Search Results (7)

Background: Quinoline-derived metabolites exhibit notable chemical complexity. What causes minor structural alterations to induce significant changes in disease outcomes? Historically, eclipsed by more straightforward scaffolds, these chemicals serve as a dynamic hub in tryptophan metabolism, linking immunomodulation, excitotoxicity, and cancer. However, many of these compounds struggle to cross the blood–brain barrier, and we still do not fully understand how certain structural changes affect their bioavailability or off-target effects. Thus, contemporary research highlights halogenation, esterification, and computational modeling to enhance structure–activity relationships. Summary: This narrative review emphasizes the integration of rational drug design, multi-target ligands, and prodrug methods in enhancing quinoline scaffolds. We explore each molecule’s therapeutic promise, refine each scaffold’s design, and develop each derivative to maximize clinical utility. Translating these laboratory findings into clinical practice, however, remains a formidable challenge. Conclusions: Through the synthesis of findings regarding NMDA receptor antagonism, improved oral bioavailability, and reduced metabolic instability, we demonstrate how single-site changes might modulate excitotoxicity and immunological signaling. Advancing quinoline-based medicines will yield significant advancements in neurology, psychiatry, and oncology. This enlarged framework fosters collaborative discovery, engages various audiences, and advances the field towards next-generation disease-modifying therapies. Robust preclinical validation, patient classification, and comprehensive toxicity evaluations are crucial stages for achieving these extensive endeavors and fostering future therapeutic discoveries globally. Full article

The synthesis of indole phytoalexin-like analogs related to alkyl (((1-(4-substitutedphenyl)-3-oxo-3-phenylpropyl)thio)carbonothioyl)-ʟ-tryptophanate 1a–d and the evaluation of their antifungal activity against the phytopathogen Fusarium oxysporum is reported. The target compounds were synthesized in the following two stages: (1) the initial esterification of ʟ-tryptophan, which reacted with trimethyl silane chloride and simple aliphatic alcohols (R = Me, Et) under microwave irradiation (MWI) at 100 °C to obtain the respective alkyl ester 2a–b; (2) the resulting mixture of ʟ-tryptophanates 2a–b with carbon disulfide and (E)-chalcone 3a–b under MWI at 50 °C during 60 min, followed by purification through classical column chromatography (55–76% yields). The products were obtained as mixtures of (S,R) and (S,S) diastereoisomers. An LC-DAD-MS analysis allowed us to establish the ratio of these diastereoisomers, and subsequent DFT/B3LYP-based computational calculations of the NMR ¹H chemical shifts suggested that the major diastereoisomer involved an (S,R) absolute configuration, comprising more than 60% of the mixture. The compounds 1a–d were subjected to an antifungal activity test against the phytopathogen F. oxysporum using an amended medium-based assay. Compound series 1 showed inhibition percentages of 80% at the first concentration and IC₅₀ values between 0.33 and 5.71 mM, demonstrating greater potential as antifungal agents compared to other ʟ-tryptophan derivatives like alkyl (2S)-3-(1H-indol-3-yl)-2-{[(1Z)-3-oxobut-1-en-1-yl]amino}propanoate, which presented lower inhibition percentages. In summary, phytoalexin analogs derived from ʟ-tryptophan and (E)-chalcones significantly inhibited the mycelial growth of Fusarium oxysporum, indicating their potential as effective antifungal agents. Full article

Abstract: Background: Accumulating research suggests that metabolites produced by gut microbiota are essential for maintaining a balanced gut and immune system. Indole-3-acetic acid (IAA), one of tryptophan metabolites from gut microbiota, is critical for gut health through mechanisms such as activating aryl hydrocarbon receptor. Delivery of IAA to colon is beneficial for treatment of gastrointestinal diseases, and one promising strategy is IAA esterified starch, which is digested by gut microbes in colon and releases loaded IAA. Amylose content is a key structural characteristic that controls the physicochemical properties and digestibility of starch. Methods: In the current study, IAA was esterified with three typical starches with distinct amylose content to obtain indolyl acetylated waxy maize starch (WMSIAA), indolyl acetylated normal maize starch (NMSIAA), and indolyl acetylated high-amylose maize starch (HAMSIAA). The study comparatively analyzed their respective physicochemical properties, how they behave under in vitro digestion conditions, their ability to deliver IAA directly to the colon, and their effects on the properties of the gut microbiota. Results: The new characteristic peak of ¹H NMR at 10.83 ppm, as well as the new characteristic peak of FTIR spectra at 1729 cm⁻¹, represented the successful esterification of IAA on starch backbone. The following in vitro digestion study further revealed that treatment with indolyl acetylation significantly elevated the resistant starch content in the starch samples. In vivo experimental results demonstrated that WMSIAA exhibited the most significant increase in IAA levels in the stomach, whereas HAMSIAA and NMSIAA demonstrated the most remarkable increases in IAA levels in the small intestine and colon, respectively. The elevated IAA levels in the colon are conducive to promoting the growth of beneficial intestinal bacteria and significantly alleviating DSS-induced colitis. Conclusions: This research presents innovative insights and options for the advancement of colon-specific drug delivery systems aimed at preventing and curing gastrointestinal disorders. Full article

