Biogenic silver nanoparticles from fungal sources: Synthesis, characterization, and antifungal potential.

Nano-biotechnology is quickly developing as an important field of modern research, generating the most promising applications in medicine and agriculture. Biosynthesis of silver nanoparticles using biogenic or green approach provide ecofriendly, clean and effective way out for the synthesis of nanoparticles. The main aim of the study was to synthesize silver nanoparticles (AgNPs) from Aspergillus niger, Aspergillus flavus and Pencillium chrysogenum using a green approach and to test the antifungal activity of these synthesized AgNPs against a variety of pathogenic fungi. The characterization of samples was done by using UV-visible spectroscopy, SEM (scanning electron microscopy), FTIR (Fourier transmission infrared spectroscopy), and XRD (X-ray diffractometry). The investigation confirmed the creation of AgNPs by the fungi Aspergillus niger, Aspergillus flavus and Pencillium chrysogenum, as evidenced by prominent plasmon absorbance bands at 420 and 450 nm.The biosynthesized AgNPs were 80-100 nm in size, asymmetrical in shape and became spherical to sub-spherical when aggregated. Agar well diffusion method was performed to evaluate the antifungal activity of AgNPs against various plant pathogenic fungi. An efficient and strong antifungal activity was shown by these biosynthesized nanoparticles against serious plant pathogenic fungi, viz. Aspergillus terreus, Fusarium oxysporum, Penicillium citrinum, Rhizopus stolonifer and Mucor mucedo. The biosynthesized AgNPs at various concentrations caused significant zone of inhibition in the test fungal pathogens. Silver nanoparticles (AgNPs) biosynthesized from Aspergillus niger at highest concentrations showed maximum zone of inhibition against Penicillium citrinum (19.33 ± 0.57 mm) followed by Rhizopus stolonifer (17.66 ± 0.57), Aspergillus terreus (16.33 ± 1.54 mm), Fusarium oxysporum (14.00 ± 1.00 mm) and Mucor mucedo (13.33 ± 1.15 mm) respectively. Therefore, the findings clearly indicate that silver nanoparticles could play a significant role in managing diverse plant diseases caused by fungi.

Production and bioprocessing of epothilone B from Aspergillus niger, an endophyte of Latania loddegesii, with a conceivable biosynthetic stability: anticancer, anti-wound healing activities and cell cycle analysis.

Epothilones are one of the common prescribed anticancer drugs for solid tumors, for their exceptional binding affinity with ß-tubulin microtubule, stabilizing their disassembly, causing an ultimate arrest to the cellular growth. Epothilones were initially isolated from Sornagium cellulosum, however, their extremely slow growth rate and low yield of epothilone is the challenge. So, screening for a novel fungal endophyte dwelling medicinal plants, with higher epothilone productivity and feasibility of growth manipulation was the objective. Aspergillus niger EFBL-SR OR342867, an endophyte of Latania loddegesii, has been recognized as the heady epothilone producer (140.2 µg/L). The chemical structural identity of the TLC-purified putative sample of A. niger was resolved from the HPLC, FTIR and LC-ESI-MS/MS analyses, with an identical molecular structure of the authentic epothilone B. The purified A. niger epothilone B showed a resilient activity against MCF-7 (0.022 µM), HepG-2 (0.037 µM), and HCT-116 (0.12 µM), with selectivity indices 21.8, 12.9 and 4, respectively. The purified epothilone B exhibited a potential anti-wound healing activity to HepG-2 and MCF-7 cells by ~ 54.07 and 60.0%, respectively, after 24 h, compared to the untreated cells. The purified epothilone has a significant antiproliferative effect by arresting the cellular growth of MCF-7 at G2/M phase by ~ 2.1 folds, inducing the total apoptosis by ~ 12.2 folds, normalized to the control cells. The epothilone B productivity by A. niger was optimized by the response surface methodology, with ~ 1.4 fold increments (266.9 µg/L), over the control. The epothilone productivity by A. niger was reduced by ~ 2.4 folds by 6 months storage as a slope culture at 4 °C, however, the epothilone productivity was slightly restored with ethylacetate extracts of L. loddegesii, confirming the plant-derived chemical signals that partially triggers the biosynthetic genes of A. niger epothilones. So, this is the first report emphasizing the metabolic potency of A. niger, an endophyte of L. loddegesii, to produce epothilone B, that could be a new platform for industrial production of this drug.

