The Effect of Cyclosporin A on Aspergillus niger and the Possible Mechanisms Involved.

Aspergillus niger is one of the major pathogenic fungi causing postharvest grape decay. The development of antifungal agents is beneficial to reduce the loss of grapes during storage. The aim of this study was to investigate the antifungal mechanism of cyclosporin A (CsA). It was indicated that the rot development on grapes caused by A. niger was almost completely inhibited with CsA in vivo at a concentration of 200 mg/L. The transcriptomic analysis revealed that the expression levels of genes involved in rRNA processing and ribosome biogenesis were down-regulated, whereas those related to ß-glucosidases and chitinases were up-regulated. The results implied that CsA may disturb rRNA and ribosome formation to obstruct protein synthesis, accelerate chitin and glucan degradation to destruct cell walls, and ultimately reduce postharvest decay caused by A. niger in grapes. This study evaluated the potential of CsA as a grape preservative and provided new insights into the mechanisms underlying the molecular response in A. niger with the treatment of CsA.

Acuminatums E and F, two new cyclic lipopeptides from Fusarium lateritium HU0053 and their antifungal activity.

Two new cyclic lipopeptides, acuminatums E (1) and F (2), together with four known cyclic lipopeptides, acuminatums A-D (3-6) were isolated from the corn culture of endophytic Fusarium lateritium HU0053. Their structures were elucidated by spectroscopic and advanced Marfey's amino acid analysis. All compounds were found to exhibit antifungal activities against Penicillium digitatum. Acuminatum F (2), a new cyclic lipopeptide containing an unusual 3, 4-dihydroxy-phenylalanine unit exhibited the strongest antifungal activities with inhibition zone of 6.5 mm at the dose of 6.25 µg. Therefore, acuminatum F might be a potential environmental-friendly preservative for citrus fruits.

The response of nutrient cycle, microbial community abundance and metabolic function to nitrogen fertilizer in rhizosphere soil of Phellodendron chinense Schneid seedlings.

Nitrogen (N) as an essential macronutrient affects the soil nutrient cycle, microbial community abundance, and metabolic function. However, the specific responses of microorganisms and metabolic functions in rhizosphere soil of Phellodendron chinense Schneid seedlings to N addition remain unclear. In this study, four treatments (CK, N5, N10 and N15) were conducted, and the soil physicochemical properties, enzyme activities, microbial community abundances and diversities, metabolism, and gene expressions were investigated in rhizosphere soil of P. chinense Schneid. The results showed that N addition significantly decreased rhizosphere soil pH, among which the effect of N10 treatment was better. N10 treatment significantly increased the contents of available phosphorus (AP), available potassium (AK), ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N) and sucrase (SU) activity, as well as fungal diversity and the relative expression abundances of amoA and phoD genes in rhizosphere soil, but observably decreased the total phosphorus (TP) content, urease (UR) activity and bacterial diversity, among which the pH, soil organic matter (SOM), AP, NH4+-N and NO3--N were the main environmental factors for affecting rhizosphere soil microbial community structure based on RDA and correlation analyses. Meanwhile, N10 treatment notably enhanced the absolute abundances of the uracil, guanine, indole, prostaglandin F2α and γ-glutamylalanine, while reduced the contents of D-phenylalanine and phenylacetylglycine in rhizosphere soil of P. chinense Schneid seedlings. Furthermore, the soil available nutrients represented a significant correlation with soil metabolites and dominant microorganisms, suggesting that N10 addition effectively regulated microbial community abundance and metabolic functions by enhancing nutrient cycle in the rhizosphere soil of P. chinense Schneid seedlings.

Antifungal Mechanism of MTE-1, a Novel Oligosaccharide Ester, against Ustilaginoidea virens.

Ustilaginoidea virens is a pathogenic fungus that causes false smut disease in rice during the flowering stage through stamen filaments. Currently, there is a need to develop safe and effective antifungal agents for the control of this disease. In our preliminary experiments, we found that MTE-1, a new trisaccharide ester, exhibits significant inhibitory activity against U. virens. Hence, the effects and inhibitory mechanism of MTE-1 in U. virens were investigated. Results showed that the MTE-1 inhibited the hyphae growth of U. virens with an IC50 of 5.67 µg/mL. Similarly, MTE-1 disrupted the endomembrane system in U. virens, especially the plasma membrane, mitochondria, and lipidosome. Moreover, transcriptome and proteome analysis indicated that MTE-1 inhibited the growth of U. virens by inhibiting the synthesis of lipids, altering the primary metabolic pathways including carbohydrates and amino acid metabolism, and affecting the intracellular redox dyshomeostasis, thus leading to the disorder of active oxygen metabolism. These findings lay the foundation for the future application of MTE-1-derived agents in the management of antifungal diseases.

