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Craft beer because of its fresh flavor, unique taste, and rich nutrition is becoming more popular to consumers. Compared with industry beer, craft beer is often nonfiltered and nonpasteurized, for this reason, it has a short shelf life and is more susceptible to microbial spoilage, which may cause the quality deterioration of craft beer and the formation of biogenic amine as a harmful factor for consumer's health. In this study, the 23 beer-spoilage bacteria were isolated from craft beer, which were identified as 15 Lactobacillus (L.) brevis, 3 L. plantarum, 1 L. parabuchneri, 2 L. paracasei, and 2 Pediococcus damnosus. Among 23 beer-spoilage isolates, 20 representatives were able to form tyramine, histamine, putrescine, cadaverine, and/or tryptamine in MRS broth. The nine Lactobacillus strains were incubated in beer and produced tyramine, histamine, putrescine, cadaverine, and/or tryptamine during beer storage process. Logistic and Gompertz model could be adopted to respectively describe the kinetics of microorganism growth and biogenic amine formation. The relationship between the biogenic amines and biomass was simulated by Luedeking-Piret model very well, and showed that the formation of biogenic amine was mainly bacteria growth-associated in beer. These findings may be helpful for finding the preventive measures to control biogenic amine formation and for enhancing the safety of craft beer. PRACTICAL APPLICATION: The selection of the biogenic amine-producing spoilage bacteria from craft beer and the investigation their kinetics of the growth and biogenic amines production under beer environmental conditions was very helpful for finding preventive measures to eliminate or reduce biogenic amine formation and for appropriate increase in food safety.

The author discussed recently the possible molecular mechanisms that cause the COVID-19 disease symptoms. Here the analysis of the recent experimental data supports the hypothesis that production of the gut microbial tryptamine can be induced by the SARS-CoV-2 fecal viral activity due to the selective pressure or positive selection of tryptamine-producing microorganisms. In this report, the author suggests that the mechanism of microbial selection bases on the abilities of tryptamine to affect the viral nucleic acid. In other words, the gut microorganisms producing tryptamine are more resistant to SARS-CoV-2 fecal viral activity than microorganisms producing no tryptamine. Earlier we demonstrated the induction of neurodegeneration by tryptamine in human cells and mouse brain. Furthermore, we were able to uncover the human gut bacteria associated with Alzheimer’s disease (AD) using PCR testing of human fecal samples with the new-designed primers targeting the tryptophan-tryptamine pathway. Likely, SARS-CoV-2 is one of the selective pressure factors in the cascade accelerating the neurodegenerative process in AD. This suggestion is consistent with a higher proportion of AD patients among COVID-19 related victims. Gut microbial tryptamine increase due to the viral infection-induced dysbiosis can synergize and potentiate the tryptamine cytotoxicity, necrotizing ability and other properties as a virulence factor.

The species-rich genus Palicourea (Rubiaceae: Palicoureeae) is source of an intriguing diversity of alkaloids derived from tryptamine and its precursor tryptophan. So far simple tryptamine analogues, polypyrroloindoline, β-carboline, and, most importantly, monoterpene-indole, i.e., tryptamine-iridoid alkaloids of various structural types including javaniside, alstrostine and strictosidine derivatives have been identified. Here the diverse alkaloids that numerous studies have found in the genus are examined and organized according to their structures and biosynthetic groups. Using a parsimony-based approach that follows the concept of retro-biogenesis usually applied in synthetic chemistry, possible biosynthetic pathways are proposed and important steps and relationships between these alkaloids are highlighted. Understanding alkaloid diversification is of importance in studying the ecological significance and evolution of biosynthetic capabilities of the genus Palicourea, and should stimulate future investigations on the biochemical and genetic background.

The total syntheses of aspidospermidine, N-methylaspidospermidine, N-acetylaspidospermidine, and aspidospermine were achieved from a common pentacyclic indoline intermediate. The common pentacyclic indoline intermediate was synthesized on a gram scale through a Stork-enamine alkylation of 1H-pyrrolo[2,3-d]carbazole derivatives, which were prepared through a Bronsted acid-catalyzed tandem cyclization of tryptamine-ynamide. The scalable synthesis of 1H-pyrrolo[2,3-d]carbazole afforded facile access and a practical approach to the Aspidosperma indole alkaloid family.

Pantothenate synthetase from Escherichia coli (PSE. coli) catalyzes the ATP-dependent condensation of (R)-pantoic acid and β-alanine to yield (R)-pantothenic acid (vitamin B5), the biosynthetic precursor to coenzyme A. Herein we show that besides the natural amine substrate β-alanine, the enzyme accepts a wide range of structurally diverse amines including 3-amino-2-fluoropropionic acid, 4-amino-2-hydroxybutyric acid, 4-amino-3-hydroxybutyric acid, and tryptamine for coupling to the native carboxylic acid substrate (R)-pantoic acid to give amide products with up to >99% conversion. The broad amine scope of PSE. coli enabled the efficient synthesis of pharmaceutically-relevant vitamin B5 antimetabolites with excellent isolated yield (up to 89%). This biocatalytic amide synthesis strategy may prove to be useful in the quest for new antimicrobials that target coenzyme A biosynthesis and utilisation., Pantothenate synthetase from Escherichia coli (PSE. coli) has a broad substrate scope, accepting diverse amines in the amidation of (R)-pantoate, enabling the facile synthesis of pharmaceutically relevant vitamin B5 antimetabolites.

Background: COVID-19 can be related to any diseases caused by microbial infection(s) because 1) co-infection with COVID-19-related virus and other microorganism(s) and 2) because metabolites produced by microorganisms such as bacteria, fungi, and protozoan can be involved in necrotizing pneumonia and other necrotizing medical conditions observed in COVID-19. Objective: By way of illustration, the microbial metabolite of aromatic amino acid tryptophan, a biogenic amine tryptamine inducing neurodegeneration in cell and animal models, also induces necrosis. Methods: This report includes analysis of COVID-19 positivity by zip codes in Florida and relation of the positivity to population density, possible effect of ecological and social factors on spread of COVID-19, autopsy analysis of COVID-19 cases from around the world, serum metabolomics analysis, and evaluation of autoantigenome related to COVID-19. Results: In the present estimations, COVID-19 positivity percent per zip code population varied in Florida from 4.65% to 44.3% (February 2021 data). COVID-19 analysis is partially included in my book Microbial Metabolism and Disease (2021). The autoantigenome related to COVID-19 is characterized by alterations in protein biosynthesis proteins including aminoacyl-tRNA synthetases. Protein biosynthesis alteration is a feature of Alzheimer’s disease. Serum metabolomics of COVID-19 positive patients show alteration in shikimate pathway metabolism, which is associated with the presence of Alzheimer’s disease-associated human gut bacteria. Conclusion: Such alterations in microbial metabolism and protein biosynthesis can lead to toxicity and neurodegeneration as described earlier in my book Protein Biosynthesis Interference in Disease (2020).

