The relationship of dietary flavonoids and periodontitis in US population: a cross-sectional NHANES analysis.

OBJECTIVES: We investigated the association between dietary flavonoids intake and periodontitis. MATERIALS AND METHODS: This cross-sectional study analyzed data from the US National Health and Nutrition Examination Survey 2009-2010 on 3025 participants aged between 30 and 80 years who had full-mouth periodontal examination and dietary flavonoids intake data. This study used periodontal pocket depth (PPD) and clinical attachment loss (CAL) as periodontitis markers. Data were analyzed using multivariate linear regression. RESULTS: After adjusting confounders, the middle tertile of total dietary flavonoids was associated with decreased mean PPD (0.06 mm, P = 0.016) and mean CAL (0.13 mm, P = 0.001) and the top tertile of total dietary flavonoids was significantly associated with decreases in mean PPD (0.05 mm, P = 0.029) and mean CAL (0.11 mm, P = 0.010). Both the middle and top tertiles of total flavonoids intake were significantly related with decreased mean CAL in females, those flossing 0 days/week, overweight and non-diabetic population but not in males, smokers, those flossing 1-6 days/week and diabetic population. Higher anthocyanidins, flavones and flavonols intake was significantly associated with decreased mean PPD and mean CAL while higher flavanones intake was only significantly associated with decreased mean CAL. Higher anthocyanidins intake was particularly related with greatest decreases in mean CAL (top tertile: 0.22 mm, middle tertile: 0.17 mm, both P < 0.010). However, no significant associations were found between isoflavones and flavan_3_ols intake and mean CAL. CONCLUSIONS: Higher dietary flavonoids intake may be beneficial for periodontal health. CLINICAL RELEVANCE: Additional anthocyanidins, flavanones, flavones and flavonols intake was associated with improved periodontal health.

Integration of Metabolomics and Transcriptomics to Explore Dynamic Alterations in Fruit Color and Quality in 'Comte de Paris' Pineapples during Ripening Processes.

Pineapple color yellowing and quality promotion gradually manifest as pineapple fruit ripening progresses. To understand the molecular mechanism underlying yellowing in pineapples during ripening, coupled with alterations in fruit quality, comprehensive metabolome and transcriptome investigations were carried out. These investigations were conducted using pulp samples collected at three distinct stages of maturity: young fruit (YF), mature fruit (MF), and fully mature fruit (FMF). This study revealed a noteworthy increase in the levels of total phenols and flavones, coupled with a concurrent decline in lignin and total acid contents as the fruit transitioned from YF to FMF. Furthermore, the analysis yielded 167 differentially accumulated metabolites (DAMs) and 2194 differentially expressed genes (DEGs). Integration analysis based on DAMs and DEGs revealed that the biosynthesis of plant secondary metabolites, particularly the flavonol, flavonoid, and phenypropanoid pathways, plays a pivotal role in fruit yellowing. Additionally, RNA-seq analysis showed that structural genes, such as FLS, FNS, F3H, DFR, ANR, and GST, in the flavonoid biosynthetic pathway were upregulated, whereas the COMT, CCR, and CAD genes involved in lignin metabolism were downregulated as fruit ripening progressed. APX as well as PPO, and ACO genes related to the organic acid accumulations were upregulated and downregulated, respectively. Importantly, a comprehensive regulatory network encompassing genes that contribute to the metabolism of flavones, flavonols, lignin, and organic acids was proposed. This network sheds light on the intricate processes that underlie fruit yellowing and quality alterations. These findings enhance our understanding of the regulatory pathways governing pineapple ripening and offer valuable scientific insight into the molecular breeding of pineapples.

Biocomposites of Epoxidized Natural Rubber Modified with Natural Substances.

This research aimed to show the possible impact of natural antioxidants on epoxidized natural rubber (ENR) and poly(lactic acid) (PLA) green composites. Thus, the ENR/PLA blends were prepared with the addition of three selected phytochemicals (catechin hydrate, eugenol and flavone). Obtained materials were submitted for solar aging. The analysis of the samples' features revealed that catechin hydrate is a natural substance that may delay the degradation of ENR/PLA blends under the abovementioned conditions. The blend loaded with catechin hydrate presented stable color parameters (dE < 3 a.u.), the highest aging coefficient (K = 0.38 a.u.) and the lowest carbonyl index based on FT-IR data (CI = 1.56) from among all specimens. What is more, this specimen prolonged the oxidation induction time in comparison with the reference samples. Gathered data prove the efficiency of catechin hydrate as an anti-aging additive. Additionally, it was found that a specimen loaded with flavone changed its color parameters significantly after solar aging (dE = 14.83 a.u.) so that it would be used as an aging indicator. Eventually, presented eco-friendly ENR-based compositions may be applied in polymer technology where materials presenting specific properties are desirable.

