Isolation and identification of a humanTRPV1 activating compound from soy sauce

Advancements in production, assessment, and food applications of salty and saltiness-enhancing peptides: A review

Salt is important for food flavor, but excessive sodium intake leads to adverse health consequences. Thus, salty and saltiness-enhancing peptides are developed for sodium-reduction products. This review elucidates saltiness perception process and analyses correlation between the peptide structure and saltiness-enhancing ability. These peptides interact with taste receptors to produce saltiness perception, including ENaC, TRPV1, and TMC4. This review also outlines preparation, isolation, purification, characterization, screening, and assessment techniques of these peptides and discusses their potential applications. These peptides are from various sources and produced through enzymatic hydrolysis, microbial fermentation, or Millard reaction and then separated, purified, identified, and screened. Sensory evaluation, electronic tongue, bioelectronic tongue, and cell and animal models are the primary saltiness assessment approaches. These peptides can be used in sodium-reduction food products to produce "clean label" items, and the peptides with biological activity can also serve as functional ingredients, making them very promising for food industry.

Formation, Identification, and Occurrence of the Furan-Containing β-Carboline Flazin Derived from l-Tryptophan and Carbohydrates

β-Carbolines (βCs) are bioactive indole alkaloids found in foods and in vivo. This work describes the identification, formation, and occurrence in foods of the βC with a furan moiety flazin (1-[5-(hydroxymethyl)furan-2-yl]-9H-pyrido[3,4-b]indole-3-carboxylic acid). Flazin was formed by the reaction of l-tryptophan with 3-deoxyglucosone but not with 5-hydroxymethylfurfural. Its formation was favored in acidic conditions and heating (70-110 °C). The proposed mechanism of formation occurs through the formation of intermediates 3,4-dihydro-β-carboline-3-carboxylic acid (imines), followed by the oxidation to C═O in the carbohydrate chain and aromatization to βC ring with subsequent dehydration steps and cyclization to afford the furan moiety. Flazin is generated in the reactions of tryptophan with carbohydrates. Its formation from fructose was higher than from glucose, whereas sucrose gave flazin under acidic conditions and heating owing to hydrolysis. Flazin was identified in foods by HPLC-MS, and its content was determined by HPLC-fluorescence. It occurred in numerous processed foods, such as tomato products, including crushed tomato puree, fried tomato, ketchup, tomato juices, and jams, but also in soy sauce, beer, balsamic vinegar, fruit juices, dried fruits, fried onions, and honey. Their concentrations ranged from not detected to 22.3 μg/mL, with the highest mean levels found in tomato concentrate (13.9 μg/g) and soy sauce (9.4 μg/mL). Flazin was formed during the heating process, as shown in fresh tomato juice and crushed tomatoes. These results indicate that flazin is widely present in foods and is daily uptaken in the diet.

Identification, Formation, and Occurrence of Perlolyrine: A β-Carboline Alkaloid with a Furan Moiety in Foods

β-Carbolines are naturally occurring bioactive alkaloids found in foods and in vivo. This research reports the identification, characterization, mechanism of formation, and occurrence of perlolyrine (1-(5-(hydroxymethyl)furan-2-yl)-9H-pyrido[3,4-b]indole), a β-carboline with a furan moiety. Perlolyrine did not arise from l-tryptophan and hydroxymethylfurfural but from the reaction of l-tryptophan with 3-deoxyglucosone, an intermediate of carbohydrate degradation. The mechanism of formation occurs through 3,4-dihydro-β-carboline-3-carboxylic acid intermediates (imines), followed by the oxidation of C1'-OH to ketoimine and oxidative decarboxylation at C-3, along with dehydration and cyclization to afford the β-carboline with a furan moiety. The formation of perlolyrine was favored in acidic conditions and temperatures in the range of 70-110 °C. Perlolyrine occurred in the reactions of tryptophan with carbohydrates. The formation rate from fructose was much higher than from glucose. Sucrose also gave perlolyrine under acidic conditions and heating. Perlolyrine was identified in many foods by HPLC-MS and analyzed by HPLC-fluorescence. It occurred in many processed foods such as tomato products including tomato puree, fried tomato, ketchups, tomato juices, and jams but also in soy sauce, beer, balsamic vinegar, fruit juices, dried fruits, fried onion, and honey. The concentrations ranged from an undetected amount to 3.5 μg/g with the highest average levels found in tomato concentrate (1.9 μg/g) and soy sauce (1.5 μg/mL). The results show that perlolyrine formed during the heating process of foods. It is concluded that perlolyrine is widely present in foods and it is daily ingested in the diet.

Maillard-reacted peptides from glucosamine-induced glycation exhibit a pronounced salt taste-enhancing effect

Reducing salt intake, as one of the most cost-effective approaches, is congruent with improved population health. Grass carp skin collagen was subjected to enzymatic hydrolysis and ultrafiltration, followed by glucosamine-induced Maillard reaction to prepare Maillard-reacted peptides. Their color, free amino acid and peptide size distribution were analyzed, while UV and fluorescence spectroscopy were utilized to characterize the progress of Maillard reaction. The salt taste-enhancing effect of Maillard-reacted peptides was investigated via sensory analysis and electronic tongue. LC-MS/MS was employed to analyze the glycation sites of Maillard-reacted peptides. The results indicated that the degree of Maillard reaction was relatively low, and thermal degradation and crosslinking simultaneously occurred. Maillard-reacted peptides exhibited a significant salt taste-enhancing effect, which may be attributed to the glucosamine-induced glycation confirmed by LC-MS/MS analysis. The current study provides a theoretical basis for preparation of salt taste-enhancing peptides and their future application to reduce salt content of formulated foods.