Monoterpene indole alkaloids (MIAs) are a diverse class of plant natural products that include a number of medicinally important compounds. We set out to reconstitute the pathway for strictosidine, a key intermediate of all MIAs, from central metabolism in Nicotiana benthamiana. A disadvantage of this host is that its rich background metabolism results in the derivatization of some heterologously produced molecules. Here we use transcriptomic analysis to identify glycosyltransferases that are upregulated in response to biosynthetic intermediates and produce plant lines with targeted mutations in the genes encoding them. Expression of the early MIA pathway in these lines produces a more favorable product profile. Strictosidine biosynthesis was successfully reconstituted, with the best yields obtained by the co-expression of 14 enzymes, of which a major latex protein-like enzyme (MLPL) from Nepeta (catmint) is critical for improving flux through the iridoid pathway. The removal of endogenous glycosyltransferases does not impact the yields of strictosidine, highlighting that the metabolic flux of the pathway enzymes to a stable biosynthetic intermediate minimizes the need to engineer the endogenous metabolism of the host. The production of strictosidine in planta expands the range of MIA products amenable to biological synthesis.

By the reaction of thiophen-2-carbaldehyde with rhodanine derivatives, 5-thiophen-2-ylmethylene-2-thioxothiazolidin-4-ones have been synthesized. The resulting (4-oxo-5-thiophen-2-ylmethylen-2-thioxothiazolidin-3-yl)alkane carboxylic acids have been used to acylate the biogenic amine tryptamine and its derivatives. As a result, a number of novel N-[2-(5-[R-1H-indol-3-yl)-ethyl]-2-(4-oxo-5-thiophen-2-ylmethylen-2-thioxothiazolidin-3-yl)carbamides have been synthesized. The antimicrobial and antitumor properties of the resulting compounds have been tested. Compounds with a high antimicrobial activity against Staphylococcus aureus and Cryptococcus neoformans have been identified.

Rising numbers of psychoactive tryptamine derivatives have become available on the drug market over the last decade, making these naturally occurring or synthetically manufactured compounds highly relevant for forensic analyses. One of these compounds is 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), a constituent of the dried poison of Incilius alvarius (Colorado River toad), which has a history of ritual and/or recreational use. Still, comprehensive and validated qualitative as well as quantitative analytical data on the psychoactive components of this poison are scarce. In this study, samples of the poison of Incilius alvarius were collected from live toads in the Sonoran Desert, Arizona (USA), and analyzed with a set of complementary methods. Acetone/water (70/30, v/v) proved to be the solvent of choice for the extraction of tryptamine derivatives. Trace compounds were enriched, and overload with 5-MeO-DMT was prevented by chromatographic separation of 5-MeO-DMT prior to qualitative analyses. The method for quantification was validated. Attenuated total reflection–Fourier transform infrared spectroscopy was suitable to identify 5-MeO-DMT as the main tryptamine in samples of the poison. The combined evaluation of analytical data gained from gas chromatography–mass spectrometry (GC–MS), high-performance liquid chromatography–quadrupole time-of-flight high-resolution MS (HPLC–qToF-HRMS) and HPLC–MS-MS confirmed the presence of 5-MeO-DMT, 5-MeO-N-methyltryptamine, 5-MeO-tryptamine, 5-MeO-tryptophol, 2-(5-methoxy-1H-indol-3-yl)-acetic-acid (5-MIAA), 5-HO-N-methyltryptamine, bufotenin, DMT and tryptophan. For the first time, 5-MeO-tryptamine and two positional isomers of hydroxylated MeO-DMT were detected in the poison of Incilius alvarius. The tryptamine present in the highest concentrations was 5-MeO-DMT (mean ± SD: 410,000 ± 30,000 μg/g). Mean concentrations of 5-MeO-tryptamine (490 ± 260 μg/g), 5-HO-N-methyltryptamine (270 ± 120 μg/g), bufotenin (2,800 ± 1,900 μg/g) and DMT (250 ± 80 μg/g) showed a relatively high variability between individual samples. The comprehensive analytical reference data of Incilius alvarius poison presented here might prove useful for forensic chemists.

A novel analogue of psilocybin was produced by hybrid chemoenzymatic synthesis in sufficient quantity to enable bioassay. Utilizing purified 4-hydroxytryptamine kinase from Psilocybe cubensis, chemically synthesized 5-methylpsilocin (2) was enzymatically phosphorylated to provide 5-methylpsilocybin (1). The zwitterionic product was isolated from the enzymatic step with high purity utilizing a solvent–antisolvent precipitation approach. Subsequently, 1 was tested for psychedelic-like activity using the mouse head-twitch response assay, which indicated activity that was more potent than the psychedelic dimethyltryptamine, but less potent than that of psilocybin.

New pyranopyridonotryptamines 3 were synthesized by a three-component reaction of pyridonotryptamines 1, aromatic aldehydes 2, and malononitrile. The structures of compounds 3 were confirmed by X-ray crystallography. A series of compounds 3 underwent primary screening for the effect on the course of mitosis in seeds of plants of the species Allium cepa L.

Biogenic amines are important messengers in neurotransmission, drawing attention to pharmaceutical applications. Here, we developed a novel biocatalytic process for the preparation of biogenic amines using aromatic l-amino acid decarboxylase (AADC) under an in situ product removal (ISPR) condition. The AADC from Bacillus atrophaeus (AADC-BA) showed broad substrate specificity for aromatic amino acids, affording > 90% conversions of 10 mM substrates to corresponding products: 2-phenylethylamine (2-PEA), tryptamine, serotonin, and dopamine. Owing to enzyme inhibitions by the reaction products, we implemented an ISPR strategy using a cation exchange resin and an open reactor system for removal of amine and CO2, respectively. Under the open-air conditions, the addition of Dowex 50WX8 afforded 81% conversion of 100 mM l-phenylalanine to 2-PEA within 1 h, whereas 56% conversion was obtained without the resin. The ISPR strategy enabled the preparative-scale production of serotonin from 5-hydroxy-l-tryptophan (405 mg), yielding > 99% conversion within 40 min.

Indole-3-acetic acid (IAA) is a critical plant hormone that regulates cell division, development, and metabolism. IAA synthesis in plants and plant-associated microorganisms cannot fulfill the requirement for large-scale agricultural production. Here, two novel IAA biosynthesis pathways, tryptamine (TAM) and indole-3-acetamide (IAM), were developed for IAA production by whole-cell catalysis and de novo biosynthesis in an engineered Escherichia coli MG1655. When 10 g/L l-tryptophan was used as a substrate, an MIA-6 strain containing a heterologous IAM pathway had the highest IAA titer of 7.10 g/L (1.34 × 103 mg/g DCW), which was 98.4 times more than MTAI-5 containing the TAM pathway by whole-cell catalysis. De novo IAA biosynthesis was optimized by improving NAD(P)H availability, resulting in an increased IAA titer of 906 mg/L obtained by the MGΔadhE::icd strain, which is 29.7% higher than the control. These strategies exhibit the potential for IAA production in engineered E. coli and possible industrial applications.

