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Tryptophan(Trp) is being explored as a potential biomarker for various diseases associated with decreased tryptophan levels; however, metabolomic methods are expensive and time-consuming and require extensive sample analysis, making them urgently needed for trace detection. To exploit the properties of Ti3C2 MXenes a rational porous methyl orange (MO)-delaminated Ti3C2 MXene was prepared via a facile mixing process for the electrocatalytic oxidation of Trp. The hollow-like 3D structure with a more open structure and the synergistic effect of MO and conductive Ti3C2 MXene enhanced its electrochemical catalytic capability toward Trp biosensing. More importantly, MO can stabilize Ti3C2 MXene nanosheets through noncovalent π–π interactions and hydrogen bonding. Compared with covalent attachment, these non-covalent interactions preserve the electronic conductivity of the Ti3C2 MXene nanosheets. Finally, the addition of MO-derived nitrogen (N) and sulfur (S) atoms to Ti3C2 MXene enhanced the electronegativity and improved its affinity for specific molecules, resulting in high-performance electrocatalytic activity. The proposed biosensor exhibited a wide linear response in concentration ranges of 0.01–0.3 µM and 0.5–120 µM, with a low detection limit of 15 nM for tryptophan detection, and high anti-interference ability in complex media of human urine and egg white matrices. The exceptional abilities of the MO/Ti3C2 nanocatalyst make it a promising electrode material for the detection of important biomolecules. [ABSTRACT FROM AUTHOR]

Sweet basil (Ocimum basilicum L.) is an endemic annual mucilaginous spicy herb plant of the mint family (Lamiaceae), growing wild in subtropical and tropical areas of America, Africa, Asia, and in southern Europe. Basil belongs to the aromatic plants that are grown all over the world nowadays. To increase the amount of phenolic and other biologically active compounds in plants, safe, effective, and ecological ways to achieve this are constantly being sought. The greatest economic losses worldwide are due to the negative effects of drought stress and extreme temperatures on plant morphological, physiological, and biochemical characteristics limiting crop growth and productivity. The aim of the study was to evaluate the effect of phenylalanine and tryptophane on the content of chlorophyll and phenolic, and the antioxidant activity of basil under drought conditions. Foliar spraying with phenylalanine and tryptophane to drought-stressed plants increased the chlorophyll a and b content. Application of phenylalanine significantly increased the total phenolic content (TPC) in the cultivar 'Aromatico Della Riviera Ligure', while foliar spraying with tryptophane increased TPC in the drought-stressed 'Palla Compato' and 'Toscano'. Foliar spraying with phenylalanine and tryptophane to drought-stressed plants increased the antioxidant activity measured by the DPPH method. Principal component analysis showed that the first factor was highly and positively related to all parameters studied. Hierarchical clustering analysis showed that the first cluster was formed due to drought-stressed 'Aromatico Della Riviera Ligure', 'Cinnamon', and 'Lemon'. The second cluster consisted of well-watered 'Aromatico Della Riviera Ligure', 'Cinnamon', and 'Lemon', and drought-stressed and phenylalanine-sprayed 'Aromatico Della Riviera Ligure' and 'Palla Compato'. The third cluster consisted of the combinations of other cultivars and treatments tested. [ABSTRACT FROM AUTHOR]

The extracts of whole plants or specific organs from different plant species are gaining increasing attention for their phytotherapy applications. Accordingly, we prepared standardized gemmotherapy extracts (GTEs) from young shoots/buds of olive (Olea europaea), sweet almond (Prunus amygdalus), and black mulberry (Morus nigra), and analyzed the corresponding phytonutrient profiles. We identified 42, 103, and 109 phytonutrients in the olive, almond, and black mulberry GTEs, respectively, containing amino acids, vitamins, polyphenols, flavonoids, coumarins, alkaloids, iridoids, carboxylic acids, lignans, terpenoids, and others. In order to assess the physiological effects generated by the GTEs, we developed a translational nutrition model based on Drosophila melanogaster and Cyprinus carpio. The results indicate that GTEs could influence, to a variable extent, viability and ATP synthesis, even though both are dependent on the specific carbohydrate load of the applied diet and the amino acid and polyphenol pools provided by the GTEs. It seems, therefore, likely that the complex chemical composition of the GTEs offers nutritional properties that cannot be separated from the health-promoting mechanisms that ultimately increase viability and survival. Such an approach sets the paves the way for the nutritional genomic descriptions regarding GTE-associated health-promoting effects. [ABSTRACT FROM AUTHOR]

