Sensory evaluation, chemical structures, and threshold concentrations of bitter-tasting compounds in common foodstuffs derived from plants and maillard reaction: A review.

The bitterness of foodstuffs is often associated with toxicity, which negatively influences product acceptability. However, bitter compounds have many benefits, and a slight bitter taste is sometimes favored. In this review, we summarize the methods used to isolate and evaluate the taste of bitter compounds in different foods. The chemical structures and threshold concentrations of these compounds are also recapped. Although the structures and thresholds of many bitter compounds have been confirmed, further studies are needed to develop detailed bitter-masking strategies and establish the relation between functional groups (hetero-cyclic substituents and bonding types) and taste quality. Furthermore, a comprehensive bitterness database and chemometric data must be provided in order to quickly assess the bitterness of unfamiliar products.

Effects of moisture content on the enolization products formation in glucose-proline Maillard reaction models.

BACKGROUND: 2,3-Dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) and 5-hydroxymethylfurfural (HMF) are two main enolization products in the Maillard reaction and found in some foodstuffs. For many years, whether they are functional or noxious to human health has been a matter of debate. Thus, insight into their formation pathways is important to manage Maillard reaction products. In this study, DDMP and HMF were quantified and compared with regard to their formation and degradation in the d-glucose and l-proline Maillard reaction models using different moisture contents (0, 0.1, 0.5, 1.0, and 4.0 mL) at 150 °C for various heating times. RESULTS: DDMP was predominantly generated in dry or low water-content heating models along with n increased 1-deoxyglucosone (1-DG) generation via 2,3-enolization. However, increasing moisture content resulted in a decay of reaction intensity, 1-DG, and DDMP due to a change in the reaction mechanism from 2,3-enolization to 1,2-enolization, which facilitated 3-deoxyglucosone (3-DG) and HMF formation. CONCLUSION: Increased moisture content in glucose-proline models reduced reaction intensity and also inhibited DDMP and facilitated HMF formation by promoting the pathway change from 2,3-enolization to 1,2-enolization to generate more 3-DG. A water content of 1.0 mL was identified as a critical value, from which the 1,2-enolization became a primary pathway occurring in the Maillard reaction. © 2022 Society of Chemical Industry.

Primary Exploration of the Clinical Application of 3D-Printed Complete Dentures.

PURPOSE: To explore the applications of 3D scanning and 3D printing techniques in the restorative treatment of edentulous patients. MATERIALS AND METHODS: A total of 30 edentulous patients (Atwood classes 1 to 4) who visited The 960th Hospital of the People's Liberation Army, Jinan, China, from March 1, 2018 to May 1, 2020 were selected, and the patients were randomly divided into two groups: a traditional complete denture group (group A) and a 3D-printed complete denture group (group B). Each group comprised 15 patients. In group A, the traditional method was used to fabricate complete dentures. In group B, 3D scanning, computer-aided design (CAD), 3D printing, and the duplicate denture technique were used to fabricate the dentures. A single-blinded method was used. Patient satisfaction was measured with a 0-10 visual analog scale (VAS) at four time points: immediately and 1 month, 3 months, and 6 months after denture delivery. SPSS version 22.0 software was used to analyze the data. RESULTS: The ability to speak, ability to chew, and comfort in the two groups gradually improved at the first three time points. VAS scores increased to a satisfactory level after 3 months. The esthetics and stability of the two groups were scored high after the initial delivery. The VAS scores of the two groups regarding esthetics, ability to speak, ability to chew, stability, and comfort were not significantly different (P > .05) at any time point. The number of visits in the 3D-printed complete denture group were significantly decreased in comparison to the traditional group. CONCLUSION: The use of 3D printing for manufacturing complete dentures can rapidly restore edentulous patients and meet patient demands regarding esthetics and function.

Robust W/O/W Emulsion Stabilized by Genipin-Cross-Linked Sugar Beet Pectin-Bovine Serum Albumin Nanoparticles: Co-encapsulation of Betanin and Curcumin.