There is significant demand for the development of rapid, sensitive, and specific methods for detecting bacterial pathogens in order to identify the causes of food poisoning. Nucleic acid amplification tests (NAATs) allow for the culture-free detection of bacterial pathogens and are not as labor intensive and time consuming as culture-based detection methods. However, suitable sample preparation methods must be developed for the realization of simple, rapid, and sensitive NAATs. To resolve this problem, we developed a new sample preparation method that integrates bacterial pathogen enrichment and DNA extraction. We engineered magnetic nanoparticles (MNPs) with a physicochemical probe (tryptamine) for single-tube sample preparation with minimal sample loss. The tryptamine-functionalized MNPs (Indole@MNPs) showed inherent hydrophobicity owing to the indole side chain and a change in their zeta potential with a decrease in the pH. Because of their physicochemical characteristics, the Indole@MNPs could adsorb bacterial pathogens, thus allowing sample enrichment and DNA binding and release through weak electrostatic interactions via pH control. We successfully detected Salmonella enterica serovar Typhimurium, a common cause of bacterial food poisoning, at a concentration of 10 CFU/10 mL in milk samples using quantitative PCR. Thus, the proposed method allows for the simple and sensitive detection of Salmonella typhimurium and can be used for nontyphoidal salmonella detection to ensure food safety.

Strictosidine synthase (STR) catalyzes the Pictet–Spengler (PS) condensation between tryptamine and secologanin, leading to the formation of (S)-strictosidine. The product is a central intermediate...

WsWRKY1-mediated transcriptional modulation of Withania somnifera tryptophan decarboxylase gene (WsTDC) helps to regulate fruit-specific tryptamine generation for production of withanamides. Withania somnifera is a highly valued medicinal plant. Recent demonstration of novel indolyl metabolites called withanamides in its fruits (berries) prompted us to investigate its tryptophan decarboxylase (TDC), as tryptophan is invariably a precursor for indole moiety. TDC catalyzes conversion of tryptophan into tryptamine, and the catalytic reaction constitutes a committed metabolic step for synthesis of an array of indolyl metabolites. The TDC gene (WsTDC) was cloned from berries of the plant and expressed in E. coli. The recombinant enzyme was purified and characterized for its catalytic attributes. Catalytic and structural aspects of the enzyme indicated its regulatory/rate-limiting significance in generation of the indolyl metabolites. Novel tissue-wise and developmentally differential abundance of WsTDC transcripts reflected its preeminent role in withanamide biogenesis in the fruits. Transgenic lines overexpressing WsTDC gene showed accumulation of tryptamine at significantly higher levels, while lines silenced for WsTDC exhibited considerably depleted levels of tryptamine. Cloning and sequence analysis of promoter of WsTDC revealed the presence of W-box in it. Follow-up studies on isolation of WsWRKY1 transcription factor and its overexpression in W. somnifera revealed that WsTDC expression was substantially induced by WsWRKY1 resulting in overproduction of tryptamine. The study invokes a key role of TDC in regulating the indolyl secondary metabolites through enabling elevated flux/supply of tryptamine at multiple levels from gene expression to catalytic attributes overall coordinated by WsWRKY1. This is the first biochemical, molecular, structural, physiological and regulatory description of a fruit-functional TDC.

International audience; Auxins are hormones that regulate growth and development in plants. Besides plants, various microorganisms also produce auxins. Here we investigate whether and how the phytopathogenic fungus Leptosphaeria maculans biosynthesizes auxins. We characterized the auxin profile of invitro grown L.maculans. The culture was further supplied with the auxin biosynthetic-precursors tryptophan and tryptamine and gene expression and phytohormone content was analyzed. L.maculans invitro produced IAA (indole-3-acetic acid) as the predominant auxin metabolite. IAA production could be further stimulated by supplying precursors. Expression of indole-3-pyruvate decarboxylase LmIPDC2, tryptophan aminotransferase LmTAM1 and nitrilase LmNIT1 genes was mainly upregulated after adding tryptophan and correlated with IAA production, suggesting that these genes are the key components of auxin biosynthesis in L.maculans. Tryptamine acted as a potent inducer of IAA production, though a pathway independent of LmIPDC2/LmTAM1 may be involved. Despite L.maculans being a rich source of bioactive IAA, the auxin metabolic profile of host plant Brassica napus was not altered upon infection. Exogenous IAA inhibited the growth of L.maculans invitro when supplied in high concentration. Altogether, we showed that L.maculans is capable of IAA production and we have identified biosynthetic genes that were responsive to tryptophan treatment.

Psilocybin, the principal indole alkaloid of Psilocybe mushrooms, is currently undergoing clinical trials as a medication against treatment‐resistant depression and major depressive disorder. The psilocybin supply for pharmaceutical purposes is met by synthetic chemistry. We replaced the problematic phosphorylation step during synthesis with the mushroom kinase PsiK. This enzyme was biochemically characterized and used to produce one gram of psilocybin from psilocin within 20 minutes. We also describe a pilot‐scale protocol for recombinant PsiK that yielded 150 mg enzyme in active and soluble form. Our work consolidates the simplicity of tryptamine chemistry with the specificity and selectivity of enzymatic catalysis and helps provide access to an important drug at potentially reasonable cost., The benefits of bulk: Future use of psilocybin as a medication will entail increased demand. We present a gram‐scale synthetic/biocatalytic approach in which the mushroom kinase PsiK replaces tedious chemical phosphorylation. A pilot‐scale protocol to make three‐digit milligram amounts of pure and active recombinant PsiK available is also described.

Light mediates plant growth through diverse mechanisms and signaling networks including plant growth regulators (PGRs). We hypothesized that a novel class of PGRs, the indoleamines, are plant signaling molecules that perceive changes in light composition and initiate a cascade of metabolic responses. We used three Scutellaria model species (skullcap): S. lateriflora, S. galericulata and S. racemosa that produce high levels of melatonin and serotonin to investigate this hypothesis. Axenic Scutellaria cultures were exposed to red, blue, green or full spectrum white light spectra provided by light emitting diode (LED) lighting systems, or daylight fluorescent bulbs. Melatonin (MEL), serotonin (5HT), abscisic acid (ABA), auxin (IAA), and jasmonic acid (JA), were quantified by liquid chromatography with tandem mass spectrometry. Melatonin was detected consistently in plants grown under blue light in all species of Scutellaria. In S. galericulata, significant quantities of ABA were detected in plants grown under white light but not detected in plants grown under other light spectra. In timeline studies of S. racemosa plants exposed to limited red or blue light spectra had significantly reduced levels of tryptamine (TRM), 5HT and MEL in the shoots initially but melatonin was detected after 12 hours and quantifiable amounts of 5HT were detected after 7 days. Supplementation of the culture medium with MEL or 5HT did not change the pattern of MEL in blue light grown cultures but did change patterns of 5HT accumulation. 5HT was highest in plants grown under red light immediately after culture and decreased over 7 days. These data indicate that the relative amounts of MEL and 5HT are responsive to light spectra and redirect metabolic resources to enable plant adaptations to changing environments.

