Promising Antifungal Activity Research Articles

Isolation of endophytic fungi from South African plants, and screening for their antimicrobial and extracellular enzymatic activities and presence of type I polyketide synthases

Endophytes are bacteria or fungi which live inside the host plant and participate in many biological processes without causing disease or other adverse effects. Endophytes are recognised as a rich source of secondary metabolites with potentially useful pharmacological properties. Many South African medicinal plants are highly under-investigated sources of potentially useful endophytic microbes. In this report six endophytic fungi were obtained from the leaves, stems and roots of South African medicinal plants which are known for their traditional uses and pharmacological properties. The endophytic fungi were isolated from Cotyledon orbiculata L., Psychotria zombamontana (Kuntze) Petit, Tecomaria capensis (Thunb.) Lindl., Catha edulis (Vahl) Endl. and Melianthus comosus Vahl. The crude extracts of the isolated endophytic fungi were investigated for their antimicrobial potential, extracellular enzymatic activity and phosphate solubilization. Additionally, the present study used genetic screening to assess the ability of the endophytic fungi to synthesize bioactive compounds, indicated by the presence of the polyketide synthase type 1 (PKS 1) gene. In preliminary microbial inhibition screening the fungal extracts had promising antifungal activity against Cryptococcus neoformans and Candida albicans. Furthermore, the endophytic fungus Talaromyces funiculosus displayed extracellular enzymatic activity, namely xylanase and cellulase. Five fungal strains demonstrated ability to solubilize phosphate and three strains demonstrated the presence of polyketide synthase type 1 (PKS 1) gene. It is worth considering further investigation of their bioactive secondary metabolites.

Synthesis and Biological Evaluation of Novel Carbazole Hybrids as Promising Antimicrobial Agents.

Two series of carbazole analogs of 8-methoxy-N-substituted-9H-carbazole-3-carboxamides (series 1) and carbazolyl substituted rhodanines (series 2) were synthesized through facile synthetic routes. All the final compounds from these two series were evaluated for their preliminary in vitro antifungal and antibacterial activity against four fungal (Candida albicans, Cryptococcus neoformans, Cryptococcus tropicalis and Aspergillus niger) and four bacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) strains, respectively. Among the tested compounds, three compounds of series 1 displayed promising antifungal and antibacterial activity, especially against C. neoformans and S. aureus. In addition, one compound of series 1 displayed notable antimicrobial activity (MIC: 6.25 μg/mL) against clinical isolates of C. albicans and C. neoformans (MIC: 12.5 μg/mL). From the second series, four compounds exhibited significant antifungal and antibacterial activity, especially against C. neoformans and S. aureus. The most active compound of series 2 displayed a prominent antimicrobial activity against C. neoformans (MIC: 3.125 μg/mL) and S. aureus (MIC: 1.56 μg/mL), respectively.

Stability assay of antagonistic activity of Serratia plymuthica strain UBCR_12 under various environmental factors

Serratia plymuthica strain UBCR_12 exhibited promising antifungal activity against Colletotrichum gloeosporioides. The development of this strain for field use requires a certain level of stability towards various environmental exposures that might occur in the natural condition. This study was aimed to evaluate the stability level of antifungal activity produced by the culture supernatants of S. plymuthica strain UBCR_12 under several environmental factors. Antifungal assay of this strain was performed through the application of culture supernatants under several parameters and was performed in five technical replications. Data were confirmed statistically using one-way and two-way ANOVA and significance among treatments were verified through DNMRT with a p<0.05. The antagonistic effect of this strain varied in each environmental parameter tested. The highest suppression was recorded at pH 8.0 [30.32%] after eight days of application indicating that the alkaline condition might trigger its defense mechanism. Other parameters showed quite similar inhibition efficacy, such as 24.06% [100 C for 45 minutes] and 21.15% [CaCl2 addition]. Compared to control, this strain could suppress anthracnose-causing fungi up to 24.06% suggesting that its antifungal activity was considered as quite stable over the presence of heat and calcium.