Broccoli serves as a functional food because it can accumulate selenium (Se), well-known bioactive amino-acid-derived secondary metabolites, and polyphenols. The chemical and physical properties of Se are very similar to those of sulfur (S), and competition between sulfate and selenate for uptake and assimilation has been demonstrated. Towards an efficient agronomic fortification of broccoli florets, the working questions were whether we could overcome this competition by exogenously applying the S-containing amino acids cysteine (Cys) or/and methionine (Met), or/and the precursors of Glucosinolate (GSL) types along with Se application. Broccoli plants were cultivated in a greenhouse and at the beginning of floret growth, we exogenously applied sodium selenate in the concentration gradient of 0, 0.2, 1.5, and 3.0 mM to study the impact of increased Se concentration on the organic S (Sorg) content of the floret. The Se concentration of 0.2 mM (Se0.2) was coupled with the application of Cys, Met, their combination, or a mixture of phenylalanine, tryptophane, and Met. The application took place through fertigation or foliar application (FA) by adding isodecyl alcohol ethoxylate (IAE) or a silicon ethoxylate (SiE) surfactant. Fresh biomass, dry mass, and Se accumulation in florets were evaluated, along with their contents of Sorg, chlorophylls (Chl), carotenoids (Car), glucoraphanin (GlRa), glucobrassicin (GlBra), glucoiberin (GlIb), and polyphenols (PPs), for the biofortification efficiency of the three application modes. From the studied selenium concentration gradient, the foliar application of 0.2 mM Se using silicon ethoxylate (SiE) as a surfactant provided the lowest commercially acceptable Se content in florets (239 μg or 0.3 μmol g−1 DM); it reduced Sorg (−45%), GlIb (−31%), and GlBr (−27%); and it increased Car (21%) and GlRa (27%). Coupled with amino acids, 0.2 mM Se provided commercially acceptable Se contents per floret only via foliar application. From the studied combinations, that of Met,Se0.2/FA,IAE provided the lowest Se content per floret (183 μg or 0.2 μmol g−1 DM) and increased Sorg (35%), Car (45%), and total Chl (27%), with no effect on PPs or GSLs. Cys,Met,Se0.2/FA,IAE and amino acid mix,Se0.2/FA,IAE increased Sorg content, too, by 36% and 16%, respectively. Thus, the foliar application with the IAE surfactant was able to increase Sorg, and methionine was the amino acid in common in these treatments, with varying positive effects on carotenoids and chlorophylls. Only the Cys,Met,Se0.2 combination presented positive effects on GSLs, especially GlRa, but it reduced the fresh mass of the floret. The foliar application with SiE as a surfactant failed to positively affect the organic S content. However, in all studied combinations of Se 0.2 mM with amino acids, the Se content per floret was commercially acceptable, the yield was not affected, the content of GSLs was increased (especially that of GlRa and GlIb), and PPs were not affected. The content of GlBr decreased except for the treatment with methionine (Met,Se0.2/FA,SiE) where GlBr remained unaffected. Hence, the combination of Se with the used amino acids and surfactants can provide enhanced biofortification efficiency in broccoli by providing florets as functional foods with enhanced functional properties. [ABSTRACT FROM AUTHOR]

Background: Indoleamine 2,3-Dioxygenase 1 (IDO1)-mediated tryptophan degradation, which is the rate-limiting enzyme of tryptophan/kynurenine pathway, may cause immune suppression in the tumor microenvironment, while potentiating proliferative and metastatic activity in the tumor focus, Phase studies of IDO1 inhibitors are ongoing, and our study aims to evaluate the potential contribution of IDO1 gene expression to the tryptophan/kynurenine pathway in tumor and tumor microenvironment foci in gastric cancer (GC) on a clinicopathological axis, METHOD: In the case-control study design, the determination of tryptophan and its metabolites in the serum of 51 GC and 49 healthy controls was made using High Pressure Liquid Chromatography-Fluorescence Detector (HPLC-FD). IDO1 expression in a total of 102 tissues with tumor and tumor microenvironment was detected by quantitative PCR (q-PCR)., Results: In gastric tumors, 3,25-fold decreased expression of IDO1 was detected according to the tumor microenvironment (p=0,05), IDO1 expression was found to be more than 2 times higher in signet ring cell carcinoma (SRCC) and poorly differentiated tumors without distant organ metastasis (p<0,05), In GC, tryptophan level was found to be 1,6 times lower than in control (AUC:0889; cut off≤21,57; p<0001), Low tryptophan level was found in advanced tumor stage compared to early stage and in the presence of perineural invasion compared to its absence (p<0,05) The level of kynurenine was found to be approximately 1,8 times lower in SRCC (p=0,04), CONCLUSION: Increased tryptophan accumulation in the gastric tumor and its microenvironment, when catabolized via IDO1, exhibits histological type, tumor differentiation, and metastasis-promoting effects more prominently in aggressive subtypes such as SRCC., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ilhan Yaylim reports financial support was provided by Istanbul University Scientific Research Projects Unit. The hypothesis setup for this study was made by Cem Horozoğlu and İlhan Yaylım. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier GmbH.)

Cette revue recense les arguments en faveur de la contribution du mycobiote à la pathogénie des spondyloarthrites. La variabilité inter- et intra-individuelle du mycobiote digestif est encore supérieure à celle du microbiote bactérien, car la plupart de ces levures (en provenance de l'alimentation ou de l'atmosphère) ne sont présentes que transitoirement. Toutefois, un noyau dur de levures pérennes existe dans l'intestin humain, qui y module la composition du microbiote bactérien. Un déséquilibre de ce mycobiote a été obervé dans les maladies de Crohn et cholangites sclérosantes (défaut de Saccharomyces cerevisiae et excès de levures plus pathogènes). Il peut diminuer la capacité de certaines bactéries commensales à métaboliser le tryptophane pour induire une immunorégulation, forçant les cellules humaines à le faire, ce qui peut induire la libération de kinurénine à l'origine d'une fatigue générale. La dysbiose du mycobiote aggrave celle du microbiote bactérien, et des antigènes bactériens et/ou mycosiques (comme les curdlans) peuvent alors traverser la muqueuse. La translocation de curdlan joue un role central dans la pathogénie des spondyloarthrites du modèle murin SKG, et la migration d'autres antigènes de levures pourrait contribuer à la pathogénie des spondyloarthrites humaines et de certaines uvéites, comme le suggère aussi la présence possible d'anticorps anti- Saccharomyces dans ce contexte. Le homing préférentiel des levures dans les sites touchés par le psoriasis et les maladies de Verneuil est un autre indice. Comme au moins deux gènes majeurs des spondyloarthrites (CARD9 et IL23R) controlent aussi les levures, l'étude des mycobiotes dans les spondyloarthrites sera d'un grand intérêt. [ABSTRACT FROM AUTHOR]