Tryptophan decarboxylase (TDC, EC 4.1.1.28) catalyzes tryptophan decarboxylation to form tryptamine through the cofactor pyridoxal-5'-phosphate (PLP), a crucial stage in the production of the terpenoid indole alkaloids like camptothecin (CPT). A new gene encoding TDC was identified from the CPT-producing plant Ophiorrhiza pumila by transcriptome analysis, termed OpTDC2. It contained a 1,536 bp open reading frame that encodes a 511 amino acid protein with a molecular mass of 57.01 kDa and an isoelectric point of 6.39. Multiple sequence alignment and phylogenetic tree analysis showed the closest similarity (85%) with the TDC from Mitragyna speciosa. Moreover, the highest expression of OpTDC2 was observed in the O. pumila root. To achieve high-efficiency expression of OpTDC2 in Escherichia coli, we fused the TF tag onto the N-terminal of the OpTDC2. Optimum enzymatic activity was observed at 45 °C, pH 8 and cofactor concentration of 0.1 mM. The catalytic reaction was strongly inhibited by metal ions of Cu2+ , Zn2+ , and Fe2+ . The l-tryptophan was particularly catalyzed compared with d-tryptophan. Besides, the Km and kcat of the OpTDC2 were 1.08 mM and 0.78 Sec-1 , respectively. The results provided information on new functional OpTDC2 that might be used in synthetic biology for the enhanced biosynthesis of CPT in O. pumila.

Biogenic amines (BAs; 2-phenylethylamine, tyramine, dopamine, epinephrine, norepinephrine, octopamine, histamine, tryptamine, serotonin, agmatine, cadaverine, putrescine, spermidine, spermine and certain aliphatic amines) are widely distributed organic molecules that play basic physiological functions in animals, plants and microorganisms. Pseudomonas species can grow in media containing different BAs as carbon and energy sources, a reason why these bacteria are excellent models for studying such catabolic pathways. In this review, we analyse most of the routes used by different species of Pseudomonas (P. putida, P. aeruginosa, P. entomophila and P. fluorescens) to degrade BAs. Analysis of these pathways has led to the identification of a huge number of genes, catabolic enzymes, transport systems and regulators, as well as to understanding of their hierarchy and functional evolution. Knowledge of these pathways has allowed the design and collection of genetically manipulated microbes useful for eliminating BAs from different sources, highlighting the biotechnological applications of these studies.

Nothapodytes foetida, an endangered tree of Indian origin, is a major source of the anti-cancer monoterpenoid indole alkaloid, camptothecin (CPT). Strictosidine synthase (STR) condenses tryptamine and secologanin to form strictosidine, a universal precursor of terpenoid indole alkaloids including CPT. We cloned full-length str cDNA with an open reading frame of 1059 bp from N. foetida (Nfstr) using a homology-based approach. Different tissues of N. foetida from in vitro grown cultures, as well as a mature tree, showed expression of STR, confirming the constitutive nature of the gene. In vitro tissues showed a positive correlation between STR expression and the CPT content, but tissues from wild-type mature plants did not show a similar pattern. Transgenic Ophiorrhiza rugosa plants overexpressing Nfstr showed 1.9-fold higher CPT than non-transformed plants. The results indicated that overexpression of Nfstr in target plants could improve the levels of CPT and may provide an alternative and sustainable source of camptothecin. We report the full-length sequence and expression analysis of strictosidine synthase cDNA from Nothapodytes foetida (Nfstr). Further, the overexpression of Nfstr in Ophiorrhiza resulted in twofold enhancement in camptothecin levels.

Two hydroxybenzoyl amines, 4-hydroxybenzoyl tyramine (4-HBT) and N-2-hydroxybenzoyl tryptamine (2-HBT), were synthesized using Escherichia coli. While 4-HBT was reported to demonstrate anti-atherosclerotic activity, 2-HBT showed anticonvulsant and antinociceptive activities. We introduced genes chorismate pyruvate-lyase (ubiC), tyrosine decarboxylase (TyDC), isochorismate synthase (entC), isochorismate pyruvate lyase (pchB), and tryptophan decarboxylase (TDC) for each substrate, 4-hydroxybenzoic acid (4-HBA), tyramine, 2-hydroxybenzoic acid (2-HBA), and tryptamine, respectively, in E. coli. Genes for CoA ligase (hbad) and amide formation (CaSHT and OsHCT) were also introduced to form hydroxybenzoic acid and amine conjugates. In addition, we engineered E. coli to provide increased substrates. These approaches led to the yield of 259.3 mg/l 4-HBT and 227.2 mg/l 2-HBT and could be applied to synthesize diverse bioactive hydroxybenzoyl amine conjugates.

The COVID-19 pandemic has highlighted the need to identify additional antiviral small molecules to complement existing therapies. Although increasing evidence suggests that metabolites produced by the human microbiome have diverse biological activities, their antiviral properties remain poorly explored. Using a cell-based SARS-CoV-2 infection assay, we screened culture broth extracts from a collection of phylogenetically diverse human-associated bacteria for the production of small molecules with antiviral activity. Bioassay-guided fractionation uncovered three bacterial metabolites capable of inhibiting SARS-CoV-2 infection. This included the nucleoside analogue N6-(Δ2-isopentenyl)adenosine, the 5-hydroxytryptamine receptor agonist tryptamine, and the pyrazine 2,5-bis(3-indolylmethyl)pyrazine. The most potent of these, N6-(Δ2-isopentenyl)adenosine, had a 50% inhibitory concentration (IC50) of 2 μM. These natural antiviral compounds exhibit structural and functional similarities to synthetic drugs that have been clinically examined for use against COVID-19. Our discovery of structurally diverse metabolites with anti-SARS-CoV-2 activity from screening a small fraction of the bacteria reported to be associated with the human microbiome suggests that continued exploration of phylogenetically diverse human-associated bacteria is likely to uncover additional small molecules that inhibit SARS-CoV-2 as well as other viral infections. IMPORTANCE The continued prevalence of COVID-19 and the emergence of new variants has once again put the spotlight on the need for the identification of SARS-CoV-2 antivirals. The human microbiome produces an array of small molecules with bioactivities (e.g., host receptor ligands), but its ability to produce antiviral small molecules is relatively underexplored. Here, using a cell-based screening platform, we describe the isolation of three microbiome-derived metabolites that are able to prevent SARS-CoV-2 infection in vitro. These molecules display structural similarities to synthetic drugs that have been explored for the treatment of COVID-19, and these results suggest that the microbiome may be a fruitful source of the discovery of small molecules with antiviral activities.

Serotonin (Ser) and melatonin (Mel) serve as master regulators of plant growth and development by influencing diverse cellular processes. The enzymes namely, tryptophan decarboxylase (TDC) and tryptamine 5-hydroxylase (T5H) catalyse the formation of Ser from tryptophan. Subsequently, serotonin N-acetyl transferase (SNAT) and acetyl-serotonin methyltransferase (ASMT) form Mel from Ser. Plant genomes harbour multiple genes for each of these four enzymes, all of which have not been identified. Therefore, to delineate information regarding these four gene families, we carried out a genome-wide analysis of the genes involved in Ser and Mel biosynthesis in Arabidopsis, tomato, rice and sorghum. Phylogenetic analysis unravelled distinct evolutionary relationships among these genes from different plants. Interestingly, no gene family except ASMTs showed monocot- or dicot-specific clustering of respective proteins. Further, we observed tissue-specific, developmental and stress/hormone-mediated variations in the expression of the four gene families. The light/dark cycle also affected their expression in agreement with our quantitative reverse transcriptase-PCR (qRT-PCR) analysis. Importantly, we found that miRNAs (miR6249a and miR-1846e) regulated the expression of Ser and Mel biosynthesis under light and stress by influencing the expression of OsTDC5 and OsASMT18, respectively. Thus, this study may provide opportunities for functional characterization of suitable target genes of the Ser and Mel pathway to decipher their exact roles in plant physiology.