An analysis of spectroscopic, computational and biological activity studies of L-shaped sulfamoylbenzoic acid derivatives: A third order nonlinear optical material

The current article focuses mainly on investigation of structural, reactivity, topology studies, and third order nonlinear optical properties of the synthesized 2-(benzylamino)-4-chloro-5-sulfamoylbenzoic acid (BACSBA) with the aid of spectroscopic techniques and computational methods. The structure in the solid state was obtained unambiguously by SCXRD study that revealed that BACSBA has L-shaped structure stabilized by N–H⋯O intramolecular hydrogen bond. Further, the two dimensional sheet like architecture formation by linking of molecules via O–H⋯O and N–H⋯O hydrogen bonds, were visualized both qualitatively and quantitatively by Hirshfeld surface analysis. Also, a topological analysis made through Quantum Theory of Atoms In Molecules (QTAIM) highlights the observations N–H⋯O bonds on solid state. The quantum chemical calculation was performed at DFT/6–311++G (d,p) level of basis set. The analysis of each vibrational wave number was performed with the help of potential energy distribution (PED) using VEDA4 software and correlation with experimental data shows good concurrence. The reactive sites have been predicted and visualized by molecular electrostatic surface potential (MESP) and Fukui function calculation, together with hydrogen bond dissociation energy (H-BDE) for the BACSBA compound. Frontier molecular orbitals (FMO), global reactivity parameters, natural bond orbital analysis (NBO), localized orbital locator (LOL) and electron localization function (ELF) properties have also been studied for the titled compound. The super molecule (SM) approach with 372,680 atoms at the DFT/CAM-B3LYP/6–311++G (d,p) level was used for calculating the nonlinear optical properties of the crystal. The electrical parameters such as total dipole moment, average linear polarizability and average second IDRI hyperpolarizability were calculated. In addition, the linear refractive index and the nonlinear third order macroscopic susceptibility of the crystal was estimated as a function of the frequency of the applied electric field. The value of third order nonlinear susceptibility for the BACSBA crystal at 532 nm was found to be 45.57 times greatest than the experimentally measured result of organic crystal (2E)-1-(3-bromophenyl)-3-[4 (methylsulfanyl)phenyl]prop-2-en-1-one (3Br4MSP) demonstrating that BACSBA crystal could be a good potential candidate for nonlinear optical applications. In addition, the thermal stability was studied showing that the crystal as potential optical devices at temperature up to 234 °C. Furthermore, preliminary studies revealed that BACSBA compound displayed promising antifungal and antioxidant activities compared with the standard drugs.

Thiophene-thiosemicarbazone derivative (L10) exerts antifungal activity mediated by oxidative stress and apoptosis in C. albicans

Reactive oxygen species (ROS) cause cell damage and death. To reverse these effects, cells produce substances such as reduced glutathione (GSH) that serve as substrates for antioxidant enzymes. One way to combat microbial resistance includes nullifying the effect of glutathione in microbial cells, causing them to die from oxidative stress. The compound 2-((5-nitrothiophen-2-yl)methylene)-N-(pyridin-3-yl) hydrazine carbothioamide (L10) is a new thiophene-thiosemicarbazone derivative with promising antifungal activity. The aim of this study was to evaluate its mechanism of action against Candida albicans using assays that evaluate its effects on redox balance. Treatment with L10 promoted significant changes in the minimum inhibitory concentration (MIC) values in ascorbic acid and GSH protection tests, the latter increasing up to 64-fold of the MIC. Using nuclear magnetic resonance, we demonstrated interaction of L10 and GSH. At concentrations of 4.0 and 8.0 μg/mL, significant changes were observed in ROS production and mitochondrial membrane potential. The cell death profile showed characteristics of initial apoptosis at inhibitory concentrations (4.0 μg/mL). Transmission electron microscopy data corroborated these results and indicated signs of apoptosis, damage to plasma and nuclear membranes, and to mitochondria. Taken together, these results suggest a possible mechanism of action for L10 antifungal activity, involving changes in cellular redox balance, ROS production, and apoptosis-compatible cellular changes.