Scheme 1. Schematic of Ag-CQDs nanozyme construction and colorimetric determination of Glucose. [Display omitted] • Ultra-trace Ag-doped CQD were synthesized by one-step microwave method. • Ag can facilitate electrons transfer from the interior of CQDs to the surface. • Peroxidase-like activity of Ag-CQDs was used for glucose colorimetric detection. Carbon quantum dots (CQDs) have significant applications in nanozymes. However, previous studies have not elucidated the structure–activity relationship and enzyme mechanism. In this study, we employed a one-step microwave method to synthesize ultra-trace Ag-doped carbon quantum dots (Ag-CQDs). In the presence of hydrogen peroxide (H 2 O 2), we used the oxidative coupling reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) to evaluate the intrinsic peroxidase-like activity, kinetics, and mechanism of Ag-CQDs. The trace amount of doped Ag (1.64 %) facilitated electron transfer from the CQDs interior to the surface. The electron transfer triggered the peroxide activity of CQDs, producing hydroxyl radical (·OH), which oxidized the colorless TMB to blue-colored TMB (oxTMB). By coupling with glucose oxidase (GOx), the Ag-CQDs/H 2 O 2 /TMB system has been used for colorimetric glucose determination. The system demonstrated a low detection limit (0.17 µM), wide linear range (0.5–5.5 µM), and satisfactory results when fruit juice was analyzed. This study reports a feasible method for the colorimetric detection of glucose by synthesizing ultra-trace Ag-doped carbon quantum dots with peroxidase‐mimicking activity. [ABSTRACT FROM AUTHOR]

Broccoli serves as a functional food because it can accumulate selenium (Se), well-known bioactive amino-acid-derived secondary metabolites, and polyphenols. The chemical and physical properties of Se are very similar to those of sulfur (S), and competition between sulfate and selenate for uptake and assimilation has been demonstrated. Towards an efficient agronomic fortification of broccoli florets, the working questions were whether we could overcome this competition by exogenously applying the S-containing amino acids cysteine (Cys) or/and methionine (Met), or/and the precursors of Glucosinolate (GSL) types along with Se application. Broccoli plants were cultivated in a greenhouse and at the beginning of floret growth, we exogenously applied sodium selenate in the concentration gradient of 0, 0.2, 1.5, and 3.0 mM to study the impact of increased Se concentration on the organic S (Sorg) content of the floret. The Se concentration of 0.2 mM (Se0.2) was coupled with the application of Cys, Met, their combination, or a mixture of phenylalanine, tryptophane, and Met. The application took place through fertigation or foliar application (FA) by adding isodecyl alcohol ethoxylate (IAE) or a silicon ethoxylate (SiE) surfactant. Fresh biomass, dry mass, and Se accumulation in florets were evaluated, along with their contents of Sorg, chlorophylls (Chl), carotenoids (Car), glucoraphanin (GlRa), glucobrassicin (GlBra), glucoiberin (GlIb), and polyphenols (PPs), for the biofortification efficiency of the three application modes. From the studied selenium concentration gradient, the foliar application of 0.2 mM Se using silicon ethoxylate (SiE) as a surfactant provided the lowest commercially acceptable Se content in florets (239 μg or 0.3 μmol g−1 DM); it reduced Sorg (−45%), GlIb (−31%), and GlBr (−27%); and it increased Car (21%) and GlRa (27%). Coupled with amino acids, 0.2 mM Se provided commercially acceptable Se contents per floret only via foliar application. From the studied combinations, that of Met,Se0.2/FA,IAE provided the lowest Se content per floret (183 μg or 0.2 μmol g−1 DM) and increased Sorg (35%), Car (45%), and total Chl (27%), with no effect on PPs or GSLs. Cys,Met,Se0.2/FA,IAE and amino acid mix,Se0.2/FA,IAE increased Sorg content, too, by 36% and 16%, respectively. Thus, the foliar application with the IAE surfactant was able to increase Sorg, and methionine was the amino acid in common in these treatments, with varying positive effects on carotenoids and chlorophylls. Only the Cys,Met,Se0.2 combination presented positive effects on GSLs, especially GlRa, but it reduced the fresh mass of the floret. The foliar application with SiE as a surfactant failed to positively affect the organic S content. However, in all studied combinations of Se 0.2 mM with amino acids, the Se content per floret was commercially acceptable, the yield was not affected, the content of GSLs was increased (especially that of GlRa and GlIb), and PPs were not affected. The content of GlBr decreased except for the treatment with methionine (Met,Se0.2/FA,SiE) where GlBr remained unaffected. Hence, the combination of Se with the used amino acids and surfactants can provide enhanced biofortification efficiency in broccoli by providing florets as functional foods with enhanced functional properties.

Quorum sensing (QS) can regulate the pathogenicity of bacteria and the production of some virulence factors. It is a promising target for screening to find anti-virulence agents in the coming post-antibiotics era. Cyclo (L-Trp-L-Ser), one variety of cyclic dipeptides (CDPs), isolated from a marine bacterium Rheinheimera aquimaris, exhibited anti-QS activity against Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Unlike the CDPs composed of phenylalanine or tyrosine, the anti-QS activity has been widely studied; however, cyclo (L-Trp-L-Ser) and derivatives, containing one tryptophan unit and one non-aromatic amino acid, have not been systematically explored. Herein, the cyclo (L-Trp-L-Ser) and seven derivatives were synthesized and evaluated. All tryptophane-contained CDPs were able to decrease the production of violacein in C.violaceum CV026 and predicted as binding within the same pocket of receptor protein CviR, but in lower binding energy compared with the natural ligand C6HSL. As for P. aeruginosa PAO1, owning more complicated QS systems, these CDPs also exhibited inhibitory effects on pyocyanin production, swimming motility, biofilm formation, and adhesion. These investigations suggested a promising way to keep the tryptophan untouched and make modifications on the non-aromatic unit to increase the anti-QS activity and decrease the cytotoxicity, thus developing a novel CDP-based anti-virulence agent.

