun Sirih Dalam Menghambat Pertumbuhan Layu Bakteri Ralstonia solanacearum Pada Tanaman Terung

Ralstonia solanacearum is one of the important diseases in eggplant plants which causes bacterial wilt in plants so control efforts need to be taken. One alternative control method is using vegetable pesticides from betel leaf powder. This research aims to determine the effectiveness of betel leaves in inhibiting the growth of R. solanacearum bacterial wilt on eggplant plants. This research used a Completely Randomized Design (CRD) with 5 treatments and 5 replications, each replication using 4 plants so there were 100 experimental units. The treatment used doses of 25 gr, 50 gr, 75 gr, 100 gr of betel leaf powder, and as a comparison, namely the control treatment in this study. Observations were made every day after inoculation to see the incubation period that occurred in the eggplant plants and once a week to observe the disease intensity and severity of the disease in the eggplant plants. The results of this study showed that an effective treatment with a dose of 100 g of betel leaf powder with an eggplant plant age of 47 days after showed the lowest treatment in suppressing Ralstonia solanacearum bacteria, namely a disease intensity percentage of 15% with a disease severity percentage of 20% and had the lowest incubation period. slow, namely 19 days, this shows that betel leaves have an effect in suppressing disease attacks caused by R. solanacearum on eggplant plants because they have antibacterial active compounds.

Cu(II) complexes with a salicylaldehyde derivative and α-diimines as co-ligands: synthesis, characterization, biological activity. Experimental and theoretical approach.

Copper(II) complexes with an α-diimine show a wide variety of biological activities, such as antibacterial, antifungal, antioxidant and anticancer. In this work, we synthesized and structurally characterized two novel Cu(II) complexes with methyl 3-formyl-4-hydroxybenzoate (HL) and α-diimines: 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). Crystal structure analysis shows that the formulas of the compounds are [Cu(bipy)(L)(BF4)] (1) and [Cu(phen)(L)(H2O)](BF4)·H2O (2), with BF4- as a ligand in complex1, which is rarely coordinated to metals. Both complexes have a square pyramidal geometry, while DFT calculations showed that the most stable structures of complexes 1 and 2 in a water/DMSO mixture are square-planar derivatives [Cu(bipy)(L)]+ and [Cu(phen)(L)]+. The antibacterial activity of compounds was evaluated in vitro on four Gram-negative and four Gram-positive bacterial strains. Complex 2 showed greater antibacterial activity towards all bacterial strains comparable to the control compound Amikacin. Complex 2 exerted a strong cytotoxic effect against the tested cancer cell lines (IC50 values ranging from 0.32 to 0.44 μM). Both complexes caused apoptotic cell death in HeLa cells and a noticeable in vitro antiangiogenic effect. In the concentration range of 5 to 100 μM, the complexes showed the absence of a genotoxic effect and displayed a protective effect against oxidative DNA damage induced by H2O2 in human peripheral blood cells. The interaction between the compounds and calf-thymus DNA was evaluated by diverse techniques suggesting a tight binding, which was also confirmed by molecular docking. In addition, it was found that the complexes bind tightly and reversibly to bovine and human serum albumin.

Vitex Negundo-Fe3O4-CuO green nanocatalyst (VN-Fe3O4-CuO): synthesis of pyrazolo[3,4-c]pyrazole derivatives via the cyclization of isoniazid with pyrazole and their antimicrobial activity, cytotoxicity, and molecular docking studies.

In this study, we developed a novel pyrazolo[3,4-c]pyrazole derivative with antibacterial and antifungal activities that shows great potential for treating infectious diseases. To evaluate the binding affinity of 1AJ0 and 1AI9 proteins for developing potent antibacterial and antifungal compounds, we used the Vitex negundo (VN) leaf extract as the capping and reducing agent and reacted it with Fe2O3 and Cu(OAc)2 solutions to synthesize the VN-Fe3O4-CuO nanocatalyst. The newly synthesized compounds were confirmed using Fourier transform infrared spectroscopy, transmission electron microscopy, UV-visible spectroscopy, and X-ray diffraction analyses. Antibacterial screening revealed that compound 1g was highly active against Escherichia coli (MIC: 1 μg mL-1) and was much more effective than the standard ciprofloxacin. Compound 1b showed a higher antifungal activity than clotrimazole against Candida albicans (MIC: 0.25 μg mL-1) and cytotoxic activity against MCF-7 cancer cell lines. Compounds 1a-1l were exhibited low cytotoxicity activity compared to the standard doxorubicin (LC50: 21.05 ± 0.82 μg mL-1). To further support the discovery of new active antibacterial agents, compounds 1g and 1b and proteins 1AJ0 and 1AI9 were examined using the AutoDock Vina program and were compared with the standards ciprofloxacin and clotrimazole. With the 1AJ0 protein, compound 1g had a higher docking score (-3.7 kcal mol-1) than ciprofloxacin (-5.6 kcal mol-1), and with the 1AI9 protein, compound 1b had a higher docking score (-4.8 kcal mol-1) than clotrimazole (-4.4 kcal mol-1). Additionally, molecular dynamics simulation was used to investigate the most probable binding mode of compounds 1b and 1g with 1AI9 and 1AJ0, respectively. The VN-Fe3O4-CuO catalyst was used to prepare pyrazolo[3,4-c]pyrazole derivatives, which were successfully characterized and screened for antimicrobial and cytotoxic activities, molecular docking, and molecular dynamics simulation studies.

