Fungal Candida Albicans Research Articles

Zebrafish (Danio rerio) as a Model System to Investigate the Role of the Innate Immune Response in Human Infectious Diseases

The zebrafish (Danio rerio) has emerged as a valuable model for studying host-pathogen interactions due to its unique combination of characteristics. These include extensive sequence and functional conservation with the human genome, optical transparency in larvae that allows for high-resolution visualization of host cell-microbe interactions, a fully sequenced and annotated genome, advanced forward and reverse genetic tools, and suitability for chemical screening studies. Despite anatomical differences with humans, the zebrafish model has proven instrumental in investigating immune responses and human infectious diseases. Notably, zebrafish larvae rely exclusively on innate immune responses during the early stages of development, as the adaptive immune system becomes fully functional only after 4–6 weeks post-fertilization. This window provides a unique opportunity to isolate and examine infection and inflammation mechanisms driven by the innate immune response without the confounding effects of adaptive immunity. In this review, we highlight the strengths and limitations of using zebrafish as a powerful vertebrate model to study innate immune responses in infectious diseases. We will particularly focus on host-pathogen interactions in human infections caused by various bacteria (Clostridioides difficile, Staphylococcus aureus, and Pseudomonas aeruginosa), viruses (herpes simplex virus 1, SARS-CoV-2), and fungi (Aspergillus fumigatus and Candida albicans).

A Comprehensive Journey of a Vanillic Aldehyde-Chloroaniline Schiff Base from Solvent-Free Synthesis to Electronic Structure, In Silico and In Vitro Biological Analysis

Schiff bases possess a range of unique physical, chemical and medicinal properties, which contribute to their potency as biological agents. A Schiff base was synthesized, which consisted of 4-chloro aniline and vanillin. The successful formation of the compound was confirmed by their comparable FTIR, UV–Vis, 1HNMR and [Formula: see text]CNMR spectra. The compound was analyzed using X-ray crystallography, which revealed that it crystallizes in the monoclinic system with the space group P21/c. The Hirshfeld surface analysis revealed valuable information about the intermolecular interactions present in the crystal lattice. The most common contacts observed were between hydrogen and hydrogen, as well as carbon and hydrogen. The obtained fluorescence values of 375 nm and 412 nm at excitation wavelength 322 nm strongly indicated the luminescent nature of the compound. The thermal stability of the compound was assessed through thermogravimetric analysis (TGA). DFT was used to optimize the geometry using the B3LYP/cc-pVDZ basis set. The compound exhibited an energy gap of 2.35 electron volts (eV). According to the analysis of molecular electrostatic potential, C and O atoms were found to be electrophilic. According to Mulliken charge analysis, C atoms possess both positive and negative charges, hydrogen atoms exclusively carry positive charges, and Cl, O and N atoms exclusively carry negative charges. Upon analysis of the molecule, the electron localization function discovered that the atoms of carbon, nitrogen and chlorine exhibited delocalized electron density. Also, the localized orbital locator identified the localized orbital positions in the hydrogen atoms. The reduced density gradient (RDG) maps exhibit a wide range of noncovalent interactions. In comparison to the standard amoxicillin, the synthesized compound demonstrated moderate antimicrobial efficacy against the gram-positive bacteria Klebsiella pneumoniae and the fungi Candida albicans. The compound’s concentration-dependent antioxidant and anti-inflammatory properties were demonstrated through in vitro biological evaluation using 2,2-diphenyl-1-picrylhydrazyl and human red blood cell (HRBC) methods. The compound was docked using the proteins 7BYE and 4LEB were chosen from both organisms. The lowest binding attractions obtained were -3.40 kcal/mol for 7BYE and -4.51 kcal/mol for 4LEB. To investigate the stability of the protein–ligand complex, molecular dynamic simulation was employed. The ligands in silico toxicity potentialities were analyzed using seven toxicity models and the results indicated that the ligand is biocompatible.