Ethnomedicinal Uses, Phytochemistry and Pharmacological Activities of Pittosporum floribundum Wight. &amp; Arn. – A Review

Objectives: Pittosporum floribundum Wight &amp; Arn. (Pittosporaceae) has been associated with many therapeutic claims, especially for its ethnomedicinal and economical uses. In this review, an extensive literature survey was carried out to compile information available about its medicinal uses, phytochemistry and pharmacological properties.&#x0D; Materials and Methods: Ethnobotanical uses of P. floribundum reported in available books on ethnobotany and ethnomedicinal research articles have been compiled. The obtained data are arranged in a tabular form, enlisting its local names, their area of presence and parts used. Therapeutic indications, external or internal dosage form and usage of the drug are also noted.&#x0D; Results and Discussion: It was found that stem bark, leaves, and root of P. floribundum are used to combat itching, rheumatism, leprosy, sprain, eczema, arthritis, diabetes, chest pain and antidote for snake bite. Bark has maximum applications in leprosy, and sprain. The extracts of the different parts were subjected to phytochemical screening for the presence of phytoconstituents such as alkaloids, flavonoids, phenols, lignins, anthroquinones, steroids, tannins, saponins, fixed oils and glycosides. Studies have shown that the methanolic extract of bark having promising antifungal, antibacterial, anti-inflammatory, antioxidant, hepatoprotective, neuropharmacological and behaviour activities.&#x0D; Conclusion: P. floribundum has multifaceted uses in varied aspects thus underlining its significance. Reported claimed anti-bacterial and anti-oxidant activities can be further strengthened through pharmacological and clinical studies to establish the ethnic claims like leprosy, sprain, bruises, sciatica, pulmonary affection and phthisis.

Synthesis of amide‐linked benzazolyl isoxazoles adopting green methods and evaluation as antimicrobials

AbstractSome new benzoxazolyl isoxazoles, benzothiazolyl isoxazoles and benzimidazolyl isoxazoles connected by amide bonds (7‐9) were prepared from N‐benzazolylcarbamoylmethylcinnamamides (1‐3) adopting eco‐friendly synthetic methodologies. In fact, cycloaddition of nitrile oxide generated from araldoxime using iodosobenzene and cetyltrimethylammonium bromide to 1‐3 followed by treatment with iodine in dimethyl sulfoxide led to the formation of title compounds with good yields and in shorter reaction times. The structures of all the synthesized compounds were confirmed by spectral parameters, viz, IR, NMR, and mass spectra and were assayed for antimicrobial activity. Among all the tested compounds, 8a and 8c displayed excellent antibacterial activity, whereas 9a and 9c showed promising antifungal activity.

Design, Synthesis, and Antimicrobial Activities of 1,2,3-Triazole Glycoside Clickamers.

Bacterial resistance remains a significant threat and a leading cause of death worldwide, despite massive attempts to control infections. In an effort to develop biologically active antibacterial and antifungal agents, six novel aryl-substituted-1,2,3-triazoles linked to carbohydrate units were synthesized through the Cu(I)-catalyzed azide-alkyne cycloaddition CuAAC of substituted-arylazides with a selection of alkyne-functionalized sugars. The chemical structures of the new derivatives were verified using different spectroscopic techniques. The novel clicked 1,2,3-triazoles were evaluated for in vitro antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa, and the obtained results were compared with the activity of the reference antibiotic “Ampicillin”. Likewise, in vitro antifungal activity of the new 1,2,3-triazoles was investigated against Candida albicans and Aspergillus niger using “Nystatin” as a reference drug. The results of the biological evaluation pointed out that Staphylococcus aureus was more susceptible to all of the tested compounds than other examined microbes. In addition, some tested compounds exhibited promising antifungal activity.

Induction of Cryptic Antifungal Pulicatin Derivatives from Pantoea agglomerans by Microbial Co-Culture.

Microbial co-culture or mixed fermentation proved to be an efficient strategy to expand chemical diversity by the induction of cryptic biosynthetic pathways, and in many cases led to the production of new antimicrobial agents. In the current study, we report a rare example of the induction of silent/cryptic bacterial biosynthetic pathway by the co-culture of Durum wheat plant roots-associated bacterium Pantoea aggolomerans and date palm leaves-derived fungus Penicillium citrinum. The initial co-culture indicated a clear fungal growth inhibition which was confirmed by the promising antifungal activity of the co-culture total extract against Pc. LC-HRMS chemical profiling demonstrated a huge suppression in the production of secondary metabolites (SMs) of axenic cultures of both species with the emergence of new metabolites which were dereplicated as a series of siderophores. Large-scale co-culture fermentation led to the isolation of two new pulicatin derivatives together with six known metabolites which were characterised using HRESIMS and NMR analyses. During the in vitro antimicrobial evaluation of the isolated compounds, pulicatin H (2) exhibited the strongest antifungal activity against Pc, followed by aeruginaldehyde (1) and pulicatin F (4), hence explaining the initial growth suppression of Pc in the co-culture environment.

