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Keywords: visible light; 3-methylindole; tryptamine; diphenyl diselenide; diphenyl phosphate EN visible light 3-methylindole tryptamine diphenyl diselenide diphenyl phosphate 3685 3692 8 10/19/23 20231102 NES 231102 Graph The incorporation of selenium into organic scaffolds is not only pivotal for understanding redox processes of biological system, [1] but also plays an important role in pharmaceuticals [5] wherein selenium-containing molecules serve as synthetic intermediates [6] and catalysts for the preparation of various bioactive compounds. When an additive diphenyl phosphate (DPP) was added, formation of desired C-2 Cbz-tryptamine selenide adduct was observed in good yield (entry 2). Transition-metal-catalyzed C2/C3-H activation of indole core (tryptamines) offers robust synthetic strategies to deliver functionalized cores. SP 1 sp H NMR (500 MHz, CDCl SB 3 sb ): = 8.56-8.46 (m, 1 H), 7.69 (d, I J i = 7.9 Hz, 1 H), 7.62 (d, I J i = 7.0 Hz, 1 H), 7.34 (d, I J i = 8.3 Hz, 1 H), 7.27 (s, 1 H), 7.23-7.18 (m, 5 H), 7.16 (s, 1 H), 4.76 (s, 1 H), 4.59 (dt, I J i = 11.6, 6.4 Hz, 2 H), 3.99 (q, I J i = 5.1, 3.1 Hz, 2 H), 3.86 (d, I J i = 4.0 Hz, 2 H), 3.24 (t, I J i = 7.1 Hz, 2 H), 2.32 (d, I J i = 3.6 Hz, 2 H), 2.22 (d, I J i = 4.7 Hz, 2 H), 1.96-1.91 (m, 3 H), 1.82-1.74 (m, 6 H), 1.68-1.66 (m, 2 H), 1.55-1.51 (m, 5 H), 1.30-1.24 (m, 4 H), 1.07 (dd, I J i = 14.4, 3.2 Hz, 2 H), 0.92 (s, 3 H), 0.67 (s, 3 H). [Extracted from the article]

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

Bronchopneumonia with interstitial pneumonia (BIP) has been considered a variant of acute interstitial pneumonia (AIP) rather than a distinct disease. This study compared 18 BIP, 24 bronchopneumonia (BP), and 13 AIP cases in feedlot beef cattle. Grossly, BIP cases typically had cranioventral lung lesions of similar morphology and extent as BP cases, but the caudodorsal lung appeared overinflated, bulged on section, and had interlobular edema and emphysema. Gross diagnosis of BIP had 83% sensitivity and 73% specificity relative to histopathology. Histologic lesions of BIP in cranioventral areas were of chronic BP, while caudodorsal lesions included alveolar and bronchiolar damage and inflammation, interstitial hypercellularity, and multifocal hemorrhages. In BIP cases, cranioventral lung lesions were more chronic than caudodorsal lesions. Histologic scores and microbiology data were comparable in cranioventral lung of BIP versus BP cases and caudodorsal lung of BIP versus AIP cases, with differences reflecting a more chronic disease involving less virulent bacteria in BIP versus BP. Mycoplasma bovis infection was similarly frequent among groups, and a viral cause of BIP was not identified. Lesion morphology and similar blood cytokine concentrations among groups argued against sepsis as a cause of lung injury. Surfactant dysfunction was identified in BIP and BP, and was only partially the result of protein exudation. These and other findings establish BIP as a distinct condition in which chronic cranioventral BP precedes acute caudodorsal interstitial lung disease, supporting a role of chronic inflammation in heightened sensitivity to 3-methylindole or another lung toxicant. [ABSTRACT FROM AUTHOR]

Herein we present an efficient method to synthesize novel complex ureas from simple ureas, with potential pharmacological activity. First, 3‐methylindole ketones are protected via a two‐phase N‐tosylation reaction catalyzed by NBu4HSO4 as the PTC. Second, an NBS bromination of the terminal methyl group is performed with high selectivity and very good yields. Finally, complex novel and promising ureas are synthesized in 46 %–92 % yields using non‐base‐catalyzed substitution reactions with simple monosubstituted and disubstituted ureas. All products were easily purified through column chromatography and/or crystallization. The overall procedure produces very high yields and selectivity for bromination. [ABSTRACT FROM AUTHOR]

3-Methylindole is a major component of organic pollutants in livestock compost, which can contribute to the deterioration of the environment in livestock farms and their surrounding areas. This study demonstrates that using microorganisms to degrade 3-methylindole is an effective method for energy conservation and environmental protection. The microbe capable of efficiently degrading 3-methylindole was isolated and screened from fecal samples. The isolated bacteria were identified as Acinetobacter oleivorans after morphological characterization and 16S rRNA sequencing. This project demonstrated that 3-methylindole was completely degraded under optimal conditions (initial concentration of 3MI: 100 mg/L, 30°C, pH8.0, and shaking at 160 rpm for 48 h). N2-Acetyl-L-ornithine, Phenylacetaldehyde, Phenylacetic acid, Indole-3-carboxylic acid, and Indole-3-carboxaldehyde were the primary metabolites of this degradation process. This study provides a theoretical foundation for other microbe-mediated environmental remediation approaches as well as a basis for future work to apply bacteria that degrade 3-methylindole for the purification of polluted environments. It has a promising application in the control of malodorous gas pollution in the large-scale livestock and poultry breeding industries.

Acute interstitial pneumonia (AIP) of cattle has been recognized for many decades. While the pathogenesis and risk factors for this condition in pastured cattle are relatively well characterized, there remains a poor understanding of the disease as it occurs in intensively fed cattle such as in beef feedlots. Specifically, in pastured cattle, AIP results from excessive ruminal production of the pneumotoxicant 3-methylindole (3-MI). In feedlot cattle, the evidence to substantiate the role of 3-MI is comparatively deficient and further investigations into the cause, pathogenesis, and control are sorely needed. This review highlights our current understanding of AIP with a focus on the disease as it occurs in feedlot cattle. Additionally, it illustrates the need for further work in understanding the specific animal factors (e.g. the ruminal microbiome, and the role of concurrent diseases), management factors (e.g. animal stocking and vaccination protocols), and dietary factors (e.g. dietary supplements) that may impact the development of AIP and which are relatively unique to the feedlot setting. All stakeholders in the beef industry stand to benefit from a greater understanding of what remains a pressing yet poorly understood issue in beef production. [ABSTRACT FROM AUTHOR]