Determination of antifungal efficacy and phytotoxicity of a unique silica coated porous zinc oxide nanocomposite medium for slow-release agrochemicals.

AIMS: In this study, the antifungal efficacy and phytotoxicity of silica coated porous zinc oxide nanoparticle (SZNP) were analyzed as this nanocomposite was observed to be a suitable platform for slow release fungicides and has the promise to bring down the dosage of other agrochemicals as well. METHODS AND RESULTS: Loading and release kinetics of tricyclazole, a potent fungicide, were analyzed by measuring surface area (SBET) using Brunauer-Emmett-Teller (BET) isotherm and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. The antifungal efficacy of ZnO nanoparticle (ZNP) and SZNP was investigated on two phytopathogenic fungi (Alternaria solani and Aspergillus niger). The morphological changes to the fungal structure due to ZNP and SZNP treatment were studied by field emission-scanning electron microscopy. Nanoparticle mediated elevation of reactive oxygen species (ROS) in fungal samples was detected by analyzing the levels of superoxide dismutase, catalase, thiol content, lipid peroxidation, and by 2,7-dichlorofluorescin diacetate assay. The phytotoxicity of these two nanostructures was assessed in rice plants by measuring primary plant growth parameters. Further, the translocation of the nanocomposite in the same plant model system was examined by checking the presence of fluorescein isothiocyanate tagged SZNP within the plant tissue. CONCLUSIONS: ZNP had superior antifungal efficacy than SZNP and caused the generation of more ROS in the fungal samples. Even then, SZNP was preferred as an agrochemical delivery vehicle because, unlike ZNP alone, it was not toxic to plant system. Moreover, as silica in nanoform is entomotoxic in nature and nano ZnO has antifungal property, both the cargo (agrochemical) and the carrier system (silica coated porous nano zinc oxide) will have a synergistic effect in crop protection.

Biotransformation of rifampicin by Aspergillus niger and antimicrobial activity of proposed metabolites.

Drug biotransformation studies emerges as an alternative to pharmacological investigations of metabolites, development of new drug candidates with reduced investment and most efficient production. The present study aims to evaluate the capacity of biotransformation of rifampicin by the filamentous fungus Aspergillus niger ATCC 9029. After incubation for 312 h, the drug was metabolized to two molecules: an isomer (m/z 455) and the rifampicin quinone (m/z 821). The monitoring of metabolite formation was performed by high-performance liquid chromatography, followed by their identification through ultra-high-performance liquid chromatography coupled to tandem mass spectrometer. In vitro antimicrobial activity of the proposed metabolites was evaluated against Staphylococus aureus microorganism, resulting in the loss of inhibitory activity when compared with the standards, with minimum inhibitory concentration of 7.5 µg/ml. The significant biotransformation power of the ATCC 9029 strain of A. niger was confirmed in this study, making this strain a candidate for pilot studies in fermentation tanks for the enzymatic metabolization of the antimicrobial rifampicin. The unprecedented result allows us to conclude that the prospect of new biotransforming strains in species of anemophilic fungi is a promising choice.

Xylarkarynone A and B: Two Bioactive Eremophilane Sesquiterpenes from Xylaria sp. HHY-2.