Pueraria flavones-loaded bile salt liposomes with improved intestinal absorption and oral bioavailability: in vitro and in vivo evaluation.

Pueraria flavone (PF), the main component of Pueraria lobata, is a traditional Chinese medicine used for the treatment of cardiovascular and cerebrovascular diseases; however, it exhibits low oral bioavailability because of its poor membrane permeability. In this study, PF-loaded sodium deoxycholate-decorated liposomes (SDC-Lips) were prepared using the reverse-phase evaporation method and optimised using the Box-Behnken design method. The morphology, particle size, zeta potential, and entrapment efficiency of these PF-loaded SDC-Lips were evaluated. The release behaviours of PF-loaded SDC-Lips in simulated gastric and intestinal fluids were consistent with the Weibull kinetic model. In situ intestinal perfusion studies showed that the absorption characteristics of free PF in rats were mainly passive diffusion and partly active transport, and the duodenum was the main absorption site. After encapsulated with SDC-Lips, the absorption of PF increased significantly. The in vivo pharmacokinetic parameters of area under the plasma concentration-time curve (AUC)(0 → 12 h) and AUC(0 → ∞) of PF-loaded SDC-Lips after intragastric administration were 1.34-fold and 1.543-fold, respectively. Overall, the PF-loaded SDC-Lips improved the oral absorption of PF by increasing its solubility and might be considered a promising formulation strategy for prolonging the biological activity time of PF.

Caffeine induces gastric acid secretion via bitter taste signaling in gastric parietal cells.

Caffeine, generally known as a stimulant of gastric acid secretion (GAS), is a bitter-tasting compound that activates several taste type 2 bitter receptors (TAS2Rs). TAS2Rs are expressed in the mouth and in several extraoral sites, e.g., in the gastrointestinal tract, in which their functional role still needs to be clarified. We hypothesized that caffeine evokes effects on GAS by activation of oral and gastric TAS2Rs and demonstrate that caffeine, when administered encapsulated, stimulates GAS, whereas oral administration of a caffeine solution delays GAS in healthy human subjects. Correlation analysis of data obtained from ingestion of the caffeine solution revealed an association between the magnitude of the GAS response and the perceived bitterness, suggesting a functional role of oral TAS2Rs in GAS. Expression of TAS2Rs, including cognate TAS2Rs for caffeine, was shown in human gastric epithelial cells of the corpus/fundus and in HGT-1 cells, a model for the study of GAS. In HGT-1 cells, various bitter compounds as well as caffeine stimulated proton secretion, whereby the caffeine-evoked effect was (i) shown to depend on one of its cognate receptor, TAS2R43, and adenylyl cyclase; and (ii) reduced by homoeriodictyol (HED), a known inhibitor of caffeine's bitter taste. This inhibitory effect of HED on caffeine-induced GAS was verified in healthy human subjects. These findings (i) demonstrate that bitter taste receptors in the stomach and the oral cavity are involved in the regulation of GAS and (ii) suggest that bitter tastants and bitter-masking compounds could be potentially useful therapeutics to regulate gastric pH.

Recruitment of specific flavonoid B-ring hydroxylases for two independent biosynthesis pathways of flavone-derived metabolites in grasses.

