29 research outputs found
Biocatalysis for biomass valorization: peptides and fatty acids from rice bran
Waste upgrading practises have attracted a significant attention in recent years with the aim of managing agrofood by-products in a gainful and sustainable way.
We describe here how biocatalysis can assist rice bran valorization, according to the biorefinery concept. [1]
Rice is the staple food for over half the world's population. Rice milling generates a massive amount of waste, namely rice bran (70 kg/ton of rice) and rice husk (200 kg/ton of rice). Rice bran (RB), containing fibers (7-11%), proteins (10-16%), lipids (15-22%), carbohydrates (34-52%), micronutrients, represents a second-generation biomass. [2]
Rice bran proteins (RBP) have a high nutritional value and optimal digestibility and are gluten-free, hypoallergenic and rich in essential amino acids. However, the first hurdle to be overcome for RBP production and large scale application is their extraction. Structural complexity, poor solubility, and strong aggregation make RBP hardly available.
The sequential treatment of RB with carbohydrases and proteases was used to prepare mixtures of water-soluble peptides (RBPHs, RBP Hydrolysates) to be tested as antibacterial, antioxidant and anticholesterol agents, as well as flavour enhancers. [3] Interestingly, sensory analysis revealed that the obtained RBPHs exert only sweet and umami taste.
Rice bran oil (RBO) is one of the most underutilized agricultural commodities. We investigated the use of RBO as a feedstock for the production of FFA-derived chemicals (e.g. sugar fatty acid esters). [4] To this aim, RBO was submitted to a preparative lipase-catalyzed hydrolysis to obtain pure FFA. [5] The high acidity of RBO, so far considered as a bottleneck in the exploitation of RBO (i.e. biodiesel production) was here turned into an advantage, making available FFA mixtures as synthetic precursors for high added value products
15N NMR Spectroscopy of Annulated \u3942- Pyrazolines and \u3942-1,2,4-Triazolines
Enantiopure \u3942-pyrazolines and \u3942-1,2,4-triazolines fused to the 1,4-benzodiazepine moiety, as well as \u3942-pyrazolines annulated to the 1,5-benzoxazocine moiety (racemic) or inserted in a bis-1,3-pyrazolophane skeleton (enantiopure) were investigated through 15N NMR spectroscopy in natural abundance. Nitrogen chemical shifts were determined by (1D)-INEPT experiments, while proton-nitrogen scalar coupling were obtained through 2D-J-HMBC experiments
15N NMR spectroscopy of partially unsaturated pyrazoles
Partially saturated pyrazoles, namely 1-(4-substituted)phenyl-3-methoxycarbonyl-5-ethoxycarbonyl-4,5-dihydropyrazoles, were submitted to extensive 15N NMR spectroscopic analyses, performed in natural abundance. Nitrogen chemical shifts were measured by means of INEPT and HMBC experiments, while long range proton\u2013nitrogen scalar coupling values were taken through J-HMBC experiments. A linear plot between nitrogen chemical shifts and Hammett \u3c3p was observed, enabling us to relate quantitatively the observed chemical shifts to the electronic features of the substituent in the 1-position of the 4,5-dihydropyrazole ring
Synthesis of tetrahydroisoquinoline-based pseudopeptides and their characterization as suitable reverse turn mimetics
reserved5G. LESMA; E. MESCHINI; T. RECCA; A. SACCHETTI; A. SILVANIG., Lesma; E., Meschini; T., Recca; Sacchetti, Alessandro; A., Silvan
Structure determination and dynamics of peptides overlapping the catalytic hairpin of the Ras-specific GEF Cdc25(Mm)
Ras proteins are small G proteins playing a major role in eukaryotic
signal transduction. Guanine nucleotide exchange factors (GEF) stimulate
GDP/GTP exchange, resulting in the formation of the active Ras-GTP
complex. In mammalian cells, two major Ras-specific GEF exist: Sos-like
and Cdc25-like. To date, structural data are available only for
Cdc25(Mm). We designed and synthesized Cdc25(Mm)-derived peptides
spanning residues corresponding to the hSos1 HI helical hairpin that has
been implicated in the GEF catalytic mechanism. NMR experiments on a
chemically synthesized Cdc25(1178-1222)(Mm) peptide proved that helix I
readily reaches a conformation very similar to the corresponding helix
in hSos 1, while residues corresponding to helix H in hSos1 show higher
conformational flexibility. Molecular dynamics studies with the
appropriate solvent model showed that different conformational spaces
are available for the peptide. Since helix H is making several contacts
with Ras and a Cdc25(1178-1222)(Mm) peptide is able to bind
nucleotide-free Ras in a BIAcore assay, the peptide must be able to
obtain the proper Ras-interacting conformation, at least transiently.
These results indicate that rational design and improvement of the
Ras-interacting peptides should take into account conformational and
flexibility features to obtain molecules with the appropriate
biochemical properties
New high-performance thermoplastic toughened epoxy thermoset
Thermal, mechanical and morphological measurements of reactive thermoplastic modified epoxy resin are
reported. Phase separation occurs during the curing. To a small decrease of the modulus of the final
materials a large increase of the toughness of the thermoset is associated, as compared with the neat epoxy
resin when cured with an usual curing agent