An excellent catalyst with a large number of weak acid centers and highly dispersed copper nanoparticles embedded in mesoporous SBA-15 carrier was successfully constructed for the purpose of efficient conversion of aniline with biomass-derived glycerin to the high value-added 3-methylindole, in which the catalyst of Cu/SBA-15 was modified with Al2O3, La2O3 and CoO in sequence. The modified carrier and the copper-based catalysts were studied by scanning electron microscopy and energy-dispersive X-ray (SEM–EDX) spectroscopy, nitrogen physical adsorption, ammonia temperature programmed desorption (NH3-TPD), hydrogen temperature programmed reduction (H2-TPR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric and differential thermal analysis (TG–DTA) and inductively coupled plasma (ICP) emission spectroscopy. The research found that the Cu/CoO/La2O3/Al2O3/SBA-15 catalyst exhibited a very good catalytic performance with 3-methylindole yield up to 73.3% and selectivity reaching 86.4%. Besides, only a 3.9% yield decreased after the catalyst was circulated seven times. The characterizations revealed that Al2O3 could enhance the polarity of the carrier, thereby the interaction between the active component and the composite carrier was strengthened and the dispersion of copper was increased significantly. Adding La2O3 to Cu/SBA-15-Al2O3 could weaken the acidity and inhibit the formation of carbon deposits. CoO promoter could increase the number of weak acid centers, which was conducive to a good dispersion of active component and the high selectivity of 3-methylindole. Furthermore, the reaction pathway of gas-phase synthesis of 3-methylindole from glycerin and aniline on Cu/CoO/La2O3/Al2O3/SBA-15 was explored. [ABSTRACT FROM AUTHOR]

Abstract Background Anopheles sinensis is an important vector for the spread of malaria in China. Olfactory-related behaviours, particularly oviposition site seeking, offer opportunities for disrupting the disease-transmission process. Results This is the first report of the identification and characterization of AsinOrco and AsinOR10 in An. sinensis. AsinOrco and AsinOR10 share 97.49% and 90.37% amino acid sequence identity, respectively, with related sequences in Anopheles gambiae. A functional analysis demonstrated that AsinOrco- and AsinOR10-coexpressing HEK293 cells were highly sensitive to 3-methylindole, but showed no significant differences in response to other test odorants when compared to DMSO. Conclusions AsinOrco was characterized as a new member of the Orco ortholog subfamily. AsinOR10, which appears to be a member of the OR2-10 subfamily, is directly involved in identification of oviposition sites. This finding will help to elucidate the molecular mechanisms underlying olfactory signaling in An. sinensis and provide many more molecular targets for eco-friendly pest control.

Oviposition attractants are environmental cues that allow Culex gravid female mosquitoes to locate suitable sites for egg-laying and, therefore, may be exploited for environmentally friendly strategies for controlling mosquito populations. Naturally occurring skatole has been identified as an oviposition attractant for the Southern House mosquito, Culex quinquefasciatus. Previously, we identified in Cx. quinquefasciatus female antennae an olfactory receptor neuron (ORN) highly sensitive to skatole and an odorant-binding protein involved in the detection of this semiochemical. Here, we describe the characterization of an odorant receptor (OR), CquiOR10, which is narrowly tuned to skatole when expressed in the Xenopus oocyte system. Odorant-induced response profiles generated by heterologously expressed CquiOR10 suggest that this OR is expressed in the mosquito ORN sensitive to skatole. However, geranylacetone, which stimulates the antennal ORN, was not detected by CquiOR10-expressing oocytes, thus raising interesting questions about reception of oviposition attractants in mosquitoes.

Summary: It has been suggested that flowers of some angiosperms mimic vertebrate faeces (dung) in order to exploit insect pollinators that utilize faeces as a source of food and/or oviposition sites.We investigated a potential case of mimicry in Wurmbea elatior (Colchicaceae), a lily that exhibits a faecal odour and pattern of dark spots on the corolla.We found that W. elatior is pollinated by a broad assemblage of coprophagous flies and is dependent on pollinator visits for seed production. The flowers emit volatiles that are characteristic of vertebrate faeces, and three of these compounds – skatole, indole, and an unidentified compound – elicited electrophysiological antennal responses from flies. Artificial flowers laced with indole and skatole or skatole alone attracted the same assemblage of flies as was recorded on flowers of W. elatior. Spotted artificial flowers attracted twice as many flies as did those lacking spots. Experimental addition of indole and skatole to flowers of Wurmbea kraussii, a congener with unscented flowers pollinated by hoverflies, induced a shift to an insect visitor assemblage dominated by coprophagous flies.This study clarifies the roles of volatile emissions (particularly skatole) and visual signals in floral dung mimicry. [ABSTRACT FROM AUTHOR]

Many constituents of tobacco smoke (TS) require bioactivation to exert toxic effects; however, few studies have examined the role of bioactivation enzymes in the adverse effects of TS exposure. This knowledge gap is a major source of uncertainty for risk assessment and chemoprevention efforts. Our aim is to test the hypothesis that cytochrome P450 (P450) enzyme-mediated bioactivation is essential to the development of TS exposure-induced lung toxicity, by determining the contributions of P450 enzymes in the mouse Cyp2abfgs gene subfamilies to environmental tobacco smoke (ETS)-induced lung inflammation. Adult female wildtype (WT) and Cyp2abfgs -null mice (both on C57BL/6J background) were exposed to filtered air or ETS, intermittently, for 1 or 2 weeks. Lung inflammation was assessed by quantification of inflammatory cells, cytokines, chemokines, and proteins in bronchoalveolar lavage fluid (BALF) and histopathological analysis. Glutathione (GSH) conjugates of 2 ETS constituents, naphthalene (NA), and 3-methylindole (3MI), were measured in mice exposed to ETS for 4 h. Persistent macrophagic and neutrophilic lung inflammation was observed in ETS-exposed WT mice; the extent of which was significantly reduced in ETS-exposed Cyp2abfgs -null mice. Levels of proinflammatory cytokines and chemokines, along with the total protein concentration, were increased in cell-free BALF from ETS-exposed WT mice, but not Cyp2abfgs -null mice. Additionally, GSH conjugates of NA and 3MI were detected in the lungs of WT, but not Cyp2abfgs -null, mice following ETS exposure. These results provide the first in vivo evidence that the mouse Cyp2abfgs gene cluster plays an important role in ETS-induced lung inflammation. [ABSTRACT FROM AUTHOR]