Betanin and curcumin hold promise as natural colorants and antioxidants for food purposes due to their anti-hypertensive, anti-inflammation, and anti-tumor effects. However, the thermal stability and bioavailability of betanin and curcumin still need improvement. Here, we fabricated sugar beet pectin-bovine serum albumin nanoparticles (SBNPs) with a mean particle size of 180 ± 5.2 nm through a genipin cross-linking strategy to stabilize a type of Pickering water-in-oil-in-water (W/O/W) emulsion and co-encapsulated betanin and curcumin. First, the W1/O emulsion was homogenized with gelatin (the gelling agent) in the water phase and polyglycerol polyricinoleate (a lipophilic surfactant) in the oil phase. Later, W1/O was homogenized with another water phase containing SBNPs. The microstructure of the emulsion was regulated by the particle concentration (c) and W1/O volume fraction (Φ), especially the gel-like high internal phase emulsions were formed at the Φ up to 70%. In this case, betanin was encapsulated in the internal water phase (encapsulation efficiency = 65.3%), whereas curcumin was in the medium-chain triglyceride (encapsulation efficiency = 84.1%). Meanwhile, the shelf stability of betanin and curcumin was improved. Furthermore, the stability of bioactive compounds was potentiated by an emulsion gel in simulated gastrointestinal digestion, resulting in higher bioaccessibility. The aforementioned results suggest that SBNP-stabilized Pickering W/O/W emulsions could be a potential alternative to co-encapsulate betanin and curcumin with enhancement of shelf stability and bioaccessibility.

Thiophene enantiomers from the aerial parts of Eclipta prostrata.

Ten thiophene derivatives (1-10), including two previously undescribed ones (1 and 2), have been obtained and structurally characterized from the aerial parts of a traditional Chinese herb Eclipta prostrata. Six of them with one chiral center were identified to be scalemic mixtures, and the pure enantiomers of two isolates (1 and 3) were successfully separated via chemical derivatization and chiral HPLC, with the absolute configurations being established by analysis of optical rotations. All the thiophenes were subjected to a series of assays and compounds 9 and 10 exhibited mild antibacterial activity against Staphylococcus aureus.[Formula: see text].

Cytotoxic ergostane-type steroids from Ganoderma lingzhi.

Two new ergostane-type steroids (1 and 2) have been isolated from the fruiting body of a medicinal macro fungus Ganoderma lingzhi. The structures including the absolute configurations of them were elucidated by a combination of different spectroscopic analyses especially 13C NMR and ECD calculations. Compound 2 features an unusual 1,2-dioxolane moiety. Our bioassays revealed that the two steroids showed remarkable cytotoxicity against human A549 (lung) and MCF-7 (breast) tumor cell lines, with IC50 values ranging from 5.15 to 8.57 µg/mL.

New antibacterial thiophenes from Eclipta prostrata.

Three new thiophene derivatives, ecliprostins A-C (1-3), have been isolated from the aerial parts of a Compositae medicinal plant Eclipta prostrata, and structures of them have been elucidated by comprehensive spectroscopic analyses. Both ecliprostins A (1) and B (2) feature an acetylenic bithiophenyl backbone and also incorporate an isovalerate moiety, while ecliprostin C (3) is a symmetrical dimer of compound 1 and represents the first example bonded via an ether bridge among the very limited natural dimers. All three compounds show antibacterial activity against Staphylococcus aureus.

Structural characterization and biological evaluation of chemical constituents from Ilex cornuta.

One new ursane-type triterpenoid (1), one new ursane-type triterpenoid glycoside (2), and one new oleanane-type triterpenoid glycoside (3), along with 20 known compounds, were isolated from the leaves of Ilex cornuta. The structures of these natural products were elucidated on the basis of detailed spectroscopic analyses and chemical derivation. Our biological evaluation established that selective compounds showed moderate to significant antioxidant activities in the 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods.

Bioactive terpenoid constituents from Eclipta prostrata.

Chemical fractionation of the ethanolic extract of Eclipta prostrata yielded a series of unreported terpenoid constituents, including a rare 6/6/6/6-fused tetracyclic triterpenoid, a pentacyclic triterpenoid, two pentacyclic triterpenoid saponins, a diterpenoid and a sesquiterpenoid. Structures were assigned to these compounds on the basis of comprehensive spectroscopic analyses, with the absolute configurations of the tetracyclic triterpenoid, the diterpenoid and the sesquiterpenoid being determined via explanation of electronic circular dichroism data. Screening of these isolates in an array of bioassays revealed antibacterial, cytotoxic and α-glucosidase inhibitory activities for selective compounds. Of particular interest, the tetracyclic triterpenoid showed very strong inhibition against α-glucosidase with an IC50 of 0.82 ±â€¯0.18 µM, being 103-fold as active as the positive control acarbose.

