Antifungal agents from the roots of Cudrania cochinchinensis against Candida,Cryptococcus, and Aspergillus species

Bioassay-guided fractionation resulted in the isolation of four antifungal agents from the roots of Cudrania cochinchinensis. Two of these were new compounds, cudraxanthone S [1, 1,3,5,6-tetrahydroxy-2-(1,1-dimethyl-2-propenyl)xanthone] and cudraflavanone B (2, 2',4',5,7-tetrahydroxy-6-prenylflavanone). The remaining two compounds were known compounds, toxyloxanthone C (3) and wighteone (4). Among these compounds, 1, 3, and 4 exhibited antifungal activities against Cryptococcus neoformans, Aspergillusfumigatus, and A. nidulans (MICs = 2-8 microg/mL). Compounds 1 and 3 also showed antifungal activity against Candida glabrata (MICs = 4-8 microg/mL).     

Antimicrobial, anti-inflammatory, antiparasitic, and cytotoxic activities of Galium mexicanum

Ethnopharmacological relevance

To study the potential benefit of the traditional Mexican medicinal plant Galium mexicanum Kunth (Rubiaceae). Hexane, chloroform, and methanol extracts as well as various fractions from these extracts were tested to determine antibacterial, antifungal, antiparasitic or anti-inflammatory activities in vitro.

Materials and methods

Aerial parts of the plant were extracted with various solvents and fractionated accordingly. Their antibacterial and antifungal activities were assessed on nine bacterial and four fungal strains. Leishmania donovani was used as a protozoan strain for antiparasitic activity. The anti-inflammatory activity of the compounds was investigated by measuring the secretion of interleukin-6 when macrophages were exposed to lipopolysaccharide.

Results

Various extracts and fractions obtained from this plant exhibit antibacterial, antifungal, antiparasitic, and anti-inflammatory activities. Of special interest was the hexane fraction HE 14b, which show antibacterial (ranging between 67 and 666 μg/ml) and antifungal (at concentrations of 333 μg/ml) activities. Also the hexane fraction HE 5 exhibited antiparasitic activity (at concentrations of 260 μg/ml), whereas the methanol fraction ME 13-15 showed a potent anti-inflammatory activity when compared to dexamethasone. Chemical analyses of the chloroform extract show the presence of triterpenes, saponins, flavonoids, sesquiterpene lactones, and glucosides, but no tannins were detected in the assayed extract.

Conclusions

The benefit of Galium mexicanum as a traditional medicinal plant was confirmed using antibacterial and antifungal assays in vitro. We also report for the first time, and to the best of our knowledge, antiparasitic and anti-inflammatory activities of this plant.     

(2S,3R)-2-aminododecan-3-ol, a new antifungal agent from the ascidian Clavelina oblonga

A new antifungal agent, (2S,3R)-2-aminododecan-3-ol (1), has been isolated from the ascidian Clavelina oblonga collected in Brazil. The structure of 1 was established by analysis of spectroscopic data, including absolute stereochemistry determined by circular dichroism analysis of the dibenzoyl derivative 2. Compound 1 displayed antifungal activity against Candida albicans ATCC 10231 with a MIC of 0.7 mug/mL and against Candida glabrata with a MIC of 30 microg/mL.     

Fatty acid synthase inhibitors from plants: isolation,structure elucidation,and SAR studies

Fatty acid synthase (FAS) has been identified as a potential antifungal target. FAS prepared from Saccharomyces cerevisiae was employed for bioactivity-guided fractionation of Chlorophora tinctoria,Paspalum conjugatum, Symphonia globulifera, Buchenavia parviflora, and Miconia pilgeriana. Thirteen compounds (1-13), including three new natural products (1, 4, 12), were isolated and their structures identified by spectroscopic interpretation. They represented five chemotypes, namely, isoflavones, flavones, biflavonoids, hydrolyzable tannin-related derivatives, and triterpenoids. 3'-Formylgenistein (1) and ellagic acid 4-O-alpha-l-rhamnopyranoside (9) were the most potent compounds against FAS, with IC(50) values of 2.3 and 7.5 microg/mL, respectively. Furthermore, 43 (14-56) analogues of the five chemotypes from our natural product repository and commercial sources were tested for their FAS inhibitory activity. Structure-activity relationships for some chemotypes were investigated. All these compounds were further evaluated for antifungal activity against Candida albicans and Cryptococcus neoformans. Although there were several antifungal compounds in the set, correlation between the FAS inhibitory activity and antifungal activity could not be defined.     

Tetrin C, a new glycosylated polyene macrolide antibiotic produced by Streptomyces sp. GK9244.

A new antifungal 26-membered polyene macrolide, tetrin C (1), has been isolated from Streptomyces sp. GK9244. Its structure has been determined by interpretation of NMR data. Compound 1 exhibited antifungal activity against Mortierella ramannianus (MIC, 5 microg/mL).     