Synthesis and characterization of a cobalt(II) complex with 5-amino-1-tosyl-1h-1,2,4-triazole as a sulfonamide ligand: antibacterial and molecular docking studies

A new cobalt(II) complex, [Co(L)4Cl2]·2C9H10N4O2S (1), was prepared by reaction of CoCl2·6H2O with a sulfonamide, 5-amino-1-tosyl-1H-1,2,4-triazole (L), in double-distilled water and ethanol (1:1 v/v). The sulfonamide was characterized by elemental analysis, and infrared and 1H-NMR spectroscopy, while the Co(II) complex was characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. The X-ray structure analysis reveals that 1 consists of a mononuclear cobalt(II) complex, [Co(L)4Cl2], and two molecules of the co-crystallized ligand (5-amino-1-tosyl-1H-1,2,4-triazole). The cobalt(II) in 1 is coordinated by four triazole ligands and two chlorides in an octahedral environment. The antimicrobial activity and molecular docking of ligand and 1 were investigated. Antibacterial and antifungal activity studies of L and 1 show that both have moderate-to-significant activity against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria and fungi (Aspergillus niger and Candida albicans). According to molecular docking results, 1 could be a promising compound for developing antibacterial drugs. The docking results provide detailed evidence for the interactions of 1 with dihydropteroate synthase protein (DHPS). The microbial evaluation and molecular docking simulation results may lead to development of new drug candidates against bacterial and fungal strains.

Alginate‑carbon dot nanocomposite: A green approach towards designing turn-on aptasenor for Candida albicans fungus

Candida albicans fungus, an opportunistic microorganism that becomes a pathogen in its host, can often cause superficial and severe infections in human body. In this work, a turn-on fluorescent aptasenor based on Alginate‑carbon dot nanocomposite has been designed through a green approach. Carbon dots (CDs) with average size of 4 ± 1 nm were synthesized hydrothermally using Philodendron bipinnatifidum plant extract as precursor. Then, mixture of carbon dot and alginate was cross-linked by Ca2+ ions to make Alginate-CD nanocomposite with negligible effect on fluorescence intensity of CDs (λex = 360 nm, λem = 400 nm). The fluorescence quantum yield and lifetime were found as 14.1 % and 3.15 ns, respectively. The nanocomposite was characterize using different spectroscopic (Photoluminescence, UV–visible, XPS, FT-IR) and microscopic (TEM and SEM) analytical techniques. An aptamer was used to selectively target (1 → 3)-β-D-glucan on the surface of the Candida albicans cell wall. It was found that the fluorescence energy resonance transfer between nanocomposite and aptamer quenches the fluorescence intensity of nanocomposite, making it suitable for designing turn-on fluorescent probe. It was found that the fluorescence could be recovered in the presence of Candida albicans fungus (in <30 min), owing to higher affinity between aptamer and (1 → 3)-β-D-glucan on the surface of Candida albicans fungus, where there were two linear ranges: low concentration of 50–200 cells/mL and high concentration of 1000–6000 cells/mL (R2 ≥ 0.989 for both linear ranges), with limit of detection of 40 cells/mL. The selectivity of the designed probe was examined against a mixture of microbial agents (Staphylococcus aureus and Escherichia coli) and Curdlan polysaccharide (1→3)-b-D-Glucan (L). The designed biosensor showed an excellent ability to directly detect Candida albicans fungus via a simple and fast (<30 min) approach. The results of this experimental study show that Alginate-CD-aptamer nanocomposite is a bright prospect in clinical applications and a suitable alternative to traditional methods of Candida albicans diagnosis.