Background: Oleanolic acid is a natural plant adaptogen, and tryptamine is a natural psychoactive drug. To compare their effects of with the effect of their derivatives, tryptamine and fluorotryptamine amides of oleanolic acid were designed and synthesized. Methods: The target amides were investigated for their pharmacological effect, and basic supramolecular self-assembly characteristics. Four human cancer cell lines were involved in the screening tests performed by standard methods. Results: The ability to display cytotoxicity and to cause selective cell apoptosis in human cervical carcinoma and in human malignant melanoma was seen with the three most active compounds of the prepared series of compounds. Tryptamine amide of (3β)-3-(acetyloxy)olean-12-en-28-oic acid (3a) exhibited cytotoxicity in HeLa cancer cell lines (IC50 = 8.7 ± 0.4 µM) and in G-361 cancer cell lines (IC50 = 9.0 ± 0.4 µM). Fluorotryptamine amides of (3β)-3-(acetyloxy)olean-12-en-28-oic acid (compounds 3b and 3c) showed cytotoxicity in the HeLa cancer cell line (IC50 = 6.7 ± 0.4 µM and 12.2 ± 4.7 µM, respectively). The fluorotryptamine amide of oleanolic acid (compound 4c) displayed cytotoxicity in the MCF7 cancer cell line (IC50 = 13.5 ± 3.3 µM). Based on the preliminary UV spectra measured in methanol/water mixtures, the compounds 3a–3c were also found to self-assemble into supramolecular systems. Conclusions: An effect of the fluorine atom present in the molecules on self-assembly was observed with 3b. Enhanced cytotoxicity has been achieved in 3a–4c in comparison with the effect of the parent oleanolic acid (1) and tryptamine. The compounds 3a–3c showed a strong induction of apoptosis in HeLa and G-361 cells after 24 h.

This study analyses the biogenic amines (BAs) formed in mackerel cooked by various methods and conditions. Five BAs, including tryptamine, β-phenylethylamine, putrescine, histamine, and spermidine, were analysed by high-performance liquid chromatography with UV detection. The level of total BAs was higher in the mackerel fillet (108.14 µg/g) than the headed and gutted fish (91.58 µg/g). Roasted, fried, and stewed mackerel recorded total BA concentrations of 54.28, 82.25, and 163.05 µg/g, respectively. Stewed mackerel contained about 3-fold more BAs than roasted mackerel. The level of total BAs in mackerel increased significantly up to 190%, 236% and 152% as the roasting temperature increased, upon frying, and as stewing temperature increased, respectively (p &lt, 0.05).

Cholinesterase inhibitors are potent therapeutics in the treatment of Alzheimer's disease. Among them, dual binding ligands have recently gained a lot of attention. We discovered novel dual-binding cholinesterase inhibitors, using “clickable” fragments, which bind to either catalytic active site (CAS) or peripheral anionic site (PAS) of the enzyme. Copper(I)-catalyzed azide-alkyne cycloaddition allowed to effectively synthesize a series of final heterodimers, and modeling and kinetic studies confirmed their ability to bind to both CAS and PAS. A potent acetylcholinesterase inhibitor with IC50 = 18 nM (compound 23g) was discovered. A target-guided approach to link fragments by the enzyme itself was tested using butyrylcholinesterase.

The divergent total syntheses of aspidospermidine, N-methylaspidospermidine, N-acetylaspidospermidine and aspidosperm-ine were achieved from a common pentacyclic indoline intermediate. The common pentacyclic indoline intermediate was synthesized on a gram scale through a Stork-type alkylation of 1H-pyrrolo[2,3-d]carbazole derivatives, which was prepared based on a Brønsted acid-catalyzed tandem cyclization of tryptamine-ynamide. Scalable synthesis of 1H-pyrrolo[2,3-d]carbazole afforded a facile access and practical approach to the Aspidosperma indole alkaloid family.

Research Areas: Environmental Sciences & Ecology ; Public, Environmental & Occupational Health : Dry-cured sausages are traditional in Mediterranean countries, and Paio do Alentejo (PA) is one of the most popular in South Portugal. The aim of the present work was to evaluate the effect of combined starters on the safety and quality of PA preserving its sensory quality. Physicochemical parameters, namely pH and water activity (aW), microbiological parameters, biogenic amines, color, texture, and sensory attributes were assessed. Three starter cultures were used, namely Staphylococcus equorum S2M7 and Lactobacillus sakei CV3C2, both separate and combined with the 2RB4 yeast strain at a concentration of 106 cfu/g. Dextrose 0.25% was added to the meat batter. Starters had a significant effect on the reduction of aW values (0.845 to 0.823). The treatment with L. sakei as well as the co-inoculation of L. sakei with S. equorum effectively reduced the L. monocytogenes counts to undetectable levels. Sausages co-inoculated with S. equorum S2M7/L. sakei CV3C2 showed a significant reduction in the content of vasoactive amines, namely tryptamine (26.21 to 15.70) and β-phenylethylamine (4.80 to 3.69). Regarding texture, control PA showed higher hardness values, and the starters promoted the cohesiveness of the batter while reducing chewiness. The studied starters did not compromise the sensory characteristics of PA. info:eu-repo/semantics/publishedVersion

The current coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights major gaps in our knowledge on the prevention control and cross-species transmission mechanisms of animal coronaviruses. Transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), and porcine delta coronavirus (PDCoV) are three common swine coronaviruses and have similar clinical features. In the absence of effective treatments, they have led to significant economic losses in the swine industry worldwide. We reported that indoles exerted potent activity against swine coronaviruses, the molecules used included melatonin, indole, tryptamine, and L-tryptophan. Herein, we did further systematic studies with melatonin, a ubiquitous and versatile molecule, and found it inhibited TGEV, PEDV, and PDCoV infection in PK-15, Vero, or LLC-PK1 cells by reducing viral entry and replication, respectively. Collectively, we provide the molecular basis for the development of new treatments based on the ability of indoles to control TGEV, PEDV, and PDCoV infection and spread.

Aromatic nitration reactions are a cornerstone of organic chemistry, but are challenging to scale due to corrosive reagents and elevated temperatures. The cytochrome P450 TxtE nitrates the indole 4‐position of l‐tryptophan at room temperature using NO, O2 and NADPH, and has potential to be developed into a useful aromatic nitration biocatalyst. However, its narrow substrate scope (requiring both the α‐amino acid and indole functionalities) have hindered this. Screening of an R59 mutant library of a TxtE‐reductase fusion protein identified a variant (R59C) that nitrates tryptamine, which is not accepted by native TxtE. This variant exhibits a broader substrate scope than the wild type enzyme and is able to nitrate a range of tryptamine analogues, with significant alterations to the aromatic and aminoethyl moieties., Directed evolution of aromatic nitration biocatalysts: Screening variants of a self‐sufficient reductase fusion of the indole‐nitrating cytochrome P450 TxtE led to the discovery of an active site mutant that nitrates tryptamine and a range of tryptamine analogues with alterations to the aminoethyl group and/or indole.