An efficient catalyst of Cu/SiO2 modified with ZnO and Fe2O3 was constructed for the one-pot synthesis of 3-methylindole originating from biomass-derived glycerol with aniline. The structure and property of as-prepared Cu/SiO2–ZnO–Fe2O3 composite were characterized by temperature programmed reduction of H2 (H2-TPR), X-ray diffraction (XRD), transmission electron microscope (TEM), temperature programmed desorption (TPD) of NH3 and CO2, inductively coupled plasma (ICP) emission spectroscopy, thermogravimetric and differential thermal analysis (TG–DTA). The results indicated that the interaction between copper and support was improved after adding ZnO to Cu/SiO2, as a result, Cu particles could be firmly anchored on the surface of SiO2–ZnO, which not only increased the dispersion of active component but also inhibited the aggregation or sintering of copper particles effectively. Meanwhile, the acid or base sites on the ZnO modified Cu/SiO2 catalyst significantly increased, which was beneficial to the hydrogenolysis of glycerol to acetol and 1,2-propanediol and promoted the synthesis of 3-methylindole. The introduction of Fe2O3 to Cu/SiO2–ZnO could promote the reduction of CuO and decrease the acidity of the catalyst, thereby the activity and stability of the catalyst were further improved. Under the optimized ZnO or Fe2O3 content of 0.100 or 0.030 mmol/g-SiO2, Cu/SiO2–ZnO–Fe2O3 exhibited excellent catalytic activity and long-term stability, which the yield of 3-methylindole was up to 73% and it was still more than 68% when the catalyst was reused four times. Moreover, the catalytic mechanism for the one-pot synthesis of 3-methylindole from glycerol and aniline over Cu/SiO2–ZnO–Fe2O3 was investigated in depth and a probable synthetic route was proposed based on the research of the catalytic reactions of glycerol, 1,2-propanediol or acetol with aniline as well as the hydrogenolysis of glycerol and the catalytic conversion of acetol, which both acetol and 1,2-propanediol were the intermediates for the production of 3-methylindole. [ABSTRACT FROM AUTHOR]

Abstract 3-Methylindole (3-MI) is a recalcitrant and toxic substance that can cause damages to human and animal lung cells and may have a pronounced effect on mood and stress levels. Rapid and sensitive detection of 3-MI is therefore of great important for its environmental safety evaluation. A novel electrochemical sensor for the determination of 3-MI was fabricated based on electropolymerization of molecular imprinted polymer (MIP) film on a glassy carbon electrode (GCE). Rational selection of the suitable monomers was conducted by evaluation of the interaction between each monomer and template using the density functional theory method. The results indicated that the stabilization energy of 3-MI- o -Phenylenediamine (o -PD) complex is greater than that obtained from other evaluated monomers, hence o -PD was used to prepare the MIP sensor. The imprinted layer was systematically characterized by cyclic voltammetry (CV), electrochemical impendence spectroscopy (EIS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Under optimal experimental conditions, a linear relationship was observed between the peak current change of the electrochemical probe [Fe(CN) 6 ]3− and the concentration of 3-MI over the range 0.01–1.2 μM, with a detection limit of 4 nM. This sensor also exhibited superb selectivity to 3-MI as minimum interferences were observed from other structurally similar compounds, thus it was successfully applied for the determination of 3-MI in real samples. Graphical abstract Unlabelled Image Highlights • A highly sensitive and selective MIP sensor was developed for the detection of 3-methylindole in water. • The computer assisted design was used to select functional monomers by calculating stabilization energy. • Theoretical predictions were verified by subsequent experiment data. • The developed sensor was successfully applied for the determination of 3-methylindole real in real samples. [ABSTRACT FROM AUTHOR]

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: In this study, we aimed to functionally and morphologically demonstrate the effectiveness of platelet-rich plasma (PRP) on anosmia in a mouse model of anosmia.Study Design: Animal study.Methods: A total of 16 male mice were included. When selecting the mice, the food-finding test (FFT) was used to make sure that the animals could smell, and anosmia was induced by administration of intraperitoneal 3-methylindole. The mice were randomly divided into two groups of eight (groups A and B). After 1 week, topical PRP was administered to the mice in group A and topical saline was administered to the mice in group B. The FFT was again administered at 7, 14, and 21 days. The mice were sacrificed on day 21, the olfactory neuroepithelium was histopathologically examined, and the epithelial damage scores and epithelial thickness were measured.Results: After topical administration of PRP and saline, the difference in the average FFT values of the groups was statistically significant at 7, 14, and 21 days (P < 0,005). During the histopathological examination, the epithelial damage score was statistically significantly lower in the PRP group (P = 0.001) than in the saline group, and epithelial thickness was statistically significantly greater in the PRP group compared to the saline group (P = 0.003).Conclusion: We showed that PRP administration has a curative effect on olfactory functions in an anosmia-induced mice model. However, there is a need for further research before PRP can be considered for use in patients with anosmia in clinical practice.Level Of Evidence: NA. Laryngoscope, 128:E157-E162, 2018. [ABSTRACT FROM AUTHOR]

The interaction between the 2- and 3-methylindole derivatives has been studied using spectroscopic technique and molecular modeling. Solvent polarity was found to play a great role in the interaction with acetonitrile showing greatest interaction with indole derivatives but less hydrogen bonding contribution. Good agreement was found between the models used for the analysis of experimental data and the theoretical calculations. Moreover, on the part of the quenching, benzonitrile was found to be better quencher over chlorobenzene, with 3-methylindole giving higher dynamic quenching constants. [ABSTRACT FROM AUTHOR]