In rice (Oryza sativa), OsF2H and OsFNSII direct flavanones to independent pathways that form soluble flavone C-glycosides and tricin-type metabolites (both soluble and lignin-bound), respectively. Production of soluble tricin metabolites requires CYP75B4 as a chrysoeriol 5'-hydroxylase. Meanwhile, the close homologue CYP75B3 is a canonical flavonoid 3'-hydroxylase (F3'H). However, their precise roles in the biosynthesis of soluble flavone C-glycosides and tricin-lignins in cell walls remain unknown. We examined CYP75B3 and CYP75B4 expression in vegetative tissues, analyzed extractable flavonoid profiles, cell wall structure and digestibility of their mutants, and investigated catalytic activities of CYP75B4 orthologues in grasses. CYP75B3 and CYP75B4 showed co-expression patterns with OsF2H and OsFNSII, respectively. CYP75B3 is the sole F3'H in flavone C-glycosides biosynthesis, whereas CYP75B4 alone provides sufficient 3',5'-hydroxylation for tricin-lignin deposition. CYP75B4 mutation results in production of apigenin-incorporated lignin and enhancement of cell wall digestibility. Moreover, tricin pathway-specific 3',5'-hydroxylation activities are conserved in sorghum CYP75B97 and switchgrass CYP75B11. CYP75B3 and CYP75B4 represent two different pathway-specific enzymes recruited together with OsF2H and OsFNSII, respectively. Interestingly, the OsF2H-CYP75B3 and OsFNSII-CYP75B4 pairs appear to be conserved in grasses. Finally, manipulation of tricin biosynthesis through CYP75B4 orthologues can be a promising strategy to improve digestibility of grass biomass for biofuel and biomaterial production.

Anti-acidogenic and anti-biofilm activity of 5,6,8-trihydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one.

OBJECTIVES: Crude extracts of Dodonaea viscosa var. angustifolia (DVA), has shown to have anticariogenic property. However the compound responsible for this activity has not been identified. The aim of this study was to investigate anti-acidogenic and anti-biofilm activity of a flavone 5,6,8-Trihydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one isolated from D. viscosa var. angustifolia (DVA) in cariogenic bacteria Streptococcus mutans. METHODS: The crude extract from DVA leaves was fractionated into six fractions (F1-F6) using chromatography. The Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) were determined. The effect of the six fractions on biofilm formation and acid production were investigated. The most active fraction (F5) was further fractionated, purified, identified and elucidated using GC-MS and NMR. The anticariogenic property of this purified compound was established. Results were analyzed using Wilcoxon rank-sum test (Mann-Whitney). RESULTS: The MIC and MBC of the fractions (F1-F6) and crude extract ranged from 0.39 to 12.5 mg/ml. F5 showed the lowest MBC. At 0.2 mg/ml, F5 reduced biofilm formation by 93.3% and reduced acid production in S. mutans. Subfraction F5.1 showed higher antimicrobial activity compared to the crude extract and F5. Purified F5.1 was identified as 5,6,8-Trihydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (TMMC). TMMC inhibited biofilm formation at both 6 h (94% reduction) and 24 h (99% reduction), which was higher compared to the crude extract (87% reduction at 0.78 mg/ml after 6 h). TMMC also exhibited a higher inhibitory effect on acid production compared to the crude extract. CONCLUSION: Flavone 5,6,8-Trihydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one derived from DVA has anti-S. mutans, anti-biofilm and anti-acidogenic activity therefore it has a potential for use in the oral cavity to prevent dental caries.

Simultaneous Separation and Purification of Five Polymethoxylated Flavones from "Dahongpao" Tangerine (Citrus tangerina Tanaka) Using Macroporous Adsorptive Resins Combined with Prep-HPLC.

In this study, a preparative separation method was established to simultaneously isolate the polymethoxylated flavones (PMFs) from the peel of "Dahongpao" tangerine using macroporous adsorptive resins (MARs) combined with prep-HPLC. The total PMFs were enriched using MARs to remove most sugars, water-soluble pigments, and flavanones, and the eluents obtained were analyzed by ultra-performance liquid chromatography (UPLC) to determine the PMF composition. The separation and purification of PMFs were carried out by using a mass spectrometry-guided prep-HPLC with a gradient elution of acetonitrile-water (v/v), simultaneously. The purity of these PMFs was determined by UPLC, and their chemical structures were confirmed by electrospray ionization mass spectrometry (ESI-MS-MS), ultraviolet (UV), and nuclear magnetic resonance (NMR). Using the present method, five PMFs, including 5,6,7,4'-tetramethoxyflavone (1), nobiletin (2), tangeretin (3), sinensetin (4), and 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone (5), can be purified simultaneously, and the purity of the compounds obtained were 95.3%, 99.7%, 99.5%, 98.9%, and 98.1%, respectively. The method reported here is simple, rapid, and efficient, and it can be used to separate PMFs from citrus fruit peels and, potentially, other plant materials.