A new compound xylarkarynone A (1), a first reported natural product compound xylarkarynone B (2) and eight known compounds (3-10) were isolated from Xylaria sp. HHY-2. Their structures were elucidated by spectroscopic methods, DP4+ probability analyses and electronic circular dichroism (ECD) calculations. The bioactivities of isolated compounds were assayed. Compound 1 exhibited obvious activity against A549 cells with an IC50 value of 6.12±0.28 µM. Additionally, compound 1 showed moderate antifungal activities against Plectosphaerella cucumerina and Aspergillus niger with minimum inhibitory concentrations (MICs) of both 16 µg/mL, which was at the same grade with positive control nystatin. Most compounds exhibited varying degrees of inhibitory activity against P. cucumerina, indicating that Xylaria sp. has potential as inhibitors against P. cucumerina.

Synthesis, Characterization, Antimicrobial and In Silico Studies of Isatin Schiff Base Linked 1,2,3-Triazole Hybrids.

A new series of isatin-Schiff base linked 1,2,3-triazole hybrids has been synthesized using CuAAC approach from (E)-3-(phenylimino)-1-(prop-2-yn-1-yl)indolin-2-one derivatives in high yield (73-91 %). These synthesized derivatives were characterized using FT-IR, 1H NMR, 13C NMR, 2D-NMR and HRMS spectral techniques. The in vitro antimicrobial activity assay demonstrated that most of the tested hybrids exhibited promising activity. Compound 5 j displayed significant antibacterial efficacy against P. aeruginosa and B. subtilis with MIC value of 0.0062 µmol/mL. While, 5 j also showed better antifungal potency against A. niger with MIC value of 0.0123 µmol/mL. The docking studies of most promising compounds were performed with the well-known antibacterial and antifungal targets i. e. 1KZ1, 5TZ1. Molecular modelling investigations demonstrated that hybrids 5 h and 5 l exhibited good interactions with 1KZN and 5TZ1, with binding energies of -9.6 and -11.0 kcal/mol, respectively. Further, molecular dynamics studies of the compounds showing promising binding interactions were also carried out to study the stability of complexes of these hybrids with both the targets.

Optimization of Antifungal Properties of Hop Cone Carbon Dioxide Extracts Based on Response Surface Methodology.

Response surface methodology (RSM) was employed to optimize the process parameters of the supercritical carbon dioxide extraction of hop cones in terms of their antifungal properties against Fusarium culmorum and Aspergillus niger. The effects of temperature (40-50 °C), pressure (200-300 bar), and CO2 consumption (25-75 kgCO2/kg) on the extraction yield, content of α- and ß-acids, as well as pathogens' growth inhibition were investigated. Both pressure and CO2 consumption had a significant effect on antifungal properties. It was observed that the best results for antifungal properties were obtained when hop cones were extracted with pure carbon dioxide at the temperature of 50 °C, under the pressure of 300 bar with CO2 consumption at the level of 75 kgCO2/kg of feed for extraction. The highest antifungal properties of hop cone supercritical carbon dioxide extracts were analyzed as 100% for Fusarium culmorum and 68% for Aspergillus niger, calculated as the growth inhibition of tested pathogens. The aim of the study was to determine the optimum values of extraction parameters to achieve the maximum response and enable us to investigate the interaction of these parameters on the antifungal properties of hop cone extracts.

Nanofiber-based Delivery of Luliconazole: Fabrication, Characterization, and Therapeutic Performance Assessment.