An efficient process for the Friedel-Crafts acylation of 3-methylindole with acid anhydrides in the presence of sulfated zirconia was developed. This catalyst shows excellent catalytic activity with good conversion and selectivity towards formation of the products of 2-acylation (3-methyl-1 H-indol-2-yl)ketones. Other advantages related to this process are the simple work-up procedure and smaller production of chemical waste. The catalyst was easily recycled and reused with a minimal loss in activity through three reaction cycles. The catalyst was characterized by FT-IR spectroscopy, X-Ray diffraction and superficial acidity. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Boar taint is the unfavourable odour and taste from pork fat, which results in part from the accumulation of skatole (3-methylindole, 3MI). The key enzymes in skatole metabolism are thought to be cytochrome P450 2E1 (CYP2E1) and cytochrome 2A (CYP2A); however, the cytochrome P450 (CYP450) isoform responsible for the production of the metabolite 6-hydroxy-3-methylindole (6-OH-3MI, 6-hydroxyskatole), which is thought to be involved in the clearance of skatole, has not been established conclusively. The aim of this study was to characterize the role of porcine CYP450s in skatole metabolism by expressing them individually in the human embryonic kidney HEK293-FT cell line. This system eliminates the problems of the lack of specificity of antibodies, inhibitors and substrates for CYP450 isoforms in the pig, and contributions of any other CYP450s that would be present. The results show that pig CYP1A1, CYP2A19, CYP2C33v4, CYP2C49, CYP2E1 and CYP3A and human CYP2E1 (hCYP2E1) are all capable of producing the major skatole metabolite 3-methyloxyindole (3MOI), as well as indole-3-carbinol (I3C), 5-hydroxy-3-methylindole (5-OH-3MI), 6-OH-3MI, 2-aminoacetophenone (2AAP) and 3-hydroxy-3-methyloxindole. CYP2A19 produced the highest amount of the physiologically important metabolite 6-OH-3MI, followed by porcine CYP2E1 and CYP2C49; CYP2A19 also produced more 6-OH-3MI than hCYP2E1. Co-transfection with CYB5A increased the production of skatole metabolites by some of the CYP450s, suggesting that CYB5A plays an important role in the metabolism of skatole. We also show the utility of this expression system to check the specificity of selected substrates and antibodies for porcine CYP450s. Further information regarding the abundance of different CYP450 isoforms is required to fully understand their contribution to skatole metabolism in vivo in the pig.

The simultaneous electrodetection of indole and 3-methylindole was investigated in this paper. The detection was performed using a boron-doped diamond (BDD) electrode to take advantage of its remarkable electrochemical properties (Fujishima et al., Diamond Electrochemistry (Elsevier, 2005) . In order to improve the selectivity between indole and 3-methylindole, square-wave voltammetry (SWV) was used. We showed that BDD electrodes fouled either from oxidation of indole or 3-methylindole could be efficiently reactivated in LiClO4 aqueous solutions using trains of short anodic and cathodic pulses applied to the working electrode. We were able with this approach to measure simultaneously both indole and 3-methylindole in aqueous solutions in the range of 10-500 μM with the limits of detection (LOD) found to be 3 × 10−2 μM for indole and 5 × 10−2 μM for 3-methylindole. Both indoles were also detected successfully following extraction from pork fat. This work opens up the way toward systematic detection of indole and 3-methylindole in processed foodstuffs, with a strong industrial interest for the detection of boar taint in pork meat. [ABSTRACT FROM AUTHOR]

We studied the in vitro metabolism of 3-methylindole (3MI) in hepatic microsomes from fish. Hepatic microsomes from juvenile and adult carp ( Cyprinus carpio ) and rainbow trout ( Oncorhynchus mykiss ) were included in the study. Incubation of 3MI with hepatic microsomes revealed the time-dependent formation of two major metabolites, 3-methyloxindole (3MOI) and indole-3-carbinol (I3C). The rate of 3MOI production was similar in both species at both ages. No differences in kinetic parameters were observed ( p = 0.799 for V max , and p = 0.809 for K m ). Production of I3C was detected only in the microsomes from rainbow trout. K m values were similar in juvenile and adult fish ( p = 0.957); V max was higher in juvenile rainbow trout compared with adults ( p = 0.044). In rainbow trout and carp, ellipticine reduced formation of 3MOI up to 53.2% and 81.9% and ketoconazole up to 65.8% and 91.3%, respectively. The formation of I3C was reduced by 53.7% and 51.5% in the presence of the inhibitors ellipticine and ketoconazole, respectively. These findings suggest that the CYP450 isoforms CYP1A and CYP3A are at least partly responsible for 3MI metabolism. In summary, 3MI is metabolised in fish liver to 3MOI and I3C by CYP450, and formation of these metabolites might be species-dependent. [ABSTRACT FROM AUTHOR]

Boar taint is an off-odour that entails negative consumer reactions. In this study two extraction and UHPLC-HRMS analysis methods, valuable for evaluation of consumer acceptance towards boar meat, were developed for quantification of indole, skatole, and androstenone in different meat products. Sample pretreatment consisted of extraction with methanol and a homogenising step (cooked ham, minced meat, tenderloin, bacon, cutlets, blade loin, uncooked ham) or a melting step (salami sausage and liver paste). Both methods were validated according to CD 2002/657/EC and ISO 17025 guidelines. Good performance characteristics were obtained. Good linearity ( R 2 ⩾ 0.99) and no lack of fit was observed (95% confidence interval; F -test, p > 0.05). Also good recovery (89–110%) and satisfactory precision: repeatability (RSD ⩽ 14.9%) and within-laboratory reproducibility (RSD ⩽ 17.2%) were obtained. Analysis of cooked ham and salami sausage samples proved the applicability of both methods for routine analysis. [ABSTRACT FROM AUTHOR]

3-Methylindole, also referred to as skatole, is a pollutant of environmental concern due to its persistence, mobility and potential health impacts. Petroleum refining, intensive livestock production and application of biosolids to agricultural lands result in releases of 3-methylindole to the environment. Even so, little is known about the aerobic biodegradation of 3-methylindole and comprehensive biotransformation pathways have not been established. Using glycerol as feedstock, the soil bacterium Cupriavidus sp. strain KK10 biodegraded 100 mg/L of 3-methylindole in 24 h. Cometabolic 3-methylindole biodegradation was confirmed by the identification of biotransformation products through liquid chromatography electrospray ionization tandem mass spectrometry analyses. In all, 14 3-methylindole biotransformation products were identified which revealed that biotransformation occurred through different pathways that included carbocyclic aromatic ring-fission of 3-methylindole to single-ring pyrrole carboxylic acids. This work provides first comprehensive evidence for the aerobic biotransformation mechanisms of 3-methylindole by a soil bacterium and expands our understanding of the biodegradative capabilities of members of the genus Cupriavidus towards heteroaromatic pollutants. [ABSTRACT FROM AUTHOR]