A functional ionic liquid is synthesized and performed as modifies on the surface of submicrometer silica spheres. Next, the obtained material is characterized by using NMR, FTIR, SEM and TGA. The chiral resolution conditions for tryptophan enantiomers are analyzed and screened in detail. It is observed that the material has the excellent capability of enantioseparation for tryptophane under optimized conditions. The optimized Ee value is up to 0.93. Meantime, the mechanism is discussed by using density functional theory. [ABSTRACT FROM AUTHOR]

A series of tripeptides TrpTrpPhe (1), TrpTrpTyr (2), and TrpTrpTyr[CH2N(CH3)2] (3) were synthesized, and their photophysical properties and non-covalent binding to polynucleotides were investigated. Fluorescent Trp residues (quantum yield in aqueous solvent ΦF = 0.03–0.06), allowed for the fluorometric study of non-covalent binding to DNA and RNA. Moreover, high and similar affinities of 2×HCl and 3×HCl to all studied double stranded (ds)-polynucleotides were found (logKa = 6.0–6.8). However, the fluorescence spectral responses were strongly dependent on base pair composition: the GC-containing polynucleotides efficiently quenched Trp emission, at variance to AT- or AU-polynucleotides, which induced bisignate response. Namely, addition of AT(U) polynucleotides at excess over studied peptide induced the quenching (attributed to aggregation in the grooves of polynucleotides), whereas at excess of DNA/RNA over peptide the fluorescence increase of Trp was observed. The thermal denaturation and circular dichroism (CD) experiments supported peptides binding within the grooves of polynucleotides. The photogenerated quinone methide (QM) reacts with nucleophiles giving adducts, as demonstrated by the photomethanolysis (quantum yield ΦR = 0.11–0.13). Furthermore, we have demonstrated photoalkylation of AT oligonucleotides by QM, at variance to previous reports describing the highest reactivity of QMs with the GC reach regions of polynucleotides. Our investigations show a proof of principle that QM precursor can be imbedded into a peptide and used as a photochemical switch to enable alkylation of polynucleotides, enabling further applications in chemistry and biology.

Les glucosinolates indoliques sont des métabolites secondaires dérivés de l'acide aminé tryptophane. Ils font partie d'un vaste ensemble de molécules soufrées rencontrées presque exclusivement parmi les Brassicales et notamment la famille des Brassicaceae, qui inclut de nombreuses espèces comestibles d'importance alimentaire majeure. Ces composés, parce qu'ils interviennent dans de nombreuses interactions entre ces plantes et leurs ennemis naturels, jouent dès lors un rôle fondamental d'un point de vue tant biologique qu'économique. Cette revue de synthèse a donc pour objectif de faire le point sur l'évolution récente de nos connaissances en ce qui concerne la biosynthèse de ces molécules, le fonctionnement des mécanismes de défense dans lesquels elles sont mobilisées et les processus écologiques où elles interviennent. Indole glucosinolates are plant secondary metabolites derived from the amino acid tryptophan. They are part of a large group of sulfur-containing molecules almost exclusively found among Brassicales, which include the mustard family (Brassicaceae) with many edible plant species of major nutritional importance. These compounds mediate numerous interactions between these plants and their natural enemies and are therefore of major biological and economical interest. This literature review aims at taking stock of recent advances of our knowledge about the biosynthetic pathways of indole glucosinolates, but also about the defense strategies and ecological processes involving these metabolites. [ABSTRACT FROM AUTHOR]

This study was conducted to determine protein and tryptophane contents of own local peas genetic resources and identify whether there is any convenient lines to develop high nutritiousness quality variety. Fortyfour lines used in experimental study, picked before, described morphologically and selected during 6 years as making selection. These lines were sowed on two different sowing times with 4 control varieties under Samsun conditions and dried grain analyzed for their raw protein ratio and tryptophane content. Statistically significant differences were found among sowing times and tested genotypes for the raw protein ratio and tryptophane content. It was determined that both properties were higher in early spring sowing. In winter sowing, raw protein ratio ranged from 17.73 (Bz16) to 28.36% (Bz42), tryptophane content from 1936.42 (Bz1) to 3119.74 mg kg-1 (Green P.). In spring sowing, raw protein ratio ranged from 19.29 (Bz2) to 27.17% (Bz 42); tryptophane content from 2231.05 (Bz31) to 2746.44 mg kg-1 (Bz16). Open green grain colored, wrinkle grainy Bz42 line gave the highest value. This line was identified as the most significant candidate line for dry grain purposefully for variety development study

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This work deals with use of FT NIR spectroscopy to speedy analysis of maturation of edam cheese. Maturation of cheese was study with the measure of soluble nitrogen, tyrosine and tryptophane. This method can be able to make optimal making raw material to production of processed cheese. Samples of edam cheese (45% fat in dry matter) were analysed with time of ripening 7 to 99 days. Soluble nitrogen, tyrosine and tryptophane were analysed on UV–VisSpectrometer (270 and 290 nm). Sequentially samples were analysed on FT NIR spectrometer of two methods: 1) slice of cheese was analysed help with optical probe, 2) grated cheese was analysed on the integration sphere. The values of correlation coefficient of calibration on the integration sphere were as follows: soluble nitrogen 0.922, tyrosine 0.911 and tryptophane 0.852. The values of correlation coefficient of calibration with optical probe were as follows: soluble nitrogen 0.996, tyrosine 0.958 and tryptophane 0.922.