Three monoterpenoid indole alkaloids (MIAs), tabernabovines A-C (1-3), were isolated from Tabernaemontana bovina. They were elucidated by spectroscopic data and computational calculations. Unlike precursors of MIAs, strictosidine and alstrostine A, alkaloid 1 consists of tryptamine and secologanin in a 2:1 ratio. Alkaloid 2 is a cage compound, and 3 possesses a bridged ring. Tabernabovine A exhibited inhibitory activity against NO production with IC50 44.1 μM compared to l-NMMA with IC50 of 48.6 μM.

IAA biosynthetic pathways in a basidiomycetous yeast, Rhodosporidiobolus fluvialis DMKU-CP293, were investigated. The yeast strain showed tryptophan (Trp)-dependent IAA biosynthesis when grown in tryptophan supplemented mineral salt medium. Gas chromatography–mass spectrometry was used to further identify the pathway intermediates of Trp-dependent IAA biosynthesis. The results indicated that the main intermediates produced by R. fluvialis DMKU-CP293 were tryptamine (TAM), indole-3-acetic acid (IAA), and tryptophol (TOL), whereas indole-3-pyruvic acid (IPA) was not found. However, supplementation of IPA to the culture medium resulted in IAA peak detection by high-performance liquid chromatography analysis of the culture supernatant. Key enzymes of three IAA biosynthetic routes, i.e., IPA, IAM and TAM were investigated to clarify the IAA biosynthetic pathways of R. fluvialis DMKU-CP293. Results indicated that the activities of tryptophan aminotransferase, tryptophan 2-monooxygenase, and tryptophan decarboxylase were observed in cell crude extract. Overall results suggested that IAA biosynthetic in this yeast strain mainly occurred via the IPA route. Nevertheless, IAM and TAM pathway might be involved in R. fluvialis DMKU-CP293.

Herbaceous peony (Paeonia lactiflora Pall.) is known as the king of herbaceous flowers. Drought stress seriously restricts P. lactiflora growth and reduces its ornamental value, but little is known about its underlying mechanism. In this study, one tryptophan decarboxylase gene (TDC), which is the first enzyme gene for melatonin biosynthesis, was obtained, and its expression level was found to be positively related to melatonin production during drought stress. In P. lactiflora, the first TDC that was isolated was comprised of 1849 bp with no intron, and was designated as PlTDC (KY765554). It encoded a 502-amino acid protein with a molecular weight of 56 kDa, which was localized in the cytoplasm of cells and catalyzed the reaction converting tryptophan into tryptamine. When PlTDC was transferred into tobacco, the transgenic plants produced approximately 1.67-fold higher levels of melatonin than that of wild-type control. Moreover, the transgenic plants had enhanced tolerance to drought and salt stresses, potentially due to the reduction in hydrogen peroxide (H2O2) and superoxide anion free radical (O2 −) accumulation. In addition, the enhanced H2O2 and O2 − scavenging under drought stress led to decreased cell membrane damage, increased potential photosynthetic capacity, and delayed plant senescence. RNA-Seq data correlated well with the protective role of melatonine because it was found an increase of gene expression involved in the oxidation-reduction process and photosynthesis. These results together suggested that PlTDC was a key factor in increasing melatonin production, to confer drought and salt stress tolerance in P. lactiflora.

In this research, biogenic amine types and quantity of Tulum and Kashar cheeses were determined. In addition, the relationship between biogenic amines and some microbiological-chemical properties of cheese samples were investigated. The contents of tryptamine, phenylethylamine, putrecine, cadaverine, histamine, tyramine of totally 40 samples (20 of each cheese) were examined. While only one sample of Tulum cheeses had no biogenic amines, different levels of biogenic amines were determined in other samples. No significant relation was confirmed between the biogenic amine quantity and total aerobic mesophilic bacteria, lactic acid bacteria, enterococci bacteria count, but there was a correlation between some biogenic amine contents and chemical properties which are tyrosine, lactic acid, pH, protein and ripening coefficient. Biogenic amine levels determined in the cheeses found below hazard limit values according to what legal limit.

Catharanthus roseus is a well-known herb with great pharmaceutical value for being the only source of natural antineoplastic drugs vinblastine and vincristine. The terpenoid indole alkaloids (TIAs) biosynthetic pathway responsible for the production of these antineoplastic drug molecules is under a strict spatiotemporal regulation that requires five different cellular as well as at least four intracellular compartmentations for its completion. Therefore, several efforts were made to investigate the cell and tissue cultures of Catharanthus roseus to establish as an alternative source of TIAs production. Cell suspension, hairy roots and callus cultures of Catharanthus roseus do not provide the required cellular complexity for the completion of entire TIAs pathway, therefore, failed to produce vinblastine and vincristine. However, the multiple shoot cultures do provide the required cellular complexity to complete the entire TIAs pathway. Therefore, in the present study, the multiple shoot cultures along with callus cultures were subjected to the abiotic elicitors and TIAs pathway precursors feeding for the first time to chase the effect of these abiotic elicitors and pathway precursors on the production of major TIAs of Catharanthus roseus. The multiple shoot cultures treated with TIAs pathway precursor tryptamine 300 mg/L accumulated highest vinblastine content (0.0277% dry wt) followed by tryptophan feeding at 300 mg/L (0.0180% dry wt) and 500 mg/L (0.0175% dry wt) whereas, callus cultures failed to produce vinblastine.

Novel Schiff bases such as N-cyclohexylidene-2(1H-indol-3-yl) ethanamine [TCH], 2-(1H-indol-3-yl)-N-((1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)ethanamine [TC], 2-(1H-indol-3-yl)-N-(1-phenylethylidene)ethanamine [TAP] were prepared by the condensation reaction of tryptamine with cyclo hexanone , camphor and aceto phenone. The imines were characterised by UV-Visible, FT-IR and H1NMR spectral data. All the three Schiff bases were screened for antibacterial (staphylococcus aureus, Bacillus substilis, salmoneila typhi and Proteus Vulgaris) and antifungal (candida alibicans, Aspergilus niger) activities by disc diffusion method. The results indicate that all imines exhibit significant antimicrobial activity.

A series of tryptamine salicylic acid derivatives were synthesized and their antiproliferative activity against MGC-803, MCF-7, HepG2, A549 and HeLa cell lines was evaluated. The structure–activity relationship (SAR) study revealed that different substitutions of the C5 and C3′–C5′ positions have certain effects on the anti-proliferation activity. The growth assay revealed that N-[2-(5-bromo-1H-indol-3-yl)-ethyl]-2-hydroxy-3-methyl-benzamide (E20) showed the most potent and broad-spectrum anticancer inhibition of all the cell lines evaluated, and was only more potent than 5-Fu for the gastric cancer cell line. Preliminary studies indicated that compound E20 could inhibit colony formation and migration of MGC-803 cells. The flow cytometry (FCM) results showed that compound E20 arrested the cell cycle in the G2/M phase and induced apoptosis of MGC-803 cells in a concentration-dependent manner. In addition, the western blot results showed that E20 can down-regulate the expression of hexokinase 2. Our studies suggest that the framework of N-[2-(5-bromo-1H-indol-3-yl)-ethyl]-2-hydroxy-3-methyl-benzamide may be consider as a new type of chemical for designing effective anti-cancer drugs targeting gastric cancer cells.

