A consortium of different Saccharomyces species enhances the content of bioactive tryptophan-derived compounds in wine fermentations.

In recent years, the presence of molecules derived from aromatic amino acids in wines has been increasingly demonstrated to have a significant influence on wine quality and stability. In addition, interactions between different yeast species have been observed to influence these final properties. In this study, a screening of 81 yeast strains from different environments was carried out to establish a consortium that would promote the improvement of indolic compound levels in wine. Two strains, Saccharomyces uvarum and Saccharomyces eubayanus, with robust fermentative capacity were selected to be combined with a Saccharomyces cerevisiae strain with a predisposition towards the production of indolic compounds. Fermentation dynamics were studied in pure cultures, co-inoculations and sequential inoculations, analysing strain interactions and end-of-fermentation characteristics. Fermentations showing significant interactions were further analyzed for the resulting indolic compounds and aroma profile, with the aim of observing potential interactions and synergies resulting from the combination of different strains in the final wine. Sequential inoculation of S. cerevisiae after S. uvarum or S. eubayanus was observed to increase indolic compound levels, particularly serotonin and 3-indoleacetic acid. This study is the first to demonstrate how the formation of microbial consortia can serve as a useful strategy to enhance compounds with interesting properties in wine, paving the way for future studies and combinations.

Plasma tryptophan pathway metabolites quantified by liquid chromatography-tandem mass spectrometry as biomarkers in neuroendocrine tumor patients.

A good and accessible biomarker is of great clinical value in neuroendocrine tumor (NET) patients, especially considering its frequently indolent nature and long-term follow-up. Plasma chromogranin A (CgA) and 5-hydroxyindoleacetic acid (5-HIAA) are currently used as biomarkers in NET, but their sensitivity and specificity are restricted. 5-HIAA is the main metabolite of serotonin, an important neurotransmitter of the tryptophan pathway. The aim of this study is to estabish a sensitive and accurate method for the quantification of tryptophan pathway metabolites in plasma. We further aimed to evaluate its utility as a clinical tool in NET disease. We obtained plasma samples from NET patients and healthy controls recruited from the University Hospital of North Norway, Tromsø. Samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and eight metabolites of the tryptophan pathway were quantified. We included 130 NET patients (72/130 small intestinal [SI] NET, 35/130 pancreatic NET, 23/130 other origin) and 20 healthy controls. In the SI-NET group, 26/72 patients presented with symptoms of carcinoid syndrome (CS). We found that combining tryptophan metabolites into a serotonin/kynurenine pathway ratio improved diagnostic sensitivity (92.3%) and specificity (100%) in detecting CS patients from healthy controls compared with plasma 5-HIAA alone (sensitivity 84.6%/specificity 100%). Further, a clinical marker based on the combination of plasma serotonin, 5-HIAA, and 5OH-tryptophan, increased diagnostic capacity identifying NET patients with metastasized disease from healthy controls compared with singular plasma 5-HIAA, serotonin, or CgA. In addition, this marker was positive in 61% of curatively operated SI-NET patients compared with only 10% of healthy controls (p < .001). Our results indicate that simultaneous quantification of several tryptophan metabolites in plasma, using LC-MS/MS, may represent a clinically useful diagnostic tool in NET disease.

PLSR-colorimetric simultaneous determination of L-Tyrosine and L-Tryptophan in different pharmaceutical and biological samples using one-pot synthesized leaf shape Ag@Ag2O core-shell nanocomposites modified by ß-CD.