When lactose was incubated with G794A-β-galactosidase (a variant with a 'closed' active site loop that binds transition state analogs well) an allolactose was trapped with its Gal moiety in a 4H3 conformation, similar to the oxocarbenium ion-like conformation expected of the transition state. The numerous interactions formed between the 4H3 structure and β-galactosidase indicate that this structure is representative of the transition state. This conformation is also very similar to that of d-galactono-1,5-lactone, a good transition state analog. Evidence indicates that substrates take up the 4H3 conformation during migration from the shallow to the deep mode. Steric forces utilizing His418 and other residues are important for positioning the O1 leaving group into a quasi-axial position. An electrostatic interaction between the O5 of the distorted Gal and Tyr503 as well as C-H-π bonds with Trp568 are also significant. Computational studies of the energy of sugar ring distortion show that the β-galactosidase reaction itinerary is driven by energetic considerations in utilization of a 4H3 transition state with a novel 4C1-4H3-4C1 conformation itinerary. To our knowledge, this is the first X-ray crystallographic structural demonstration that the transition state of a natural substrate of a glycosidase has a 4H3 conformation. [ABSTRACT FROM AUTHOR]

This study was conducted to determine protein and tryptophane contents of own local peas genetic resources and identify whether there is any convenient lines to develop high nutritiousness quality variety. Fortyfour lines used in experimental study, picked before, described morphologically and selected during 6 years as making selection. These lines were sowed on two different sowing times with 4 control varieties under Samsun conditions and dried grain analyzed for their raw protein ratio and tryptophane content. Statistically significant differences were found among sowing times and tested genotypes for the raw protein ratio and tryptophane content. It was determined that both properties were higher in early spring sowing. In winter sowing, raw protein ratio ranged from 17.73 (Bz16) to 28.36% (Bz42), tryptophane content from 1936.42 (Bz1) to 3119.74 mg kg-1 (Green P.). In spring sowing, raw protein ratio ranged from 19.29 (Bz2) to 27.17% (Bz 42); tryptophane content from 2231.05 (Bz31) to 2746.44 mg kg-1 (Bz16). Open green grain colored, wrinkle grainy Bz42 line gave the highest value. This line was identified as the most significant candidate line for dry grain purposefully for variety development study. [ABSTRACT FROM AUTHOR]

Quorum sensing (QS) can regulate the pathogenicity of bacteria and the production of some virulence factors. It is a promising target for screening to find anti-virulence agents in the coming post-antibiotics era. Cyclo (L-Trp-L-Ser), one variety of cyclic dipeptides (CDPs), isolated from a marine bacterium Rheinheimera aquimaris, exhibited anti-QS activity against Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Unlike the CDPs composed of phenylalanine or tyrosine, the anti-QS activity has been widely studied; however, cyclo (L-Trp-L-Ser) and derivatives, containing one tryptophan unit and one non-aromatic amino acid, have not been systematically explored. Herein, the cyclo (L-Trp-L-Ser) and seven derivatives were synthesized and evaluated. All tryptophane-contained CDPs were able to decrease the production of violacein in C.violaceum CV026 and predicted as binding within the same pocket of receptor protein CviR, but in lower binding energy compared with the natural ligand C6HSL. As for P. aeruginosa PAO1, owning more complicated QS systems, these CDPs also exhibited inhibitory effects on pyocyanin production, swimming motility, biofilm formation, and adhesion. These investigations suggested a promising way to keep the tryptophan untouched and make modifications on the non-aromatic unit to increase the anti-QS activity and decrease the cytotoxicity, thus developing a novel CDP-based anti-virulence agent. [ABSTRACT FROM AUTHOR]

This chapter includes the aspects of melatonin. The drug is synthesized in the pineal gland starting from tryptophane or synthetically by using indole as starting material. Melatonin has been used as an adjunct to interleukin-2 therapy for malignant neoplasms, as contraceptive, in the management of various forms of insomnia, to alleviate jet lag following long flights, and finally as free radical scavenger and hence as an antioxidant and an anti-inflammatory. The chapter discusses the drug metabolism and pharmacokinetics and presents various method of analysis of this drug such as biological analysis, spectroscopic analysis, and chromatographic techniques of separation. It also discusses its physical properties such as solubility characteristics, X-ray powder diffraction pattern, and thermal methods of analysis. The chapter is concluded with a discussion on its biological properties such as activity, toxicity, and safety. [ABSTRACT FROM AUTHOR]

The birdseed Phalaris canariensis (Pc) is popularly used as an antihypertensive agent. The aqueous extract of Pc (AEPc) was administered in adult normotensive Wistar rats and spontaneously hypertensive rats (SHR) and in prehypertensive young SHR (SHRY, 3 weeks old). Animals received AEPc (400 mg·kg-1·day-1, by gavage) for 30 days, then groups were divided into 2 subgroups: one was treated for another 30 days and the other received water instead of AEPc for 30 days. AEPc reduced systolic blood pressure (SBP) in both adult groups; however, treatment interruption was followed by a gradual return of the SBP to baseline levels. SHRY became hypertensive 30 days after weaning. AEPc minimized the increase in SBP in SHRY, but blood pressure rose to levels similar to those in the untreated group with treatment interruption. There were no changes in renal function, diuresis, or Na+ excretion. Pc is rich in tryptophan, and the inhibition of the metabolism of tryptophan to kynurenine, a potential vasodilator factor, prevented the blood pressure reducing effect of AEPc. Moreover, AEPc significantly reduced sympathoexcitation. Data indicate that the metabolic derivative of tryptophan, kinurenine, may be a mediator of the volume-independent antihypertensive effect of Pc, which was at least in part mediated by suppression of the sympathetic tonus. [ABSTRACT FROM AUTHOR]

A novel fluorescence quenching method for the determination of tetracaine hydrochloride (TA·HCl) concentration with some aromatic amino acids as fluorescence probe has been developed. In pH 6.3 acidic medium, tryptophane (Trp), tyrosine (Tyr) or phenylalanine (Phe) can react with tetracaine hydrochloride to form an ion-association complex by electrostatic attraction, aromatic stacking interaction and Van der Waals' force, which lead to fluorescence quenching of above amino acids. The maximum fluorescence excitation and emission wavelengths of them are located at 278, 274, 258 nm and 354, 306, 285 nm, respectively. The relative fluorescence intensity ( F/ F) is proportional to the TA·HCl concentration in certain range. The linear ranges and detection limits are 1.2-5.0 μg/mL and 0.37 μg/mL for Tyr-TA·HCl system, 1.3-6.0 μg/mL and 0.38 μg/mL for Trp-TA·HCl system, and 1.4-6.0 μg/mL and 0.41 μg/mL for Phe-TA·HCl system. The optimum reaction conditions, influencing factors and the effect of coexisting substances are investigated. And the results show the method has a good selectivity. Judging from the effect of temperature, the Stern-Volmer plots and fluorescence lifetime determination, the quenching of fluorescence of amino acids by TA·HCl is a static quenching process. [ABSTRACT FROM AUTHOR]

