Search Results (14)

The antifreeze and antioxidant capacities of tilapia (Oreochromis mossambicus) gelatin hydrolysates were investigated, after glycosylation with saccharides of varying molecular weights, to enhance their functional properties to widen its commercial application in frozen aquatic products. Glycosylation was conducted by mixing gelatin hydrolysates with ribose, glucose, maltose, and dextran (20 kDa) at a 1:1 mass ratio; the glycosylation products had a pH of 10 and were incubated at 80 °C for 1 h. The results showed that the glycosylation degree ranked as: ribose > glucose > maltose > dextran. The mass spectrometry analysis showed that 17, 32, and 5 glycosylation sites were identified for ribose, glucose, and maltose, respectively, suggesting a molecular weight-dependent effect. Spectroscopic analyses, including ultraviolet and infrared spectroscopy, revealed that the gelatin hydrolysate structure was expanded, with chromophores in hydrophilic environments; a blue shift in the amide A and II bands confirmed that the amino group was involved. Fluorescence spectroscopy showed conformational changes with a red shift at 303.4 nm and a reduction in intensity. Antifreeze activity, such as catalase freezing protection and shrimp surimi protein stability, and antioxidant activity, including radical scavenging and metal ion chelation, were significantly improved. Ribose exhibited the strongest effects, followed by maltose and glucose. These results demonstrate the potential of glycosylation to improve gelatin hydrolysates for functional applications. Full article

Autolysis in the sea cucumber Apostichopus japonicus is typically triggered by degradation caused by microorganisms within their bodies. However, information on this topic remains limited. Recently, we isolated and purified a bacterial strain from hydrolyzed instant sea cucumber samples. To investigate its potential role in the autolysis process, this study employed whole-genome sequencing and metabolomics to explore its genetic and metabolic characteristics. The identified strain was classified as Lysinibacillus xylanilyticus and designated with the number XL-2024. Its genome size is 5,075,210 bp with a GC content of 37.33%, encoding 5275 genes. Functional database comparisons revealed that the protein-coding genes were distributed among glucose metabolism hydrolase, metal hydrolase, lysozyme, cell wall hydrolase, and CAZymes. Compared to 20 closely related strains, L. xylanilyticus XL-2024 shared 1502 core homologous genes and had 707 specific genes. These specific genes were mainly involved in the carbohydrate metabolism pathway and exhibited glycosyl bond hydrolase activity. Metabolomic analysis showed that L. xlanilyticus XL-2024 produced several metabolites related to polysaccharide degradation, including peptidase, glucanase, and pectinase. Additionally, the presence of antibacterial metabolites such as propionic acid and ginkgo acid among its metabolites may enhance the stability of the sea cucumber hydrolysate. In summary, L. xylanilyticus XL-2024 may play a pivotal role in the autolysis of A. japonicus. The results of this study provide a strong foundation for understanding how to prevent autolysis in A. japonicus and for better utilizing L. xylanilyticus XL-2024. Full article

Sulfite and kraft pulping are two principal methods of industrial delignification of wood. In recent decades, those have been considered as possibilities to pretreat recalcitrant wood lignocellulosics for the enzymatic hydrolysis of polysaccharides and the subsequent fermentation of obtained sugars to valuable bioproducts. Current work compares chemistry and technological features of two different cooking processes in the preparation of polysaccharide substrates for deep saccharification with P. verruculosum glycosyl hydrolases. Bleached kraft and sulfite pulps were subjected to hydrolysis with enzyme mixture of high xylanase, cellobiohydrolase, and β-glucosidase activities at a dosage of 10 FPU/g of dry pulp and fiber concentration of 2.5, 5, and 10%. HPLC was used to analyze soluble sugars after hydrolysis and additional acid inversion of oligomers to monosaccharides. Kraft pulp demonstrated higher pulp conversion after 48 h (74–99%), which mostly resulted from deep xylan hydrolysis. Sulfite-pulp hydrolysates, obtained in similar conditions due to higher hexose concentration (more than 50 g/L), had higher fermentability for industrial strains producing alcohols, microbial protein, or organic acids. Along with saccharification, enzymatic modification of non-hydrolyzed residues occurred, which led to decreased degree of polymerization and composition changes in two industrial pulps. As a result, crystallinity of kraft pulp increased by 1.3%, which opens possibilities for obtaining new types of cellulosic products in the pulp and paper industry. The high adaptability and controllability of enzymatic and fermentation processes creates prospects for the modernization of existing factories. Full article

