Monaspin B, a Novel Cyclohexyl-furan from Cocultivation of Monascus purpureus and Aspergillus oryzae, Exhibits Potent Antileukemic Activity.

Natural products are a rich resource for the discovery of innovative drugs. Microbial cocultivation enables discovery of novel natural products through tandem enzymatic catalysis between different fungi. In this study, Monascus purpureus, as a food fermentation strain capable of producing abundant natural products, was chosen as an example of a cocultivation pair strain. Cocultivation screening revealed that M. purpureus and Aspergillus oryzae led to the production of two novel cyclohexyl-furans, Monaspins A and B. Optimization of the cocultivation mode and media enhanced the production of Monaspins A and B to 1.2 and 0.8 mg/L, respectively. Monaspins A and B were structurally elucidated by HR-ESI-MS and NMR. Furthermore, Monaspin B displayed potent antiproliferative activity against the leukemic HL-60 cell line by inducing apoptosis, with a half-maximal inhibitory concentration (IC50) of 160 nM. Moreover, in a mouse leukemia model, Monaspin B exhibited a promising in vivo antileukemic effect by reducing white blood cell, lymphocyte, and neutrophil counts. Collectively, these results indicate that Monaspin B is a promising candidate agent for leukemia therapy.

An Aerolysin-like Pore-Forming Protein Complex Targets Viral Envelope to Inactivate Herpes Simplex Virus Type 1.

Because most of animal viruses are enveloped, cytoplasmic entry of these viruses via fusion with cellular membrane initiates their invasion. However, the strategies in which host cells counteract cytoplasmic entry of such viruses are incompletely understood. Pore-forming toxin aerolysin-like proteins (ALPs) exist throughout the animal kingdom, but their functions are mostly unknown. In this study, we report that ßγ-crystallin fused aerolysin-like protein and trefoil factor complex (ßγ-CAT), an ALP and trefoil factor complex from the frog Bombina maxima, directly blocks enveloped virus invasion by interfering with cytoplasmic entry. ßγ-CAT targeted acidic glycosphingolipids on the HSV type 1 (HSV-1) envelope to induce pore formation, as indicated by the oligomer formation of protein and potassium and calcium ion efflux. Meanwhile, ßγ-CAT formed ring-like oligomers of ∼10 nm in diameter on the liposomes and induced dye release from liposomes that mimic viral envelope. Unexpectedly, transmission electron microscopy analysis showed that the ßγ-CAT-treated HSV-1 was visibly as intact as the vehicle-treated HSV-1, indicating that ßγ-CAT did not lyse the viral envelope. However, the cytoplasmic entry of the ßγ-CAT-treated HSV-1 into HeLa cells was totally hindered. In vivo, topical application of ßγ-CAT attenuated the HSV-1 corneal infection in mice. Collectively, these results uncovered that ßγ-CAT possesses the capacity to counteract enveloped virus invasion with its featured antiviral-acting manner. Our findings will also largely help to illustrate the putative antiviral activity of animal ALPs.

[Research on using 3-D fluorescence spectroscopy-wavelet transform-PSO for rapid discrimination of compositions of phytoplankton population].

Three-dimensional fluorescence of 17 red tide algae species that belong to 13 genera of five divisions was measured by fluorescence excitation-emission matrix spectroscopy. And 2-D wavelet db7 was selected to decompose the spectra at different levels to choose the alternative characteristic spectra. Based on the norm reference spectra constructed by cluster analysis, the linear regression model was solved by particle swarm optimization (PSO) algorithm and the discrimination method was established at the division and genus level. Some samples were tested: for single algal samples, and the correct discrimination ratios (CDRs) were 96.1% and 73.6%, respectively; For simulative mixed algal samples, when the dominance were 60%, 75%, 80% and 90% of the total biomass, the CDRs of the dominant algae were 86.7%, 96.9%, 98.7% and 99.4% with the average relative contents of 62.6%, 72.7%, 76.0% and 81.6%, respectively at the division level. And the CDRs were 51.0%, 68.9%, 72.0%, and 78.8% at the genus level, respectively. For 364 actual mixture samples, the CDRs of the dominant species (75%) were 99.4% at the division level and 75.9% at the genus level . For the particular field samples from mesocosm experiment and corrected from Jiaozhou Bay, results showed that the method can be used to realize the identification of red tide algae population and estimate the relative abundance of different classes, especially between diatoms and dinoflagellates.

[Research on the 3D discrete fluorescence spectrum technique for differentiation of phytoplankton population].

The present research was targeted to develop a fluorescence analyser for phytoplankton population which uses a series of LEDs as the light source. So the 3D discrete fluorescence spectra with 12 excitation wavelengths (400, 430, 450, 460,470, 490, 500, 510, 525, 550, 570 and 590 nm) were determined by fluorescence spectrophotometer for 43 phytoplankton species. Then, the wavelet, Daubechies-7 (Db7), and Bayes Classifier were applied to extract the characteristics for each classes from the 3D discrete fluorescence spectra. Lastly, the fluorescence differentiation method for phytoplankton populations was established by multivariate linear regression and non-negative least squares, which could differentiate phytoplankton populations at the levels of both divisions and genus. This method was tested: for simulatively mixed samples(the dominant species accounted for 70%, 80%, 90% and 100% of the gross biomass, respectively) from 32 red tide algal species, and the correct discrimination rates at the level of genus were 67.5%, 75.8%, 81.4% and 79.4%, respectively. For simulatively mixed samples (the dominant divisions algae accounted for 50%, 75% and 100% of the gross biomass, respectively) from 43 algal species, the discrimination rates at the level of division were 95.2%, 99.7% and 91.9% with average relative content of 38.1%, 63.2% and 90.5%, respectively.

[Study on extractive spectrophotometry for determination of amoxicillin with ionic associate].

A method of extractive spectrophotometry has been proposed for the determination of amoxicillin (AMO). The ion pairs complex of amoxicillin with methylene blue (MB) can be extracted into 1,2-dichloroethane at pH 3.3 and has absorption maximum at 657 nm. The ratio of amoxicillin to methylene blue in the ion pairs complex is 1:1. The apparent molar obsorptivity of ion pairs complex is 5.0 x 10(4) L x mol(-1) x cm(-1) at 657 nm. The calibration graph generated is linear over the range of 0.4-6.8 mg x L(-1) drug in solution with a correlation of 0.9989. The detection limit is 0.01 mg x L(-1) and the recovery of AMO is 97.5%-101.3%. The present method has been applied to the determination of amoxicillin in pharmaceutical formulations and urine samples with satisfactory results.