CeO₂ was prepared using a hydrothermal method, modified by radio-frequency plasma in the form of glow discharge, and then the solid superacid ${\mathrm{S}}_2{\mathrm{O}}_8^{2-}$/CeO₂ was prepared by the impregnation method. A series of properties such as pore structure was characterized by N₂ adsorption–desorption experiments, surface morphology was characterized by TEM, crystal phase was characterized by XRD, and surface acidity of the catalyst was characterized by Py-IR and Hammett titration. The methyl esterification reaction of tryptophan was used to evaluate the activity of the solid superacid. The results showed that the catalyst modified by radio-frequency plasma had a larger specific surface area, more surface oxygen vacancies, smaller particle size, and higher total acid content. The yield of tryptophan methyl ester reached a higher level of 94.5% (150 °C, 1 MPa, 2 h), catalyzed by the modified ${\mathrm{S}}_2{\mathrm{O}}_8^{2-}$/CeO₂. This work verified the feasibility of plasma technology in the field of catalytic activity enhancement of solid superacid. Full article

Natural products suited for prophylaxis and therapy of inflammatory diseases have gained increasing importance. These compounds could be beneficially integrated into bacterial cellulose (BC), which is a natural hydropolymer applicable as a wound dressing and drug delivery system alike. This study presents experimental outcomes for a natural anti-inflammatory product concept of boswellic acids from frankincense formulated in BC. Using esterification respectively (resp.) oxidation and subsequent coupling with phenylalanine and tryptophan, post-modification of BC was tested to facilitate lipophilic active pharmaceutical ingredient (API) incorporation. Diclofenac sodium and indomethacin were used as anti-inflammatory model drugs before the findings were transferred to boswellic acids. By acetylation of BC fibers, the loading efficiency for the more lipophilic API indomethacin and the release was increased by up to 65.6% and 25%, respectively, while no significant differences in loading could be found for the API diclofenac sodium. Post-modifications could be made while preserving biocompatibility, essential wound dressing properties and anti-inflammatory efficacy. Eventually, in vitro wound closure experiments and evaluations of the effect of secondary dressings completed the study. Full article

This study evaluates a novel handheld sensor technology coupled with pattern recognition to provide real-time screening of several soybean traits for breeders and farmers, namely protein and fat quality. We developed predictive regression models that can quantify soybean quality traits based on near-infrared (NIR) spectra acquired by a handheld instrument. This system has been utilized to measure crude protein, essential amino acids (lysine, threonine, methionine, tryptophan, and cysteine) composition, total fat, the profile of major fatty acids, and moisture content in soybeans (n = 107), and soy products including soy isolates, soy concentrates, and soy supplement drink powders (n = 15). Reference quantification of crude protein content used the Dumas combustion method (AOAC 992.23), and individual amino acids were determined using traditional protein hydrolysis (AOAC 982.30). Fat and moisture content were determined by Soxhlet (AOAC 945.16) and Karl Fischer methods, respectively, and fatty acid composition via gas chromatography-fatty acid methyl esterification. Predictive models were built and validated using ground soybean and soy products. Robust partial least square regression (PLSR) models predicted all measured quality parameters with high integrity of fit (R_Pre ≥ 0.92), low root mean square error of prediction (0.02–3.07%), and high predictive performance (RPD range 2.4–8.8, RER range 7.5–29.2). Our study demonstrated that a handheld NIR sensor can supplant expensive laboratory testing that can take weeks to produce results and provide soybean breeders and growers with a rapid, accurate, and non-destructive tool that can be used in the field for real-time analysis of soybeans to facilitate faster decision-making. Full article

In this paper, we describe the solvent-free three-component synthesis of 2,4,5-trisubstituted-1H-pyrrol-3-ol-type compounds from L-tryptophan. The first step of the synthetic methodology involved the esterification of L-tryptophan in excellent yields (93–98%). Equimolar mixtures of alkyl 2-aminoesters, 1,3-dicarbonyl compounds, and potassium hydroxide (0.1 eq.) were heated under solvent-free conditions. The title compounds were obtained in moderate to good yields (45%–81%). Density functional theory using “Becke, 3-parameter, Lee–Yang–Parr” correlational functional (DFT-B3LYP) calculations were performed to understand the molecular stability of the synthesized compounds and the tautomeric equilibrium from 3H-pyrrol-3-one type intermediates to 1H-pyrrol-3-ol type aromatized rings. Full article