In vitro cytotoxic, antileishmanial and antifungal activities of ethnopharmacologically selected Gabonese plants

Seventy-seven crude extracts from leaves and stem barks of 15 Gabonese plants used in traditional medicine were evaluated for their cytotoxic, antileishmanial and antifungal activities. Most of the extracts exhibited cytotoxic activities toward human monocytes, and most particularly the hydromethanolic 50% (v/v) fraction of Ganophyllum giganteum leaves (IC(50)=1.3 microg/ml) as well as the methanolic extracts of Polyalthia suaveolens, Dioscorea preussii, Augouardia letestui leaves and Cola lizae stem barks (IC(50)<5 microg/ml). The methanolic extract of Polyalthia suaveolens displayed a strong antiproliferative activity against the promastigote form of Leishmania infantum parasites and presented a good antifungal activity on all the tested strains (IC(50)<1mg/ml). This extract was divided into six fractions: fraction F6 demonstrated a cytotoxic activity stronger than those of the crude extract (IC(50)=0.6 microg/ml), fractions F4 and F5 were devoid of cytotoxicity (IC(50)>100 microg/ml) and displayed interesting antileishmanial activity against the intracellular amastigote form of the parasite (IC(50)=5.6 and 12.4 microg/ml), respectively. However, the antifungal activity observed for the crude extract could not be recovered in the corresponding fractions.     

Essential oil of Daucus carota subsp. halophilus: composition, antifungal activity and cytotoxicity

Ethnopharmacological relevance: Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria and fungi. Daucus carota L. is used since olden times in traditional medicine, due to recognized therapeutic properties, namely the antimicrobial activity of their essential oils. Aim of the study: In the present study the composition and the antifungal activity of the oils of Daucus carota L. subsp. halophilus (Brot.) A. Pujadas (Apiaceae), an endemic plant from Portugal, were evaluated. Moreover, their cytotoxicity in mouse skin dendritic cells at concentration showing significant antifungal activity was also evaluated. Material and methods: The oils were investigated by GC and GC-MS and the antifungal activity (MIC and MLC) were evaluated against yeasts, dermatophyte and Aspergillus strains. Assessment of cell viability was made by the MTT assay. Results: The results showed large variations in the compositions during ontogenesis, particularly in the amounts of elemicin that increased significantly in the ripe umbels (5.9% vs. 31.0%). The results also demonstrated that the oil with high amounts of elemicin, which have stronger antifungal activity, showed no cytotoxic effect, at concentrations ranging from 0.16 to 0.64 mul/ml, for as long as 24h. Conclusion: It is possible to find appropriate doses of Daucus carota oil showing both antifungal activity and very low detrimental effect on mammalian cells.     

Antimicrobial properties of heartwood,bark/sapwood and leaves of Juniperus species

Hexane and methanol extracts of heartwood, bark/sapwood and leaves of twelve taxa of Juniperus from the United States were assayed for antifungal and antibacterial activities. The hexane extract of the heartwood of several junipers appeared comparable in antibacterial activity to streptomycin. Antibacterial activity of the hexane extracts from the bark/sapwood of J. monosperma and J. californica were comparable to streptomycin. No appreciable antibacterial activities were found in the leaf extracts from any species examined. No antifungal activities comparable to amphotericin B were found in either hexane or methanol extracts of the heartwood nor from the bark/sapwood. Antifungal activity against Cryptococcus neoformans comparable to amphotericin B was found in the hexane extract of the leaves of J. occidentalis var. australis. The methanol extracts from the leaves of J. osteosperma and J. californica had antifungal activities comparable to amphotericin B against Trichophyton mentagrophytes.     

Antifungal cyclic depsipeptide, eujavanicin A, isolated from Eupenicillium javanicum

In the course of searching for new antifungal agents, a new cyclic depsipeptide, eujavanicin A (1), was isolated from Eupenicillium javanicum as an antifungal agent against the human pathogenic filamentous fungus Aspergillus fumigatus. The structure of 1 was established by spectroscopic and chemical investigations. The absolute stereochemistry was elucidated by Marfey's method and by chiral HPLC analysis.     

Screening of solanum surrattense for antibacterial, antifungal, phytotoxic and haemagglutination

Objective

Plants produce a variety of useful bioactive materials that have been used to cure different ailments of human beings. With the same idea in mind, the crude methanolic extract and various fractions of Solanum surrattense were screened for antibacterial, antifungal, phytotoxic and heamagglutination activities.

Methods

Standardized assays were followed for the determination of antibacterial, antifungal phytotoxic and heamagglutination activity.

Results

The results of the antibacterial showed that crude methanolic extract was significantly active against Staphylococcus aureus (86%) The n-hexane fraction showed good activity against Pseudomonas aerogenosa (66.6%) and Bacillus subtilus (66.6%). The crude methanolic extract and various fractions were inactive against all test fungi. The crude methanolic extract, n-hexane, CHCI₃ and aqueous fractions showed moderate phytotoxic activities of 46.67%, 40.00%, 33.34% and 33.34% respectively at 1000 μg/mL. The crude methanolic extract and various fractions S. surrattense were unable to agglutinate RBCs of the human blood indicating that this species lack phytolectins.

Conclusion

The test sample showed significant antibacterial activity, no antifungal and heamagglutination activity while moderate phytotoxic was observed against Lemna minor L.