Structural, spectroscopic, and biological properties of an asymmetric Cu (II) Schiff-base complex: Synthesis, DNA/BSA interactions, and antimicrobial potential with experimental and computational insights

A copper (II) complex with the asymmetric bidentate Schiff-base ligand (E)-2-(((4-chlorophenyl) imino) methyl) phenol was synthesized and characterized using FTIR and UV–VIS spectroscopy. Photoluminescence studies were conducted on both the copper (II) complex and the free ligand. XRD analysis revealed the copper (II) complex crystallizes in the monoclinic system, space group P21/c. The complex structure was optimized using DFT calculations with B3LYP/6-31G+(d,p) and Lanl2dz basis sets, with QTAIM and NBO analyses confirming complex formation. The energy gap of the copper (II) complex was determined to be 3.701 eV (alpha state) and 2.764 eV (beta state). MEP analysis of the optimized structure indicated a hydrophobic environment around the nitrogen atom, with the molecule exhibiting overall hydrophobicity. The chlorine atoms were identified as potential nucleophilic sites. The antimicrobial efficacy of a Schiff base copper (II) complex was evaluated against selected pathogenic bacteria (B. subtilis, B. megaterum, K. pneumoniae, E. coli) and the fungus Candida albicans. Among these C. albicans for complex showed larger zones (11–15.5 mm) at higher concentrations such as 2 and 2.5 mg/mL. Molecular docking studies suggested strong binding affinity between the complex and the target protein, this was further supported by obtained root means square deviations, root means square fluctuations, radius of gyration and hydrogen bond values during simulations. The binding free energy between BSA and the copper (II) complex was calculated as −8.7 kcal/mol, indicating significant interaction. However, only weak van der Waals interactions were observed between the complex and DNA. Toxicity studies revealed the copper (II) complex had minimal irritant effects on ocular and cutaneous tissues, with a low lethal dose. In comparison, Tricresyl phosphate showed moderate to severe ocular irritancy and modest cutaneous irritancy.

Antifungal Activity of Butterfly Pea Flower (Clitoria Ternatea L.) against Candida Albicans Causes of Dandruff

Dandruff is a common scalp problem characterized by flaking, itching, and redness. One of the causes of dandruff is the fungus Candida albicans. Under certain conditions, such as excessive oil production, this fungus can grow and become pathogenic. Butterfly pea flower is a plant known to contain antifungal compounds, including tannins, flavonoids, saponins, and alkaloids. This study aims to determine the antifungal activity of ethanol extract from butterfly pea flower against Candida albicans using SDA (Sabouraud Dextrose Agar) medium with the disk diffusion method. The concentrations of butterfly pea extract used were 5%, 15%, 30%, 60%, and 90%. The positive control used was ketoconazole, while the negative control was 1% CMC-Na. The results of the study indicate that the butterfly pea extract exhibits antifungal activity, as evidenced by the formation of an inhibition zone at a concentration of 90%, with an average inhibition zone of 3.7 mm. The positive control showed an inhibition zone of 14.38 mm, categorized as strong. In contrast, the negative control did not show any inhibition zone due to the lack of antifungal activity. Based on these results, it can be concluded that butterfly pea (Clitoria ternatea L.) has the potential for weak antifungal activity against Candida albicans.

Design, synthesis, characterization, and theoretical calculations, along with in silico and in vitro antimicrobial proprieties of new isoxazole-amide conjugates

Abstract Functionalized isoxazoles provide valuable structural motifs, opening up a wide range of uses in the medicinal, pharmacological, and pharmaceutical fields. Within this scope, an efficient approach has been adopted to synthesize a novel series of functionalized isoxazole derivatives, starting from aza-aurone, providing reproducible access to the desired isoxazoles in excellent yields. All synthesized compounds were structurally elucidated through the use of various spectroscopic techniques and mass spectrometry. The derivatives generated were screened for their antimicrobial potential against the fungus Candida albicans as well as three bacterial strains. The results show that almost all of the tested isoxazole derivatives were found to be significantly potent against the fungus C. albicans. The functionalized isoxazoles were also computed using the Gaussian software package with the 6-31++G(d,p) basis set at B3LYP, HF, and M062X levels, and their chemical activities were compared. Moreover, the molecular docking studies of tested isoxazole compounds were performed against the C. albicans receptor. The results suggest that the newly synthesized compounds exhibit docking scores ranging from −10.29 to −15.08 kcal/mol, revealing a high affinity for the target enzyme (5V5Z). Lastly, drug similarity studies and ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties assessments indicate that isoxazole derivatives have favorable absorption, distribution, and metabolism properties associated with a proven lack of toxicity.

