Promising Antidiabetic and Antimicrobial Agents Based on Fused Pyrimidine Derivatives: Molecular Modeling and Biological Evaluation with Histopathological Effect.

Diabetes is the most common metabolic disorder in both developing and non-developing countries, and a well-recognized global health problem. The WHO anticipates an increase in cases from 171 million in 2000 to 366 million by 2030. In the present study, we focus on the preparation of pyrimidine derivatives as potential antidiabetic and antimicrobial agents. Thein vivoeffect on total serum glucose concentration, cholesterol and antioxidant activity was assessed in adult male albino Wister rats and compared to the reference drug glimperide. Promising results were observed for compound 5. The histopathological study confirms that compound 5 results in significant activity with liver maintenance. The antimicrobial activities were evaluated against several bacterial strains such as Salmonella typhimurium ATCC 25566, Bacillus cereus, Escherichia coli NRRN 3008, Pseudomonas aeruginosa ATCC 10145, Staphylococcus aureus ATCC 6538and fungi such as Rhizopus oligosporus, Mucor miehei and Asperillus niger. Compounds 4 and 5 showed a good inhibition of the bacterial zone compared to the reference drug cephradine. Finally, we suggest protein targets for these drugs based on computational analysis, and infer their activities from their predicted modes of binding using molecular modeling. The molecular modeling for compounds 4 and 5 resulted in improved docking scores and hydrogen bonding. The docking studies are in good agreement with the in vitro and in vivo studies.

Inhibitory kinetics and bioactivities of Nuciferine and Methyl Ganoderate on Mucor miehei lipase and 3T3-L1 preadipocytes.

In this study, inhibitory kinetics of Nuciferine and Methyl Ganoderate extrated from Lotus Leaves and Ganoderma lucidum on Mucor miehei Lipase were studied first. The molecular structure of Nuciferine and Methyl Ganoderate were determined. The inhibitory effects of two extracts on lipase were reversible, with the IC50 values of 0.194 and 0.332 mg/mL, respectively. The inhibition kinetic analysis by Lineweaver-Burk plots showed that they were a mixed-type inhibitor of lipase, with inhibition constants KI of 0.16 and 0.29 mg/mL, and KIS of 0.36 and 0.49 mg/mL, respectively. Results of spectral analysis showed that the UV absorption and the molecule fluorescence spectrum of the lipase hydrolyzate were significantly decreased after the inhibitor was added. The molecular docking further suggested that the interaction site between the active substance and inhibitor was located in an α-helix and a ß-sheet of the lipase, and the lipase active site was interfered by the inhibitor near the cap structure. In addition, the proliferation and differentiation of 3 T3-L1 preadipocytes were inhibited by two extracts. Total triglycerides and cholesterol were significantly reduced in the cells. The results confirmed that Nuciferine and Methyl Ganoderate can be used as potential obesity treatment drugs.

Cerebral Rhizomucor Infection Treated by Posaconazole Delayed-Release Tablets in an Allogeneic Stem Cell Transplant Recipient.

Mucormycosis (zygomycosis) is an emerging fungal disease in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. A 30-year-old woman diagnosed with acute myelomonocytic leukemia and needing allo-HSCT presented pulmonary and cerebral infection due to Rhizomucor pusillus. This fungal infection was treated with surgical treatment and posaconazole delayed-release tablets. This strategy allowed reaching high drug levels that could not be obtained with the posaconazole solution.

Stress response in medically important Mucorales.

Mucorales are saprobes, ubiquitously distributed and able to infect a heterogeneous population of human hosts. The fungi require robust stress responses to survive in human host. We tested the growth of Mucorales in the presence of different abiotic stress. Eight pathogenic species of Mucorales, including Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, Apophysomyces elegans, Licthemia corymbifera, Cunninghamella bertholletiae, Syncephalastrum racemosum and Mucor racemosus, were exposed to different stress inducers: osmotic (sodium chloride and d-sorbitol), oxidative (hydrogen peroxide and menadione), pH, cell wall and metal ions (Cu, Zn, Fe and Mg). Wide variation in stress responses was noted: R. arrhizus showed maximum resistance to both osmotic and oxidative stresses, whereas R. pusillus and M. indicus were relatively sensitive. Rhizopus arrhizus and R. microsporus showed maximum resistance to alkaline pH, whereas C. bertholletiae, L. corymbifera, M. racemosus and A. elegans were resistant to acidic pH. Maximum tolerance was noted in R. microsporus to Cu, R. microsporus and R. arrhizus to Fe and C. bertholletiae to Zn. In contrast, L. corymbifera, A. elegans and M. indicus were sensitive to Cu, Zn and Fe respectively. In conclusion, R. arrhizus showed high stress tolerance in comparison to other species of Mucorales, and this could be the possible reason for high pathogenic potential of this fungi.

Identification and susceptibility of Rhizomucor spp. isolated from patients with cutaneous zygomycosis in China.

Zygomycosis is a relatively uncommon mycosis with a morbidity that is increasing worldwide. Cutaneous zygomycosis, one of the clinical manifestations of the disease, has also emerged in recent decades. The major reported etiologic agents in China include Rhizomucor spp., Rhizopus spp., Mucor spp., and Lichtheimia spp. (formerly Absidia spp.). This study examined 11 clinical isolates of Rhizomucor that belong to three species (R. variabilis, R. regularior, and R. chlamydosporus). They were identified by both morphological and molecular methods and were found to have a high degree of correlation. In vitro susceptibility of the Rhizomucor isolates to seven antifungal drugs (amphotericin B, itraconazole, terbinafine, voriconazole, fluconazole, flucytosine, and micafungin) were tested, which resulted in amphotericin B being found to be the most active agent against all species evaluated in this study. The investigation also reviewed case reports of cutaneous zygomycosis in China.