New e:b-Friedo-Hopane Type Triterpenoids from Euphorbia peplus with Simiarendiol Possessing Significant Cytostatic Activity against HeLa Cells by Induction of Apoptosis and S/G2 Cell Cycle Arrest.

Seven rare e:b-friedo-hopane-type triterpenoids including four new (1-4) and three known (5-7) ones with 5 being first reported as a natural product, together with five other known triterpenoids (8-12), were isolated from the nonpolar fractions of the ethanolic extract of Euphorbia peplus. Structural assignments for these compounds were based on spectroscopic analyses and quantum chemical computation method. The structural variations for the C-21 isopropyl group, including dehydrogenation (1 and 3) and hydroxylation at C-22 (simiarendiol, 2), were the first cases among e:b-friedo-hopane-type triterpenoids. Simiarendiol (2) bearing a 22-OH showed significant cytostatic activity against HeLa and A549 human tumor cell lines with IC50 values of 3.93 ± 0.10 and 7.90 ± 0.31 µM, respectively. The DAPI staining and flow cytometric analysis revealed that simiarendiol (2) effectively induced cell apoptosis and arrested cell cycle at the S/G2 phases in a dose-dependent manner in HeLa cells.

Bioactive sesquiterpenoids and sesquiterpenoid glucosides from the flowers of Inula japonica.

Three new sesquiterpenoids (1-3) and two new sesquiterpenoid glucosides (4 &5), along with 24 known analogues (6-29), were obtained from the flowers of Inula japonica. Structures of the new compounds were determined by interpretation of spectroscopic data, and their absolute configurations were established via comparison of experimental with computed ECD curves. All the isolates were tested in an in vitro cytotoxic assay against human A549, MCF-7 and MDA-MB-231 cancer cell lines, and selective ones displayed significant activity close to the positive control adriamycin. The new molecules 1-5 were also evaluated for their nitric oxide (NO) release inhibitory effect in murine macrophage RAW264.7 cells, with compound 1 showing comparable activity (IC50 16.2 ±â€¯0.8 µM) to the positive control dexamethasome. A preliminary mechanistic study of the effect of 8 toward A549 cells revealed that it could arrest cell cycle at G2/M phase and induce cell apoptosis in a dose-dependent manner.

Insights into the Regulation Effects of Certain Phenolic Acids on 2,3-Dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one Formation in a Microaqueous Glucose-Proline System.

The control of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) formation in the Maillard reaction is important to improve the thermally treated food quality as a result of its intense bitterness and potential toxicity. In this work, phenolic acids, such as gallic, protocatechuic, caffeic, and ferulic acids, were applied to modulate DDMP formation in a microaqueous glucose-proline model. The formation of DDMP was inhibited at low concentrations (from 0.1 to 5.0 mM) while enhanced at 10.0 mM gallic, protocatechuic, and caffeic acids. Ferulic acid always inhibited DDMP formation as a result of the absence of catechol groups on its benzene ring. The result indicated that the control of DDMP formation depended upon the concentration and chemical structures of phenolic acids, such as the number of hydroxyl groups. Further studies indicated that the hydroxyl distribution of phenolic acids regulated the peroxide formation in the model reaction system and further changed the development of the oxidation reaction, which affected the degradation of glucose via caramel or Maillard reaction, Amadori rearrangement product oxidation, and 1-deoxyglucosone degradation to form the intermediates.

Absolute structure assignment of an iridoid-monoterpenoid indole alkaloid hybrid from Dipsacus asper.