Antibacterial and antioxidant activity of endophytic fungi extracts isolated from the petiole of sungkai plant (Peronema canescens)

Abstract. Oktiansyah R, Elfita, Widjajanti H, Salni, Setiawan A. 2023. Antibacterial and antioxidant activity of endophytic fungi extracts isolated from the petiole of sungkai plant (Peronema canescens). Biodiversitas 24: 6516-6526. Indonesia has a diverse number of medicinal plants that are very helpful in preventing infectious diseases. Sungkai (Peronema canescens) is a medicinal plant of the family Verbenaceae that is often used and found in Indonesia. Its leaves possessed antibacterial and antioxidant properties that boost immunity and lessen the signs of infectious disorders. This study explored the types of endophytic fungi found in sungkai petioles and examined their relationship to previously reported sungkai leaf endophytic fungal isolates and spectrum of compounds contained them. Endophytic fungal were isolated from fresh leaf petioles of host plants, and their morphological and molecular characteristics were determined. Endophytic fungal extracts were tested for antibacterial and antioxidant properties. Utilizing the paper disk diffusion technique, the antibacterial characteristics were ascertained, while the DPPH method was used to determine antioxidant activity. Molecular identification was carried out on the fungal isolate with the most potential, and chemical compounds were isolated using column chromatography. The structures of the compounds were determined using spectroscopy, including 1D and 2D NMR. Eight endophytic fungal isolates were obtained from sungkai leaf stalks (RA1-RA8) of various species of the genus Trichoderma. Differences in the diversity of endophytic fungi found in leaf stalks and endophytic fungi from leaves were identified. RA1 showed the strongest antibacterial and antioxidant activity and was molecularly identified as T. harzianum. Spectroscopic analysis showed that the pure compound contained within was 9-hydroxy-7-methylenebenzo[c]oxepin-3(7H)-one (1), which had never previously been found in sungkai plants and endophytic fungi. The antibacterial activity of Compound 1 is in the strong category (MIC = 64 µg/mL) but is not active as an antioxidant. In terms of producing medicinal ingredients from endophytic fungi, T. harzianum in extract form has more potential to be developed.

Skrining Fitokimia dan Uji Antibakteri Nanopartikel Perak Ekstrak Daun Pepaya (Carica papaya L) terhadap Bakteri Staphylococcus epidermidis dan Salmonella typhi

Infections caused by bacteria are still common in developing countries, among them Staphylococcus epidermidis and Salmonella typhi. In Indonesia, papaya leaves (Carica papaya L.) are widely used as traditional medicine because they contain compounds that are antibacterial. The combination of silver nanoparticles with papaya leaves has the potential to increase antibacterial effectiveness. The purpose of this study was to determine the effectiveness of papaya leaf extract silver nanoparticles in inhibiting Staphylococcus epidermidis and Salmonella typhi bacteria. This research method is a true experiment with a post-test only design with a control group. The results showed that papaya leaf metabolites consisted of flavonoids, steroids, and tannins, while the total levels contained in flavonoids 791.209%, and tannins 11.138%. The diameter of the inhibition zone concentrations of 100, 150, 200, and 250 ppm proved that papaya leaf extract combined with silver nanoparticles had good antibacterial active compounds but was more powerful in killing Staphylococcus epidermidis bacteria than Salmonella typhi bacteria.

