scholarly journals Advances in synthetic approach to and antifungal activity of triazoles

2011 ◽  
Vol 7 ◽  
pp. 668-677 ◽  
Author(s):  
Kumari Shalini ◽  
Nitin Kumar ◽  
Sushma Drabu ◽  
Pramod Kumar Sharma

Several five membered ring systems, e.g., triazole, oxadiazole dithiazole and thiadiazole with three heteroatoms at symmetrical or asymmetrical positions have been studied because of their interesting pharmacological properties. In this article our emphasis is on synthetic development and pharmacological activity of the triazole moiety which exhibit a broad spectrum of pharmacological activity such as antifungal, antibacterial, anti-inflammatory and anticancer etc. Triazoles have increased our ability to treat many fungal infections, for example, candidiasis, cryptococcal meningitis, aspergillosis etc. However, mortality due to these infections even with antifungal therapy is still unacceptably high. Therefore, the development of new antifungal agents targeting specific fungal structures or functions is being actively pursued. Rapid developments in molecular mycology have led to a concentrated search for more target antifungals. Although we are entering a new era of antifungal therapy in which we will continue to be challenged by systemic fungal diseases, the options for treatment will have greatly expanded.

2019 ◽  
Vol 85 (9) ◽  
Author(s):  
Xiaodan Li ◽  
Yikui Li ◽  
Ren Wang ◽  
Qizhi Wang ◽  
Ling Lu

ABSTRACTFungal infections not only cause extensive agricultural damage but also result in serious diseases in the immunodeficient populations of human beings. Moreover, the increasing emergence of drug resistance has led to a decrease in the efficacy of current antifungals. Thus, screening of new antifungal agents is imperative in the fight against antifungal drug resistance. In this study, we show that an endophytic bacterium,Burkholderia gladioliHDXY-02, isolated from the medicinal plantLycoris aurea, showed broad-spectrum antifungal activity against plant and human fungal pathogens. An antifungal ability assay indicated that the bioactive component was produced from strain HDXY-02 having an extracellular secreted component with a molecular weight lower than 1,000 Da. In addition, we found that this new antifungal could be produced effectively by liquid fermentation of HDXY-02. Furthermore, the purified component contributing to the antifungal activity was identified to be toxoflavin, a yellow compound possessing a pyrimido[5,4-e][1,2,4]triazine ring.In vitrobioactivity studies demonstrated that purified toxoflavin fromB. gladioliHDXY-02 cultures had a significant antifungal activity against the human fungal pathogenAspergillus fumigatus, resulting in abolished germination of conidia. More importantly, the growth inhibition by toxoflavin was observed in both wild-type and drug-resistant mutants (cyp51Aand non-cyp51A) ofA. fumigatus. Finally, an optimized protocol for the large-scale production of toxoflavin (1,533 mg/liter) has been developed. Taken together, our findings provide a promising biosynthetic resource for producing a new antifungal reagent, toxoflavin, from isolates of the endophytic bacteriumB. gladioli.IMPORTANCEHuman fungal infections are a growing problem associated with increased morbidity and mortality. Moreover, a growing number of antifungal-resistant fungal isolates have been reported over the past decade. Thus, the need for novel antifungal agents is imperative. In this study, we show that an endophytic bacterium,Burkholderia gladioli, isolated from the medicinal plantLycoris aurea, is able to abundantly secrete a compound, toxoflavin, which has a strong fungicidal activity not only against plant fungal pathogens but also against human fungal pathogensAspergillus fumigatusandCandida albicans,Cryptococcus neoformans, and the model filamentous fungusAspergillus nidulans. More importantly, toxoflavin also displays an efficacious inhibitory effect against azole antifungal-resistant mutants ofA. fumigatus. Consequently, our findings provide a promising approach to abundantly produce toxoflavin, which has novel broad-spectrum antifungal activity, especially against those currently problematic drug-resistant isolates.