Rhizobium tropici CIAT 899 is a strain known by its ability to nodulate a broad range of legume species, to synthesize a variety of Nod factors, its tolerance of abiotic stresses, and its high capacity to fix atmospheric N2, especially in symbiosis with common bean (Phaseolus vulgaris L.). Genes putatively related to the synthesis of indole acetic acid (IAA) have been found in the symbiotic plasmid of CIAT 899, in the vicinity of the regulatory nodulation gene nodD5, and, in this study, we obtained mutants for two of these genes, y4wF and tidC (R. tropiciindole-3-pyruvic acid decarboxylase), and investigated their expression in the absence and presence of tryptophan (TRP) and apigenin (API). In general, mutations of both genes increased exopolysaccharide (EPS) synthesis and did not affect swimming or surface motility; mutations also delayed nodule formation, but increased competitiveness. We found that the indole-3-acetamide (IAM) pathway was active in CIAT 899 and not affected by the mutations, and-noteworthy-that API was required to activate the tryptamine (TAM) and the indol-3-pyruvic acid (IPyA) pathways in all strains, particularly in the mutants. High up-regulation of y4wF and tidC genes was observed in both the wild-type and the mutant strains in the presence of API. The results obtained revealed an intriguing relationship between IAA metabolism and nod-gene-inducing activity in R. tropici CIAT 899. We discuss the IAA pathways, and, based on our results, we attribute functions to the y4wF and tidC genes of R. tropici.

Substantial effort has been devoted toward understanding the psychopharmacological effects of tryptamine hallucinogens, which are thought to be mediated by activation of 5-HT(2A) and 5-HT(1A) receptors. Recently, several psychoactive tryptamines based on the N,N-diallyltryptamine (DALT) scaffold have been encountered as recreational drugs. Despite the apparent widespread use of DALT derivatives in humans, little is known about their pharmacological properties. We compared the binding affinities of DALT and its 2-phenyl-, 4-acetoxy-, 4-hydroxy-, 5-methoxy-, 5-methoxy-2-methyl-, 5-fluoro-, 5-fluoro-2-methyl-, 5-bromo-, and 7-ethyl-derivatives at 45 receptor and transporter binding sites. Additionally, studies in C57BL/6J mice examined whether these substances induce the head twitch response (HTR), a 5-HT2A receptor-mediated response that is widely used as a behavioral proxy for hallucinogen effects in humans. Most of the test drugs bound to serotonin receptors, σ sites, α2-adrenoceptors, dopaminergic D3 receptors, histaminergic H1 receptors, and the serotonin transporter. DALT and several of the ring-substituted derivatives were active in the HTR assay with the following rank order of potency: 4-acetoxy-DALT > 5-fluoro-DALT > 5-methoxy-DALT > 4-hydroxy-DALT > DALT > 5-bromo-DALT. 2-Phenyl-DALT, 5-methoxy-2-methyl-DALT, 5-fluoro-2-methyl-DALT, and 7-ethyl-DALT did not induce the HTR. HTR potency was not correlated with either 5-HT1A or 5-HT2A receptor binding affinity, but a multiple regression analysis indicted that 5-HT2A and 5-HT1A receptors make positive and negative contributions, respectively, to HTR potency (R(2) = 0.8729). In addition to supporting the established role of 5-HT2A receptors in the HTR, these findings are consistent with evidence that 5-HT1A activation by tryptamine hallucinogens buffers their effects on HTR.

A novel library of C2-substituted tryptamines (based on diverse C2-aroyl/arylimino indoles and indole-diketopiperazine hybrids) possessing antimitotic properties were designed, synthesized and screened for their inhibitory activity against tubulin polymerization, and against proliferation of A549 lung cancer, HeLa cervical cancer, MCF7 breast cancer and HePG2 liver cancer cell lines. The design of molecules were inspired from known antimitotic compounds and natural products. The molecular docking of the designed compounds indicated that they bind to the colchicin binding site of tubulin. They were synthesized by a unique iodine catalysed oxidative ring opening reaction of 1-aryltetrahydro-β-carbolines. Among the compounds synthesized quite a few compounds induced cytotoxicity on the cancer cells by disrupting the tubulin polymerization. They were found to be non-toxic for healthy cells. Immuno Fluorescence study for the most active molecules (between ~6 μM concentration) against A549 and HeLa cells demonstrated complete disruption and shrinkage of the microtubule structures. These compounds also inhibited indoleamine-2, 3-dioxygenase with low micromolar IC50.

Background and Aims Tryptophan is involved in the formation of bioactive compounds, such as melatonin (MEL) and 3‐indoleacetic acid (3‐IAA), by yeast. Melatonin is a neurohormone whose occurrence in wine has been widely reported in recent years. The occurrence, however, of MEL and other indolic compounds related to tryptophan metabolism by wine yeast strains has been scarcely reported in grape musts. This work examined the occurrence of these compounds during the alcoholic fermentation (AF) of musts from seven grape cultivars, Corredera, Chardonnay, Moscatel, Palomino Fino, Sauvignon Blanc, Tempranillo and Vijiriega. Methods and Results Must was fermented with three Saccharomyces cerevisiae strains and then in two cases an additional sequential inoculation with the non‐Saccharomyces yeast Torulaspora delbrueckii was carried out. Fermented must samples were analysed by UHPLC/HRMS to determine the concentration of: l‐tryptophan, 5‐hydroxytryptophan, 5‐hydroxytryptamine, N‐acetyl‐5‐hydroxytryptamine, MEL, 3‐IAA, tryptamine, tryptophol and l‐tryptophan ethyl ester. The profile of indolic compounds during AF with the Aroma White strain depended on the cultivar. The yeast strain did not influence the profile of indolic compounds; instead, fermentation time was found to be a more influential factor. Conclusions The production of indolic compounds during the AF depends largely on the cultivar used and the day of fermentation on natural grape musts. Significance of the Study This is the first study that quantifies 5‐hydroxytryptophan and N‐acetyl‐5‐hydroxytryptamine during the AF of grape must. The occurrence of compounds with bioactive potential, for example 3‐IAA and ML, during fermentation with commercial yeast strains is also described.

Pleurotus eryngii produces various functional molecules that mediate physiological functions in humans. Recently, we observed that P. eryngii produces molecules that have antidepressant functions. An ethanol extract of the fruiting body of P. eryngii was obtained, and the extract was purified by XAD-16 resin using an open column system. The ethanol eluate was separated by HPLC, and the fraction with an antidepressant function was identified. Using LC-MS, the molecular structure of the HPLC fraction with antidepressant function was identified as that of tryptamine, a functional molecule that is a tryptophan derivative. The antidepressant effect was identified from the ethanol extract, XAD-16 column eluate, and HPLC fraction by a serotonin receptor binding assay and a cell-based binding assay. Furthermore, a forced swimming test (FST) showed that the mice treated with purified fractions of P. eryngii exhibited decreased immobility time compared with nontreated mice. From these results, we suggest that the extract of P. eryngii has an antidepressant function and that it may be employed as an antidepressant health supplement.