This study introduces and assesses the potential of a Luliconazole-loaded nanofiber (LUL-NF) patch, fabricated through electrospinning, for enhancing topical drug delivery. The primary objectives involve evaluating the nanofiber structure, characterizing physical properties, determining drug loading and release kinetics, assessing antifungal efficacy, and establishing the long-term stability of the NF patch. LUL-NF patches were fabricated via electrospinning and observed by SEM at approximately 200 nm dimensions. The comprehensive analysis included physical properties (thickness, folding endurance, swelling ratio, weight, moisture content, and drug loading) and UV analysis for drug quantification. In vitro studies explored sustained drug release kinetics, while microbiological assays evaluated antifungal efficacy against Candida albicans and Aspergillus Niger. Stability studies confirmed long-term viability. Comparative analysis with the pure drug, placebo NF patch, LUL-NF patch, and Lulifod gel was conducted using agar diffusion, revealing enhanced performance of the LUL-NF patch. SEM analysis revealed well-defined LUL-NF patches (0.80 mm thickness) with exceptional folding endurance (> 200 folds) and a favorable swelling ratio (12.66 ± 0.73%). The patches exhibited low moisture uptake (3.4 ± 0.09%) and a moisture content of 11.78 ± 0.54%. Drug loading in 1 cm2 section was 1.904 ± 0.086 mg, showing uniform distribution and sustained release kinetics in vitro. The LUL-NF patch demonstrated potent antifungal activity. Stability studies affirmed long-term stability, and comparative analysis highlighted increased inhibition compared to a pure drug, LUL-NF patch, and a commercial gel. The electrospun LUL-NF patch enhances topical drug delivery, promising extended therapy through single-release, one-time application, and innovative drug delivery strategies, supported by thorough analysis.

Evaluation of multi-heavy metal tolerance traits of soil-borne fungi for simultaneous removal of hazardous metals.

The demand for environment-friendly cleanup techniques has arisen due to an increase in environmental pollutants. Fungi is the most prevalent and effective class of heavy metal-resistant microorganisms with the ability to leach metals. The objective of the present study was to isolate the fungi from the agricultural soil of Kashmir valley, investigate their multi-metal tolerance to heavy metals and evaluate the metal uptake capacities of the resistant fungi. The fungi were isolated and identified on the basis of morphological and molecular approach (ITS1 and ITS4). The tolerance limits of the isolated fungal strains to various doses of lead (Pb), cadmium (Cd), zinc (Zn), chromium (Cr), copper (Cu), nickel (Ni), and cobalt (Co) was evaluated. Five fungal strains, Aspergillus niger, Fusarium oxysporum, Fusarium verticillioides, Aspergillus fischeri, Epicoccum mackenziei were isolated from the soil samples. To the best of our knowledge, this is the first report on the study of metal resistance of Aspergillus fischeri and Epicoccum mackenziei. Among the identified fungal species, Aspergillus niger and Fusarium oxysporum were found to be most tolerant with a minimum inhibitory concentration (MIC) of 600 ppm against Cu and Cr respectively. Results indicated removal of considerable amount of heavy metals by some of the fungi. The highest metal uptake of 8.31 mg/g was found in Fusarium verticillioides for Zn. Surprisingly, these fungal strains demonstrated resistance to metal concentrations above the levels that are universally acceptable for polluted soils, and hence prove to be appealing contenders for use as bioremediation agents for cleaning up heavy metal-polluted environments.

Synthesis, structure, properties and antimicrobial activity of para trifluoromethyl phenylboronic derivatives.

The [2-formyl-4-(trifluoromethyl)phenyl]boronic acid as well as its benzoxaborole and bis(benzoxaborole) derivatives were obtained and their properties studied. The 2-formyl compound displays an unusual structure in the crystalline state, with a significant twist of the boronic group, whereas in DMSO solution it tautomerizes with formation of a cyclic isomer. All the studied compounds exhibit relatively high acidity as well as a reasonable antimicrobial activity. Docking studies showed interactions of all the investigated compounds with the binding pocket of Candida albicans LeuRS. High activity against Bacillus cereus was determined for the 2-formyl compound as well as for the novel bis(benzoxaborole), whereas the studied benzoxaborole shows high antifungal action with MIC values equal to 7.8and 3.9 µg/mL against C. albicans and A. niger respectively. None of the studied compounds exhibits reasonable activity against E. coli.

Design, synthesis, biological screening and molecular docking studies of novel multifunctional 1,4-di (aryl/heteroaryl) substituted piperazine derivatives as potential antitubercular and antimicrobial agents.

