Glicoalcaloides antifúngicos, flavonoides e outros constituintes químicos de Solanum asperum

Two glycoalkaloids: solamargine and solasonine; three flavonoids: tiliroside, 7-O-α-L-ramnopyranosyl-kaempferol and 3-O-[ß-D-glucopyranosyl-(1→6)-α-L-ramnopyranosyl]-7- O-α-L-ramnopyranosyl-kaempferol, in addition to the tripeptide Leu-Ile-Val, the aminoacid proline and the eicosanoic acid were isolated from Solanum asperum (Solanaceae). The structures of all compounds were determined by interpretation of their spectra (IR, MS, ¹H and 13C NMR) and comparison with the literature data. All compounds, except the glycoalkaloids, are being reported for the first time for S. asperum. Solasonine showed strong activity (MIC < 0.24 μg/mL) against four filamentous fungi species of the genera Microsporum and Trichophyton.

Chemical composition, acetylcholinesterase inhibitory and antifungal activities of Pera glabrata (Schott) Baill. (Euphorbiaceae)

Pera glabrata (Schott) Baill. was selected for this study after showing a preliminary positive result in a screening of Atlantic Forest plant species in the search for acetylcholinesterase inhibitors and antifungal compounds. The bioassays were conducted with crude ethanol extract of the leaves using direct bioautography method for acetylcholinesterase and antifungal activities. This extract was partitioned with hexane, chloroform and ethyl acetate solvents. The active chloroform fraction was submitted to silica gel chromatography column affording 12 groups. Caffeine, an alkaloid, which showed detection limits of 0.1 and 1.0 µg for anticholinesterasic and antifungal activities, respectively, was isolated from group nine. After microplate analyses, only groups four, nine, 10, 11 and 12 showed acetylcholinesterase inhibitory activity of 40% or higher. The group 12 was purified by preparative layer chromatography affording four sub-fractions. Two sub-fractions from this group were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. The first sub-fraction showed anticholinesterasic activity and contained two major compounds: 9-hydroxy-4-megastigmen-3-one (84%) and caffeine (6%). The second sub-fraction presented five major compounds identified as 9-hydroxy-4-megastigmen-3-one, isololiolide, (-) loliolide, palmitic acid and lupeol and did not show activity.

Screening for antifungal activities of extracts of the brazilian seaweed genus Laurencia (Ceramiales, Rhodophyta)

The resistance of pathogens to commonly used antibiotics has enhanced morbidity and mortality and has triggered the search for new drugs. Several species of the red alga genus Laurencia are very interesting candidates as potential sources of natural products with pharmaceutical activity because they are known to produce a wide range of chemically interesting halogenated secondary metabolites. This is an initial report of the antifungal activities of the secondary metabolites of five species of Laurencia, collected in the state of Espírito Santo, against three strains of pathogenic fungi: Candida albicans (CA), Candida parapsilosis (CP), and Cryptococcus neoformans (CN). Minimum inhibitory concentrations (MIC) of the algal extracts were determined by serial dilution method in RPMI 1640 Medium in 96-well plates according to the NCCLS and microbial growth was determined by absorbance at 492nm. A result showing maintenance or reduction of the inoculum was defined as fungistatic, while fungicidal action was no observed growth in the 10 µL fungistatic samples subcultured in Sabouraud Agar. Our results indicate that apolar extracts of Laurencia species possess antifungal properties and encourage continued research to find new drugs for therapy of infectious diseases in these algae.

Antifungal activity of bacterial strains from the rhizosphere of Stachytarpheta crassifolia

This study evaluated the antifungal action of biomolecules produced from the secondary metabolism of bacterial strains found in the rhizosphere of semi arid plants against human pathogenic Candida albicans. Crude extracts were obtained using ethyl acetate as an organic solvent and the bioactivity was assessed with a bioautography technique. The results showed that bacterial strains, Alcaligenes faecalis MRbS12 and Bacillus cereus MRbS26, had compounds with antifungal bioactivity. The largest inhibition zones for both compounds were located on spots with Rf values below 0.500, indicating that the molecules possibly had polar characteristics. These results suggested that microorganisms found in the environment could have bioprospecting potential.