In the present study, a simple, innovative, and economically beneficial method has been proposed for the synthesis of Ag@Ag2O core-shell nanocomposites using Acanthophora muscoides algae extract. The host-guest recognition of targets was performed by modification of the Ag@Ag2O surface using ß-CD. The Ag@Ag2O- ß-CD NCs were used as a colorimetric sensor to determine L-Tryptophan and L-Tyrosine using a partial least square (PLS) approach. A crystalline hybrid structure of Ag core and an Ag2O shell was confirmed by XRD, FTIR, TEM and AFM research. Also, DLS analysis and surface zeta potential spectra illustrated the aggregated nature of nanocomposites in the presence of analytes. The literature review shows that the colorimetric simultaneous determination of L-Tryptophan (L-Try) and L-Tyrosine (L-Tyr) has not been reported. The Ag@Ag2O- ß-CD sensor exhibited outstanding sensing capability in a broad linear range of 2.0 -200 µM for both amino acids and low detection limit of 0.32 and 0.51 µM, for L-Try and L-Tyr, respectively. The good sensitivity and excellent selectivity regarding possible interfering species, originated from the synergistic effect of host-guest recognition in combination with colorimetric sensing. Additionally, determination of analytes in various pharmaceutical, supplement and urine samples, approved the practical applicability of the constructed sensor. The computed results confirmed that colorimetric sensing in conjunction with a PLS technique was appropriate for the precise and accurate simultaneous determination of target amino acids in complex mixtures with RMSEP less than 2.5% and recovery in the range of 103-108% with R.S.D. values less than 3%.

Paper-based microfluidic system and chiroptical functionalized gold nano-oval for colorimetric detection of L-Tryptophan.

"The development and deployment of a practical and portable technology for on-site chiral identification of enantiomers hold immense significance in the fields of medical and biological sciences. Among the essential amino acids, Tryptophan (Trp) plays a crucial role in human metabolism and serves as a diagnostic marker for various metabolic disorders. In this study, we introduce an innovative approach that combines an enantio-selective ZIF-8-His MOF-MIPs packed-bed centrifugal microfluidic system with an enantioselective colorimetric sensor probe. This system is further integrated with smartphone-based on-site data recording. The basis of this colorimetric sensor's operation lies in the controlled morphology and surface passivation of gold nano-ovals (Au-NOs) through DL-Alanine. To confirm the successful synthesis of the chiral recognition elements, we employed various characterization techniques, including FE-SEM, TEM, FTIR, CD, UV-Vis, zeta potential, DLS, and XRD. Our focus was on optimizing operational parameters for the effective separation and determination of L-chiral tryptophan on-site. The sensor exhibited two linear ranges for L-Trp detection: 0-5.42 and 5.42-80.47 mM, with a detection limit of 0.5 mM. The integrated system possesses advantages such as ease of availability, preparation, high stability, desirable selectivity even in the presence of similar biomolecules, and rapid detection capabilities. Furthermore, our method demonstrated successful enantioselective sensing of L-Trp in various biological samples, including human blood plasma, urine, milk, and bovine serum albumin (BSA), yielding promising results. The integrated microfluidic platform follows a "sample-in and answer-out" approach, making it highly applicable in healthcare, environmental monitoring, food safety analysis, and point-of-care testing. The chiral recognition pretreatment assay and self-contained, automated colorimetric detection on the microfluidic disc represent a promising avenue for cutting-edge research in these domains".

MoS2/S@g-CN Composite Electrode for L-Tryptophan Sensing.

L-tryptophan (L-TRP) is an essential amino acid responsible for the establishment and maintenance of a positive nitrogen equilibrium in the nutrition of human beings. Therefore, it is vital to quantify the amount of L-tryptophan in our body. Herein, we report the MoS2/S@g-CN-modified glassy carbon electrode for the electrochemical detection of L-tryptophan (L-TRP). The MoS2/S@g-CN composite was successfully synthesized using an efficient and cost-effective hydrothermal method. The physical and chemical properties of the synthesized composite were analyzed using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray analysis (EDX). The crystallite size of the composite was calculated as 39.4 nm, with porous balls of MoS2 decorated over the S@g-CN surface. The XPS spectrum confirmed the presence of Mo, S, O, C, and N elements in the sample. The synthesized nanocomposite was further used to modify the glassy carbon (GC) electrode (MoS2/S@g-CN/GC). This MoS2/S@g-CN/GC was used for the electrochemical detection of L-TRP using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. For the purpose of comparison, the effects of the scanning rate and the concentration of L-TRP on the current response for the bare GC, S@g-CN/GC, MoS2/GC, and MoS2/S@g-CN/GC were studied in detail. The MoS2/S@g-CN-modified GC electrode exhibited a rational limit of detection (LoD) of 0.03 µM and a sensitivity of 1.74 µA/ µMcm2, with excellent stability, efficient repeatability, and high selectivity for L-TRP detection.