Overexposure to solar radiation has become an increasingly worrying problem due to the damage to the skin caused by ultraviolet radiation (UVR). In previous studies, the potential of an extract enriched with glycosylated flavonoids from the endemic Colombian high-mountain plant Baccharis antioquensis as a photoprotector and antioxidant was demonstrated. Therefore, in this work we sought to develop a dermocosmetic formulation with broad-spectrum photoprotection from the hydrolysates and purified polyphenols obtained from this species. Hence, the extraction of its polyphenols with different solvents was evaluated, followed by hydrolysis and purification, in addition to the characterization of its main compounds by HPLC–DAD and HPLC–MS, and evaluation of its photoprotective capacity through the measurement of the Sun Protection Factor (SPF), UVA Protection Factor (UVAPF), other Biological Effective Protection Factors (BEPFs), and its safety through the cytotoxicity. In the dry methanolic extract (DME) and purified methanolic extract (PME), flavonoids such as quercetin and kaempferol were found, which demonstrated antiradical capacity, as well as UVA–UVB photoprotection and prevention of harmful biological effects, such as elastosis, photoaging, immunosuppression, DNA damage, among others, which demonstrates the potential of the ingredients in this type of extract to be applied in photoprotection dermocosmetics. Full article

The effects of limited hydrolysis following glycosylation with dextran on the structural properties and antioxidant activity of the soybean protein isolate (SPI) were investigated. Three SPI hydrolysate (SPIH) fractions, F30 (>30 kDa), F30-10 (10–30 kDa), and F10 (<10 kDa), were confirmed using gel permeation chromatography. The results demonstrated that the glycosylation of F30 was faster than that of F30-10 or F10. The enzymolysis caused the unfolding of the SPI to expose the internal hydrophobic cores, which was further promoted by the grafting of dextran, making the obtained conjugates have a loose spatial structure, strong molecular flexibility, and enhanced thermal stability. The grafting of dextran significantly enhanced the DPPH radical or •OH scavenging activity and the ferrous reducing power of the SPI or SPIH fractions with different change profiles due to their different molecular structures. The limited enzymolysis following glycosylation was proven to be a promising way to obtain SPI-based food ingredients with enhanced functionalities. Full article

In the bio-based era, cellulolytic and hemicellulolytic enzymes are biocatalysts used in many industrial processes, playing a key role in the conversion of recalcitrant lignocellulosic waste biomasses. In this context, many thermophilic microorganisms are considered as convenient sources of carbohydrate-active enzymes (CAZymes). In this work, a functional genomic annotation of Alicyclobacillus mali FL18, a recently discovered thermo-acidophilic microorganism, showed a wide reservoir of putative CAZymes. Among them, a novel enzyme belonging to the family 9 of glycosyl hydrolases (GHs), named AmCel9, was identified; in-depth in silico analyses highlighted that AmCel9 shares general features with other GH9 members. The synthetic gene was expressed in Escherichia coli and the recombinant protein was purified and characterized. The monomeric enzyme has an optimal catalytic activity at pH 6.0 and has comparable activity at temperatures ranging from 40 °C to 70 °C. It also has a broad substrate specificity, a typical behavior of multifunctional cellulases; the best activity is displayed on β-1,4 linked glucans. Very interestingly, AmCel9 also hydrolyses filter paper and microcrystalline cellulose. This work gives new insights into the properties of a new thermophilic multifunctional GH9 enzyme, that looks a promising biocatalyst for the deconstruction of lignocellulose. Full article