Composition and screening of antifungal activity against Cladosporium sphaerospermum and Cladosporium cladosporioides of essential oils of leaves and fruits of Piper species

This study investigated the composition and antifungal activity against Cladosporium sphaerospermum and Cladosporium cladosporioides of essential oils of leaves of Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper solmsianum and Piper umbelata and fruits of P. cernuum and P. diospyrifolium. The essentials oils were analyzed by GC-MS and submitted of the antifungal activity tests. The essential oils of fruits from P. cernuum and leaves of P. crassinervium and P. solmsianum showed potential antifungal activity against C. sphaerospermum and C. cladosporioides. In addition, this is the first report of the composition of essential oils of fruits of P. cernuum and P. diospyrifolium.

Alterations in growth and branching of Neurospora crassa caused by sub-inhibitory concentrations of antifungal agents

Six antifungal agents at subinhibitory concentrations were used for investigating their ability to affect the growth and branching in Neurospora crassa. Among the antifungals herein used, the azole agent ketoconazole at 0.5 mu g/ml inhibited radial growth more than fluconazole at 5.0 mu g/ml while amphotericin B at 0.05 mu g/ml was more effective than nystatin at 0.05 mu g/ml. Morphological alterations in hyphae were observed in the presence of griseofulvin, ketoconazole and terbinafine at the established concentrations. The antifungal agents were more effective on vegetative growth than on conidial germination. Terbinafine markedly reduced growth unit length (GU) by 54.89%, and caused mycelia to become hyperbranched. In all cases, there was a high correlation between hyphal length and number of tips (r > 0.9). All our results showed highly significant differences by ANOVA, (p < 0.001, alpha = 0.05). Considering that the hyphal tip is the main interface between the fungus and its environment/through which enzymes and toxins are secreted and nutrients absorbed, it would not be desirable to obtain a hyperbranched mycelia with inefficient doses of antifungal drugs.

Candida albicans and Candida tropicalis in Oral Candidosis: Quantitative Analysis, Exoenzyme Activity, and Antifungal Drug Sensitivity

Candida albicans and C. tropicalis obtained from whole saliva of patients presenting signs of oral candidosis were assayed for quantification of colony forming units, exoenzyme activity (phospholipase and proteinase) and antifungal drug sensitivity (amphotericin B, fluconazole and itraconazole) by the reference method of the Clinical and Laboratory Standards Institute. The number of colony forming units per milliliter varied according to the Candida species involved and whether a single or mixed infection was present. Proteinase activity was observed in both C. albicans and C. tropicalis, but phospholipase activity was noted only in C. albicans. In vitro resistance to antifungals was verified in both species, but C. tropicalis appears to be more resistant to the tested antifungals than C. albicans.

Trypanocidal, leislimanicidal and antifungal potential from marine red alga Bostrychia tenella J. Agardli (Rhodomelaceae, Ceraniiales)

Specimens of the red alga Bostrychia tenella J Agardh (Rhodomelaceae, Ceramiales) were collected from the Sao Paulo coast and submitted to loom temperature solvent extraction The resulting extract was fractionated by partitioning with organic solvent The n-hexane (BT-H) and dichloromethane (BT-D) fractions showed antiprotozoal potential in biological tests with Trypanosoma cruzi and Leishmania amazonensis and presented high activity in an antifungal assay with the phytopathogenic fungi Cladosporium cladosporioides and Cladosporium sphaerospermum Chromatography methods were used to generate subfractions from BT-H (H01 to H11) and from BT-D (D01 to 019) The subtractions were analyzed by gas chromatography-mass spectrometry (GC/MS). and the substances were identified by retention index (Kovats) and by comparison to databases of commercial mass spectra The volatile compounds found in marine algae were identified as fatty acids, low molecular mass hydrocarbons, esters and steroids, some of these have been previously described in the literature based on other biological activities Moreover, uncommon substances. such as neophytadiene were also identified In a trypanocidal assay, fractions BT-H and BT-D showed IC(50) values of 168 and 19 1 mu g/mL. respectively, and were mote active than the gentian violet standard (31 mu g/ml.); subfractions H02. H03, D01 and D02 were active against L amasonensis, exhibiting IC(50) values of 1 S. 2 7, 4 4. and 4 3 mu g/mL., respectively (standard amphotericin B IC(50) = 13 mu g/mL.) All fractions showed antifungal potential this work reports the biological activity and identification of compounds by GC/MS for the marine red alga B tenella for the first time (C) 2010 Elsevier B V All lights reserved