Abstract: The combination of biomolecules-functionalized multiwalled carbon nanotube (MWNTs) and ionic liquid (IL) yields nanostructured biointerfaces, formed a novel kind of structurally uniform and bioelectrocatalytic activity material. Rutin was chosen as a model biomolecules to investigate the composite system. The MWNTs–Rutin–IL composite film was characterized by different methods including thermogravimetric analysis (TGA), UV–vis spectra, electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscope (SECM). A pair of well-defined quasi reversible redox peaks of rutin was obtained at the MWNTs–Rutin–IL composite film modified glassy carbon electrode (GCE) by direct electron transfer between the rutin and the GCE electrode. Dramatically enhanced biocatalytic and electrocatalytic activity was exemplified at the MWNTs–Rutin–IL/GCE electrode by the oxidized of tryptophane. The oxidation peak currents of tryptophane in such modified electrode increased linearly with the concentrations of tryptophane in the range from 8×10−8 to 2×10−5 molL−1 with a detection limit of 3.0×10−8 molL−1. The unique composite material based on biomolecules-functionalized carbon nanotube and ionic liquid have wide potential applications in direct electrochemistry, biosensors, and biocatalysis. [Copyright &y& Elsevier]

This study investigated the effects of high-dose large neutral amino acid (LNAA) supplementation on attenuating fatigue-induced decrements in exercise and motor skill performance in Australian Rules Football (ARF) players. Fifteen subelite ARF players participated in 3 testing sessions separated by 7 days. Players completed an initial control trial involving a reactive motor skills test (RMST) and a reactive agility test (RAT) carried out before and after fatiguing exercise. In the subsequent experimental trials, players ingested a serotonin-depleting or protein control (PC) LNAA mixture 3 h before testing, allocated in a double-blind randomized cross-over design. Blood samples were taken at presupplementation and pre- and postexercise for analysis of plasma amino acid, insulin, and metabolite concentrations. The effect of the LNAA was established as the difference in the change in the mean RMST and RAT test scores among the depleting, PC, and baseline (BL) trials. Mean overall repetition time of the RAT was moderately improved by -5.2% ± 3.4% (mean ± 90% confidence limits; effect size -0.45 ± 0.28) after ingestion of the serotonin-depleting mixture compared with the BL trial. Serotonin-depleting and PC supplements had a divergent effect on mean repetition time after fatiguing exercise in RMST: depleting serotonin elicited a small improvement (-3.0% ± 2.7%) in motor skill performance in contrast to a small decrement (2.4% ± 2.7%) after ingestion of the PC mixture, when compared to the BL. High-dose serotonin-'depleting' LNAA supplementation given 3 h prior to intermittent high-intensity exercise improved reactive motor skill and agility performance in ARF players. [ABSTRACT FROM AUTHOR]

Summary: In the field of depression, inflammation-associated depression stands up as an exception since its causal factors are obvious and it is easy to mimic in an animal model. In addition, quasi-experimental studies can be carried out in patients who are treated chronically with recombinant cytokines for a medical condition since these patients can be studied longitudinally before, during and after stimulation of the immune system. These clinical studies have revealed that depression is a late phenomenon that develops over a background of early appearing sickness. Incorporation of this feature in animal models of inflammation-associated depression has allowed the demonstration that alterations of brain serotoninergic neurotransmission do not play a major role in the pathogenesis. This is in contrast to the activation of the tryptotphan degrading enzyme indoleamine 2,3-dioxygenase that generates potentially neurotoxic kynurenine metabolites such as 3-hydroxy kynurenine and quinolinic acid. Although the relative importance of peripherally versus centrally produced kynurenine and the cellular source of production of this compound remain to be determined, these findings provide new targets for the treatment of inflammation-associated depression that could be extended to other psychiatric conditions mediated by activation of neuroimmune mechanisms. [ABSTRACT FROM AUTHOR]

Copyright of Medicina Naturista is the property of Sociedad Europea de Medicina Naturista Clasica (Seccion Espanola) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Previously we found that the trophinin-binding peptide GWRQ (glycine, tryptophane, arginine, glutamic acid) activated human trophoblastic cells. Although trophinin is expressed in human sperm, to our knowledge the function of this protein is not known. In this study we tested the effect of GWRQ on human sperm to evaluate whether the peptide enhances human sperm motility. Materials and Methods: Immunohistochemistry was performed using monoclonal antibodies specific to trophinin, bystin or tastin. GWRQ-MAPS (multivalent 8-branched GWRQ peptide) was chemically synthesized. Human sperm from 4 volunteers with a mean ± SD age of 35.75 ± 3.4 years was suspended in buffer with GWRQ or control peptides. In 23 volunteers with a mean age of 25.5 ± 2.5 years the number of immotile sperm was counted and subtracted from the total number of sperm to determine the number of motile sperm. A Transwell assay was used to measure swim-down motility. Levels of adenosine triphosphate and intracellular calcium in sperm cells incubated with GWRQ or control peptide were measured using a luminescent cell viability assay and a fluo-4 calcium assay, respectively. Results: The presence of trophinin and the trophinin associated proteins bystin and tastin in human sperm was confirmed by immunohistochemistry. Human sperm incubated with GWRQ-MAPS showed enhanced motility on sperm count assay and swim-down Transwell assay. Sperm cells incubated with GWRQ-MAPS showed decreased adenosine triphosphate and increased intracellular calcium. Conclusions: Results suggest that GWRQ-MAPS may facilitate optimized in vitro fertilization outcomes and help avert the need for intracytoplasmic sperm injection in cases of severely low sperm motility. Trophinin may have a role in regulating adenosine triphosphatase in human sperm. [Copyright &y& Elsevier]