[Chemcial constituents of Eclipta prostrata].

A total of twenty-two compounds were isolated from the 95% EtOH extract of Eclipta prostrata by various purification steps, and their structures were established as ecliptalignin A (1)，ecliptasaponin Ⅰ (2), ecliptasaponin Ⅱ (3), echinocystic acid (4), 3-oxo-16α-hydroxy-olean-12-en-28-oic acid (5), acacetin-7-O-rutinoside (6), luteoloside (7), apigenin (8), luteolin (9), acacetin (10), skullcapflavone Ⅱ (11), kaempferol (12), kaempferide (13), quercetin (14), 4',7-dihydroxyl-3',6'-dimethoxylisoflavone-7-O-glucoside (15), ecliptal (16), 5-hydroxymethyl-(2,2',5',2″)-terthienyl tiglate (17), psoralen (18), isopsoralen (19), wedelolactone (20), crinumaquine (21), and 2,3,9,12-tetramethoxyprotoberberine (22) mainly based on the spectroscopic techniques, of which 1 was a new lignin analogue, and 5, 6, 10-13, 15, 18, 19, 21 and 22 were isolated form this plant for the first time.

Maize Tricin-Oligolignol Metabolites and Their Implications for Monocot Lignification.

Lignin is an abundant aromatic plant cell wall polymer consisting of phenylpropanoid units in which the aromatic rings display various degrees of methoxylation. Tricin [5,7-dihydroxy-2-(4-hydroxy-3,5-dimethoxyphenyl)-4H-chromen-4-one], a flavone, was recently established as a true monomer in grass lignins. To elucidate the incorporation pathways of tricin into grass lignin, the metabolites of maize (Zea mays) were extracted from lignifying tissues and profiled using the recently developed 'candidate substrate product pair' algorithm applied to ultra-high-performance liquid chromatography and Fourier transform-ion cyclotron resonance-mass spectrometry. Twelve tricin-containing products (each with up to eight isomers), including those derived from the various monolignol acetate and p-coumarate conjugates, were observed and authenticated by comparisons with a set of synthetic tricin-oligolignol dimeric and trimeric compounds. The identification of such compounds helps establish that tricin is an important monomer in the lignification of monocots, acting as a nucleation site for starting lignin chains. The array of tricin-containing products provides further evidence for the combinatorial coupling model of general lignification and supports evolving paradigms for the unique nature of lignification in monocots.

Inhibitory potential of flavonoids on PtdIns(3,4,5)P3 binding with the phosphoinositide-dependent kinase 1 pleckstrin homology domain.

Many membrane-associated proteins are involved in various signaling pathways, including the phosphoinositide 3-kinase (PI3K) pathway, which has key roles in diverse cellular processes. Disruption of the activities of these proteins is involved in the development of disease in humans, making these proteins promising targets for drug development. In most cases, the catalytic domain is targeted; however, it is also possible to target membrane associations in order to regulate protein activity. In this study, we established a novel method to study protein-lipid interactions and screened for flavonoid-derived antagonists of PtdIns(3,4,5)P3 binding with the phosphoinositide-dependent kinase 1 (PDK1) pleckstrin homology (PH) domain. Using an enhanced green fluorescent protein (eGFP)-tagged PDK1 PH domain and 50% sucrose-loaded liposomes, the protein-lipid interaction could be efficiently evaluated using liposome pull-down assays coupled with fluorescence spectrophotometry, and a total of 32 flavonoids were screened as antagonists for PtdIns(3,4,5)P3 binding with the PDK1 PH domain. From this analysis, we found that two adjunct hydroxyl groups in the C ring were responsible for the inhibitory effects of the flavonoids. Because the flavonoids shared structural similarities, the results were then subjected to quantitative structure-activity relationship (QSAR) analysis. The results were then further confirmed by in silico docking experiments. Taken together, our strategy presented herein to screen antagonists targeting lipid-protein interactions could be an alternative method for identification and characterization of drug candidates.

Luteolin, quercetin, genistein and quercetagetin inhibit the effects of lipopolysaccharide obtained from Porphyromonas gingivalis in H9c2 cardiomyoblasts.