This work describes investigation of the fragmentation mechanism of tryptophan N-indolyl radical cation, H3N+-TrpN• ( m/ z 204) studied via DFT calculations and several gas-phase experimental techniques. The main fragment ion at m/ z 131, shown to be a mixture of up to four isomers including 3-methylindole (3MI) π-radical cation, was found to undergo further loss of an H atom to yield one of the two isomeric m/ z 130 ions. 3-Methylindole radical cation generated independently (via CID of [Cu(terpy)3MI]) displayed gas-phase reactivity partially similar to that of the m/ z 131 fragment, further confirming our proposed mechanism. CID of deuterated tryptophan N-indolyl radical cation ( m/ z 208) suggested that up to six H atoms are involved in the pathway to formation of the m/ z 131 ion, consistent with hydrogen atom scrambling during CID of protonated Trp. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The protonation of 3-methylindole, D-tryptophan, 3-formylindole, 3-acetylindole and indolyl-2-carboxylic acid in sulfuric acid media was studied by UV spectro-scopy. The measurement of the absorbance at four selected wavelengths enabled the calculation of the corresponding molar absorptivities. The results were used to calculate the pKa value of the protonated form of the indole derivatives by the Hammett Method. The Hammett postulate (the slope of the plot log [c(BH+)/c(B)] vs. H should be equal to 1) was tested. The dissociation constants and solvent parameter m* were also obtained by applying the Excess Acidity Method. The position of the additional protons in the protonated compounds is discussed.

The protonation of 3-methylindole, D-tryptophan, 3-formylindole, 3-acetylindole and indolyl-2-carboxylic acid in sulfuric acid media was studied by UV spectroscopy. The measurement of the absorbance at four selected wavelengths enabled the calculation of the corresponding molar absorptivities. The results were used to calculate the pKa value of the protonated form of the indole derivatives by the Hammett Method. The Hammett postulate (the slope of the plot log [c(BH+)/c(B)]vs. H should be equal to 1) was tested. The dissociation constants and solvent parameter m* were also obtained by applying the Excess Acidity Method. The position of the additional protons in the protonated compounds is discussed.

The aim of this study was to investigate the efficacy of active immunisation against recombinant maltose binding protein-gonadotropin releasing hormone I (MBP-GnRH-I6) in preventing boar taint. The concentrations of testosterone and anti-GnRH-I antibodies in serum were determined by radioimmunoassay and enzyme linked immunosorbent assay, respectively. The mRNA levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) in testes were analysed by real time quantitative PCR. The concentrations of androstenone and 3-methylindole in backfat were assayed by HPLC. Active immunisation against MBP-GnRH-I6 increased the serum concentration of anti-GnRH-I antibodies (P<0.05) and the levels of 3β-HSD and 17β-HSD mRNA in testis. However, it reduced the serum concentrations of testosterone (P<0.05) and androstenone. The concentration of 3-methylindole in backfat (P>0.05) was not changed. Thus, we conclude that vaccination against MBPGnRH- I6 is a practical and effective method to suppress the synthesis of androstenone. [ABSTRACT FROM AUTHOR]

Abstract: Tenderness, flavour, overall liking and odour are important components of sheepmeat eating quality. Consumer assessment of these attributes has been made for carcasses from the Information Nucleus Flock (INF) of the Cooperative Research Centre for Sheep Industry Innovation. The concentrations of three branched chain fatty acids, 4-methyloctanoic (MOA), 4-ethyloctanoic (EOA) and 4-methylnonanoic acids (compounds related to ‘mutton flavour’ in cooked sheepmeat) and 3-methylindole and 4-methylphenol (compounds related to ‘pastoral’ flavour) were determined for 178 fat samples taken from INF carcasses. Statistical modelling revealed that both MOA and EOA impacted on the ‘Like Smell’ consumer sensory score of the cooked meat product (P <0.05), with increasing concentration causing lower consumer acceptance of the product. None of the compounds though had an effect on the liking of flavour. Obviously, reducing the effect of MOA and EOA on the odour of grilled lamb will improve consumer acceptance of the cooked product but other factors affecting the eating quality also need to be considered. [Copyright &y& Elsevier]

Highlights: [•] Zeolites-supported Cu-based catalysts were used in the synthesis of 3-methylindole. [•] Cu/NaY exhibited higher activity and selectivity than Cu/5A, Cu/HZSM-5 or Cu/MCM-41. [•] The addition of Na2O to Cu/NaY improved the selectivity of the catalyst remarkably. [•] Over Cu/NaY–Na2O, the selectivity and yield of 3-methylindole reached 72.3 and 50.4%, respectively. [•] The catalytic mechanism for the synthesis of 3-methylindole was proposed. [ABSTRACT FROM AUTHOR]

3-Methylindole (3MI) is a substance with an unpleasant odor that is found in intact male pigs and is known to negatively affect consumers of pork. The growth of four strains of lactic acid bacteria [Lactobacillus brevis 1.12 (L. brevis 1.12), L. plantarum 102, L. casei 6103 and L. plantarum ATCC8014] in incubation medium with 3MI was studied. The four strains were tested for their ability to remove 3MI from the medium. The growth of L. brevis 1.12 remained steady as the levels of 3MI increased 3MI from 0.2 to 1.0 µg/ml. The 3MI removal ability of L. brevis 1.12 was the strongest among the four strains, and the highest removal rate was 65.35±0.3% in 1 ml incubation medium containing 1.0 µg/ml 3MI for 120 h. Furthermore, the supernatant fluid of the fermentation broth of L. brevis 1.12 had a stronger ability to remove 3MI than cell pellets and cell extracts and the removal rate was 14.4±0.3% in 24 h. Further results indicate that the mode of removal of 3MI was not through the physical binding of cells by L. brevis 1.12. [ABSTRACT FROM AUTHOR]

An AlO-modified Cu/SiO catalyst was used in the vapor-phase synthesis of 3-methylindole from glycerol and aniline. The effect of AlO and the preparation method of the Cu-AlO/SiO catalyst on the activity and selectivity of the catalyst were investigated. The catalysts were characterized by XRD, TEM, H-TPR, NH-TPD and TG techniques. The results indicated that the addition of AlO to Cu/SiO increased the activity and selectivity remarkably. Cu-AlO/SiO prepared by co-precipitation (COP) exhibited better catalytic performance compared with the catalyst prepared by incipient wetness impregnation (IWI) or ultrasonic impregnation (UI), because the catalyst possessed a good dispersion of Cu particles, a better resistance to the sintering of Cu particles as well as a larger amount of weak acid sites. Over Cu-AlO/SiO (COP) with the AlO content of 1.1 mmol/g, the yield of 3-methylindole reached 44 % at the third hour of reaction, and the yield could be kept to 41 % even after the reaction time of 51 h. [ABSTRACT FROM AUTHOR]