Margaritaria nobilis is a shrubby species widely distributed in Brazil from the Amazon to the Atlantic Rainforest. Its bark and fruit are used in the Peruvian Amazon for disinfecting abscesses and as a tonic in pregnancy, respectively, and its leaves are used to treat cancer symptoms. From analyses via UHPLC-MS/MS, we sought to determine the chemical profile of the ethanolic extract of M. nobilis leaves by means of putative analyses supported by computational tools and spectral libraries. Thus, it was possible to annotate 44 compounds, of which 12 are phenolic acid derivatives, 16 are O-glycosylated flavonoids and 16 hydrolysable tannins. Among the flavonoids, although they are known, except for kaempferol, which has already been isolated from this species, the other flavonoids (10, 14, 15, 21, 24–26, 28–30, 33–35, 40 and 41) are being reported for the first time in the genus. Among the hydrolysable tannins, six ellagitannins present the HHDP group (6, 19, 22, 31, 38 and 43), one presents the DHHDP group (5), and four contain oxidatively modified congeners (12, 20, 37 and 39). Through the annotation of these compounds, we hope to contribute to the improved chemosystematics knowledge of the genus. Furthermore, supported by a metric review of the literature, we observed that many of the compounds reported here are congeners of authentically bioactive compounds. Thus, we believe that this work may help in understanding future pharmacological activities. Full article

The objective of the research was to analyze and compare the oxidative and physical stabilities of conjugated linoleic acid (CLA) emulsions stabilized by two glycosylated hydrolysates (GPP-A and GPP-B) that were formed via two different pathways. This study showed that GPP-A exhibited higher browning intensity and DPPH radical scavenging ability in comparison with GPP-B. Moreover, the CLA emulsion formed by GPP-A exhibited a lower creaming index, average particle size, primary and secondary oxidative products, in comparison with GPP-B-loaded emulsion. However, the GPP-A-loaded emulsion showed a higher absolute potential and fraction of interfacial adsorption than that of the CLA emulsion formed by GPP-B. Therefore, the CLA emulsion formed by GPP-A exhibited stronger stabilities in comparison with the GPP-B-loaded emulsion. These results suggested that GPP-A showed an emulsification-based delivery system for embedding CLA to avoid the loss of biological activities. Additionally, the development of CLA emulsions could exert its physiological functions and prevent its oxidation. Full article

Spondias mangifera is a drupaceous fruit popular for its flavour and health advantages. There is little scientific knowledge about S. mangifera, despite its widespread usage in traditional medicine, in the North-Eastern region of India. Inhibiting the key carbohydrate hydrolysing enzymes is one of the strategies for managing diabetes. Therefore, this study studied the antioxidant and anti-diabetic properties of different fraction S. mangifera fruit extract (SMFFs) from Indian geographical origin by in vitro experimental assays and silico docking simulation studies. The ADMET prediction for active substances was also investigated using the AdmetSAR database. Based on the binding affinity/molecular interactions between phytocompounds and target enzymes, in silico investigations were done to confirm the in vitro enzymatic inhibitory capability. β-sitosterol in EtOH-F was analysed using RP-HPLC with RP-C18 column as stationary phase and photo diode array detector. The percentage of β-sitosterol was found to be 1.21% ± 0.17% of total weight of extract (w/w). S. mangifera fruit ethanolic extract had a significant inhibitory concentration of 50% against free radicals produced by ABTS (89.71 ± 2.73%) and lipid peroxidation assay (88.26 ± 2.17%) tests. Similarly, the in vitro antidiabetic test findings indicated that S. mangifera inhibited alpha-amylase (73.42 ± 2.01%) and alpha-glucosidase (79.23 ± 1.98%) enzymes dose-dependently. The maximum glycosylated Hb percentage inhibitory activity shown in the ethanolic fraction was (83.97 ± 2.88%) at 500 µg/mL. The glucose uptake of the ethanolic fraction by the yeast cell showed significant (p < 0.05) at 500 µg/mL when compared with metformin (91.37 ± 1.59%), whereas the other fraction did not show the uptake of glucose by the yeast cell at the same concentration. In the docking study, the main phytoconstituents of S. mangifera fruit, such as oleanolic acid, beta-sitosterol, and beta amyrin, show strong affinity for pancreatic α-amylase. These results imply that S. mangifera has α-amylase and α-glucosidase inhibitory properties and may be used as antidiabetic with antioxidant characteristics. Full article