2020 ◽  
Vol 63 (2) ◽  
pp. 7-17
Author(s):  
Evelyn Rivera-Toledo ◽  
Alan Uriel Jiménez-Delgadillo ◽  
Patricia Manzano-Gayosso

The first compounds with specific antifungal activity were identified in the middle of the last century as a product of the secondary metabolism of bacteria of the order Actinomycetales, and their clinical use significantly diminished the morbidity and mortality associated with severe fungal infections. Many of such biosynthetic compounds are characterized by a chemical polygenic structure, with a variable number of carbon-carbon double bonds. Currently, besides polygenic antimycotics, there are other antifungal agents, such as the azole compounds, that have less toxicity in patients; however, cases of therapeutic failure with such compounds have been documented, therefore, the use of polygenics is still the best alternative in such cases. This review presents data about the properties and applications of antifungal-polygenic compounds using amphotericin B as a model. Key words: Amphotericin B; antifungal polyenes; ergosterol


2015 ◽  
Vol 10 (4) ◽  
pp. 1934578X1501000
Author(s):  
Charlie Basset ◽  
Véronique Eparvier ◽  
Laila S. Espindola

The anti-fungal activity of 60 extracts from 15 tree species in the French Guiana rainforest against human and wood-rotting fungi was studied. In this way (+)-mopanol (1) was isolated from the ethyl acetate extract of Peltogyne sp. (Caesalpiniaceae) wood. This work demonstrated that (1) the natural durability of wood can indeed guide the search for antifungal agents, (2) that extracts selected in this bio-inspired process exhibit a broad spectrum of antifungal activity and (3) that the method allows for the isolation of strongly active antifungals.


1993 ◽  
Vol 13 (2_suppl) ◽  
pp. 380-382 ◽  
Author(s):  
A. Fabris ◽  
M. V. Pellanda ◽  
C. Gardin ◽  
A. Contestabile ◽  
R. Bolzonella

The authors have evaluated the pharmacokinetics of four antifungal agents used in the therapy of fungal peritonitis. Amphotericin B (Amph B) poorly diffuses from blood into peritoneal fluid, which Intraperitoneal administration induces severe abdominal pain. 5-Fluorocytosine (5FC) easily crosses peritoneum, but resistance may appear when the drug is used alone. Ketoconazole (K) poorly penetrates into peritoneal fluid, while Fluconazole (F), used per os or intraperitoneally, shows a good antifungal activity both in serum and In the peritoneal fluid. In conclusion, from a pharmacokinetic point of view, all the antifungal agents examined, perhaps with the exception of F, do not offer, when used alone, sufficient guarantees In curing peritonitis. Therefore, for treating fungal infections in CAPD, drug combinations such as AmphB + 5FC, K + 5FC or 5FC + F have to be used.


2006 ◽  
Vol 55 (7) ◽  
pp. 809-818 ◽  
Author(s):  
D. A. Enoch ◽  
H. A. Ludlam ◽  
N. M. Brown

Fungi are increasingly recognised as major pathogens in critically ill patients. Candida spp. and Cryptococcus spp. are the yeasts most frequently isolated in clinical practice. The most frequent filamentous fungi (moulds) isolated are Aspergillus spp., but Fusarium spp., Scedosporium spp., Penicillium spp., and Zygomycetes are increasingly seen. Several reasons have been proposed for the increase in invasive fungal infections, including the use of antineoplastic and immunosuppressive agents, broad-spectrum antibiotics, and prosthetic devices and grafts, and more aggressive surgery. Patients with burns, neutropenia, HIV infection and pancreatitis are also predisposed to fungal infection. The epidemiology and clinical features of fungal infections are reviewed, together with antifungal agents currently or soon to be available.


2020 ◽  
Author(s):  
Angelo Frei ◽  
A. Paden King ◽  
Gabrielle J. Lowe ◽  
Amy K. Cain ◽  
Francesca L. Short ◽  
...  

Resistance to currently available antifungal drugs has quietly been on the rise but overshadowed by the alarming spread of antibacterial resistance. There is a striking lack of attention to the threat of drug resistant fungal infections, with only a handful of new drugs currently in development. Given that metal complexes have proven to be useful new chemotypes in the fight against diseases such as cancer, malaria, and bacterial infections, it stands to reason to explore their possible utility in treating fungal infections. Herein we report a series of cobalt(III) Schiff base complexes with broad spectrum antifungal activity. Some of these complexes (1-3) show minimum inhibitory concentrations (MIC) in the low micro- to nanomolar range against a series of Candida and Cryptococcus yeasts. Additionally, we demonstrate that these compounds show no cytotoxicity against both bacterial and human cells. Finally, we report first in vivo toxicity data on these compounds in Galleria mellonella, showing that doses as high as 266 mg/kg are tolerated without adverse effects, paving the way for further in vivo studies of these complexes. <br>


2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Gina Wall ◽  
Jose L. Lopez-Ribot