An anti-fouling wearable molecular imprinting sensor based on semi-interpenetrating network hydrogel for the detection of tryptophan in sweat.

The challenge of heavy biofouling in complex sweat environments limits the potential of electrochemical sweat sensors for noninvasive physiological assessment. In this study, a novel semi-interpenetrating hydrogel of PSBMA/PEDOT:PSS was engineered by interlacing PEDOT:PSS conductive polymer with zwitterionic PSBMA network. This versatile hydrogel served as the foundation for developing an anti-fouling wearable molecular imprinting sensor capable of sensitive and robust detection of tryptophan (Trp) in complex sweat. The incorporation of PEDOT:PSS conductive polymer into the semi-interpenetrating hydrogel introduced diverse physical crosslinks, including hydrogen bonding, electrostatic interactions, and chain entanglement. This incorporation considerably boosted the hydrogel's mechanical robustness and imparted commendable self-healing property. At the same time, the synergistic coupling between the well-balanced charge of the zwitterionic network and the high conductivity of the PEDOT:PSS polymer facilitated efficient charge transfer. The formation of the desired molecular imprinting membrane of semi-interpenetrating hydrogel was triggered by self-polymerization of dopamine (DA) in the presence of Trp. The designed biosensor demonstrated good sensitivity, selectivity and stability in detecting the target Trp. Notably, it also exhibited exceptional anti-fouling abilities, allowing for accurate Trp detection in complex real sweat samples, yielding results comparable to commercial enzyme-linked immunoassay (ELISA).

A High-Throughput Absolute Quantification of Protein-Bound Tryptophan from Model and Crop Seeds.

This protocol describes a high-throughput absolute quantification protocol for the aromatic essential amino acid, tryptophan (Trp). This procedure consists of a milligram-scale alkaline hydrolysis followed by an absolute quantification step using a multiple reaction monitoring tandem mass spectrometric (LC-MS/MS) detection method. The approach facilitates the analysis of a few hundred samples per week by using a 96-well plate extraction setup. Importantly, the method uses only ∼4 mg of tissue per sample and uses the common alkaline hydrolysis protocol, followed by water extraction that includes L-Trp-d5 as an internal standard to enable the quantification of the absolute level of the bound Trp with high precision, accuracy, and reproducibility. The protocol described herein has been optimized for seed samples for Arabidopsis thaliana, Glycine max, and Zea mays but could be applied to other plant tissues. © 2023 Wiley Periodicals LLC. Basic Protocol: Analysis of protein-bound tryptophan from seeds.

[Repair stimulator alpha-glutamyl-tryptophan in the complex therapy of chronic atrophic gastritis: results of histological examination]. / Stimulyator reparatsii al'fa-glutamil-triptofan v kompleksnoi terapii khronicheskogo atroficheskogo gastrita: rezul'taty gistologicheskogo issledovaniya.