Hydrolysable tannins (HTs) are useful secondary metabolites that are responsible for pharmacological activities and astringent taste, flavor, and quality in fruits. They are also the main polyphenols in Canarium album L. (Chinese olive) fruit, an interesting and functional fruit that has been cultivated for over 2000 years. The HT content of C. album fruit was 2.3–13 times higher than that of berries with a higher content of HT. 1-galloyl-β-d-glucose (βG) is the first intermediate and the key metabolite in the HT biosynthesis pathway. It is catalyzed by UDP-glucosyltransferases (UGTs), which are responsible for the glycosylation of gallic acid (GA) to form βG. Here, we first reported 140 UGTs in C. album. Phylogenetic analysis clustered them into 14 phylogenetic groups (A, B, D–M, P, and Q), which are different from the 14 typical major groups (A~N) of Arabidopsis thaliana. Expression pattern and correlation analysis showed that UGT84A77 (Isoform0117852) was highly expressed and had a positive correlation with GA and βG content. Prokaryotic expression showed that UGT84A77 could catalyze GA to form βG. These results provide a theoretical basis on UGTs in C. album, which will be helpful for further functional research and availability on HTs and polyphenols. Full article

Members of the genera Proteiniphilum and Petrimonas were speculated to represent indicators reflecting process instability within anaerobic digestion (AD) microbiomes. Therefore, Petrimonas mucosa ING2-E5A^T was isolated from a biogas reactor sample and sequenced on the PacBio RSII and Illumina MiSeq sequencers. Phylogenetic classification positioned the strain ING2-E5A^T in close proximity to Fermentimonas and Proteiniphilum species (family Dysgonomonadaceae). ING2-E5A^T encodes a number of genes for glycosyl-hydrolyses (GH) which are organized in Polysaccharide Utilization Loci (PUL) comprising tandem susCD-like genes for a TonB-dependent outer-membrane transporter and a cell surface glycan-binding protein. Different GHs encoded in PUL are involved in pectin degradation, reflecting a pronounced specialization of the ING2-E5A^T PUL systems regarding the decomposition of this polysaccharide. Genes encoding enzymes participating in amino acids fermentation were also identified. Fragment recruitments with the ING2-E5A^T genome as a template and publicly available metagenomes of AD microbiomes revealed that Petrimonas species are present in 146 out of 257 datasets supporting their importance in AD microbiomes. Metatranscriptome analyses of AD microbiomes uncovered active sugar and amino acid fermentation pathways for Petrimonas species. Likewise, screening of metaproteome datasets demonstrated expression of the Petrimonas PUL-specific component SusC providing further evidence that PUL play a central role for the lifestyle of Petrimonas species. Full article

We report herein a novel ChemMatrix^® Rink resin functionalised with two phenylboronate (PhB) moieties linked on the N-α and N-ε amino functions of a lysine residue to specifically capture deoxyfructosylated peptides, compared to differently glycosylated peptides in complex mixtures. The new PhB-Lys(PhB)-ChemMatrix^® Rink resin allows for exploitation of the previously demonstrated ability of cis diols to form phenylboronic esters. The optimised capturing and cleavage procedure from the novel functionalised resin showed that only the peptides containing deoxyfructosyl-lysine moieties can be efficiently and specifically detected by HR-MS and MS/MS experiments. We also investigated the high-selective affinity to deoxyfructosylated peptides in an ad hoc mixture containing unique synthetic non-modified peptides and in the hydrolysates of human and bovine serum albumin as complex peptide mixtures. We demonstrated that the deoxyfructopyranosyl moiety on lysine residues is crucial in the capturing reaction. Therefore, the novel specifically-designed PhB-Lys(PhB)-ChemMatrix^® Rink resin, which has the highest affinity to deoxyfructosylated peptides, is a candidate to quantitatively separate early glycation peptides from complex mixtures to investigate their role in diabetes complications in the clinics. Full article