BACKGROUND: One of the microorganisms from dental plaque associated with severe inflammatory responses in infectious endocarditis is Porphyromonas gingivalis. It is a Gram-negative bacteria harvested from chronic periodontitis patients. Lipopolysaccharide (LPS) obtained from P. gingivalis promotes the expressions of interleukin-1 (IL-1), IL-6 and tumor necrosis factor alpha (TNF-α). Flavonoids are thought to participate in processes that control inflammation, such as the expression of cyclooxygenase-2 (COX-2). METHODS: We investigated the effects of luteolin, quercetin, genistein and quercetagetin on cardiomyoblasts treated with LPS alone or in combination with following inhibitors p38 (SB203580), ERK (PD98059), JNK (SP600125) and PKC (Calphostin C) for 1 h. The kinase activation and COX-2 expression levels were determined at the gene and protein levels. RESULTS: These flavonoids are considered to inhibit the activation of mitogen-activated protein kinase (MAPK) and the degradation of inhibitor of kappa B-alpha (IκB-α). They also play a role in COX-2 expression. CONCLUSION: We conclude that the tested flavonoids inhibit inflammatory responses induced by LPS in H9c2 cells.

Kynurenine Modulates MMP-1 and Type-I Collagen Expression Via Aryl Hydrocarbon Receptor Activation in Dermal Fibroblasts.

Dermal fibrosis is characterized by a high deposition of extracellular matrix (ECM) and tissue cellularity. Unfortunately all means of treating this condition are unsatisfactory. We have previously reported the anti-fibrotic effects of Kynurenine (Kyn), a tryptophan metabolite, in fibrotic rabbit ear model. Here, we report the mechanism by which Kyn modulates the expression of key ECM components in dermal fibroblasts. The results showed that Kyn activates aryl hydrocarbon receptor (AHR) nuclear translocation and up-regulates cytochrome-P450 (CYP1A-1) expression, the AHR target gene. A specific AHR antagonist, 6,2',4'-trimethoxyflavone, inhibited the Kyn-dependent modulation of CYP1A-1, MMP-1, and type-I collagen expression. Establishing the anti-fibrogenic effect of Kyn and its mechanism of action, we then developed nano-fibrous Kyn slow-releasing dressings and examined their anti-fibrotic efficacy in vitro and in a rat model. Our results showed the feasibility of incorporating Kyn into PVA/PLGA nanofibers, prolonging the Kyn release up to 4 days tested. Application of medicated-dressings significantly improved the dermal fibrosis indicated by MMP-1 induction, alpha-smooth muscle actin and type-I collagen suppression, and reduced tissue cellularity, T-cells and myofibroblasts. This study clarifies the mechanism by which Kyn modulates ECM expression and reports the development of a new slow-releasing anti-fibrogenic dressing. J. Cell. Physiol. 231: 2749-2760, 2016. © 2016 Wiley Periodicals, Inc.

Rapid isolation, reliable characterization, and water solubility improvement of polymethoxyflavones from cold-pressed mandarin essential oil.

Polymethoxyflavones possess many biological properties, as lipid-lowering, hypoglycaemic, anti-inflammatory, antioxidant, and anticancer activities, therefore, they may be employed as nutraceuticals or therapeutic agents. The scarcity of pure polymethoxyflavones on the market as well as their low water solubility limited in vivo studies and the use of polymethoxyflavones as food or pharmaceutical supplements. Since mandarin peels are a rich source of polymethoxyflavones, tangeretin, nobiletin, sinensetin, tetra-O-methyl scutellarein, and heptamethoxyflavone were purified from a nonvolatile residue of a cold-pressed mandarin essential oil using a multidimensional preparative liquid chromatographic system coupled with a photodiode array detector and a single quadrupole mass spectrometer. A new prototype, consisting of a nano-liquid chromatography system coupled with an electron ionization mass spectrometer, was used for the characterization of the pure isolated molecules. Finally, due to the collection of highly pure nobiletin and tangeretin, the ability of 2-hydroxypropyl-ß-cyclodextrin to enhance the water solubility of both polymethoxyflavones was evaluated by phase solubility studies and Job's plot method.

A niosomal bilayer of sorbitan monostearate in complex with flavones: a molecular dynamics simulation study.