Quinoline Based Monocarbonyl Curcumin Analogs as Potential Antifungal and Antioxidant Agents: Synthesis, Bioevaluation and Molecular Docking Study.

In search for new fungicidal and free radical scavenging agents, we synthesized a focused library of 2-chloroquinoline based monocarbonyl analogs of curcumin (MACs). The synthesized MACs were evaluated for in vitro antifungal and antioxidant activity. The antifungal activity was evaluated against five different fungal strains such as Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger, and Cryptococcus neoformans, respectively. Most of the synthesized MACs displayed promising antifungal activity compared to the standard drug Miconazole. Furthermore, molecular docking study on a crucial fungal enzyme sterol 14α-demethylase (CYP51) could provide insight into the plausible mechanism of antifungal activity. MACs were also screened for in vitro radical scavenging activity using butylated hydroxytoluene (BHT) as a standard. Almost all MACs exhibited better antioxidant activity compared to BHT.

Promising antifungal activity of new oxadiazole against Candida krusei.

Candida krusei is one of the most common agents of invasive candidiasis and candidemia worldwide, leading to high morbidity and mortality rates. This species has become a problem due to its intrinsic resistance and reduced susceptibility to azoles and polyenes. Moreover, the number of antifungal drugs available for candidiasis treatment is limited, demonstrating the urgent need for the discovery of novel alternative therapies. In this work, the in vivo and in vitro activities of a new oxadiazole (LMM11) were evaluated against C. krusei. The minimum inhibitory concentration ranged from 32 to 64 μg/mL with a significant reduction in the colony forming unit (CFU) count (~3 log10). LMM11 showed fungicidal effect, similar to amphotericin, reducing the viable cell number (>99.9%) in the time-kill curve. Yeast cells presented morphological alterations and inactive metabolism when treated with LMM11. This compound was also effective in decreasing C. krusei replication inside and outside macrophages. A synergistic effect between fluconazole and LMM11 was observed. In vivo treatment with the new oxadiazole led to a significant reduction in CFU (0.85 log10). Furthermore, histopathological analysis of the treated group exhibited a reduction in the inflammatory area. Taken together, these results indicate that LMM11 is a promising candidate for the development of a new antifungal agent for the treatment of infections caused by resistant Candida species such as C. krusei.

Antifungal activity of successive extracts of Citrus limon peel for an antidandruff shampoo formulation

The peel of Citrus limon which is a rich source of acid contents had been identified as the potential anti-fungal as well as anti-dandruff agent. This study was aimed to focus on determining the best solvent responsible for extraction of maximum active anti-fungal constituents. Defatted peel powder of C. limon was successively extracted with chloroform, ethanol and water using Soxhlet extractor. Phytochemical tests were done for all extracts. The anti-fungal activity against Candida albicans of all extracts was determined using well diffusion methods at three concentrations: 50, 100 & 200mg/mL followed by minimum inhibition concentration (MIC) determination using well dilution method. The extract showing best anti-fungal activity was chosen for formulation and evaluation. Flavonoids presence in all extracts while ethanol is considered as the optimal solvent to obtain various phytochemical constituents. The ethanolic extract exhibited the highest anti-fungal activity (MIC=6.25mg/mL) when compared to other extracts (MIC≥25mg/mL). All extract showed antifungal activity with zone of inhibition (ZOI) ranging from 7.00–19.67mm while ethanolic extract demonstrated the highest ZOI (19.67±0.09mm) at 200mg/mL. Analysis carried out using one-way ANOVA indicated no significant different between extracts and standard (p>0.05) when compared individually at all concentrations except for petroleum ether extract. The promising anti-fungal activity from ethanolic extract was due to the presence of various secondary metabolites.