OBJECTIVE: To study the effect of the repair stimulator alpha-glutamyl-tryptophan on the morphological characteristics of the gastric mucosa and the expression of CXCL-12 and CDX-2 in chronic atrophic gastritis associated with Helicobacter pylori. MATERIAL AND METHODS: Biopsy samples of 116 patients with a verified diagnosis of chronic atrophic gastritis associated with Helicobacter pylori were analyzed in a multicenter double-blind randomized placebo-controlled study. During the morphological study, the parameters characterizing the process of atrophy were evaluated: the number of glands per 1 mm2 of the gastric mucosa, the depth of the gastric mucosa glands, the number of parietal cells per 100 epithelial cells of the gastric mucosa, and the presence of signs of intestinal metaplasia. Primary antibodies Anti-CXCL-12 (MA5-23759) and Anti-CDX-2 (EP25) were used to set up immunohistochemical reactions to verify the expression of CXCL-12 and CDX-2. RESULTS: In patients taking the studied drug, a statistically significant increase in the number of glands per 1 mm2 of the gastric mucosa was revealed when compared with the initial screening indicators by 26.1% (p=0.028) and with the placebo group (p=0.026), a tendency to decrease the signs of intestinal metaplasia was determined. There was a statistically significant increase in the expression in the relative area of CXCL-12 expression in patients taking placebo when compared with the parameters of the initial data (p=0.045) and the absence of statistically significant changes in the main group. A statistically significant increase in the relative area of the CDX-2 expression was revealed in the group taking alpha-glutamyl-tryptophan in comparison with the baseline data (p=0.015), no statistically significant dynamics of this indicator was found in the placebo group. CONCLUSION: A statistically significant positive effect of the study drug on regenerative mechanisms leading to stabilization and/or improvement of the histological picture in the atrophic area of the gastric mucosa was found in comparison with the control of the initial state and with placebo. The results of an immunohistochemical study to increase CDX-2 expression while taking the study drug can also be regarded as an indicator of improvement in reparative processes.

Targeted Amino Acids Profiling of Human Seminal Plasma from Teratozoospermia Patients Using LC-MS/MS.

Identifying the metabolome of human seminal plasma (HSP) is a new research area to screen putative biomarkers of infertility. This case-control study was performed on HSP specimens of 15 infertile patients with teratozoospermia (defined as normal sperm morphology < 4%) and 12 confirmed fertile normozoospermic men as the control group to investigate the seminal metabolic signature and whether there are differences in the metabolome between two groups. HSPs were subjected to LC-MS-MS analysis. MetaboAnalyst5.0 software was utilized for statistical analysis. Different univariate and multivariate analyses were used, including T-tests, fold change analysis, random forest (RF), and metabolite set enrichment analysis (MSEA). Teratozoospermic samples contained seventeen significantly different amino acids. Upregulated metabolites include glutamine, asparagine, and glycylproline, whereas downregulated metabolites include cysteine, γ-aminobutyric acid, histidine, hydroxylysine, hydroxyproline, glycine, proline, methionine, ornithine, tryptophan, aspartic acid, argininosuccinic acid, α-aminoadipic acid, and ß-aminoisobutyric acid. RF algorithm defined a set of 15 metabolites that constitute the significant features of teratozoospermia. In particular, increased glutamine, asparagine, and decreased cysteine, tryptophan, glycine, and valine were strong predictors of teratozoospemia. The most affected metabolic pathways in teratozoospermic men are the aminoacyl-tRNA, arginine, valine-leucine, and isoleucine biosynthesis. Altered metabolites detected in teratozoospermia were responsible for various roles in sperm functions that classified into four subgroups as follows: related metabolites to antioxidant function, energy production, sperm function, and spermatogenesis. The altered amino acid metabolome identified in this study may be related to the etiology of teratozoospermia, and may provide novel insight into potential biomarkers of male infertility for therapeutic targets.

The contradictory roles of tightly bound and loosely bound extracellular polymeric substances of activated sludge in trimethoprim adsorption process.