ABSTRACT Fungal organisms are ubiquitous in nature, and progress of modern medicine is creating an expanding number of severely compromised patients susceptible to a variety of opportunistic fungal infections. These infections are difficult to diagnose and treat, leading to high mortality rates. The limited antifungal arsenal, the toxicity of current antifungal drugs, the development of resistance, and the emergence of new multidrug-resistant fungi, all highlight the urgent need for new antifungal agents. Unfortunately, the development of a novel antifungal is a rather long and expensive proposition, and no new classes of antifungal agents have reached the market in the last 2 decades. Drug repurposing, or finding new indications for old drugs, represents a promising alternative pathway to drug development that is particularly appealing within the academic environment. In the last few years, there has been a growing interest in repurposing approaches in the antifungal arena, with multiple groups of investigators having performed screenings of different repurposing libraries against different pathogenic fungi in search for drugs with previously unrecognized antifungal effects. Overall, these repurposing efforts may lead to the fast deployment of drugs with novel antifungal activity, which can rapidly bring benefits to patients, while at the same time reducing health care costs.


2008 ◽  
Vol 11 (2) ◽  
pp. 44 ◽  
Author(s):  
Mohsen Daneshtalab

Life-threatening fungal infections have increased dramatically in recent decades in immunocompromised patients. An estimated 40% of all deaths from hospital-acquired infections are due to infections caused by opportunistic fungi. The current treatment options are either causing serious toxicity, or becoming inactive against the drug-resistant fungal strains. Thus, the discovery and development of new antifungal agents that are economically feasible, have excellent therapeutic value, and address the problems of toxicity and species resistance is very important. We have recently designed and synthesized a series of chlorogenic acid-based peptidimimetics using structure-based methodology starting with cyclic peptides of the candin class of antifungals. These novel and totally synthetic compounds exhibit promising antifungal activity against pathogenic fungi with very low toxicity against brine shrimps. The possible novelty in their mechanism of action and economically feasible synthetic approach are the attractive features of this class of compounds that make them different from the already utilized antifungal agents.


Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 354 ◽  
Author(s):  
Hilania Valéria Dodou Lima ◽  
Carolina Sidrim de Paula Cavalcante ◽  
Gandhi Rádis-Baptista

Venoms from ants comprise a rich source of bioactive peptides, including antimicrobial peptides. From the proteome and peptidome of the giant ant Dinoponera quadriceps venom, members of five known classes of antimicrobial peptides were disclosed (e.g., dermaseptin-, defensin-, ICK-, pilosulin- and ponericin-like types). Based on comparative analysis, these family members have structural determinants that indicate they could display antimicrobial activities. In previous works, pilosulin- and ponericin-like peptides were demonstrated to be active against bacteria, fungi, and parasites. Herein, the antifungal activity of ponericin- and pilosulin-like peptides were assessed, aiming at the expansion of the knowledge about AMPs in predatory ants and the development of new microbicide strategies to deal with difficult-to-treat fungal infections. Synthetic pilosulin- (Dq-2562, Dq-1503, and Dq-1319) and ponericin-like (Dq-3162) peptides were evaluated for their fungicide and fungistatic activities against different species of Candida, including a drug-resistant clinical strain. The MICs and MLCs were determined for all peptides individually and in combination with general antifungal drugs by the microdilution method. The time-kill kinetic curves were set up by means of a luminescent reagent, of which the light signal is proportional to the number of viable cells. The candicidal synergism observed by the combination of subinhibitory concentrations of peptides and general antimycotic drugs were quantified by the checkerboard test and fluorescent dye permeation assay. The influence of ergosterol on the antifungal activity was verified by supplementation of culture medium. The pilosulin- (Dq-2562 and Dq-1503) and ponericin-like (Dq-3162) were the most active peptides, displaying a broad spectrum of antifungal activity in vitro, with MICs in the range of 0.625 to 10 µM. The combination of peptides and conventional antimycotic drugs displayed a synergistic reduction in the MIC values of individual peptides and drugs, while soluble ergosterol in the culture medium increased the MICs. The fungicide and fungistatic activity of the individual peptides and peptides in combination with antimycotics were time-dependent with a rapid onset of action and long-lasting effect, which involved membrane disruption as an underlying mechanism of their action. Altogether, pilosulin- and ponericin-like peptides from the giant ant D. quadriceps venom display a broad-spectrum of candicidal activity, what allows their inclusion in the row of the antifungal peptides and gives support for further studies on the development of strategies to fight candidiasis.


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