Experiments were performed to determine whether seed priming with different concentrations (100, 150, and 200 mg/L) of auxins (indoleacetic acid (IAA), indolebutyric acid (IBA), or their precursor tryptophane (Trp)) could alter salinity induced perturbances in salicylic acid and ion concentrations and, hence, growth in wheat ( Triticum aestivum L.) cultivars, namely M.H.-97 (salt intolerant) and Inqlab-91 (salt tolerant). Primed and non-primed seeds were sown in Petri dishes in a growth room, as well as in a field treated with 15 dS/m NaCl salinity. All priming agents, except IBA, increased the final germination percentage in both cultivars. The seedlings of either cultivar raised from Trp-treated seeds had greater dry biomass when under salt stress. In field experiments, Trp priming was much more effective in mediating the increase in grain yield, irrespective of the cultivar, under salt stress. The alleviatory effect of Trp was found to be associated with reduced uptake of Na+ in the roots and subsequent translocation to the shoots, as well as increased partitioning of Ca2+ in the roots of salt-stressed wheat plants. Plants of both cultivars raised from Trp- and IAA-treated seeds accumulated free salicylic acid in their leaves when under salt stress. Overall, the Trp priming-induced improvement in germination and the subsequent growth of wheat plants could be related to ion homeostasis when under salt stress. The possible involvement of salicylic acid in the Trp priming-induced better growth under conditions of salt stress is discussed. [ABSTRACT FROM AUTHOR]

Rhizospheric bacterial strains are known to produce indole-3-acetic acid (IAA) through different pathways, and such IAA may be beneficial to plants at low concentrations. IAA biosynthesis by a natural isolate of Azospirillum brasilense SM was studied and observed to be tryptophan-inducible and -dependent in nature. While our work demonstrated the operation of the indole pyruvic acid pathway, the biochemical and molecular evidence for the genes of the indole acetamide (IAM) pathway were lacking in A. brasilense SM. This led us to use the IAM pathway genes as targets for metabolic engineering, with the aim of providing an additional pathway of IAA biosynthesis and improving IAA levels in A. brasilense SM. The introduction of the heterologous IAM pathway, consisting of the iaaM and iaaH genes, not only increased the IAA levels by threefold but also allowed constitutive expression of the same genes along with efficient utilization of IAM as a substrate. Such an engineered strain showed a superior effect on the lateral branching of sorghum roots as well as the dry weight of the plants when compared with the wild-type strain. Such an improved bioinoculant could be demonstrated to enhance root proliferation and biomass productivity of treated plants compared with the parental strain. [ABSTRACT FROM AUTHOR]