Network Pharmacology/Metabolomics-Based Validation of AMPK and PI3K/AKT Signaling Pathway as a Central Role of Shengqi Fuzheng Injection Regulation of Mitochondrial Dysfunction in Cancer-Related Fatigue

Chinese herbal medicines have multiple targets and properties, and their use in multidisciplinary cancer therapies has consequently received increasing attention. Here, we have investigated the possible active ingredients associated with cancer-related fatigue (CRF) in the Shengqi Fuzheng Injection (SFI). In vitro cell models were used to measure the regulation effects of SFI on CRF. Metabolomic analysis was used to identify the potential genes and pathways in C2C12 mouse myoblasts treated with SFI, and the interaction of compounds and CRF targets was predicted using network pharmacology and molecular docking analyses. The putative pathways were further verified using immuno-blotting assays. The results showed that SFI significantly inhibited muscle cell apoptosis and increased the mitochondrial membrane potential of muscle cells. The network pharmacology analysis results identified 36 candidate compounds, and 244 potential targets were yielded by SFI, and they shared 10 key targets associated with cancer-related fatigue. According to the enrichment analysis and experimental validation, SFI might ameliorate muscle cell mitochondrial function by activating AMPK and inhibiting the PI3K/Akt signaling pathways, and the expression changes of mitochondrial metabolic enzymes MnSOD and apoptosis-associated proteins Bax and Bcl-2 were also triggered. The functions and mechanisms of SFI in anticancer-related fatigue were found here to be at least partly due to the targeting of the AMPK and PI3K/Akt signaling pathways, and this has highlighted new potential applications for network pharmacology when researching Chinese Medicines.

Sweet scent lactones activate hot capsaicin receptor, TRPV1

In this study, we investigated the activation of Transient receptor potential vanilloid subtype 1, TRPV1, by lactones, a representative flavor ingredient currently used for foods and beverages. As a result, we found that some lactones having C4 acyl chain length, γ-octalactone, δ-nonalactone and β-methyl-γ-octalactone, γ-undecalactone with C7 acyl chain length and δ-undecalactone with C6 acyl chain length activated TRPV1. TRPV1 is known as a non-selective cation channels that respond to a wide range of physical and chemical stimuli such as high temperature, protons, capsaicin and so on. Furthermore, it has been also demonstrated that activation of TRPV1 induced energy expenditure enhancement and thermogenesis, suppressed accumulation of visceral fat in mice and prevented non-alcoholic fatty acid liver. Thus, lactones that function as TRPV1 agonists are thought to be important candidates for decreasing the risks of developing a metabolic syndrome.

Total alkaloids from the rhizomes of Ligusticum striatum: a review of chemical analysis and pharmacological activities

Rhizome Chuanxiong (RCX), the dried rhizomes of Ligusticum striatum DC., is a geoauthentic TCM herb distributed in Sichuan province of China that possesses efficacy in promoting blood circulation, removing blood stasis and alleviating pain. Rhizome Chuanxiong total alkaloids (RCXTAs) are one of the major characteristic constituents of RCX with the effects of antimigraine, neuroprotective, cardioprotective and other cardiovascular and cerebrovascular diseases. Over the past years, rapid development of technology has advanced some aspects of RCXTAs. The aim of this review is to illustrate the recent advances in the chemical analysis and biological activities of RCXTAs, and to highlight new challenges.

Browning and pigmentation in food through the Maillard reaction

The Maillard reaction was discovered in 1912 by Louis C. Maillard when he observed the browning phenomena with aroma formation in a heated solution containing a sugar and an amino acid. The Maillard reaction starts from the reactions between carbonyl groups of various sugars and amino groups of amino acids/ proteins, following the formation of intermediate compounds or poly-carbonyl compounds, which further react with each other and amino acids/proteins. Through various chemical reactions such as condensation, polymerization, degradation, cyclization etc., color and aroma are formed. The imparting of brown color is mainly attributed to melanoidins. However, the chemical structure of melanoidins remains unclear because melanoidins are complex and heterogeneous polymers. On the other hand, various kinds of low-molecular-weight pigments formed through the Maillard reaction have been isolated and their structures have been identified. Even though the contribution of each pigment is small, the recognition of color is cumulative. In some case, these pigments form brown polymers or significantly contribute to the total color of a model solution. These chemically clear information gives us a novel aspect for an overview of browning or pigmentation through the Maillard reaction. Graphical abstract.

Chemoinformatic Database Building and in Silico Hit-Identification of Potential Multi-Targeting Bioactive Compounds Extracted from Mushroom Species

Mushrooms are widely-consumed fungi which contain natural compounds that can be used both for their nutritive and medicinal properties, i.e., taking advantage of their antimicrobial, antiviral, antitumor, anti-allergic, immunomodulation, anti-inflammatory, anti-atherogenic, hypoglycemic, hepatoprotective and antioxidant effects. Currently, scientific interest in natural compounds extracted from the fungal species is increasing because these compounds are also known to have pharmacological/biological activity. Unfortunately, however, their mechanisms of action are often unknown, not well understood or have not been investigated in their entirety. Given the poly-pharmacological properties of bioactive fungal compounds, it was decided to carry out a multi-targeted approach to predict possible interactions occurring among bioactive natural fungal extracts and several macromolecular targets that are therapeutically interesting, i.e., proteins, enzymes and nucleic acids. A chemical database of compounds extracted from both edible and no-edible mushrooms was created. This database was virtually screened against 43 macromolecular targets downloaded from the Protein Data Bank website. The aim of this work is to provide a molecular description of the main interactions involving ligand/multi-target recognition in order to understand the polypharmacological profile of the most interesting fungal extracts and to suggest a design strategy of new multi-target agents.