Bilayers prepared from sorbitan fatty acid esters (Span) have been frequently used for delivery of drugs including flavonoids. We applied molecular dynamics simulation to characterize the structure of a sorbitan monostearate (Span 60) bilayer in complex with three representative flavones, a subclass of flavonoids. At a low concentration, unsubstituted flavone, the most hydrophobic member, was able to flip over and cross the bilayer with a large diffusion coefficient. At a high concentration, it was accumulated at the bilayer center resulting in a phase separation. The leaflets of the bilayer were pushed in the opposite directions increasing the membrane thickness. Order parameter of the stearate chain of Span 60 was not affected significantly by unsubstituted flavone. In contrast, chrysin with hydroxylated ring A was lined up with the acyl chains of Span 60 with its hydroxyl group facing the membrane surface. Neither flipping nor transbilayer movement were allowed. Diffusion coefficient was only 15-25% of that of unsubstituted flavone and order parameter decreased with the concentration of chrysin. Luteolin, the most hydroxylated member, interacted mainly with the headgroup of Span 60 and assumed many different orientations without crossing the bilayer. Unlike chrysin and unsubstituted flavone the bilayer integrity was disrupted at 50 mol% luteolin. These behaviors and structures of flavones in a Span 60 bilayer can be accounted for by their hydrophobicity and sites of hydroxylation.

FTIR, (1)H NMR and EPR spectroscopy studies on the interaction of flavone apigenin with dipalmitoylphosphatidylcholine liposomes.

Apigenin (5,7,4'-trihydroxyflavone) is a cancer chemopreventive agent and a member of the family of plant flavonoids. Apigenin interaction with liposomes formed with dipalmitoylphosphatidylcholine (DPPC) was investigated by means of FTIR spectroscopy, (1)H NMR and EPR techniques. Fluorescent microscopy and electron microscopy were applied to study the apigenin effects on colon myofibroblasts and human skin fibroblasts. The strong rigidifying effect of apigenin with respect to polar head groups was concluded on the basis of the action of the flavone on partition coefficient of Tempo spin label between the water and lipid phases. The ordering effect was also found in hydrophobic region at the depth monitored by 5-SASL and 16-SASL spin labels. The inclusion of apigenin to the membrane restricted the motional freedom of polar head groups lowering penetration of Pr(3+) ions to the membranes. The (1)H NMR technique supported also the restriction of motional freedom of the membrane in the hydrophobic region, especially in the zone of CH(2) groups of alkyl chains. FTIR analysis showed that apigenin incorporates into DPPC liposomes via hydrogen bonding between its own hydroxyl groups and lipid polar head groups in the C-O-P-O-C segment. It is also very likely that hydroxyl groups of apigenin link with polar groups of DPPC by water bridges. Electron and fluorescence microscopic observations revealed changes in the internal membrane organization of the examined cells. In conclusion, the changes of the structural and dynamic properties of membranes can be crucial for processes involving tumor suppression signal transduction pathways and cell cycle regulation.

Identifying inhibitory compounds in lignocellulosic biomass hydrolysates using an exometabolomics approach.

BACKGROUND: Inhibitors are formed that reduce the fermentation performance of fermenting yeast during the pretreatment process of lignocellulosic biomass. An exometabolomics approach was applied to systematically identify inhibitors in lignocellulosic biomass hydrolysates. RESULTS: We studied the composition and fermentability of 24 different biomass hydrolysates. To create diversity, the 24 hydrolysates were prepared from six different biomass types, namely sugar cane bagasse, corn stover, wheat straw, barley straw, willow wood chips and oak sawdust, and with four different pretreatment methods, i.e. dilute acid, mild alkaline, alkaline/peracetic acid and concentrated acid. Their composition and that of fermentation samples generated with these hydrolysates were analyzed with two GC-MS methods. Either ethyl acetate extraction or ethyl chloroformate derivatization was used before conducting GC-MS to prevent sugars are overloaded in the chromatograms, which obscure the detection of less abundant compounds. Using multivariate PLS-2CV and nPLS-2CV data analysis models, potential inhibitors were identified through establishing relationship between fermentability and composition of the hydrolysates. These identified compounds were tested for their effects on the growth of the model yeast, Saccharomyces. cerevisiae CEN.PK 113-7D, confirming that the majority of the identified compounds were indeed inhibitors. CONCLUSION: Inhibitory compounds in lignocellulosic biomass hydrolysates were successfully identified using a non-targeted systematic approach: metabolomics. The identified inhibitors include both known ones, such as furfural, HMF and vanillin, and novel inhibitors, namely sorbic acid and phenylacetaldehyde.