Extracellular polymeric substances (EPS) of activated sludge are a mixture of high molecular weight polymers secreted by microorganisms, which have the double structure of tightly-bound EPS (TB-EPS) in inner layer and loosely-bound EPS (LB-EPS) in outer layer. The characteristic of LB- and TB-EPS were different, which would affect their adsorption of antibiotics. However, the adsorption process of antibiotics on LB- and TB-EPS was still unclear yet. Therefore, in this work, the roles of LB-EPS and TB-EPS in adsorption of a typical antibiotic-trimethoprim (TMP) at environmentally relevant concentration (25.0 µg/L) were investigated. The results showed the content of TB-EPS was higher than that of LB-EPS, which was 17.08 and 10.36 mg/g VSS, respectively. The adsorption capacity of raw, LB-EPS extracted and both LB- and TB-EPS extracted activated sludges for TMP were 5.31, 4.65 and 9.51 µg/g VSS, respectively, which indicated LB-EPS had positive effect on TMP removal, while TB-EPS had negative effect. The adsorption process can be well described by a pseudo-second-order kinetic model (R2 > 0.980). The ratio of different functional groups was calculated and the CO and C-O bond might be responsible for the adsorption capacity difference between LB- and TB-EPS. The fluorescence quenching results indicated that tryptophan protein-like substances in LB-EPS provided more binding sites (n = 0.36) than that of tryptophan amino acid in TB-EPS (n = 0.1). Furthermore, the extend DLVO results also demonstrated that LB-EPS promoted the adsorption of TMP, while TB-EPS inhibited the process. We hope the results of this study were helpful for understanding the fate of antibiotics in wastewater treatment systems.

Highly Efficient versus Null Electrochemical Enantioselective Recognition Controlled by Achiral Colinkers in Homochiral Metal-Organic Frameworks.

Chiral materials capable of electrochemical enantiomeric recognition are highly desirable for many applications, but it is still very challenging to achieve high recognition efficiency for lack of the knowledge of structure-property relationships. Here, we report the completely distinct enantiomeric recognition related to slightly different achiral colinkers in isomorphic homochiral metal-organic frameworks with the same chiral linker. Cu-TBPBe, for which the achiral colinker has two pyridyl rings connected by ─CH═CH─, shows excellent enantioselectivity and sensitivity for electrochemical recognition of l-tryptophan (Trp) with a detection limit of 3.16 nM. The l-to-d ratio of differential pulse voltammetric (DPV) currents reaches 53, which is much higher than the values (2-14) reported for previous electrochemical sensors. By contrast, Cu-TBPBa, in which the achiral colinker has -CH2-CH2- between pyridyl rings, is incapable of discrimination between l-Trp and d-Trp. Structural and spectral analyses suggest that the achiral conjugated colinker and the chiral moieties around it cooperate to produce a chiral pocket in favor of enantioselective adsorption through multiple hydrogen-bonding and π-π stacking interactions. The work demonstrated that Cu-TBPBe can be used to fabricate reliable electrochemical sensors for ultrasensitive quantification of Trp enantiomers in racemic mixtures and in complex biological systems such as urine. The work also highlights that an achiral coligand can be of vital importance in determining enantiomeric discrimination, opening up a new avenue for the design of chiral sensing materials.

Quantification of disaccharides in solution using isomer-selective ultraviolet photodissociation of hydrogen-bonded clusters in the gas phase.

Chemical properties of gas-phase hydrogen-bonded clusters were investigated as a model for interstellar molecular clouds. Cold gas-phase hydrogen-bonded clusters of tryptophan (Trp) enantiomers and disaccharide isomers, including d-maltose and d-cellobiose, were generated by electrospray ionization and collisional cooling in an ion trap at 8 K. Product ion spectra in the 265-290 nm wavelength range were obtained using tandem mass spectrometry. NH2CHCOOH loss via the Cα-Cß bond cleavage of Trp occurred frequently in homochiral H+(d-Trp)(d-maltose) compared with heterochiral H+(l-Trp)(d-maltose) at 278 nm, indicating that an enantiomeric excess of l-Trp was formed via the enantiomer-selective photodissociation. The photoreactivity differed between the enantiomers and isomers contained in the clusters at the photoexcitation of 278 nm. A calibration curve for the quantification of disaccharide isomers in solution was constructed by photoexcitation of the hydrogen-bonded clusters of disaccharide isomers with H+(l-Trp) at 278 nm. A linear relationship between the natural logarithm of the relative product ion abundance and the mole fraction of d-maltose to d-cellobiose ratio in the solution was obtained, indicating that the mole fraction could be determined from a single product ion spectrum. A calibration curve, for quantification of Trp enantiomers, was also obtained using d-maltose as a chiral auxiliary.

[Metabolomics study on the difference of tongue coating metabolites between patients with intra-oral halitosis and healthy individual].