An Assay on the Antibactericidal Functionality of Synthesized Mg-Doped ZnO Nanoparticles on the DentalMicrobes.

We succeeded in producing pure and magnesium-doped zinc oxide nanoparticles (Mg-Zn NPs) by making use of a Prosopis farcta leaf extract and subsequently distinguished the quality of our NPs with the use of field energy scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), powder X-ray diffraction (PXRD), and UV-vis. In correlation to our observations, the particulates were spherically produced at a size of 20 nm with the ability to cause antimicrobial impacts on Streptococcus mutans bacteria and Candida albicans fungi. Inhibition zones of 18 ± 0.3 and 24 ± 0.3 mm were obtained for 5% Mg-Zn NPs against bacteria and fungi, respectively. Based on these results, our work suggests a practicable proposition for our synthesized product to be considered as a worthy alternative for dental and oral utilizations.

Antimicrobial effects and phytochemical analysis of guava leaf extracts on selected microorganisms

The misuse of antimicrobial agents can lead to emergence of resistance to microbes which in turn can lead to the search for alternative therapy. The use of phytopharmaceuticals and herbal medicines have a positive impact and represents a promising alternative. Guava extract has been reported to have antimicrobial properties. However, the aim of this study was to determine the antimicrobial activities of methanol and ethanol extract of guava leave against some certain bacteria (Staphylococus aureus and Escherichia coli) and a fungus (Candida albicans). Qualitative phytochemical screening showed that phenols, tannins, saponins, terpenoids, flavonoids and glycosides are all present in the leaf extract; phenols and tannins are moderately present while others are present in minute quantities. Out of the different concentrations use (50, 100, 200 and 250), The highest concentration which is 250mg/ml showed the highest zone of inhibition for both methanolic and ethanolic extracts against the isolates. Minimum inhibitory concentration and Minimum Bactericidal Concentrations value for both S. aureus and E. coli are 200mg/ml and 250mg/ml respectively; while 50mg/ml and 100mg/ml are for Candida albicans.

Synthetic Antimicrobial Peptides. V. Histidine-containing Antifungal Peptides with a “Linear” Type of Amphipathicity

A number of histidine-containing synthetic antifungal peptides with a “linear” type of amphipathicity (SAMP LTA) (F2Hx, H10F2, H10, where x = 7, 10, 13 and 16) have been synthesized and studied. Biological screening of such histidine-containing peptides for their antifungal and hemolytic activity was carried out. It has been shown that the presented histidine-containing SAMP LTAs are capable of effectively inhibiting the growth of opportunistic fungi Candida albicans and have low hemolytic activity in most cases not exceeding 10% even at their relatively high concentration of 400 μM in a medium containing erythrocytes. The antifungal activity of the studied peptides increases with increasing histidine residues in their composition, reaching the maximum value for the histidine-containing peptide F2H16 (MIC50 = 1.0 µM). It has been shown that as the chain length of peptides increases, their hemolytic toxicity also increases. In terms of therapeutic significance, the optimal peptides in the presented series of peptides were F2H10 and F2H13, which have higher selectivity than the short or longer peptides F2H7 or F2H16. The therapeutic index (TI) for these peptides was 233, 247, 79 and 60, respectively. It has been shown that histidine-containing derivatives of peptides with phenylalanine residues at the N-terminus of the peptide (F2H10) are less effective compared to similar peptides (H10F2) containing phenylalanine residues at the C-terminus. Among all the studied peptides, the most active was the H10 peptide (MIC50 = 0.7 µM), which does not contain phenylalanine residues, which in its antifungal activity is not only more effective than all other histidine-containing peptides, including the F2H16 peptide with 16 histidine residues, but also 4-5 times more effective than the antifungal peptide P113 (MIC50 = 3.4 µM), a short active fragment of natural histatin 5, well known in the literature. Due to its relatively low hemolytic and high antifungal activity, the presented histidine-containing SAMP LTAs have relatively high TI values, more than 60. Among all the studied peptides, peptides H10 and P113 have minimal, almost zero, hemolytic activity. However, due to its higher antifungal activity, the selectivity of peptide H10 (TI 1400) exceeds that of peptide P113 (TI 340) by more than 4 times. Thus, peptide H10, due to its high antifungal activity, low hemolytic toxicity and, accordingly, high therapeutic significance, can be used as a promising antifungal peptide drug.