COX-2 and STAT3 are two key culprits in the glioma microenvironment. Herein, to inhibit COX-2 and block STAT3 signaling, we disclosed 27 N-anthraniloyl tryptamine compounds based on the combination of melatonin derivatives and N-substituted anthranilic acid derivatives. Among them, NP16 showed the best antiproliferative activity and moderate COX-2 inhibition. Of note, NP16 decreased the level of p-JAK2 and p-STAT3, and blocked the nuclear translocation of STAT3 in GBM cell lines. Moreover, NP16 downregulated the MMP-9 expression of BV2 cells in a co-culture system of BV2 and C6 glioma cells, abrogated the proliferative/invasive/migratory abilities of GBM cells, induced apoptosis by ROS and the Bcl-2-regulated apoptotic pathway, and induced obvious G2/M arrest in glioma cells in vitro. Furthermore, NP16 displayed favorable pharmacokinetic profiles covering long half-life (11.43 ± 0.43 h) and high blood-brain barrier permeability. Finally, NP16 effectively inhibited tumor growth, promoted the survival rate, increased the expression of E-cadherin and reduced overproduction of PGE2, MMP-9, VEGF-A and the level of p-STAT3 in tumor tissue, and improved the anxiety-like behavior in C6 glioma model. All these evidences demonstrated N-anthraniloyl tryptamine derivatives as multifunctional anti-glioma agents with high potency could drain the swamp to beat glioma.

The phytohormone indole-3-acetic acid (IAA) has been demonstrated to contribute to the plant growth-promoting effect of rhizobacteria, but the IAA biosynthesis pathway in rhizobacteria remains unclear. The ysnE gene, encoding a putative tryptophan acetyltransferase, has been demonstrated to be involved in and strongly contribute to IAA production in Bacillus, but the mechanism is unknown. In this study, to investigate how ysnE participates in IAA biosynthesis in the plant growth-promoting rhizobacterium Bacillus amyloliquefaciens SQR9, differences in the produced IAA biosynthesis intermediates between wild-type SQR9 and ΔysnE were analyzed and compared, and the effects of different intermediate compounds on the production of IAA and the accumulation of other intermediates were also investigated. The results showed that the mutant ΔysnE produced more indole-3-lactic acid (ILA) and tryptamine (TAM) than the SQR9 wild-type strain (nearly 1.6- and 2.1-fold), while the production of tryptophol (TOL) was significantly decreased by 46%. When indole-3-pyruvic acid (IPA) served as the substrate, the concentration of ILA in the ΔysnE fermentation broth was much higher than that of the wild type, while IAA and TOL were significantly lower, and ΔysnE was lower than SQR9 in IAA and TOL with the addition of TAM. The TOL content in the ΔysnE fermentation broth was much lower than that in the wild-type SQR9 with the addition of ILA. We suggest that ysnE may be involved in the IPA and TAM pathways and play roles in indole acetaldehyde (IAAld) synthesis from IPA and TAM and in the conversion of ILA to TOL.

Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, is involved in several biological processes including circadian rhythm and the regulation of abiotic stress. A systematic understanding of the circadian regulation of melatonin biosynthesis-related genes has not been achieved in rice. In this study, key genes for all of the enzymes in the melatonin biosynthetic pathway that showed a peak of expression at night were identified by microarray data analysis and confirmed by qRT&ndash, PCR analysis. We further examined the expression patterns of the four genes under drought, salt, and cold stresses. The results showed that abiotic stresses, such as drought, salt, and cold, affected the expression patterns of melatonin biosynthetic genes. In addition, the circadian expression patterns of tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), and serotonin N-acetyltransferase (SNAT) genes in wild-type (WT) plants was damaged by the drought treatment under light and dark conditions. Conversely, N-acetylserotonin O-methyltransferase (ASMT) retained the circadian rhythm. The expression of ASMT was down-regulated by the rice gigantea (OsGI) mutation, suggesting the involvement of the melatonin biosynthetic pathway in the OsGI-mediated circadian regulation pathway. Taken together, our results provide clues to explain the relationship between circadian rhythms and abiotic stresses in the process of melatonin biosynthesis in rice.

Probiotics and natural products can promote humoral transport and effectively relieve intestinal motility. This study investigated the effects of probiotics in combination with konjac glucomannan (KGM) and an aqueous extract of Prunus persica on constipation. The growth promotion effect of these natural products on probiotics was investigated using co-culture in vitro. The combined effect of probiotics and natural products on constipation was observed in mice. The tryptophan, tryptamine and short-chain fatty acid levels were determined using enzyme-linked immunosorbent assay, reverse-phase high-performance liquid chromatography, and gas chromatography. The key genes and proteins involved in humoral transport were identified using real-time polymerase chain reaction, western blotting and fluorescence immunoassay. KGM promoted the growth of Bifidobacterium animalis F1-7 in vitro, and a mixture of KGM and B. animalis F1-7 effectively promoted defaecation in mice, increased the faecal water content, shortened the defaecation time and improved the gastrointestinal transit rate. In mice, the KGM + F1-7 mixture reduced the tryptophan level and increased the levels of tryptamine, acetic acid, propionic acid, butyric acid and valeric acid. In addition, the KGM + F1-7 mixture effectively increased the mRNA level of 5-HT4-G-protein-coupled receptors (5-HT4GPCR)/mucins-2 (MUC-2) and reduced the level of aquaporins (AQP3); furthermore, it upregulated the protein level of 5-HT4GPCR/MUC-2 and downregulated the protein level of AQP3. These findings indicated that the KGM + F1-7 mixture effectively improved intestinal motility and alleviated constipation through humoral transport-related pathways.

Scope This study aims to investigate the effect of tryptophan sources on tryptophan catabolism by gut microbiota and the aryl hydrocarbon receptor (AhR) activation. Methods and Results Four substrates (free tryptophan, soybean protein, single and clustered soybean cells) containing an equimolar amount of tryptophan, but with a different bioaccessibility are studied using in vitro batch fermentation. Tryptophan catabolites are identified by LC‐MS/MS. AhR activity is measured by HepG2‐Lucia AhR reporter cells. The total amount of tryptophan‐derived catabolites increases with decreasing level of substrate complexity. Indole is the major catabolite produced from tryptophan and it is the most abundant in the free tryptophan fermentation. Indole‐3‐acetic acid and indole‐3‐aldehyde are abundantly generated in the soybean protein fermentation. The soybean cell fermentation produced high concentrations of tryptamine. Interestingly, large amounts of short‐chain fatty acids (SCFAs) are also found in the soybean cell and protein fermentation. Both tryptophan‐derived catabolites and SCFAs are able to increase AhR reporter activity over time in all four groups. Conclusion This study illustrates that bacterial catabolism of tryptophan and resulting AhR activation in the gut is modulated by the food matrix, suggesting a role for food design to improve gut health., Microbiota‐directed food is recognized as the trend of healthy food design that targets gut microbiota. This study demonstrates that structural and compositional elements of the food matrix can modulated the fermentative behavior of gut microbiota, resulting in varying concentration, type, and bioactivity of bioactive microbial metabolites.