PURPOSE: To analyze the difference of metabolites of tongue coating between patients with intra-oral halitosis and healthy individuals by untargeted metabolomics, and to explore significant differences in metabolites of intra-oral halitosis as biomarkers. METHODS: The untargeted metabolomics of tongue coating samples from 12 patients with intra-oral halitosis and 12 healthy individuals were studied by liquid chromatography and mass spectrometry combined with principal component analysis and orthogonal partial least squares discriminant analysis. The value of variable importance in projection ＞1 and P＜0.05 of Student's t test in the orthogonal partial least squares-discriminant analysis model were used as the criteria to screen and determine the differential metabolites. RESULTS: There were differences in the metabolites of tongue coating between patients with intra-oral halitosis and healthy individuals, and 11 different metabolites were identified. They were valyl-arginine, glycine-phenylalanine, tryptophyl-proline, deoxyadenosine, 4,5-dihydroniveusin A, N-acetyl-DL-tryptophan, paramethasone acetate, cyclopentanol, [(2-hexylcyclopentylidene) amino]thiourea, L-pipecolic acid and taurine. In the intra-oral halitosis group, the expressions of Glycine-phenylalanine and N-acetyl-DL-tryptophan were significantly up-regulated, while the expressions of taurine were significantly down-regulated. CONCLUSIONS: There are differences in the metabolites of tongue coating between patients with intra-oral halitosis and healthy individuals. The differential metabolites with diagnostic value may be used as diagnostic markers of intra-oral halitosis.

Hypsizygus marmoreus as a Source of Indole Compounds and Other Bioactive Substances with Health-Promoting Activities.

Hypsizygus marmoreus is an edible medicinal mushroom species with a high dietary value. In this study, the fruiting bodies of commercial and self-cultivated crops and mycelium from in vitro H. marmoreus cultures (both white and brown varieties) were evaluated. This study aimed to analyze the presence of indole compounds and other biologically active substances and determine the effect that the addition of zinc and magnesium ions to the culture medium has on the content of the tested compounds in mycelial cultures. The content of indole compounds and other organic compounds was determined using high-performance liquid chromatography, the content of bioelements was determined using flame atomic absorption spectrometry, the glucan content was determined spectrophotometrically, and the antioxidant activity of extracts was estimated using DPPH, FRAP, and ABTS methods. The results showed that H. marmoreus mycelium from in vitro cultures is a good source of indole compounds, bioelements, glucans, and lovastatin. Mycelia from in vitro cultures showed the most diverse composition of indole compounds (L-tryptophan, 5-hydroxy-L-tryptophan, tryptamine, 5-methyltryptamine, and melatonin). Additionally, in vitro cultures of H. marmoreus enriched with Zn and Mg salts increased the contents of Na, Ca, Zn, 5-methyltryptamine, melatonin, protocatechuic acid, sterols, and total glucans. Only in the case of the white variety of mycelial enriched cultures, ergothioneine and Mg levels also increased. To summarize, the content of the active compounds differed depending on the H. marmoreus variety and the tested material.

Comparison of the Main Metabolites in Different Maturation Stages of Camelliavietnamensis Huang Seeds.

Camellia vietnamensis Huang is an important woody oil crop in China, which has attracted much attention because of its abundant nutritional components and pharmaceutical value. Its seeds undergo a complex series of physiological and biochemical changes during maturation, with consequent alterations in metabolites. In order to investigate the endogenous metabolism of C. vietnamensis on Hainan Island during seed development, in this study, ultra-high-performance liquid tandem chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) and multivariate statistical analysis (MSA) were used to analyze the differences in the chemical compounds of C. vietnamensis seeds among the four maturation stages. A total of 293 metabolites were identified from the methanol extract of the seeds of C. vietnamensis. Five metabolites, belonging to benzene and substituted derivatives, 5'-deoxyribonucleosides and linear 1,3-diarylpropanoids, were found in all three comparison groups, with consistently down-regulated trends. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that phloretin and 5'-methylthioadenosine were the differentially expressed metabolites when seeds were in the growth periods of S2 and S3, and indole and L-tryptophan were the differentially expressed metabolites when seeds were in the growth periods of S3 and S4. In addition, 34 flavonoid metabolites were detected, of which 4 were differentially expressed. It was indicated that flavonoids dynamically change during all the oil-tea camellia seed development stages. The findings provide data for the better understanding of endogenous metabolic pathways during C. vietnamensis seed development.