In this paper, two series of novel multifunctional 1, 4-di (aryl/heteroaryl) substituted piperazine derivatives (6a-d & 7a-d) were synthesized, characterized, and evaluated for their antitubercular, antibacterial, and antifungal activities. A step-wise reduction, bromination and substitution reactions on various aldehydes resulted in alcohols (2a-d), bromides (3a-d), and titled novel compounds (6a-d & 7a-d) in moderate to good yields (48-85%). The novel compounds were evaluated for their antitubercular and antimicrobial activities. Compound 7a exhibited promising antitubercular activity (MIC: 0.65 µg/mL) almost equal to the Rifampicin, while the rest of the compounds were moderately active against MTB H37Rv except 6b. Compounds 7a and 6b showed good activity against tested fungal pathogens. Compounds 7a and 7b were proven as the best bacterial agents. Molecular docking studies were in agreement with the in-vitro results. Docking analyses show that all the synthesized molecules bind to the target protein Mtb RNAP (PDB ID: 5UHC) fairly strongly. All the compounds were evaluated for their in vitro cytotoxicity effect using the MTT assay method against human cancer cell line MCF-7. The compounds demonstrated growth inhibitory effect on the cell line with significant IC50 values ranging between 8.20 and 34.45 µM. Most importantly, compound 7a displayed good binding affinity towards the tested protein with binding energy -7.30 kcal/mol and a stronger hydrogen bond distance of 2.2 Å with ASN-493 residue. Thus, the present research highlighted the potential role of novel piperazine derivatives as potential antitubercular, and antimicrobial candidates and further good research into optimization might result in the development of new antitubercular drug candidates.

Contribution to the Evaluation of Physicochemical Properties, Total Phenolic Content, Antioxidant Potential, and Antimicrobial Activity of Vinegar Commercialized in Morocco.

Vinegar is a natural product widely used in food and traditional medicine thanks to its physicochemical properties and its richness in bioactive molecules. However, its direct use by consumers can have complications and undesirable effects. Therefore, this study contributes to investigating the physicochemical and biological properties of eleven vinegars marketed in Morocco. Determination of pH, acetic acid, conductivity, total soluble solids and alcohol content in vinegar was carried out. The polyphenols (TP), flavonoids (TF), and condensed tannins (CT) content was determined, and their antioxidant activities were evaluated using 2,2-diphenyl-1-picryl Hydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Phosphomolybdenum Reduction Assay (TAC). Then, the antimicrobial activity was studied against four pathogenic bacteria and two fungal strains, using the disk diffusion and the microdilution method. This study showed a wide range of acetic acid values from 0.65 ± 0.29 to 5.15 ± 0.20%. The high value of TP, TF, and CT in our samples V10, V9, and V4 was 655.00 ± 22.2 µgGAE/mL, 244.53 ± 11.32 µgQE/mL and 84.63 ± 1.00 µgTAE/mL, respectively. The tested strains showed variable sensitivities to the different samples with inhibition zones ranging from 6.33 ± 2.08 to 34.33 ± 0.58 mm. The lowest minimum inhibition concentrations were recorded against Staphylococcus aureus ATCC29213 ranging from 1.95 to 7.81 µL/mL. While Aspergillus niger ATCC16404 showed resistance against all of the analyzed samples. In general, vinegar commercialized in Morocco presents a variable range of products with variable properties. Indeed, must take into account this diversity when using it. A future study is needed to identify the phytochemical composition that will further the comprehension of this variability and contribute to its valorization.

Novel Antifungal Dimers from the Roots of Taiwania cryptomerioides.

Five new dimer compounds, namely Taiwaniacryptodimers A-E (1-5), were isolated from the methanol extract of the roots of Taiwania cryptomerioides. Their structures were established by mean of spectroscopic analysis and comparison of NMR data with those of known analogues. Their antifungal activities were also evaluated. Our results indicated that metabolites 1, 2, 4, and 5 displayed moderate antifungal activities against Aspergillus niger, Penicillium italicum, Candida albicans, and Saccharomyces cerevisiae.