Synthesis, Reactions, and Antimicrobial Activity of Novel Heterocyclic Compounds Containing Cyclopenta[d]thieno[2,3-b]pyridine Moiety and Related Fused Heterocycles

We describe a simple method to synthesize novel 4-cyano-1-morpholin-4-yl-6,7-dihydro-5H-cyclopenta[c]pyridine-3-thione by the reaction of 3-amino-1-thioxo-1,5,6,7-tetrahydrocyclopenta[c]thiopyran-4-carbonitrile with morpholine through Dimroth rearrangement. The 1-amino-5-morpholin-4-yl-7,8-dihydro-6H-cyclopenta[d]thieno[2,3-b]pyridine-2-carboxamide, which was synthesized by two methods, was used as a versatile precursor for synthesis of new thienopyrimidines fused to cyclopenta[d]pyridine ring system. Consequently, reaction of the amino-carboxamide with diethylmalonate, triethyl orthoformate, and cycloalkanones afforded the corresponding fused pyrimidine heterocycles. On the other hand, chloroacetylation of the amino-carboxamide using chloroacetyl chloride in dioxane produced the chloroacetyl amino derivative that in turn underwent cyclocondensation upon reaction with acetic anhydride to give the chloromethyl pyrimidinone. The latter compound was subjected to react with various nitrogen nucleophiles by nucleophilic substitution reactions to yield the akyl (aryl)amino methyl pyrimidinones. Subsequently, treatment of the phenyl aminomethyl derivative with formaldehyde under Mannich conditions produced the imidazopyridothienopyrimidine ring system. Similarly, reaction of the phenyl aminomethyl pyrimidonone with chloroacetyl chloride afforded a new heterocyclic system namely, cyclopentapyridothienopyrimidopyrazine. On the other hand, reaction of the amino-carboxamide with carbon disulfide in pyridine led to the formation of oxopyrimidine thione, which was alkylated by the reaction with different α-halo carbonyl compounds. The newly synthesized compounds were fully characterized on the basis of elemental and spectral analyses. Alternatively, some of these compounds revealed promising antibacterial and antifungal activities through the in vitro screening.

Synthesis of Nʹ-Nicotinoyl Sulfonohydrazides and their Antimicrobial Activity

Nʹ-Nicotinoyl sulfonohydrazide derivatives 3-13 were synthesized from nicotinyl hydrazide and evaluated for their antimicrobial potential against Gram positive bacterial strains (Bacillus cereus, Bacillus subtilis, Corynebacterium diphtheriae, Staphylococcus fecalis, Staphylococcus aureus, and MRSA (Methicillin-resistant Staphylococcus aureus)) and Gram negative bacterial strains (Escherichia.coli, Pseudomonas aeruginosa, Salmonella ParatyphiB, Salmonella tyhpi). Compound 13 showed outstanding antibacterial activity against Staphylococcus fecalis and compounds 7 and 13 were found to be moderately activite against Salmonella Paratyphi B, shown by their zone of inhibition values. In addition to that compond 9 also showed moderate activity against Escherichia coli. All derivatives 3-13 were also subjected for the evaluation of their antifungal activity against Saccharomyces cerevisiae, Microsporum canin, Rhizopus, Aspergillus niger, Candida albicans, and Candida tropicalis. Compound 13 showed promising antifungal activity against Rhizopus sp. and compounds 9 and 10 showed moderate antifungal potential against Microsporum canis, Aspergillus niger, and Candida tropicalis. Other molecules demonstrated weak zone of inhibitions.

INCORPORATION OF ESSENTIAL OILS FROM Piper aduncum INTO FILMS MADE FROM ARROWROOT STARCH: EFFECTS ON THEIR PHYSICOCHEMICAL PROPERTIES AND ANTIFUNGAL ACTIVITY

Starch is a promising source of biopolymers and the incorporation of essential oils (EOs) into it can improve some biological properties of films. This study aimed at developing and characterizing barrier, biodegradability and optical properties of biopolymeric films made from arrowroot starch and at incorporating EOs from Piper aduncum leaves and inflorescences in order to analyze their antifungal activity against Rhizopus microsporus and Colletotrichum gloeosporioides. The casting method was used for developing arrowroot starch films and incorporating EOs into them. Resulting films exhibited satisfactory barrier properties, low water vapor permeability (WVP), transparency and good barrier property against UV-vis light, besides being 100% biodegradable. In addition, films enriched with EOs at 0.75% and 1.0% revealed promising antifungal activity. Results showed, for the first time, that arrowroot starch enriched with EOs from P. aduncum can potentially be used as an active film due to its excellent physicochemical properties and antimicrobial activity.