In Vitro Antifungal Activity and Toxicity of Itraconazole in DMSA-PLGA Nanoparticles

Itraconazole (ITZ) is a drug used to treat various fungal infections and may cause side effects. The aim of this study was to develop and evaluate the in vitro activity of DMSA-PLGA nanoparticles loaded with ITZ against Paracoccidioides brasiliensis, as well as their cytotoxicity. Nanoparticles were prepared using the emulsification-evaporation technique and characterized by their encapsulation efficiency, morphology (TEM), size (Nanosight) and charge (zeta potential). Antifungal efficacy in P brasiliensis was determined by minimal inhibition concentration (MIC), and cytotoxicity using MU assay. ITZ was effectively incorporated in the PLGA-DMSA nanoparticles with a loading efficiency of 72.8 +/- 3.50%. The shape was round with a solid polymeric structure, and a size distribution of 174 +/- 86 nm (Average +/- SD). The particles were negatively charged. ITZ-NANO presented antifungal inhibition (MIC = 6.25 ug/mL) against P brasiliensis and showed lower in vitro cytotoxicity than free drug (ITZ).

Seven-year trend analysis of nosocomial candidemia and antifungal (fluconazole and caspofungin) use in Intensive Care Units at a Brazilian University Hospital

Candidemia is associated with high morbidity and mortality resulting in significant increases in the length of patients` hospitalization and in healthcare costs. Critically ill patients are at particular risk for candidemia because of their debilitated condition and frequent need for invasive procedures. The aim of this study was to characterize the incidence and epidemiology of candidemia over a seven-year period in intensive care units (ICUs) and the use of fluconazole and caspofungin in a large university-affiliated hospital. All cases of candidemia were identified by surveillance, using the Centers for Diseases Control and Prevention criteria. Demographic variables, use of antifungal (fluconazole and caspofungin) and patient outcomes were evaluated. The 2 test for linear trend was employed to evaluate the distribution of Candida spp. and the use of fluconazole and caspofungin by defined daily dose (DDD) per 1,000 patients-days during the study period. One hundred and eight episodes of candidemia were identified. The overall incidence of candidemia (P=0.20) and incidence of non-Candida albicans Candida infections (P=0.32) remained stable over the study period and ranged from 0.3-0.9 episodes per 1,000 catheter-days and 0.39-0.83 episodes per 1,000 patients-days. However, the use of fluconazole and caspofungin increased significantly (P0.001). While there were no reports of the use of fluconazole for prophylaxis in 1999, its use for this purpose increased from 3% in 2000 to 7.0% (P=0.07) in 2006. C. albicans was the most frequent specie isolated and burns and cancer were the most frequent underlying conditions. The overall mortality was 76%. There was no difference between C. albicans and non-C. albicans Candida infections when the crude and 14-day mortality rates were compared. Our data demonstrated that C. albicans is still the most frequent species causing candidemia in our intensive care units. Our rates of candidemia are lower than those reported from the region and similar to American and European hospitals. Although the incidence of blood stream infections (BSI) and candidemia remained stable, the use of fluconazole and caspofungin increased significantly over the years included in this study but had no impact on the incidence of infections caused by non-C. albicans Candida species.