Evaluation of antidiabetic, antioxidant, and cytotoxic potential of maize (zea mays l.) husk leaf extracts.

In current study, Maize (Zea mays L.) husk leave extracts were appraised for biological activities such as cytotoxicity, antidiabetic, antioxidant and antimicrobial. Maceration was performed to collect various fractions of husk leave extracts using a pool of solvents i.e., n-hexane, chloroform, ethyl acetate, butanol and methanol. Antioxidant potential was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, reducing power and linoleic acid oxidation assay, using butylated hydroxy toluene (BHT) as a positive control. Total phenolic and flavonoid contents were found to be 18.47-425.11 mg/100 g GAE and 5.83-16.72 mg/100 g CE, respectively. The DPPH scavenging assay was exhibited in the range of 76.36 to 88.53%. The percentage inhibition in linoleic acid oxidation was found from 10.16 to 79.51%. Significant antimicrobial activity was demonstrated by husk leaf extracts against bacterial strains and fungal strains using disc diffusion and minimum inhibitory concentration (MIC) method. Amylase alpha assay was employed to analyze the antidiabetic activity which ranged between 9.52-24.81%. Cytotoxicity was evaluated by % age lysis (0.35-9.54%), while thrombolytic activity ranged between 7.67 to 31.27%. The results presented in this study revealed that maize (Zea mays L.) husk leaf extracts can be a valuable source of biologically active compounds and may be consumed as a source of potent herbal medicine in pharmaceuticals.

Caprylic acid enhances hydroxyhexylitaconic acid production in Aspergillus niger S17-5.

AIM: Aspergillus niger S17-5 produces two alkylitaconic acids, 9-hydroxyhexylitaconic acid (9-HHIA) and 10-hydroxyhexylitaconic acid (10-HHIA), which have cytotoxic and polymer building block properties. In this study, we characterized the production of 9-HHIA and 10-HHIA by addition of their expected precursor, caprylic acid, to a culture of A. niger S17-5, and demonstrated batch fermentation of 9-HHIA and 10-HHIA in a jar fermenter with DO-stat. METHODS AND RESULTS: Production titres of 9-HHIA and 10-HHIA from 3% glucose in a flask after 25 days cultivation were 0·35 and 1·01 g l-1 respectively. Addition of 0·22 g l-1 of caprylic acid to a suspension of resting cells of A. niger S17-5 led to 32% enhancement of total 9-HHIA and 10-HHIA production compared to no addition. No enhancement of the production of 9-HHIA or 10-HHIA by the addition of oxaloacetic acid was observed. Addition of caprylic acid to the culture at mid-growth phase was more suitable for 9-HHIA and 10-HHIA production due to less cell growth inhibition by caprylic acid. DO-stat batch fermentation with 3% glucose and 14·4 g l-1 of caprylic acid in a 1·5 l jar fermenter resulted in the production titres of 9-HHIA and 10-HHIA being 0·48 and 1·54 g l-1 respectively after 10 days of cultivation. CONCLUSIONS: Addition of caprylic acid to the culture of A. niger S17-5 enhances 9-HHIA and 10-HHIA production. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest that 9-HHIA and 10-HHIA are synthesized with octanoyl-CoA derived from caprylic acid, and that the supply of octanoyl-CoA is a rate-limiting step in 9-HHIA and 10-HHIA production. To the best of our knowledge, this is the first report regarding the fermentation of naturally occurring itaconic acid derivatives in a jar fermenter.

Tolerance of three fungal species to lithium and cobalt: Implications for bioleaching of spent rechargeable Li-ion batteries.