Common materials, extraordinary behavior: An ultrasensitive and enantioselective strategy for D-Tryptophan recognition based on electrochemical Au@p-L-cysteine chiral interface.

The poly-L-cysteine modified Au nanoparticles (Au@p-L-Cys) were constructed on electrode surface as a highly efficient chiral interface for tryptophan (Trp) enantiomers recognition via one step electropolymerization. With the aid of Cu2+, L-Cys residues and D-Trp target formed a sandwich complex D-Trp-Cu2+-L-Cys, while L-Trp was unable to form such complex due to the steric hindrance provided by the chiral interface, which was confirmed by the electrochemical and SEM results. With the introduction of ferricyanide probe, D-Trp produced significant current decrease while L-Trp produced a slight current increase, which implied the successful enantioselective recognition of Trp enantiomers (specifically D-Trp) in the true sense. This novel sensor showed a surprisingly wide linear range toward D-Trp of 6 × 10-7 M to 1 × 10-2 M, with a detection limit as low as 75 nM (S/N = 3). Moreover, the exclusive enantioselectivity toward D-Trp was discovered since other amino acids showed negligible interference to detection of D-Trp. The recovery of D-Trp in human serum was between 91.30 and 109.3%, which further verified the satisfying specificity and practicality of the proposed strategy. The coordination thermodynamics by UV-Vis spectroscopy and DFT simulation were also used to investigate the enantioselective mechanism. These results highlight the great potential of using Au@p-L-Cys to construct chiral interface for enantiomers recognition and hold the promise of practical application of electrochemical chiral sensors in fields like pharmaceutics and bioanalysis.

[Decocting kinetics of Moringa oleifera leaves: based on correlation of decocting factors and multiple components].

Content of multiple components (neochlorogenic acid,L-tryptophan,vicenin-2,isoquercitrin,and astragalin) in Moringa oleifera leaves was determined by high-performance liquid chromatography (HPLC),and the absolute content-time curves were plotted.Based on Fick's law of diffusion and Higbie's penetration theory,the parameters of the equations were calculated,and the measured results were substituted into the mathematical model to fit the equations.The n and a obtained from the equations on the decocting time factor and the solvent volume were close to each other.The dynamic models of the five components are as follows:■.The variation of the content of multiple components in M.oleifera leaves with time and solvent volume was explored.It was found that the content of the components was the highest when the leaves were decocted for 30 min with solvent volume 12 folds of the medicinal material.The dissolution and destruction of components and the diffusion movement of components are the main causes of the content change of M.oleifera leaves at different time and with different solvent volumes.The R~2of the linear equations on the content and the equations on the decocting process (5-30min and solvent volume 12-20 folds of the medicinal materials) was≥0.999 8 and≥0.9,respectively.Thus,the content determination and the decocting kinetic model had high accuracy,which can reflect the change law of the content of key components in M.oleifera leaves during the decoction.This study is expected to serve as a reference for optimizing the decocting technology.

Tryptophan degradation enzymes and Angiotensin (1-7) expression in human placenta.