Synthesis of Nʹ-Nicotinoyl Sulfonohydrazides and their Antimicrobial Activity

Nʹ-Nicotinoyl sulfonohydrazide derivatives 3-13 were synthesized from nicotinyl hydrazide and evaluated for their antimicrobial potential against Gram positive bacterial strains (Bacillus cereus, Bacillus subtilis, Corynebacterium diphtheriae, Staphylococcus fecalis, Staphylococcus aureus, and MRSA (Methicillin-resistant Staphylococcus aureus)) and Gram negative bacterial strains (Escherichia.coli, Pseudomonas aeruginosa, Salmonella ParatyphiB, Salmonella tyhpi). Compound 13 showed outstanding antibacterial activity against Staphylococcus fecalis and compounds 7 and 13 were found to be moderately activite against Salmonella Paratyphi B, shown by their zone of inhibition values. In addition to that compond 9 also showed moderate activity against Escherichia coli. All derivatives 3-13 were also subjected for the evaluation of their antifungal activity against Saccharomyces cerevisiae, Microsporum canin, Rhizopus, Aspergillus niger, Candida albicans, and Candida tropicalis. Compound 13 showed promising antifungal activity against Rhizopus sp. and compounds 9 and 10 showed moderate antifungal potential against Microsporum canis, Aspergillus niger, and Candida tropicalis. Other molecules demonstrated weak zone of inhibitions.

Antifungal activity of silver salts of Keggin-type heteropolyacids against Sporothrix spp.

Sporotrichosis is a chronic and subacute mycosis causing epidemiological outbreaks involving sick cats and humans in southeastern Brazil. The systemic disease prevails in cats, and in humans, the symptoms are restricted to skin in immunocompetent individuals. Under these conditions, the prolonged treatment of animals and cases of recurrence justify the discovery of new treatments for sporotrichosis. This work addresses the antifungal activity of silver salts of Keggin-type heteropolyacid salts (Ag-HPA salts) such as Ag3[PW12O40], Ag6[SiW10V2O40], Ag4[SiW12O40] and Ag3[PMo12O40] and interactions with the antifungal drugs itraconazole (ITC), terbinafine (TBF) and amphotericin B (AMB) on the yeast and mycelia forms of Sporothrix spp. Sporothrix spp. yeast cells were susceptible to Ag-HPA salts at minimum inhibitory concentration (MIC) values ranging from 8 to 128 μg/mL. Interactions between Ag3[PW12O40] and Ag3[PMo12O40] with itraconazole and amphotericin B resulted in higher antifungal activity with a reduction in growth and melanization. Treated cells showed changes in cell membrane integrity, vacuolization, cytoplasm disorder, and membrane detachment. Promising antifungal activity for treating sporotrichosis was observed for the Ag-HPA salts Ag3[PMo12O40] and Ag3[PW12O40], which have a low cost, high yield and activity at low concentrations. However, further evaluation of in vivo tests is still required.

Pharmacokinetic evaluation of fulvic acid-ketoconazole complexes: A validation and line extension study

