Enzyme oxidation of plant galactomannans yielding biomaterials with novel properties and applications,including as delivery systems

Applied Microbiology and Biotechnology - New biomaterials from renewable sources and the development of “functionalized biopolymers” are fields of growing industrial interest. Plant...     

3-Amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles: a new class of CDK2 inhibitors

We have recently reported about a new class of Aurora-A inhibitors based on a bicyclic tetrahydropyrrolo[3,4-c]pyrazole scaffold. Here we describe the synthesis and early expansion of CDK2/cyclin A-E inhibitors belonging to the same chemical class. Synthesis of the compounds was accomplished using a solution-phase protocol amenable to rapid parallel expansion. Compounds with nanomolar activity in the biochemical assay and able to efficiently inhibit CDK2-mediated tumor cell proliferation have been obtained.     

Benzodipyrazoles: a new class of potent CDK2 inhibitors

The synthesis and the preliminary expansion of this new class of CDK2 inhibitors are presented. The synthesis was accomplished using a solution-phase protocol amenable to rapid parallel expansion and suitable to be scaled-up in view of possible lead development. Following a medicinal chemistry program aimed at improving cell permeability and selectivity, a series of compounds with nanomolar activity in the biochemical assay and able to efficiently inhibit tumor cell proliferation has been obtained.     

Detection of enterotoxigenic Staphylococcus aureus isolates in raw milk cheese

AIM: To develop an easy, rapid and efficient DNA extraction procedure for Staphylococcus aureus detection with a low number of steps and removing completely the PCR inhibitors, applicable to raw milk cheese samples, and to compare phenotypical and genotypical method to detect Staph. aureus isolates and staphylococcal enterotoxins (SEs) production. METHODS AND RESULTS: A total of 33 bovine and caprine raw milk cheese samples were analysed by means of both classic microbiological and molecular techniques. All samples were positive for Staph. aureus contamination. The DNA extraction protocol optimized was found to achieve a detection limit of 100 CFU g(-1) for Staph. aureus. None of the samples tested with immunological assays contained SEs but in 14 of 33 samples a mixture of se positive (sea, sec, sed, seg, sel, sej) isolates were identified. CONCLUSIONS: Staphylococcus aureus is a food-borne pathogen mainly detected in finished dairy products. The rapid and efficient detection of Staph. aureus isolates from dairy products is essential for consumer safety. The direct detection of pathogens from food is possible with careful attention to sample preparation and nucleic acid amplification optimization. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that raw milk cheese samples can be tested for Staph. aureus contamination with a rapid, simple and reproducible procedure.     

Redox potential to discriminate among species of lactic acid bacteria

AIMS: To verify to what degree reducing capacity is a characterizing parameter of a species, and of the strains themselves within a given species, of lactic acid bacteria. METHODS AND RESULTS: Eighty-eight strains belonging to 10 species of lactic acid bacteria (LAB) isolated from traditional Italian cheeses were studied for their reduction activity: Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Streptococcus thermophilus, Lactococcus lactis ssp. lactis, Lactobacillus paracasei ssp. paracasei, Lactobacillus plantarum, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus and Pediococcus pentosaceus. It was observed that the lactococci reached minimum redox potential before the lactobacilli. The reduction rate of Enterococcus spp. and L. lactis ssp. lactis was higher than that of the streptococci and Lactobacillus spp. All the P. pentosaceus strains had poor reduction activity compared with the other species. CONCLUSIONS: The evolution of the redox potential in milk over a time span of 24 h has been found to be a parameter that characterizes a species: the different courses corresponding to the species in question are clearly evident, and interesting differences can also be noted within the same species. SIGNIFICANCE AND IMPACT OF THE STUDY: The reduction aptitude of strains might be used to select and adapt appropriate strains for use as starters for dairy products.     

Endophytic bacterial diversity in grapevine (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.) leaves described by 16S rRNA gene sequence analysis and length heterogeneity-PCR

Diversity of bacterial endophytes associated with grapevine leaf tissues was analyzed by cultivation and cultivation-independent methods. In order to identify bacterial endophytes directly from metagenome, a protocol for bacteria enrichment and DNA extraction was optimized. Sequence analysis of 16S rRNA gene libraries underscored five diverse Operational Taxonomic Units (OTUs), showing best sequence matches with γ-Proteobacteria, family Enterobacteriaceae, with a dominance of the genus Pantoea. Bacteria isolation through cultivation revealed the presence of six OTUs, showing best sequence matches with Actinobacteria, genus Curtobacterium, and with Firmicutes genera Bacillus and Enterococcus. Length Heterogeneity-PCR (LH-PCR) electrophoretic peaks from single bacterial clones were used to setup a database representing the bacterial endophytes identified in association with grapevine tissues. Analysis of healthy and phytoplasma-infected grapevine plants showed that LH-PCR could be a useful complementary tool for examining the diversity of bacterial endophytes especially for diversity survey on a large number of samples.     

5-(2-amino-pyrimidin-4-yl)-1H-pyrrole and 2-(2-amino-pyrimidin-4-yl)-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one derivatives as new classes of selective and orally available Polo-like kinase 1 inhibitors

The discovery and characterization of two new chemical classes of potent and selective Polo-like kinase 1 (PLK1) inhibitors is reported. For the most interesting compounds, we discuss the biological activities, crystal structures and preliminary pharmacokinetic parameters. The more advanced compounds inhibit PLK1 in the enzymatic assay at the nM level and exhibit good activity in cell proliferation on A2780 cells. Furthermore, these compounds showed high levels of selectivity on a panel of unrelated kinases, as well as against PLK2 and PLK3 isoforms. Additionally, the compounds show acceptable oral bioavailability in mice making these inhibitors suitable candidates for further in vivo activity studies.     

A practical synthesis of the major 3-hydroxy-2-pyrrolidinone metabolite of a potent CDK2/cyclin A inhibitor

The synthesis of the major metabolite of a potent 3-aminopyrazole CDK2/cyclin A inhibitor is presented. A stereoconservative approach starting from malic acid was employed to construct the hydroxy-substituted pyrrolidinone moiety. In the key step of the synthesis the use of cyanoborohydride immobilized on Amberlyst 26 in trifluoroethanol represented a valid alternative to conventional solution-phase reducing agents.     

Optimization of 6,6-dimethyl pyrrolo[3,4-c]pyrazoles: Identification of PHA-793887, a potent CDK inhibitor suitable for intravenous dosing

We have recently reported CDK inhibitors based on the 6-substituted pyrrolo[3,4-c]pyrazole core structure. Improvement of inhibitory potency against multiple CDKs, antiproliferative activity against cancer cell lines and optimization of the physico-chemical properties led to the identification of highly potent compounds. Compound 31 (PHA-793887) showed good efficacy in the human ovarian A2780, colon HCT-116 and pancreatic BX-PC3 carcinoma xenograft models and was well tolerated upon daily treatments by iv administration. It was identified as a drug candidate for clinical evaluation in patients with solid tumors.