Cu (II)-catalyzed: synthesis of imidazole derivatives and evaluating their larvicidal, antimicrobial activities with DFT and molecular docking studies

This paper deals with the evaluation of novel imidazole molecules for their antimicrobial and larvicidal activities. A series of imidazole derivatives 1(a–f) and 2(a–e) were prepared by the Mannich base technique using a Cu(II) catalyst. The Cu(phen)Cl2 catalyst was found to be more effective than other methods. FTIR, elemental analyses, mass spectrometry, 1H NMR, and 13C NMR spectroscopy were performed to elucidate the structures of the synthesised compounds. Antimicrobial and larvicidal activities were investigated for all compounds. The antibacterial activity of compounds (2d) and (2a) were highly active in S.aureus (MIC: 0.25 μg/mL) and K.pneumoniae (MIC: 0.25 μg/mL) compared to ciprofloxacin. Compound (1c) was significantly more effective than clotrimazole in C.albicans (MIC: 0.25 μg/mL). Molecular docking studies of compound 2d showed a higher binding affinity for the 1BDD protein (− 3.4 kcal/mol) than ciprofloxacin (− 4.4 kcal/mol). Compound 1c had a higher binding affinity (− 6.0 kcal/mol) than clotrimazole (− 3.1 kcal/mol) with greater frontier molecular orbital energy and reactivity properties of compound 1c (∆E gap = 0.13 eV). The activity of compound 1a (LD50: 34.9 μg/mL) was more effective in the Culex quinquefasciatus than permethrin (LD50: 35.4 μg/mL) and its molecular docking binding affinity for 3OGN protein (− 6.1 kcal/mol). These newly synthesised compounds can act as lead molecules for the development of larvicides and antibiotic agents.

Ternifoliasaponin, a new triterpenoid saponin from the roots of Gardenia ternifolia Schumach & Thonn (Rubiaceae)

A new triterpenoid saponin, Ternifoliasaponin (1), together with four known compounds (2–5) chikusetsusaponin IVa (2), chikusetsusaponin IVa methyl ester (3), bonushenricoside B (4) and Dianoside C (5) were isolated from roots of Gardenia ternifolia Schumach. & Thonn (Rubiaceae). The structures of isolated compounds were elucidated on the basis of spectroscopic analysis and chemical methods. The antibacterial activities of compounds (3), and (4) were performed by the Muller–Hinton agar diffusion method. The antimicrobial activities of the compounds were studied on Salmonella typhi (Enterobacteriaceae), Staphylococcus aureus and Pseudomonas aeruginosa microorganisms. Compound (3) at 25 mg/mL, showed moderately sensitive effect (8.0 ˂ DIZ ˂14.0 mm) on S. typhi, S. aureus and P. aeruginosa. Compound (4) at 25 mg/mL and compound (3) at 12.5 mg/mL exhibited moderately sensitive effect on S. typhi and S. aureus. Compound (4) inhibited moderately sensitive the S. typhi and P. aeruginosa colonies at 12.5 mg/mL.

DAYA HAMBAT EKSTRAK DAUN MANGROVE (Rhizophora apiculata) ASAL PESISIR SUKADANA TERHADAP BAKTERI Escherichia coli (INHIBITION THE LEAF EXTRACT OF Rhizophora apiculata FROM THE SUKADANA COAST AGAINST Escherichia coli)

Rhizophora apiculata is a plant that is widely found in mangrove forests in Sukadana subdistrict, and has the potential to inhibit of Escherichia coli. This research aims to determine the activity of R. apiculata which grows in the Sukadana mangrove forest in inhibiting E. coli. The leaves of R. apiculata were macerated with methanol solvent, partitioned into three fractions (n-hexane fraction, dichloromethane fraction, and methanol fraction), and tested for phytochemical screening. The results of phytochemical screening of R. apiculata leaves were positive for flavonoids, alkaloids, phenolics, terpenoids, tannins, and saponins. The potential of R. apiculata leaf samples in inhibiting bacterial growth was measured by the size of the clear zone in the antibacterial test with the agar well diffusion method that uses variations in concentration, namely 250 mg/mL, 125 mg/mL, and 62.5 mg/mL. Based on the research results, it is known that R. apiculata leaves can inhibit the growth of the test bacteria with a minimum inhibitory concentration for methanol extract of 250 mg/mL. The methanol and dichloromethane fractions had minimum inhibitory concentrations of 125 mg/mL and 250 mg/mL respectively, while the n-hexane fraction did not inhibit at all test concentrations. So it can be concluded that the leaves of R. apiculata have the potential as an alternative for antibacterial active compounds