Poor aqueous solubility and bioavailability of the drugs is the major impediment in the field of drug development. Amongst the various solubility enhancing techniques, complexation of the ketoconazole with the peat sourced fulvic acid was adopted in the current study. Phase solubility study revealed that at 4%w/v of fulvic acid, maximum amount of drug gets entrapped. Further the complex of fulvic acid with ketoconazole was prepared in a molar ratio of 1:1 (w/w) by freeze drying method and characterized by differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and Fourier Transforms Infra-Red Spectroscopy (FT-IR). All these studies confirm the formation of an amorphous inclusion complex. Phase solubility study with fulvic acid indicates that maximum percentage increase in solubility of the KTZ was found to be 621 ± 2.3%, whereas with the Shilajit derived HA it was reported as 645.2%. In 60 min, 45% release was obtained with the pure drug, 82% with the peat sourced fulvic acid complexed drug and 81% with the shilajit derived humic acid complex. It was found that 68% of the pure drug and 95% of the complexed drug gets permeated across the intestinal gut sac whereas it is reported that with shilajit derived humic acid 3.7 times drug gets permeated. With the pure drug Cmax, tmax and AUC was found to be as 2.64 µg/ml, 0.5 h and 7.39 µg/ml*h, whereas with the complexed drug Cmax, tmax and AUC was found to be as 5.1 µg/ml, 1.0 h and 15.51 µg/ml*h.Antifungal study conducted on Candida albicans and Tricophytonrubrum indicates that the fulvic acid alone does not have promising anti-fungal activity but when complexed with KTZ, it enhances the antifungal activity of the pure drug. Hence it can be concluded that peat sourced derived fulvic acid can be used as a promising complexing agent for enhancing the solubility and bioavailability of the ketoconazole.

Transcriptional Profiling of Diffusible Lipopeptides and Fungal Virulence Genes During Bacillus amyloliquefaciens EZ1509-Mediated Suppression of Sclerotinia sclerotiorum.

Sclerotinia sclerotiorum is a devastating necrotrophic pathogen that infects multiple crops, and its control is an unremitting challenge. In this work, we attempted to gain insights into the pivotal role of lipopeptides (LPs) in the antifungal activity of Bacillus amyloliquefaciens EZ1509. In a comparative study involving five Bacillus strains, B. amyloliquefaciens EZ1509 harboring four LPs biosynthetic genes (viz. surfactin, iturin, fengycin, and bacilysin) exhibited promising antifungal activity against S. sclerotiorum in a dual-culture assay. Our data demonstrated a remarkable upsurge in LPs biosynthetic gene expression through quantitative reverse transcription PCR during in vitro interaction assay with S. sclerotiorum. Maximum upregulation in LPs biosynthetic genes was observed on the second and third days of in vitro interaction, with iturin and fengycin being the highly expressed genes. Subsequently, Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry analysis confirmed the presence of LPs in the inhibition zone. Scanning electron microscope analysis showed disintegration, shrinkage, plasmolysis, and breakdown of fungal hyphae. During in planta evaluation, S. sclerotiorum previously challenged with EZ1509 showed significant suppression in pathogenicity on detached leaves of tobacco and rapeseed. The oxalic acid synthesis was also significantly reduced in S. sclerotiorum previously confronted with antagonistic bacterium. The expression of major virulence genes of S. sclerotiorum, including endopolygalacturonase-3, oxalic acid hydrolase, and endopolygalacturonase-6, was significantly downregulated during in vitro confrontation with EZ1509.

Sertraline as a promising antifungal agent: inhibition of growth and biofilm of Candida auris with special focus on the mechanism of action in vitro.

The aim of this present study was to investigate the antifungal mechanism of sertraline against Candida auris (C. auris) and its effect on biofilm formation. Sertraline, a repurposing drug with a history of human use for the treatment of depression was screened against three different isolates of C. auris, and was found to possess efficient antifungal activity. The antifungal activity of sertraline was further confirmed by killing kinetics assay and post-antifungal effect (PAFE). Sertraline inhibited C. auris yeast to hyphae conversion and further the inhibition of biofilm formation showed 71% inhibition upon treatment. Cell damage caused due to C. auris after treatment with sertraline was observed using SEM and cell membrane damage was ascertained using flow cytometry by Propidium Iodide (PI) uptake assay. The results of sorbitol protection assay and ergosterol effect assay suggested that sertraline did not affect the cell wall and did not act by binding to membrane ergosterol. The mechanism of action of sertraline against C. auris was understood through in silico docking studies that revealed the binding nature of sertraline to the sterol 14 alpha demethylase which is involved in ergosterol biosynthesis. Ergosterol that was quantified from treated cells showed a 5·5-fold decrease in ergosterol production. Sertraline displayed promising antifungal activity against C. auris involved in candidiasis infection and the mechanism of action was predicted. The results of this study can encourage for the development of new antifungal agents and can be promising antifungal agentagainst C. auris infection.