Advance Screening of Bis- Azetidinone Derivatives: Synthesis, Spectroscopy, Antioxidant and Antimicrobial Analysis with Molecular Docking Assessment

Introduction: This study includes synthesis, characterizations, antimicrobial, antiox-idant, and docking molecular study of novel Bis-Azetidinone compounds that combined two units of β-lactam rings .In the present investigation, the aromatic aldehydes with primary amine were condensed to create Schiff's base, which was then reacted with chloroacetylchloride to pro-duce bis-Azetidinone compounds. Methods: Melting points, FTIR, and NMR spectrum analyses were used to examine the mor-phological and topological characteristics of the Bis-Azetidinone compounds. The results indi-cate that the prepared Compounds synthesis has excellent antimicrobial activity against both Gram-negative (Escherichia coli,), Gram-positive bacteria (Staphylococcus aureus) and fungal (Candida albicans) and also indicated that the Compounds synthesis (A2) gave a higher antimi-crobial effect than the B2, C2. The synergistic activity was examined against the pathogenic microbial strains. It was observed that employing compound synthesis combined with antibiot-ics enhanced the synergistic efficacy compared to using compound synthesis alone or antibiotic alone on Gram-positive bacteria and fungi. Results: The antioxidant efficiency was assessed by DPPH, the results show that the compound synthesis has antioxidant activity, and also indicated that the synthesized compound (A2) gave a higher antioxidant effect than the B2, C2. Docking study confirmed via redocking of crystal-ized substrate or inhibitor within target binding pocket. The docking results reveal that the syn-thesized compounds, with a total binding affinity of less than -48 kcal/mol, could be clinically used for future therapeutic purposes. Conclusion: The present research demonstrates the advantageous effectiveness of a simpler pro-duction procedure, novel Bis-Azetidinone compounds, for producing high-purity with low haz-ard that may be utilized as future possible medical therapies.

Synthesis, Characterization, and Antimicrobial Evaluation of Thiadiazole Derivatives Derived from 2-Amino-5-Thio-1,3,4-Thiadiazole

This manuscript introduces a series of novel Schiff base and heterocyc-licring compounds, focusing on derivatives of 1,3-oxazepine and thiazo-lidinone.The derivative (2-Hydroxy-N-(5-mercapto-[1,3,4] thiadiazol-2-yl)-2-phenyl-acetamide was created by reacting ethyl mandelate ester[M1] and 2-amino-5-thio-1,3,4-thiadiazole compound to produce new compound [M2] and after that, compound [M2] was reacted with hydrazine hydrate 99% in dry DMF solvent, yielding the compound (N-(5-Hydrazino-[1,3,4]thiadiazol-2-yl)-2-hydroxy-2-phenyl-acetamide [M3]. In contrast , the Schiff base compound [M4] were synthesized by reacting compound [M3] with aromatic heterocyclic aldehyde (furan-2-carbaldehyde) in the presence of glacial acetic acid as a catalyst, and then Schiff base [M4] was reacted with maleic anhydride in dry benzene as a solvent to produce (1,3-Oxazepine) derivative [M5]. Additionally, the thiazolidinone derivative [M6] was synthesized through the reaction of equimolar amounts of (N-[5-(N'-Furan-2-yl-methylene-hydrazino)-[1,3,4]thiadiazol-2-yl]-2-hydroxy-2-phenyl-acetamide [M4] with thioacetic acid compound in chloroform as a solvent. The structural formula of all derivatives was confirmed by FT-IR and (1HNMR, 13CNMR) spectroscopy. The synthesized derivatives [M1-M6] were screened for their evaluated for antibacterial activity against S. aureus, S. epidermidis, E. coli, Klebsiella sp., and the fungus Candida albicans. Dimethyl sulfoxide (DMSO) was used as the solvent. Also, the ampicillin compound was used as the standard drug for comparison.