The iron-binding protein lactoferrin is a multifunctional protein that has antibacterial, antifungal, antiviral, antitumour, anti-inflammatory, and immunoregulatory properties. All of these additional properties appear to be related to its highly basic N-terminal region. This part of the protein can be released in the stomach by pepsin cleavage at acid pH. The 25-residue antimicrobial peptide that is released is called lactoferricin. In this work, we review our knowledge about the structure of the peptide and attempt to relate this to its many functions. Microcalorimetry and fluorescence spectroscopy data regarding the interaction of the peptide with model membranes show that binding to net negatively charged bacterial and cancer cell membranes is preferred over neutral eukaryotic membranes. Binding of the peptide destabilizes the regular membrane bilayer structure. Residues that are of particular importance for the activity of lactoferricin are tryptophan and arginine. These two amino acids are also prevalent in "penetratins", which are regions of proteins or synthetic peptides that can spontaneously cross membranes and in short hexapeptide antimicrobial peptides derived through combinatorial chemistry. While the antimicrobial, antifungal, antitumour, and antiviral properties of lactoferricin can be related to the Trp/Arg-rich portion of the peptide, we suggest that the anti-inflammatory and immunomodulating properties are more related to a positively charged region of the molecule, which, like the alpha- and beta-defensins, may act as a chemokine. Few small peptides are involved in as wide a range of host defense functions as bovine and human lactoferricin.Key words: lactoferricin, penetratin, tryptophan, arginine, membrane perturbation, fluorescence spectroscopy, NMR spectroscopy, microcalorimetry.La lactoferrine est une protéine liant le fer, multifonctionnelle, ayant des propriétés antibactériennes, antifongiques, antivirales, antitumorales, anti-inflammatoires et immunorégulatrices. Toutes ces propriétés semblent reliées à sa région N-terminale fortement basique. Cette portion de la protéine peut être libérée dans l'estomac par la pepsine en milieu acide. Le peptide antimicrobien libéré comporte 25 résidus et se nomme lactoferricine. Dans ce travail, nous faisons la revue de nos connaissances concernant la structure de ce peptide et nous tentons d'établir une relation entre sa structure et ses diverses fonctions. Les résultats des études de l'interaction de ce peptide avec des membranes par microcalorimétrie et spectrofluoroscopie indiquent que le peptide se lie préférentiellement aux membranes des bactéries et des cellules tumorales qui ont une charge globale négative, plutôt qu'aux membranes des cellules eucaryotes qui sont neutres. La liaison du peptide déstabilise la structure membranaire normale à deux couches. Le tryptophane et l'arginine sont les résidus particulièrement importants pour l'activité de la lactoferricine. Ces deux acides aminés sont également abondants dans les « pénétratines », des régions de protéines ou de peptides synthétiques pouvant traverser spontanément les membranes et dans de petits hexapeptides antimicrobiens produits par chimie combinatoire. Alors que les propriétés antimicrobiennes, antifongiques, antitumorales et antivirales de la lactoferricine peuvent être reliées à la portion du peptide riche en Trp et Arg, nous suggérons que les propriétés anti-inflammatoires et immunorégulatrices sont plus reliées à une région du peptide ayant une charge positive. Ce peptide agirait comme une chimiokine, telles les défensines alpha et beta. La lactoferricine bovine et humane est un des rares petits peptides ayant de multiples fonctions dans le système de défense de l'hôte.Mots clés : lactoferricine, pénétratine, tryptophane, arginine, perturbation de membranes, spectrofluoroscopie, spectroscopie de résonance magnétique nucléaire (RMN), microcalorimétrie.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This review focuses on important structural features affecting the antimicrobial activity of 15-residue derivatives of lactoferricins. Our investigations are based on an alanine-scan of a 15-residue bovine lactoferricin derivative that revealed the absolute necessity of two tryptophan residues for antimicrobial activity. This "tryptophan-effect" was further explored in homologous derivatives of human, caprine, and porcine lactoferricins by the incorporation of one additional tryptophan residue, and by increasing the content of tryptophan in the bovine derivative to five residues. Most of the resulting peptides display a substantial increase in antimicrobial activity. To identify which molecular properties make tryptophan so effective, a series of bovine lactoferricin derivatives were prepared containing non-encoded unnatural aromatic amino acids, which represented various aspects of the physicochemical nature of tryptophan. The results clearly demonstrate that tryptophan is not unique since most of the modified peptides were of higher antimicrobial potency than the native peptide. The size and three-dimensional shape of the inserted "super-tryptophans" are the most important determinants for the high antimicrobial activity of the modified peptides. This review also describes the use of a "soft-modeling" approach in order to identify important structural parameters affecting the antimicrobial activity of modified 15-residue murine lactoferricin derivatives. This QSAR-study revealed that the net charge, charge asymmetry, and micelle affinity of the peptides were the most important structural parameters affecting their antimicrobial activity.Key words: antimicrobial peptides, lactoferricin, non-encoded aromatic amino acids, tryptophan.Cette revue porte principalement sur les paramètres structuraux importants pour l'activité antimicrobienne de peptides de 15 acides aminés dérivés de lactoferricines. Notre balayage avec de l'alanine d'un peptide de 15 acides aminés dérivé de la lactoferricine bovine a déjà montré que deux résidus tryptophane sont absolument essentiels pour l'activité antimicrobienne. L'étude de cet « effet du tryptophane » a été poursuivie par l'incorporation d'un résidu tryptophane supplémentaire dans les dérivés homologues des lactoferricines humaine, caprine et porcine et par la production d'un dérivé bovin comportant 5 résidus tryptophane. La plupart des peptides produits ont une activité antimicrobienne accrue substantiellement. Afin d'identifier les caractéristiques moléculaires rendant le tryptophane si efficace, des dérivés de la lactoferricine bovine comportant des acides aminés aromatiques non naturels et non codés, ayant diverses caractéristiques physico-chimiques du tryptophane, ont été préparés. Les résultats montrent clairement que le tryptophane n'est pas irremplaçable, puisque la plupart des peptides modifiés ont un pouvoir antimicrobien plus grand que le peptide originel. La dimension et la forme tridimensionnelle des « super-tryptophanes » insérés sont les déterminants les plus importants de l'activité antimicrobienne élevée des peptides modifiés. Cette revue décrit également l'utilisation d'une approche de « modélisation indulgente » pour identifier les paramètres structuraux importants pour l'activité antimicrobienne de peptides de 15 acides aminés dérivés de la lactoferricine de souris. Cette étude de relation structure-activité quantitative (QSAR) révèle que la charge globale, l'asymétrie des charges et l'affinité micellaire des peptides sont les paramètres structuraux les plus importants pour leur activité antimicrobienne.Mots clés : peptides antimicrobiens, lactoferricine, acides aminés aromatiques non codés, tryptophane.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

A series of tripeptides TrpTrpPhe (1), TrpTrpTyr (2), and TrpTrpTyr[CH2N(CH3)2] (3) were synthesized, and their photophysical properties and non-covalent binding to polynucleotides were investigated. Fluorescent Trp residues (quantum yield in aqueous solvent ΦF = 0.03–0.06), allowed for the fluorometric study of non-covalent binding to DNA and RNA. Moreover, high and similar affinities of 2×HCl and 3×HCl to all studied double stranded (ds)-polynucleotides were found (logKa = 6.0–6.8). However, the fluorescence spectral responses were strongly dependent on base pair composition: the GC-containing polynucleotides efficiently quenched Trp emission, at variance to AT- or AU-polynucleotides, which induced bisignate response. Namely, addition of AT(U) polynucleotides at excess over studied peptide induced the quenching (attributed to aggregation in the grooves of polynucleotides), whereas at excess of DNA/RNA over peptide the fluorescence increase of Trp was observed. The thermal denaturation and circular dichroism (CD) experiments supported peptides binding within the grooves of polynucleotides. The photogenerated quinone methide (QM) reacts with nucleophiles giving adducts, as demonstrated by the photomethanolysis (quantum yield ΦR = 0.11–0.13). Furthermore, we have demonstrated photoalkylation of AT oligonucleotides by QM, at variance to previous reports describing the highest reactivity of QMs with the GC reach regions of polynucleotides. Our investigations show a proof of principle that QM precursor can be imbedded into a peptide and used as a photochemical switch to enable alkylation of polynucleotides, enabling further applications in chemistry and biology. [ABSTRACT FROM AUTHOR]

L-Tryptophane, an essential amino acid and a precursor of serotonin, is shown to have definite effects on human sleep. In normal subjects it reduces sleep latency and slightly increases sleep length without altering the qualitative characteristics of polygraphically recorded sleep. In a double-blind study of 24 hospitalized insomniac patients, doses of 4 g or 5 g of L-tryptophane significantly increased sleep time, reduced sleep latency, and reduced the number of awakenings. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)