Iridoid-monoterpenoid indole alkaloid hybrids (IMIAHs) represent a rare class of natural products reported from only several plants of Rubiaceae and Dipsacaceae families, while their structural assignments remain a very challenging work due to complexity and flexibility. In the current study, a new IMIAH (1) was isolated from the roots of Dipsacus asper and its structure with absolute configuration was unambiguously established by a combination of spectroscopic analyses, chemical degradation and ECD calculation. A new oleanane-type triterpenoid saponin (2) and 15 known co-metabolites were also obtained and structurally characterized. Our biological evaluations showed that compound 2 exhibited moderate inhibition against acetylcholine esterase (AChE) with an IC50 value of 15.8 ±â€¯0.56 µM, and compound 15 displayed potent cytotoxicity selectively against human A549 and H157 lung cancer cells with IC50 values of 6.94 ±â€¯0.24 and 9.06 ±â€¯0.12 µM, respectively.

New octadecanoid derivatives from the seeds of Ipomoea nil.

Four new octadecanoid derivatives (1-4) including a pair of enantiomers (1/2), along with 12 known analogues (5-16), were isolatedfrom the seeds of Ipomoea nil. Their structures were determined by detailed spectroscopic analyses and comparison with reported data of structurally related compounds, with the absolute configurations of 1 and 2 being assigned by an in situ dimolybdenum ECD method. Our bioassays revealed that these isolates did not show ABTS radical scavenging activity while 10 and 13 displayed better α-glucosidase inhibitory activity than the positive control acarbose (IC50 167.7 ± 1.55 µmol·L-1), with IC50 of 92.73 ± 3.12 and 11.39 ± 2.18µmol·L-1, respectively.

Defining the regulatory role of programmed cell death 4 in laryngeal squamous cell carcinoma.

Programmed cell death 4 (PDCD4) is decreased in many different kinds of malignant tumors. EMT endows tumor cells invasive and metastatic properties. However, few studies have determined the role of PDCD4 in the regulation of EMT in the context of laryngeal carcinoma. We examined the relationship between PDCD4 and EMT-associated proteins E-cadherin and N-cadherin using laryngeal carcinoma tissues. Gene manipulation was used to define the regulatory capacity of PDCD4. We report that PDCD4 and E-cadherin/N-cadherin expression were significantly changed in the carcinoma tissues, and their expression was associated with pathological grade, metastatic state, and clinical stage. The suppression of PDCD4 (and consequently, E-cadherin) was concomitant with increased proliferation and G2-phase arrest, decreased apoptosis, and increased cell invasion. PDCD4 upregulation reversed the above-mentioned results. In nude mice, PDCD4 knockdown increased tumor growth and pathological features, confirming the tumorigenic role of PDCD4. Finally, PDCD4 silencing was associated with dysregulation of the carcinogenic Wnt-ß-catenin and the STAT3-miR-21 signaling pathways. This study revealed a dynamic regulatory relationship between PDCD4 and critical factors for EMT, establishing a broad, functional role for PDCD4 in laryngeal carcinoma, which may be propagated by the STAT3-miR-21 pathway. These findings provide new information on an EMT-associated target that may lead to a novel therapy.

Review of pentosidine and pyrraline in food and chemical models: formation, potential risks and determination.

Pyrraline and pentosidine are advanced Maillard reaction products derived from the reaction of glucose with the lysine amino group on proteins. They have been implicated in uremia, diabetes, and related complications, including inflammation, retinopathy, and nephropathy. This review focuses on the formation mechanism, human potential risks, and detections of pentosidine and pyrraline and lays the foundation for further study of pentosidine and pyrraline. © 2017 Society of Chemical Industry.

The evolution of refractive status in Chinese infants during the first year of life and its affected factors.

AIM: To study the evolution of the refractive status and examine the affected factors in infants during the first year of life in a large sample size in China. METHODS: A total of 1258 babies (2516 eyes) aged 32wk gestational age to 1y participated in the study, including 766 premature and 492 full-term infants. First, each baby received an orthoptic examination, slit-lamp checking and fundus imaging. Patients with diseases which might affect refractive status were excluded from the cohort. The cycloplegia retinoscopy was performed. Their neonatal histories were reviewed. Each measurement contained the refractive status and calculation of the spherical equivalent (SE). RESULTS: Refractive state showed an average hyperopia of +0.94±1.63 D at early ages, followed by a trend toward more hyperopia. The refractive state reached the top (+2.43±1.46 D) at the age of one to two months. Then gliding till one year old when the refractive state reached +0.59±1.41 D. The prevalence of astigmatism was 42.17% in the study, being 2.82% myopic astigmatism and 39.35% hyperopic astigmatism. The 94.1% of hyperopic astigmatism was with-the-rule astigmatism and 71.83% of myopic astigmatism was with-the-rule astigmatism. Refractive state between boys and girls was different. The mean SE of boys was +1.97±1.57 D, while that of girls was +1.79±1.46 D, and the difference was significant. CONCLUSION: Before one year old, the change of refractive status is associated with checking age and sex. At the age of one to two months, the degree of hyperopia reaches the top. Boys have more hyperopic degree than girls, and with-the-rule astigmatism is predominant. Excluding premature infants with advanced retinopathy of prematurity, premature and full-term children have same refraction status.