A novel PhoPQ-potentiated mechanism of colistin resistance impairs membrane integrity in Pseudomonas aeruginosa.

Polymicrobial communities are often recalcitrant to antibiotic treatment because interactions between different microbes can dramatically alter their responses and susceptibility to antimicrobials. However, the mechanisms of evolving antimicrobial resistance in such polymicrobial environments are poorly understood. We previously reported that Mg 2+ depletion caused by the fungus Candida albicans can enable Pseudomonas aeruginosa to acquire significant resistance to colistin, a last-resort antibiotic targeting bacterial membrane. Here, we dissect the genetic and biochemical basis of this increased colistin resistance. We show that P. aeruginosa cells can acquire colistin resistance using three distinct evolutionary trajectories involving mutations in genes involved in lipid A biosynthesis, lipid A modifications that are dependent on low Mg 2+ , and a putative Mg 2+ transporter, PA4824. These mutations confer colistin resistance by altering acyl chains, hydroxylation, and aminoarabinose modification of lipid A moieties on the bacterial outer membrane. In all cases, enhanced colistin resistance initially depends on the low Mg 2+ -responsive PhoPQ pathway, which potentiates the evolution of resistance mutations and lipid A modifications that do not occur without Mg 2+ depletion. However, the PhoPQ pathway is not required to maintain high colistin resistance in all cases. In most cases, the genetic and biochemical changes associated with these novel forms of colistin resistance also impair bacterial membrane integrity, leading to fitness costs. Our findings provide molecular insights into how nutritional competition drives a novel antibiotic resistance mechanism and its ensuing fitness tradeoffs.

The Effect of Aloe vera on Skin and Its Commensals: Contribution of Acemannan in Curing Acne Caused by Propionibacterium acnes

Aloe vera is one of the most significant therapeutical plant species that belongs to the family Liliaceae. Aloe vera is composed of a high amount of water, with the remainder being dry matter. The dry matter contains a lot of bioactive compounds like carbohydrates, fats, and enzymes, with various therapeutic and antimicrobial properties. It can enhance the proliferation of cells and prevent cell damage by anti-oxidative properties (stimulating the secretion of superoxide dismutase and peroxidase). Human skin is colonized by microbes like fungi (Candida albicans), bacteria (Propionibacterium acnes, Staphylococcus aureus), and mites. These commensals are responsible for skin characteristics such as acidic pH, the pungent smell of sweat, etc. Human fetuses lack skin microbiota, and their skin is colonized after birth. Commensals present on the skin have a crucial role in training the human immune system against other pathogenic microbes. Propionibacterium acnes act as an opportunistic pathogen when the balance between the commensals is disturbed. We also emphasize the recent progress in identifying the aloe metabolite biosynthesis pathways and the associated enzyme machinery. The hyperproliferation of Propionibacterium acnes causes acne, and acemannan plays a significant role in its cure. Hence, we need to consider a new treatment approach based on the root cause of this dysbiosis.

Exploring Thermal Stability, Vibrational Properties, and Biological Assessments of Dichloro(l-histidine)copper(II): A Combined Theoretical and Experimental Study.