AIMS: This paper aims to quantify the growth and organic acid production of Aspergillus niger, Penicillium chrysogenum and Penicillium simplicissimum when these fungi are exposed to varying levels of lithium (Li) and cobalt (Co). The study also tests whether pre-exposing the fungi to these metals enables the fungi to develop tolerance to Li or Co. METHODS AND RESULTS: When cultures of A. niger, P. chrysogenum or P. simplicissimum were exposed to 250 mg l-1 of Li or Co, biomass production and excretion of organic acids were significantly inhibited after 5 days of growth compared to cultures grown in the absence of these metals. Pre-exposing cultures of A. niger to 250 mg l-1 of Li or Co for 20 days significantly increased biomass production when the fungus was subsequently sub-cultured into 250 or 500 mg l-1 of Li or Co. However, pre-exposure of P. chrysogenum or P. simplicissimum to 250 mg l-1 of Li or Co for 20 days did not increase biomass production. CONCLUSIONS: Aspergillus niger, but not the Penicillium species, developed tolerance to Li and to Co during the 20-day pre-exposure period. Therefore, processes that utilize fungal bioleaching with A. niger to mobilize and recover valuable metals such as Li or Co should consider a pre-exposure step for fungi to improve their tolerance to metal toxicity. SIGNIFICANCE AND IMPACT OF THE STUDY: Fungi may have the ability to extract valuable metals such as Li and Co from spent rechargeable batteries. However, the toxicity of the extracted metals can inhibit fungal growth and organic acid production. Pre-exposure to metals may alleviate toxicity for some fungal species. This knowledge can be used to improve the design of bioleaching protocols, increasing the potential for fungal bioleaching to become an economical and environmentally friendly method of recovering Li and Co from spent batteries.

Synthesis, biological evaluation and molecular docking studies of novel quinazolinones as antitubercular and antimicrobial agents.

In the present study, a series of novel quinazolinone hybrids, viz. triazepino-quinazolinones 4, thiazolo-triazolo-quinazolinones 7 and triazolo-quinazolinones 8 have been synthesized from the key intermediate 3-(substituted phenyl)-2-hydrazinoquinazolin-4(3H)-ones 3. All the newly synthesized compounds were characterized by means of spectral (IR, 1H NMR, 13C NMR) and elemental analysis. The target compounds were biologically screened for their in vitro antimicrobial and antitubercular activities against pathogenic strain. The results of bioassay demonstrated that some of the compounds exhibited pronounced antimicrobial activity comparable to that of standard drugs tested under similar conditions. Compounds 4c, 4e, 7e and 8b showed relatively very good inhibitory activity against pathogenic bacteria with minimum inhibitory concentration (MIC) of 2.6 µg/mL, 5.2 µg/mL, while the rest of the compounds showed moderate activity. Compounds 4c and 8b were found to be nearly equipotent with ciprofloxacin against P. aeruginosa with MIC 5.2 µg/mL, while compound 8b was more potent against pathogenic bacteria S. aureus. It is very remarkable that four compounds, 4c, 4e, 7e and 8b showed pronounced antifungal activity against selected pathogenic fungi, A. niger, C. albicans with MIC 2.6 µg/mL and 5.2 µg/mL. The antitubercular activity of synthesized compounds reveal that compound 8b showed better activity than the other compounds with a MIC of 5.2 µg/mL against M. tuberculosis (H37Rv). Molecular docking studies of the compounds were performed to rationalize the inhibitory properties of these compounds and results showed that these compounds have good binding energy and better binding affinity within the active pocket, thus these compounds may be considered as potent inhibitors towards selective targets.

Microwave prompted solvent-free synthesis of new series of heterocyclic tagged 7-arylidene indanone hybrids and their computational, antifungal, antioxidant, and cytotoxicity study.