The functions of the Hippo signaling pathway in immune cells.

The Hippo signaling pathway, first identified in Drosophila, has emerged as a critical regulator for controlling the size of organs. Activation of the Hippo signaling pathway negatively regulates the Yorkie ortholog YAP in multiple organs, important in the regulation of cell proliferation, differentiation, and apoptosis during development. The Serine/Threonine protein kinases MST1 and MST2, mammalian homologs of the Drosophila Hippo kinase, play central roles in the Hippo signaling pathway in mammals. Recent studies reveal that non-canonical Hippo signaling pathways are also involved in the regulation of various other biological processes, particularly the important roles of MST1 and MST2 kinases in immune cell activation, adhesion, migration, growth, and apoptosis. In this review, we summarize the recent advances in understanding the roles of MST1 and MST2 kinases in the regulation of the functions of T lymphocytes and innate immune cells.

Effects of Four Different Crown Materials on the Peri-Implant Clinical Parameters and Composition of Peri-Implant Crevicular Fluid.

This study aimed to identify the preferred crown material by measuring the peri-implant clinical parameters and the concentrations of receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), and calcium in peri-implant crevicular fluid (PICF) with 4 different crown materials. A total of 196 patients with a single missing posterior tooth received crown restoration with cobalt-chromium (Co-Cr) porcelain-fused-to-metal (PFM; n = 50), aurum platinum (Au-Pt) PFM (n = 48), titanium (Ti) PFM (n = 52), or zirconia (Zi) all-ceramic crown (n = 46). Fifty-one natural counterpart teeth served as controls. Before and 12 months after restoration, the PICF was collected, and the concentrations of RANKL, OPG, and calcium were quantified. The peri-implant clinical parameters (plaque index, bleeding on probing, and probing depth [PD]) and gingival crevicular fluid (GCF) volumes were assessed. Twelve months after restoration, the PD and GCF volumes for the 4 experimental groups were significantly greater than those for the control group and before restoration. The Co-Cr group showed the greatest PD, GCF volume, RANKL/OPG, RANKL, and calcium ion concentration, followed by the Au-Pt group. The Ti group had the highest OPG concentration, followed by the Zi group. The RANKL and calcium ion concentrations of the Ti and Zi groups were the smallest. The Ti group had the smallest RANKL/OPG ratio, followed by the Zi group. Different crown materials differentially affected the PD, volume, RANKL/OPG ratio, OPG, RANKL, and calcium concentration. Among the 4 tested crown materials, Zi and Ti are preferred. However, some limitations of the present study should be considered.

Promotion effect of sulfite on deoxyosones and 4-methylimidazole in caramel model system.

In this study, hydrogen-deuterium (H/D) exchange experiment was carried out to reveal the promotion effect of sulfite on the formation of deoxyosones and 4-methylimidazole (4-MeI) in the Maillard reaction. Glucose-ammonium (40mmol/L, pH 7.4 in PBS) model systems with different levels of sulfite were incubated at 110°C for 2h. Alpha-dicarbonyls were detected after derivatization by a high-performance liquid chromatography with a diode array detector (HPLC-DAD). 4-MeI in the Maillard reaction was tested using a high-performance anion exchange chromatography with an electrochemical detector (HPAEC-ED). The H/D exchange ratios of hexose (fructose, glucose and mannose) were tested by HPAEC-MS. Results showed that the aldo-enol transition of enediol was promoted by sulfite, which promoted the formation of deoxyosones and 4-MeI. In addition, the oxidation reaction of enediols was inhibited by the antioxidant sulfite, which caused the inhibition of osones formation in the Maillard reaction.