Dichloro(l-histidine)copper(II) crystal ([Cu(l-His)Cl2] complex) was obtained by the slow evaporation method and characterized concerning its thermal stability, phase transformations, and electronic and vibrational properties. X-ray diffraction (XRPD) confirmed that this complex crystallizes with an orthorhombic structure (P212121 space group). Thermal analyses (TG and DTA) demonstrate stability from ambient temperature up to 460 K, followed by a phase transition from the orthorhombic structure to the amorphous form around 465 K, as confirmed by temperature-dependent XRPD studies. The active modes in Fourier transform infrared (FT-IR) and Raman spectroscopy spectra were suitably assigned via density functional theory (DFT) calculations. Additionally, Hirshfeld surface analysis uncovered the prominence of Cl···H, O···H, and H···H interactions as the primary intermolecular forces within the crystal structure. The antimicrobial activity of the [Cu(l-His)Cl2] complex was investigated, demonstrating significant efficacy against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Pseudomonas aeruginosa), and fungi (Candida albicans). The minimum inhibitory concentration and cell viability tests showed that the complex inhibits the growth of S. aureus bacteria at a concentration of 1.5 μM without causing damage to the human cell line. The pharmacokinetic parameters corroborate the other tested parameters and highlight the [Cu(l-His)Cl2] complex as a promising alternative for future clinical trials and medicinal applications. The alignment of the pharmacokinetic parameters with other tested criteria highlights the potential of the [Cu(l-His)Cl2] complex as a promising candidate for future clinical studies.

Quaternized 1,2,3-Triazolyl Content and Modulation Potentiate Antibacterial and Antifungal Activities of Amphipathic Peptoids.

Bioinspired from cationic antimicrobial peptides, sequence-defined triazolium-grafted peptoid oligomers (6- to 12-mer) were designed to adopt an amphipathic helical polyproline I-type structure. Their evaluation on a panel of bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis), pathogenic fungi (Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus), and human cells (hRBC, BEAS-2B, Caco-2, HaCaT, and HepG2) enabled the identification of two heptamers with improved activity to selectively fight Staphylococcus aureus pathogens. Modulation of parameters such as the nature of the triazolium and hydrophobic/lipophilic side chains, the charge content, and the sequence length drastically potentiates activity and selectivity. Besides, the ability to block the proinflammatory effect induced by lipopolysaccharide or lipoteichoic acid was also explored. Finally, biophysical studies by circular dichroism and fluorescence spectroscopies strongly supported that the bactericidal effect of these triazolium-grafted oligomers was primarily due to the selective disruption of the bacterial membrane.

An efficient synthesis, characterization, and in silico studies of novel chromenes, thiophenes, pyrazolo[1,5-a]pyrimidines, and pyrimidines as potential antimicrobial and anticancer agents using the bio-buffer tris(hydroxymethyl)aminomethane (THAM)

Novel 2-imino-6-(aryldiazenyl)-2H-chromene-3-carboxamides 6a–e, 2-amino-4H-cyclopenta or benzo[b]thiophene-3-carboxamides 10a,b, 2,7-diaminopyrazolo[1,5-a]pyrimidine-6-carboxamides 13a–e, pyrimidine-5-carboxamides 14, 15 and 3-amino-1H-pyrazole-4-carboxamide 16 were synthesized from the reaction of 2-cyano-N-(1,3-dihydroxy-2-(hydroxyl-methyl) propan-2-yl) acetamide 2 with 4-arylazosalicylaldehydes 5a-e, cyclopentanone and/or cyclohexanone, guanidine derivatives and hydrazine hydrate, respectively. Some new compounds were evaluated for antibacterial activity in vitro, and exhibited good efficacy compared to gentamicin. Compound 4c showed greater activity against gram negative bacteria (Klebsiella pneumonia and Pseudomonas aeruginosa) than standard antibiotic. Compound 4c with two withdrawing groups also showed the higher activity (38.7 ± 0.6) against fungi (Candida albicans) than the Nystatin (20 ± 0.5). On the other hand, compounds 13a, 13c, and 13e have strong cytotoxic activity among the tested compounds in the three selected cancer cell lines (HePG2, MCF7 and Hela). Physicochemical characterization by Swiss ADME predication was also performed for some synthesized compounds exhibiting better biological and antimicrobial properties.