Highlights: [•] The predicted extracellular loop-2 of insect odorant receptors are well-conserved. [•] Mutation of Pro residues impaired function of mosquito and moth ORs. [•] Pro and corner Gly residues seem to form Pro-xxx-Gly and Pro-Gly β-turns. [•] Tyr and Leu residues contribute to side–chain interactions. [•] ECL-2 is not specificity determinant but may cover odorant binding cavity. [ABSTRACT FROM AUTHOR]

Abstract: The multi-state fluorescence characteristics of 3-methylindole (MI) make its spectra rich in chemical information and the spectral interpretation rather challenging. The trilinear decomposition method could be appropriate for this task and provide a deeper insight into the hydrogen bonding to MI. Taking the excitation fluorescence spectra together with the emission counterparts to formulate a three-way data array and solving the data array using the Alternating Trilinear Decomposition (ATLD) algorithm is beneficial for studying hydrogen bonding to MI in several aspects. Firstly, making full use of the excitation spectra could guarantee that the experimentally collected data contain sufficient information necessary for investigating signals originated from the weak interactions buried in the strong interaction background. Secondly, the resolution of a three-way data array could theoretically guarantee the uniqueness of the resolved component spectra with actual physical meaning. Thirdly, the ATLD algorithm resolves spectra of complex mixture and determines the spectra of corresponding individual components of different states without disturbing the complex chemical equilibrium involved. The hydrogen bonding interaction of MI with other molecules has been studied using the ATLD algorithm. A detailed investigation has been undertaken for the 1La and 1Lb states as the lowest excited singlet states which dominate the fluorescence emission of MI depending on the effect of other molecules and the surrounding microenvironment. The hydrogen bonding between indole derivatives and other molecules has been examined and some association constants involving hydrogen bond formation have been estimated and compared with theoretical simulation results or experimental observations of previous researchers. [Copyright &y& Elsevier]

Abstract: Methylation reaction of indole was studied in supercritical methanol (350°C, 215atm) catalyzed by TMOS and TEOS. Use of both orthosilicates shows the same result of indole methylation. The indole conversion is ∼30% for 5h of the reaction with and without catalysts. But catalytic reaction is more high-selective on 3-methyl-1H-indole formation – 95–96mol% against 60mol% for non-catalytic methylation. Indole conversion in catalytic reaction increases by a quarter (with no change of selectivity) when two equivalents of water are added into reaction mixture. Methylating system was assumed to be the TMOS–MeOH, and methylation proceeds via cyclic, multi-centered transition state (TS). The TS involves molecules of indole, TMOS, methanol, and water (if used), which are orientated in a certain way to each other by hydrogen and coordinate bonding. The reaction does not occur in supercritical ethanol or isopropanol with and without using the catalysts. [Copyright &y& Elsevier]

Background: Despite the importance of olfactory function, no effective medications have been identified to treat olfactory disorders. This study was performed to evaluate the functional recovery of olfaction damaged by 3-methylindole (3MI) in a mouse model with hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins). Methods: In a randomized placebo-controlled trial, 24 healthy female BALB/c mice (aged 9-10 weeks and weighing 18-20 g each) were randomly allocated to statin-treated or control groups. Olfactory loss was induced by i.p. injections of 3MI. Atorvastatin (10 mg/kg) or normal saline was then administered per os with a gastric tube for 3 weeks. The effects of treatment were evaluated by food-finding tests and Western blot analysis. Results: Both groups showed complete losses of olfactory function 1 week after 3MI injection. Three weeks after 3MI injection, 9 of the 12 mice in the statin-treated group (75%) passed a food-finding test, in which they were able to find the food within 3 minutes, at least two times out of three trials. However, only two mice in the control group (16.6%) passed the food-finding test, and this difference was statistically significant (p = 0.004; chi-square test). The expression level of the olfactory marker protein was also elevated in the statin-treated group (p = 0.030; Wilcoxon rank sum test). Conclusion: Statins are associated with recovery of olfaction after 3MI injection in a mouse model. [ABSTRACT FROM AUTHOR]

Background: 3-Methyl indole(Skatole, 3-MI) is produced by microfloral fermentation of tryptophan in rumen and production of that has relation with the onset of respiratory problems in cattle. The aim of this study was to compare complications of 3-MI dissolved in two solvents, Cremophor and Propylene Glycol on BALB/c mice by histopathologic and stereologic studies. Materials, Methods & Results: Female Balb/C mice 56 days of age (23 - 27 g) were divided into 13 groups of eight and had access to food and water ad libitum. Mice were housed in plastic cages (4 per cage) with wire bar lids on bedding of sawdust in an air-conditioned room with 12 h light: dark cycles. After a 7-day acclimation period, for 5 groups, Mice were injected with 400, 500, 600, 700 and 800 mg/kg from solution of 3-MI in propylene glycol and similarly for 5 other groups with Cremophor. As well as 2 groups were injected with Propylene glycol and Cremophor with the dosage that is necessary for solving the highest dose of 3-MI. One group received normal saline with the volume equal with Cremophor (drug vehicle) group. Briefly, 125 mg of 3-MI was dissolved per mL of sterile filtered Propylene glycol and 30 mg of 3-MI was dissolved per mL of sterile filtered Cremophor. Once injected intra peritoneally, mice were monitored 3-4 h for external reaction signs from the injection. LD50 was determined 610.16 mg/kg 3-Methylindole and 687.5 mg/kg 3-Methylindole dissolved in Propylene glycol and Cremophor respectively with linear regression. Increase in respiration rate, tachypnea and shallow respiration was observed in clinical examination. In necropsy, alveolar and bronchial hyperemia was significant in lungs. Some superficial wounds were observed in upper respiratory airways. Trachea and Hungarian airways were severely hyperemic. There were some debris's in airways canals. We couldn't find any lesion in other organs. Histopathology showed noticeable alveolar edema and emphysema, type I pneumocytes necrosis, Slight endothelial lesions, rare degeneration of type II pneumocytes and raised nutrophil infiltration around vessels were observed in higher dosages of both groups. Moderate interstitial edema, hyperemia and increase of alveolar macrophages were observed too. Increase of lymphocytes was noticed after the dose 600 mg/kg moderately on a dose dependent manner. There was a Hyaline membrane in the wall of air sacs. Endothelial capillary damage in Cremophor dissolved 3-MI groups were slightly lower. Although damage to the vessels was not that much progressed in both groups. Stereologic study of type II pneumocytes showed a significant increase in the percentage of them in alveoli of treatment groups in a dose dependent manner compare to control and drug vehicle groups. At the highest dose (800 mg/kg) the group with Propylene glycol as solvent had significant difference with Cremophor dissolved 3-Methyl indole group and epithelialization was more severe in that. Bronchiole injuries raised in a dose dependent manner in both treatment groups. Discussion: The results of this research indicate that intraperitoneal infusion of 3-MI dissolved in Propylene glycol and Cremophor cause noticeable changes in the respiratory systems of mice. Effects of 3-MI in Propylene glycol is more severe than 3-MI dissolved in Cremophor but type of the lesions is not different. Bronchiolar lesions were moderate compare to the effects of 3-MI in some other animals. Severity of vascular lesions in Propylene glycol dissolved 3-MI was greater than groups that received the Cremophor dissolved 3-MI. Although the vascular injuries were not that much noticeable at all. [ABSTRACT FROM AUTHOR]