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) are key enzymes for tryptophan degradation, regulating immune tolerance during pregnancy. The intrauterine renin-angiotensin system is also involved in the progression of a healthy pregnancy. Angiotensin(1-7) maintains the integrity of fetal membranes via counteracting the pro-inflammatory actions of Angiotensin II. No data are available on placental Angiotensin(1-7) co-expression with TDO. We aimed to characterize TDO mRNA expression and its localization in different areas of the placenta of physiological pregnancies delivered at term; its co-expression with Angiotensin(1-7) and its correlation with the plasma kynurenine/tryptophan (Kyn/Trp) ratio was investigated. This prospective observational study included a nonconsecutive series of 20 singleton uncomplicated pregnancies delivered vaginally. TDO mRNA was expressed in both maternal and fetal sides of the placentas and TDO protein also in the villi and it was co-expressed with IDO1 in almost half of the placental cells at these sites. The percentage of TDO+ and IDO1+ cells appeared to be influenced by maternal pre-gestational smoking and newborn weight. A strong correlation was found between the percentage of TDO+ and IDO1+ cells in the villi. TDO+ cells also expressed Angiotensin(1-7), with a higher percentage on the fetal side and in the villi compared to the maternal one. Kyn/Trp plasma ratio was not correlated with IDO and TDO expression nor with the patient's characteristics. Collectively, our data indicate that TDO is detectable in placental tissue and is co-expressed with IDO and with Angiotensin(1-7)+ on the fetal side and in the villi.

Omics profiles of fecal and oral microbiota change in irritable bowel syndrome patients with diarrhea and symptom exacerbation.

BACKGROUND: Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction, including dysregulation of the hypothalamic-pituitary-adrenal axis with salivary cortisol changes. However, the role of gastrointestinal microbiota during IBS symptom exacerbation remains unclear. We tested the hypothesis that the microbial species, gene transcripts, and chemical composition of fecal and oral samples are altered during the exacerbation of IBS symptoms. METHODS: Fecal, salivary, and dental plaque samples were collected at baseline from 43 men with IBS with diarrhea (IBS-D) and 40 healthy control (HC) men. Samples in the IBS-D patients were also collected during symptom exacerbation. The composition of the fecal microbiota was determined by analyzing the 16S rRNA gene, RNA-based metatranscriptome, and metabolites in samples from HC and IBS patients with and without symptom exacerbation. Oral samples were also analyzed using omics approaches. RESULTS: The fecal microbiota during IBS symptom exacerbation exhibited significant differences in the phylogenic pattern and short-chain fatty acid compared with fecal samples during defecation when symptoms were not exacerbated. Although there were no significant differences in the phylogenic pattern of fecal microbiota abundance between HCs and IBS-D patients, significant differences were detected in the expression patterns of bacterial transcriptomes related to butyrate production and neuroendocrine hormones, including tryptophan-serotonin-melatonin synthesis and glutamine/GABA. The composition of plaque microbiota was different between HC and IBS-D patients during normal defecation. CONCLUSIONS: Our findings suggest that colonic host-microbial interactions are altered in IBS-D patients during exacerbation of symptoms. There were no overlaps between feces and oral microbiomes.

Tryptophan Residues Are Critical for Portal Protein Assembly and Incorporation in Bacteriophage P22.

The oligomerization and incorporation of the bacteriophage P22 portal protein complex into procapsids (PCs) depends upon an interaction with scaffolding protein, but the region of the portal protein that interacts with scaffolding protein has not been defined. In herpes simplex virus 1 (HSV-1), conserved tryptophan residues located in the wing domain are required for portal-scaffolding protein interactions. In this study, tryptophan residues (W) present at positions 41, 44, 207 and 211 within the wing domain of the bacteriophage P22 portal protein were mutated to both conserved and non-conserved amino acids. Substitutions at each of these positions were shown to impair portal function in vivo, resulting in a lethal phenotype by complementation. The alanine substitutions caused the most severe defects and were thus further characterized. An analysis of infected cell lysates for the W to A mutants revealed that all the portal protein variants except W211A, which has a temperature-sensitive incorporation defect, were successfully recruited into procapsids. By charge detection mass spectrometry, all W to A mutant portal proteins were shown to form stable dodecameric rings except the variant W41A, which dissociated readily to monomers. Together, these results suggest that for P22 conserved tryptophan, residues in the wing domain of the portal protein play key roles in portal protein oligomerization and incorporation into procapsids, ultimately affecting the functionality of the portal protein at specific stages of virus assembly.