Synthesis , characterization and biological activity study of N-substituted sulfonamido maleimides substituted with different heterocycles

Eighteen new cyclic imides (maleimides) conncted to benzothiazole moiety through sulfonamide group were synthesized via multistep synthesis.The first step involved preparation of two maleamic acids N-phenylmaleamic acid and N-benzylmaleamic acid via reaction of maleic anhydride with aniline or benzyl amine.Dehydration of the prepared amic acids by treatment with acetic anhydride and anhydrous sodium acetate in the second step afforded N-phenylmaleimide and N- benzyl maleimide which in turn were treated with chlorosulfonic acid in the third step to afford 4-(N-maleimidyl) phenyl sulfonyl chloride and 4-(N-maleimidyl) benzyl sulfonyl chloride respectively.In the Fourth step of this work each one of the two prepared maleimidyl sulfonyl chlorides was introduced in reaction with nine substituted-2-amino benzothiazole compounds producing nine N-(4-(N-substituted benzothiazole -2-yl) sulfonamido phenyl) maleimides and nine N-(4-(N-substituted benzothiazole-2-yl)snlfonamido benzyl) maleimides.More over another new six sulfonamide phenyl and benzyl maleimides substituted with other heterocycles (pyridine and phenazone )were prepared via reaction of 4-(N-maleimidyl) phenyl and benzyl sulfonyl chlorides with heterocyclic amines including (2-amino pyridine,4-amino-pyridine,4-aminophenazone). Microbiological activity of the prepared compounds against two typs of bacteria(staphylococcus aureus and klebsiella pneumonia) and (candida albicans) fungi were evaluated and the results showed that these compounds have good antibacterial and good antifungal activities.

Synthesis and biological evaluation of some new heterocyclic compounds incorporating sulfapyridine as potential antimicrobial agents

This study investigated the cyanoacylation of the sulfapyridine moiety using cyanoacetyl pyrazole as a key synthetic intermediate for the construction of diverse bioactive scaffolds. The intermediate, 2-cyano-N-(4-(N-pyridin-2-yl) sulfamoyl) phenylacetamide, served as a valuable precursor for the synthesis of acrylamide, thiophene, thiazole, chromene, pyridone, 1,2,4-triazine, and hydrazone derivatives all incorporating the sulfapyridine core. The structural elucidation of the synthesized compounds was achieved using infrared (IR), nuclear magnetic resonance (1H and 13C), and mass spectrometry techniques. The biological activity of the newly synthesized compounds was evaluated against a panel of microorganisms, including Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and the fungus Candida albicans. Notably, the thiol derivative (compound 12), the pyrazole derivative (compound 15), and the 1,2,4-triazine derivatives (compound 21) exhibited significant to good antibacterial and antifungal activity. Interestingly, compounds 12 and 15 displayed a broader spectrum of activity, demonstrating efficacy against all tested microbial strains.

Harnessing Endophytic Fungi from Terminalia chebula: A Dual Approach to Antimicrobial and Phytochemical Exploration

Endophytic fungi isolated from Terminalia chebula exhibit potent antimicrobial activity, showcasing their potential to develop novel therapeutic agents. Additionally, these fungi produce diverse phytochemicals, which may contribute to their medicinal properties and offer new avenues for natural product research. This research study investigated the endophytic fungi isolated from T. chebula and assessed their antimicrobial and phytochemical potential. A total of 28 endophytic fungal species were isolated from leaf and bark tissues. Antimicrobial assays revealed significant inhibitory effects against pathogenic fungi Candida albicans - MTCC 183 &amp; Saccharomyces cerevisiae - MTCC 174 and bacteria Escherichia coli - MTCC 2939, &amp; Bacillus subtilis - MTCC 1305, with endophytic Alternaria sp. exhibiting maximum inhibition zone for antifungal activity and endophytic Aspergillus flavus demonstrating potent activity for their antibacterial analysis. A wide array of phytochemical compounds like alkaloids, flavonoids, phenols, steroids, terpenoids, tannin, saponin, etc, were observed whereas, phytochemical screening indicated the presence of alkaloids and flavonoids in all selected endophytes. These findings suggest that T. chebula harbors a rich endophytic community with the potential for producing novel antimicrobial compounds.