Abstract: A novel efficient method for vapor-phase synthesis of 3-methylindole from aniline and glycerol has been developed over Cu-based catalysts. The catalysts were characterized by BET, XRD, H2-TPR and NH3-TPD techniques. The results indicated that Cu/SiO2-Al2O3 catalyst exhibited high activity. The yield of 3-methylindole could be up to 40% when the Cu loading was 5.41wt% and the reaction temperature was 240°C. Moreover, the catalyst could be reused without obvious loss of the yield even after reaction time of 46h. Copper-based catalyst with good dispersion and large amount of weak acid sites was favorable for producing 3-methylindole. A possible reaction pathway for the catalytic synthesis of 3-methylindole was proposed. [ABSTRACT FROM AUTHOR]

Abstract: The ring-methylation of pyrrole or indole using supercritical methanol proceeded at 623K without the further addition of catalysts. Pyrrole produced a mixture of unreacted pyrrole and mono-, di-, tri-, and tetra-methylpyrroles at the reaction time of 8h. On the other hand, indole was selectively methylated at the C3 position to afford 3-methylindole in 79% yield at the reaction time of 5h. The ring-methylation of indole using supercritical methanol was claimed to proceed via (1H-indol-3-yl)methanol. The conversion of indole to (1H-indol-3-yl)methanol would be achieved by the electrophilic aromatic substitution between the indol-1-ide (indole anion) and H2C+–OH. The (1H-indol-3-yl)methanol must be reduced to 3-methylindole in the presence of supercritical methanol. [Copyright &y& Elsevier]

Background: This study was performed to investigate whether statins can enhance the recovery of the olfactory epithelium (OE) damaged by 3-methylindole (3MI), an olfactotoxicant, and to compare the effects with those of steroids. Methods: Randomized placebo-controlled trial was performed. Fifty-four healthy female Sprague-Dawley rats (aged 9-10 weeks and weighing 160-180 g each) were randomly allocated to the statin-treated, steroid-treated, or control groups. Olfactory loss was induced using i.p. injection of 3MI in adult rats. Atorvastatin (10 mg/kg for 4 weeks), prednisolone (1 mg/kg for 2 weeks), or normal saline (1 cc for 4 weeks) was then administered per os with a gastric tube. Hematoxylin and eosin (H&E) staining and immunohistochemical staining were performed to evaluate the change of thickness and the arrangement of the OE, and immunoreactivity to protein gene product (PGP) 9.5 and proliferating cell nuclear antigen (PCNA). Results: The statin-treated group showed the earliest increase of the thickness of the OE (p = 0.002 at 7 days after 3MI injection) and the immunoreactivity to PCNA (p = 0.032 at 7 days after 3MI injection) among the three groups. The immunoreactivity to PGP 9.5 showed significantly better improvement at the 7th and 28th days after 3MI injection compared with the steroid-treated or control groups (p = 0.002 and p < 0.001, respectively). Conclusion: Statins might enhance the proliferation and neuroregenesis of the OE after 3MI injection. [ABSTRACT FROM AUTHOR]

Previous work has shown that bioactivation of the cigarette smoke pneumotoxicant 3-methylindole (3MI) by pulmonary cytochrome P450 enzymes is directly associated with formation of DNA adducts. Here, we present evidence that normal human lung epithelial cells, exposed to low micromolar concentrations of 3MI, showed extensive DNA damage, as measured by the comet assay, with similar potency to the prototypical genotoxic agents, doxorubicin and irinotecan. The DNA damage caused by 3MI was predominantly caused by single-strand breaks. Furthermore, we show that this damage decreased with time, given a subtoxic concentration, with detectable DNA fragmentation peaking 4 h after exposure and diminishing to untreated levels within 24 h. Pretreatment with an inhibitor of poly(ADP-ribose) polymerase 1 (PARP1), NU1025, nearly doubled the DNA damage produced by 5μM 3MI, implying that PARP1, which among other activities, functions to repair single-strand breaks in DNA, repaired at least some of the 3MI-induced DNA fragmentation. A key cellular response to DNA damage, phosphorylation, and nuclear localization of p53 was seen at subtoxic levels of 3MI exposure. 3MI was highly mutagenic, with essentially the same potency as the prototype carcinogen, benzo[a]pyrene, only when a lung-expressed CYP2F3 enzyme was used to dehydrogenate 3MI to its putative DNA-alkylating intermediate. Conversely, a rat liver S9 metabolic system did not bioactivate 3MI to its mutagenic intermediate(s). Concentrations higher than 25μM caused apoptosis, which became extensive at 100μM, similar to the response seen with 10μM doxorubicin. Our findings indicate that there is a low concentration window in which 3MI can cause extensive DNA damage and mutation, without triggering apoptotic defenses, reinforcing the hypothesis that inhaled 3MI from cigarette smoke may be a potent lung-selective carcinogen. [ABSTRACT FROM PUBLISHER]

Abstract: In order to understand the influence of the methyl group in the stability of the indole unit, the standard () molar enthalpies of formation of 1-, 2-, and 3-methylindoles, in the gaseous phase, were determined at T =298.15K. For that, combustion calorimetry was used to determine the massic energies of combustion and consequently the standard molar enthalpies of formation in the condensed phase, and Calvet microcalorimetry was employed to measure the standard molar enthalpy of phase transition (vaporization for the liquid 1-methylindole and sublimation for the other two solid compounds). The G3(MP2)//B3LYP composite approach was used to calculate the gas-phase enthalpies of formation, at T =298.15K, of all possible single methylated indoles using four different working reactions. The enthalpies calculated for the 1-, 2-, and 3-methylindoles are in excellent agreement with the values derived from the experimental work. [Copyright &y& Elsevier]