Antifungal activity of statins and their interaction with amphotericin B against clinically important Zygomycetes.

The in vitro antifungal activity of different statins and the combinations of the two most effective ones (fluvastatin and rosuvastatin) with amphotericin B were investigated in this study on 6 fungal isolates representing 4 clinically important genera, namely Absidia, Rhizomucor, Rhizopus and Syncephalastrum . The antifungal effects of statins revealed substantial differences. The synthetic statins proved to be more effective than the fungal metabolites. All investigated strains proved to be sensitive to fluvastatin. Fluvastatin and rosuvastatin acted synergistically and additively with amphotericin B in inhibiting the fungal growth in clinically available concentration ranges. Results suggest that statins combined with amphotericin B have a therapeutic potential against fungal infections caused by Zygomycetes species.

In vitro synergistic interactions of the effects of various statins and azoles against some clinically important fungi.

The treatment of opportunistic fungal infections is often difficult as the number of available antifungal agents is limited. Nowadays, there is increasing interest in the investigation of the antifungal activity of nonantifungal drugs, and in the development of efficient antifungal combination therapy. In this study, the in vitro interactions of the effects of various statins (lovastatin, simvastatin, fluvastatin, atorvastatin (ATO), rosuvastatin (ROS) and pravastatin) and various azole antifungals [miconazole, ketoconazole, itraconazole and fluconazole (FLU)] against different opportunistic pathogenic fungi were investigated using a standard chequerboard broth microdilution method. When the investigated strains were sensitive to both compounds of the combination, additive interactions were frequently noticed. Synergistic interactions were observed in many cases when a strain was sensitive only to the azole compound (as in certain combinations with ATO or ROS) or the statin compound (as in certain combinations with FLU). In many combinations with an additive effect, the concentrations of drugs needed for total growth inhibition could be decreased by several dilution steps. Similar interactions were observed when the variability of the within-species sensitivities to some selected drug combinations was investigated.

Posaconazole enhances the activity of amphotericin B against hyphae of zygomycetes in vitro.

The in vitro activity of posaconazole plus amphotericin B against conidia and hyphae of 30 clinical zygomycetes was investigated. The combination of posaconazole with amphotericin B was found to be significantly more synergistic (40%) against hyphae (P < 0.05) than against conidia (10%). Antagonism was not observed.

Diversity of cutaneous bacteria with antifungal activity isolated from female four-toed salamanders.

Among the microbiota of amphibian skin are bacteria that produce antifungal compounds. We isolated cutaneous bacteria from the skins of three populations of the nest-attending plethodontid salamander Hemidactylium scutatum and subsequently tested the bacterial isolates against two different fungi (related to Mariannaea elegans and Rhizomucor variabilis) that were obtained from dead salamander eggs. The culturable antifungal bacteria were phylogenetically characterized based on 16S rRNA phylogeny, and belonged to four phyla, comprising 14 bacterial families, 16 genera and 48 species. We found that about half of the antifungal bacterial genera and families were shared with a related salamander species, but there was virtually no overlap at the species level. The proportion of culturable antifungal bacterial taxa shared between two large populations of H. scutatum was the same as the proportion of taxa shared between H. scutatum and Plethodon cinereus, suggesting that populations within a species have unique antifungal bacterial species. Approximately 30% of individuals from both salamander species carried anti-M. elegans cutaneous bacteria and almost 90% of P. cinereus and 100% of H. scutatum salamanders carried anti-R. variabilis cutaneous bacteria. A culture independent method (PCR/DGGE) revealed a shared resident bacterial community of about 25% of the entire resident bacterial community within and among populations of H. scutatum. Thus, the culturable antifungal microbiota was far more variable on salamander skins than was the bacterial microbiota detected by PCR/DGGE. The resident cutaneous antifungal bacteria may play an important role in amphibians' innate defense against pathogens, including the lethal chytrid fungus Batrachochytrium dendrobatidis.

Differentiation of Rhizomucor species on the basis of their different sensitivities to lovastatin.

The opportunistic pathogens Rhizomucor pusillus and Rhizomucor miehei may be agents of frequently fatal mycotic diseases. In the present study, the susceptibilities of 27 clinical and environmental isolates of R. miehei and R. pusillus to lovastatin under different culturing conditions were investigated. Most of the R. miehei strains grew at lovastatin concentrations as high as 64 to 128 microg/ml. In contrast, the inhibitory effect of lovastatin on all of the R. pusillus strains was evident at lovastatin concentrations as low as 1 to 2 microg/ml. A simple and reliable method for species-level differentiation, based on the significantly higher sensitivity of R. pusillus to lovastatin than that of R. miehei, was elaborated. According this, on malt extract agar containing 6 mug of lovastatin/ml, R. pusillus is not able to produce colonies, while R. miehei will form compact colonies.

[Study of the cerbiden spectrum of antifungal activity against fungi pathogenic to humans]. / Vyvchennia spektra antyfunhal'noï diï tserbidenu na umovno patohenni dlia liudyny gryby.

A comparatively wide spectrum of cerbiden antifungal activity against the fungi pathogenic for human has been determined. Cerbiden is active against clinical and museum strains of Candida spp. and other yeasts; Trichophyton spp., Microsporum spp. of Dermatophytaceae family, museum strains of some species from Mucor, Rhizopus, Rhizomucor genera of Mucoraceae family; and it is not active with respect to studied fungi of Aspergillus and Penicillium genera of Moniliaceae family.