A large number of mutations causing PMM2-CDG, which is the most frequent disorder of glycosylation, destabilize phosphomannomutase2. We looked for a pharmacological chaperone to cure PMM2-CDG, starting from the structure of a natural ligand of phosphomannomutase2, α-glucose-1,6-bisphosphate. The compound, β-glucose-1,6-bisphosphate, was synthesized and characterized via ³¹P-NMR. β-glucose-1,6-bisphosphate binds its target enzyme in silico. The binding induces a large conformational change that was predicted by the program PELE and validated in vitro by limited proteolysis. The ability of the compound to stabilize wild type phosphomannomutase2, as well as frequently encountered pathogenic mutants, was measured using thermal shift assay. β-glucose-1,6-bisphosphate is relatively resistant to the enzyme that specifically hydrolyses natural esose-bisphosphates. Full article

Chemical defences are key components in insect–plant interactions, as insects continuously learn to overcome plant defence systems by, e.g., detoxification, excretion or sequestration. Cyanogenic glucosides are natural products widespread in the plant kingdom, and also known to be present in arthropods. They are stabilised by a glucoside linkage, which is hydrolysed by the action of β-glucosidase enzymes, resulting in the release of toxic hydrogen cyanide and deterrent aldehydes or ketones. Such a binary system of components that are chemically inert when spatially separated provides an immediate defence against predators that cause tissue damage. Further roles in nitrogen metabolism and inter- and intraspecific communication has also been suggested for cyanogenic glucosides. In arthropods, cyanogenic glucosides are found in millipedes, centipedes, mites, beetles and bugs, and particularly within butterflies and moths. Cyanogenic glucosides may be even more widespread since many arthropod taxa have not yet been analysed for the presence of this class of natural products. In many instances, arthropods sequester cyanogenic glucosides or their precursors from food plants, thereby avoiding the demand for de novo biosynthesis and minimising the energy spent for defence. Nevertheless, several species of butterflies, moths and millipedes have been shown to biosynthesise cyanogenic glucosides de novo, and even more species have been hypothesised to do so. As for higher plant species, the specific steps in the pathway is catalysed by three enzymes, two cytochromes P450, a glycosyl transferase, and a general P450 oxidoreductase providing electrons to the P450s. The pathway for biosynthesis of cyanogenic glucosides in arthropods has most likely been assembled by recruitment of enzymes, which could most easily be adapted to acquire the required catalytic properties for manufacturing these compounds. The scattered phylogenetic distribution of cyanogenic glucosides in arthropods indicates that the ability to biosynthesise this class of natural products has evolved independently several times. This is corroborated by the characterised enzymes from the pathway in moths and millipedes. Since the biosynthetic pathway is hypothesised to have evolved convergently in plants as well, this would suggest that there is only one universal series of unique intermediates by which amino acids are efficiently converted into CNglcs in different Kingdoms of Life. For arthropods to handle ingestion of cyanogenic glucosides, an effective detoxification system is required. In butterflies and moths, hydrogen cyanide released from hydrolysis of cyanogenic glucosides is mainly detoxified by β-cyanoalanine synthase, while other arthropods use the enzyme rhodanese. The storage of cyanogenic glucosides and spatially separated hydrolytic enzymes (β-glucosidases and α-hydroxynitrile lyases) are important for an effective hydrogen cyanide release for defensive purposes. Accordingly, such hydrolytic enzymes are also present in many cyanogenic arthropods, and spatial separation has been shown in a few species. Although much knowledge regarding presence, biosynthesis, hydrolysis and detoxification of cyanogenic glucosides in arthropods has emerged in recent years, many exciting unanswered questions remain regarding the distribution, roles apart from defence, and convergent evolution of the metabolic pathways involved. Full article