In this study, we report the expeditious synthesis of ten new antifungal and antioxidant agents containing heterocyclic linked 7-arylidene indanone moiety. The solvent-free microwave technique, ample substrate scope, superfast synthesis, and very simple operation are noteworthy features of this protocol. Antifungal activities of the newly synthesized compounds were evaluated against four fungal strains namely Rhizophus oryzae, Mucor mucido, Aspergillus niger, and Candida albicans. Most of the compounds were shown strong inhibition of the investigated fungal agents. In vitro, antioxidant potential against DPPH and OH radicals affirmed that the synthesized compounds are good to excellent radicals scavenging agents. The cytotoxicity data of the synthesized compounds towards HL-60 cells uncovered that the synthesized compounds display very low to negligible cytotoxicity. The structural and quantum chemical parameters of the synthesized compounds were explored by employing density functional theory (DFT) at B3LYP functional using 6-311G(d,p) basis set. The compound 3a is discussed in detail for the theoretical and experimental correlation. Time-dependent density functional theory (TD-DFT) at CAM-B3LYP functional with 6-311G(d,p) basis set was used for the electronic absorption study in the gas phase and indichloromethane and benzene solvents. The UV-Visible absorption peaks and fundamental vibrational wavenumbers were computed and a good agreement between observed and theoretical results has been achieved. From the DFT and antifungal activity correlation, it has been found that the 7-heteroarylidene indanones with more stabilized LUMO energy levels display good antifungal potential.

Synthesis, characterization, antimicrobial, antioxidant and computational evaluation of N-acyl-morpholine-4-carbothioamides.

The present research paper reports the convenient synthesis, successful characterization, in vitro antibacterial, antifungal, antioxidant potency and biocompatibility of N-acyl-morpholine-4-carbothioamides (5a-5j). The biocompatible derivatives were found to be highly active against the tested bacterial and fungal strains. Moreover, some of the screened N-acyl-morpholine-4-carbothioamides exhibited excellent antioxidant potential. Docking simulation provided additional information about possibilities of their inhibitory potential against RNA. It has been predicted by in silico investigation of the binding pattern that compounds 5a and 5j can serve as the potential surrogate for design of novel and potent antibacterial agents. The results for the in vitro bioassays were promising with the identification of compounds 5a and 5j as the lead and selective candidate for RNA inhibition. Results of the docking computations further ascertained the inhibitory potential of compound 5a. Based on the in silico studies, it can be suggested that compounds 5a and 5j can serve as a structural model for the design of antibacterial agents with better inhibitory potential. Binding mode of compound 5j inside the active site of RNA in 3D space. 5j displayed highest antibacterial potential than the reference drug ampicillin with ZOI 10.50 mm against Staphylococcus aureus. 5j also displayed highest antifungal potential than the reference drug amphotericin B with ZOI 18.20 mm against Fusarium solani.

Essential Oils of Polyalthia suberosa Leaf and Twig and Their Cytotoxic and Antimicrobial Activities.

Essential oils from the leaf and twig of Polyalthia suberosa (Roxb.) Thwaites were analyzed using GC/MS/FID. A total of sixty-three constituents were namely identified accounting for 96.03 and 94.12 % in the hydrodistilled oils of the leaf and twig, respectively. Monoterpenes, monoterpenoids, sesquiterpenes, and sesquiterpenoids were characteristic derivatives of P. suberosa essential oils. Sesquiterpenes bicyclogermacrene (26.26 %) and (E)-caryophyllene (7.79 %), and monoterpene ß-pinene (12.71 %) were the major constituents of the leaf oil. Sesquiterpenes (E)-caryophyllene (17.17 %) and α-humulene (9.55 %), sesquiterpenoid caryophyllene oxide (9.41 %), and monoterpenes camphene (8.16 %) and tricyclene (6.35 %) were to be main components in the twig oil. The leaf oil indicated cytotoxic activity against three cancer cell lines HepG2, MCF7 and A549 with the IC50 values of 60.96-69.93 µg/mL, while the twig oil inhibited MCF7 with the IC50 value of 66.70 µg/mL. Additionally, the twig oil successfully suppressed the growth of the negative Gram bacterium Pseudomonas aeruginosa, fungus Aspergillus niger, and yeast Candida albicans with the same MIC value of 50 µg/mL, whereas the leaf oil had the same result on the negative Gram bacterium Escherichia coli.