Fluorescence characteristics of some flavones probes in different micellar media.

The fluorescence characteristics of five hydroxiflavones (HFs) (some typical models of flavonols), (3 - HF, 6 - HF, 7-HF, 3, 6 - diHF and 3, 7-diHF) in the micellar media of non-ionic surfactant (Triton X-100), anionic surfactant (SDS) and the block copolymer Pluronic F127, have been investigated by means of UV-Vis and steady-state and time resolved fluorescence spectroscopies. Attention is paid to both excited-state intra-molecular proton transfer (ESIPT) as well as ground-state intermolecular proton transfer. The influence of the -OH groups as well as the effect of temperature on the dual fluorescence emission, the Normal and Tautomer emissions, are also investigated. The fluorescence quantum yield of the HFs in mentioned micellar media has been also determined. The results are discussed with relevance to the local environment of HFs as sensitive fluorescence probe in biological membrane systems.

Preparation of magnetic molecularly imprinted polymers for selective isolation and determination of kaempferol and protoapigenone in Macrothelypteris torresiana.

Novel uniform-sized magnetic molecularly imprinted polymers (MMIPs) were synthesized for selective recognition of active antitumor ingredients of kaempferol (KMF) and protoapigenone (PA) in Macrothelypteris torresiana (M. torresiana) by surface molecular imprinting technique in this study. Super paramagnetic core-shell nanoparticles (γ-MPS-SiO2@Fe3O4) were used as seeds, KMF as template molecule, acrylamide (AM) as functional monomer, and N, N'-methylene bisacrylamide (BisAM) as cross-linker. The prepared MMIPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), transmission electron microscopy (TEM) and thermo-gravimetric analysis (TGA), respectively. The recognition capacity of MMIPs was 2.436 times of non-imprinted polymers. The adsorption results based on kinetics and isotherm analysis were in accordance with the pseudo-second-order model (R (2)=0.9980) and the Langmuir adsorption model (R (2)=0.9944). The value of E (6.742 kJ/mol) calculated from the Dubinin-Radushkevich isotherm model suggested that the physical adsorption via hydrogen-bonding might be predominant. The Scatchard plot showed a single line (R (2)=0.9172) and demonstrated the homogeneous recognition sites on MMIPs for KMF. The magnetic solid phase extraction (MSPE) based on MMIPs as sorbent was established for fast and selective enrichment of KMF and its structural analogue PA from the crude extract of M. torresiana and then KMF and PA were detected by HPLC-UV. The established method showed good performance and satisfactory results for real sample analysis. It also showed the feasibility of MMIPs for selective recognition of active structural analogues from complex herbal extracts.

Bilirubin/morin self-assembled nanoparticle-engulfed collagen/polyvinyl alcohol hydrogel accelerates chronic diabetic wound healing by modulating inflammation and ameliorating oxidative stress.

Chronic diabetic wounds pose a serious threat to human health and safety because of their refractory nature and high recurrence rates. The formation of refractory wounds is associated with wound microenvironmental factors such as increased expression of proinflammatory factors and oxidative stress. Bilirubin is a potent endogenous antioxidant, and morin is a naturally active substance that possesses anti-inflammatory and antioxidant effects. Both hold the potential for diabetic wound treatment by intervening in pathological processes. In this study, we developed bilirubin/morin-based carrier-free nanoparticles (BMn) to treat chronic diabetic wounds. In vitro studies showed that BMn could effectively scavenge overproduced reactive oxygen species and suppress elevated inflammation, thereby exerting a protective effect. BMn was then loaded into a collagen/polyvinyl alcohol gel (BMn@G) for an in vivo study to maintain a moist environment for the skin and convenient biomedical applications. BMn@G exhibits excellent mechanical properties, water retention capabilities, and in vivo safety. In type I diabetic mice, BMn@G elevated the expression of the anti-inflammatory factor IL-10 and concurrently diminished the expression of the proinflammatory factor TNF-α in the tissues surrounding the wounds. Furthermore, BMn@G efficiently mediated macrophage polarization from the M1-type to the M2-type, thereby fostering anti-inflammatory effects. Additionally, BMn@G facilitated the conversion of type III collagen fiber bundles to type I collagen fiber bundles, resulting in a more mature collagen fiber structure. This study provides a promising therapeutic alternative for diabetic wound healing.