In vitro antifungal drug susceptibilities of dermatophytes microconidia and arthroconidia

Objectives: Arthroconidia have been considered as the primary cause of infection by dermatophytes. However, the in vitro antifungal testing evaluates the responses mainly of microconidia or hyphae, and dermatophytes in vivo often produce arthroconidia, a cellular structure presumably more resistant to antifungals. The aim of this study was to compare the in vitro susceptibility of microconidia and arthroconidia of Trichophyton rubrum, Trichophyton tonsurans and Trichophyton equinum to griseofulvin, itraconazole, terbinafine, fluconazole, amphotericin B and hygromycin B. Methods: Microconidia and arthroconidia were produced in vitro, and their susceptibility to each drug was evaluated by assessing the CLSI M38-A broth microdilution method. Results: Arthroconidia of all strains analysed appeared to be more resistant to fluconazole, griseofulvin and itraconazole than microconidia. The MIC of terbinafine was the same for microconidia and arthroconidia for all strains, and the MIC of amphotericin B for microconidia and arthroconidia was the same for isolates of T. equinum and T. tonsurans, but differed for T. rubrum. Finally, the level of resistance of microconidia for all strains towards the antibiotic hygromycin B was from 25 to 400 mg/L. Conclusions: The difference in the susceptibility between microconidia and arthroconidia depends on the drug and on the strain, and may be one of the causes of therapeutic failure. Also, the level of resistance to the antibiotic hygromycin B presented by microconidia of these isolates will allow the use of hygromycin resistance as a dominant marker in fungal transformation procedures in future studies of gene function.

Antifungal Resistance Mechanisms in Dermatophytes

Although fungi do not cause outbreaks or pandemics, the incidence of severe systemic fungal infections has increased significantly, mainly because of the explosive growth in the number of patients with compromised immune system. Thus, drug resistance in pathogenic fungi, including dermatophytes, is gaining importance. The molecular aspects involved in the resistance of dermatophytes to marketed antifungals and other cytotoxic drugs, such as modifications of target enzymes, over-expression of genes encoding ATP-binding cassette (ABC) transporters and stress-response-related proteins are reviewed. Emphasis is placed on the mechanisms used by dermatophytes to overcome the inhibitory action of terbinafine and survival in the host environment. The relevance of identifying new molecular targets, of expanding the understanding about the molecular mechanisms of resistance and of using this information to design new drugs or to modify those that have become ineffective is also discussed.

Antifungal alkyl amino alcohols from the tropical marine sponge Haliclona n. sp.

Three new amino alcohols presumably deriving from L-alanine were isolated from the tropical marine sponge Haliclona n. sp. and characterized by 2D NMR, while a fourth amino alcohol was characterized as an acetamide derivative. Relative stereochemistry was deduced from the NMR characteristics of oxazolidinone derivatives and absolute stereochemistry secured by preparation and analysis of an MPA ester. The amino alcohol fraction from Haliclona n. sp, acts as an antifungal agent and inhibits the development of larvae of the ascidian Herdmania curvata.

Antifungal activity of Imidazolidin-4-ones of the antimalarial primaquine

The 5-Isopropyl-3-[4-(6-methoxy-quinolin-8-ylamino)-pentyl]-2,2-dimethyl-imidazolidin-4-one (ValPQacet) was sinthesized through acylation of the anti-malarial primaquine with α-valine and subsequent reaction of the resulting -aminoamide with propanone (Sheme 1).Imidazolidin-4-ones of the anti malarial primaquine are being sinthesized to develop new variants in order to improve more effective treatments against malaria . Recently it has been observed that primaquine derivates could have effect in a new kind of yeast . To study the fungicidal activity against Candida albicans, Candida tropicalis, Issatchenkia orientalis, Sacharomyces cerevisae, the ValPQacet was put in the form of the hydrochloride salt. The minimal inhibitory concentration (MIC) could be determined for all yeast in the concentration range assayed. Also was determined MIC’s of primaquine hydrochloride salt for all yeast, and this shows that the parent drug is less active than our compound. Further studies are being performed to determine viability and cellular injury with this drugs.