Isolation and identification of flavonoids components from Pteris vittata L.

BACKGROUND: Pteris vittata L. is rich in flavonoids which exhibit different bioactivities. In order to investigate the flavonoids components of P. vittata L., extracts of the plant were isolated by column chromatography on silica gel and Sephadex LH-20. RESULTS: Four flavonoids compounds were obtained, the structures were identified as kaempferol (1), quercetin (2), kaempferol-3-O-d-glucopyranoside (3) and rutin (4), respectively, on the basis of NMR spectroscopic analyses. CONCLUSIONS: Compound 3 was reported for the first time from P. vittata L.

Evaluation of antioxidant activities of extracts from 19 Chinese edible flowers.

Extracts of 19 selected edible flowers were investigated for their free radical scavenging activity (FRSA), polyphenolic contents and flavonoid contents in the paper. The results showed the extracts of Paeonia suffruticosa Andr., Paeonia lactiflora Pall., and Rosa rugosa Thunb. possessed obviously stronger DPPH FRSA (94.221 ± 0.102; 93.739 ± 0.424 and 94.244 ± 0.163%, respectively), superoxide FRSA (55.818 ± 1.518; 52.142 ± 1.374 and 57.321 ± 0.608%, respectively), hydroxyl FRSA (85.872 ± 0.873; 89.307 ± 0.803 and 88.560 ± 0.277%, respectively) and polyphenolic contents (96.208 ± 0.689; 87.938 ± 1.187 and 92.164 ± 0.799 mg CE/g, respectively) that were superior or comparable to black and green teas. Polyphenolic contents did correlate well with DPPH FRSA (r = 0.943, P < 0.01), superoxide FRSA (r = 0.833, P < 0.01), and hydroxyl FRSA (r = 0.500, P < 0.05). It indicated that this potent FRSA may be attributed to its phenolic compounds. These findings showed that the tested flowers could be considered as new sources of safe natural antioxidants and preservatives of food industry.

[Chemical constituents from Canarium pimela fruits].

OBJECTIVE: To investigate the chemical constituents from Canarium pimela fruits. METHODS: Compounds were obtained after separation and purification by silica gel and Sephadex LH-20. The structures were identified on the basis of physico-chemical properties and spectrum data. RESULTS: Eight compounds were isolated from Canarium pimela fruits. The structures were identified as amentoflavone (1), kaempferol-3-O-ß-D-galactopyranoside (2), shikimic acid (3), quercetin (4), kaempferol (5), 3,3'-di-O-methylellagic acid (6), 3,3',4-tri-O-methylellagic acid (7) and stigmasterol (8). CONCLUSION: Compounds 1-8 are isolated from Canarium pimela fruits for the first time.

Effects of Ficus hirta Vahl. (Wuzhimaotao) extracts on growth inhibition of HeLa cells.

Ficus hirta Vahl. (Wuzhimaotao) is widely used as a folk medicine by Hakka people in southern China. In order to ascertain if any major fraction can be attributed to have pronounced anticancer effect, extracts of Wuzhimaotao on cytotoxic and apoptosis of HeLa cell lines were evaluated. HeLa cells were cultured and incubated with different concentrations of crude aqueous extracts (CAE), ethyl acetate extracts (EAE), and butyl alcohol extracts (BAE). It showed CAE, EAE, and BAE decreased cell viability on HeLa cells as a dose-dependent manner, and induced a sub-G1 peak in flow cytometry histogram of treated cells compared to the control. Apoptotic cell death is involved in CAE, EAE, and BAE toxicity, with EAE having a significant decrease in G1 population. An over all analysis of results showed that Wuzhimaotao extracts exert antiproliferative action and growth inhibition on HeLa cells through apoptosis induction which indicates its anticancer properties and deserves further investigation.