Abstract: Vapor-phase methylation of indole with methanol and dimethylcarbonate (DMC) was carried out over Ni1− x Mn x Fe2O4 (x =0, 0.25, 0.5, 0.75, 1.0) type ferrospinel in a fixed-bed reactor. 3-Methylindole was found to be the major product. It was observed that systems possessing higher ‘x’ values were highly selective for 3-methylindole. A maximum yield of 54.6% with selectivity 88.3% of 3-methylindole was obtained when methanol was used as alkylating agent, while yield of 48.6% with selectivity 80.1% was obtained using DMC as alkylating agent over MnFe2O4 under optimized conditions. Ni2+/Mn2+ ionic distribution in the spinel lattice influences the acido-basic properties. Effect of alkylating agent and different reaction parameters are discussed. [Copyright &y& Elsevier]

Aims: To develop a defined medium for Clostridium scatologenes ATCC 25775, which produces the malodorants 3-methylindole (skatole) and 4-methylphenol ( p-cresol). Methods and Results: Clostridium scatologenes was cultured in anaerobic broth medium (pH 6·3) at 37°C containing ammonia, minerals and a commercial vitamin solution. Data indicate α-ketoglutarate,l-glutamate orl-glutamine is a required nutrient that can also serve as a primary carbon and energy source. When cultured in defined medium containing glutamate; glucose, fructose and betaine served as primary carbon and energy sources.l-Tryptophan,l-tyrosine, sorbitol and indole acetic acid did not enhance growth. In the absence of tryptophan, cells produced indole when grown using glucose or fructose. 4-Methylphenol was produced when growing cells were supplied with tyrosine. When supplied with tryptophan, 3-methylindole was produced by glucose- or fructose-growing cells but not from glutamate-growing cells. Cells grown in the presence of pyruvate produced indole, 3-methylindole and 4-methylphenol. Conclusions: Clostridium scatologenes requires α-ketoglutarate,l-glutamate, orl-glutamine for growth in defined medium. Cells produce indole when glucose or fructose is included in defined medium. Significance and Impact of the Study: The development of a defined medium will assist in physiology studies and genetic analysis of this strain. [ABSTRACT FROM AUTHOR]

A new method is described for simultaneous determination of 3-methylindole (3MI) and indole in porcine adipose tissue. Sample preparation included liquid–liquid extraction with n-hexane and 75% aqueous acetonitrile. The acetonitrile extracts were analysed by liquid chromatography–mass spectrometry (LC–MS) using atmospheric pressure chemical ionization (APCI) with selective ion monitoring of protonated ions [M + H]+. This method showed excellent linearity over the concentration range tested (from 2 to 500 ng mL−1 for 3MI and from 1 to 500 ng mL−1 for indole) and good accuracy (recovery of 92 ± 10% for 3MI and 91 ± 10% for indole). This new LC–MS method was compared with traditional colorimetric method for 3MI equivalent. Additionally, the correlation between 3MI concentrations in adipose tissue and plasma was studied. The described LC–MS method can be used to quantify 3MI and indole in porcine adipose tissue in various endocrinological or meat science studies. [ABSTRACT FROM AUTHOR]

Indolic compounds are N-heterocyclic aromatic chemicals and have been detected at contaminated sites. Biodegradation of 1-methylindole (1MI) and 3-methylindole (3MI) was investigated initially using enrichment cultures with mangrove sediment obtained from Mai Po Nature Reserve of Hong Kong and subsequently with a pure culture of Pseudomonas aeruginosa Gs confirmed with 16S rRNA gene. At 2.0 mM, 1MI and 3MI were degraded in 4 and 3 days, respectively, by the respective 1MI- and 3MI-degrading enrichment cultures. When substrate concentrations were increased to 3.0,mM and 3.5,mM, slower degradation of 1MI and 3MI was observed indicating inhibitory effects from the substrates, possibly due to toxicity. In addition, no colony of bacteria could be observed on the agar plates amended with 3.5,mM 1MI or 4.0,mM 3MI, indicating that 1MI was more toxic than 3MI. Pseudomonas aeruginosa Gs, isolated from the enrichment culture, effectively utilized both substrates as the sole source of carbon and energy. Complete degradation of 1MI and 3MI was achieved after more than 40 days and 24 days, respectively, at an initial concentration of 2,mM in the culture. Effects of initial substrate concentration, pH and salinity on degradation of 1MI and 3MI by P. aeruginosa Gs were also studied in batch culture. The optimum pH and salinity for degrading both substrates by P. aeruginosa Gs was 7.0 and 5Ȩ, respectively. Biodegradation kinetics of 1MI and 3MI by P. aeruginosa Gs could be described using a first-order kinetic model. Our results suggest that both 1MI and 3MI are biodegradable in the mangrove environment and that toxicity of 1MI could be a potential factor limiting the removal of the chemical in the environment by microorganisms. [ABSTRACT FROM AUTHOR]

3-Methylindole (3MI), an N -heterocyclic aromatic compound also called skatole, is associated with animal waste and industrial processing. A pure culture of bacterium capable of using 3MI as the sole source of carbon and energy was isolated from mangrove sediment using an enrichment technique and identified as Pseudomonas aeruginosa Gs based on 16S rDNA sequence. Microbial degradation of 3MI was studied in batch culture experiments for several factors, including initial substrate concentrations, pH, and salinity. The optimum pH and salinity was 7.0 and 5‰, respectively. Degradation of 3MI by P. aeruginosa Gs was quantified by reversed-phase high-performance liquid chromatography. Two metabolites of 3MI degradation were detected and proposed to be indoline-3-carboxylic acid and indoline-3-ol based on data obtained from HPLC/MS. Our results suggest that 3MI can be rapidly degraded by indigenous microorganisms found in mangrove sediment. [ABSTRACT FROM AUTHOR]

Abstract: 3-Methylindole (3MI), which serves as a structural model for the tryptophan side chain in proteins, has been investigated using vapor phase Raman spectroscopy. The vapor phase spectrum of 3MI identifies the Raman signature of the indolyl moiety free of intermolecular interaction and extends previously reported solution Raman studies of 3MI and related tryptophan derivatives. The Raman spectrum of 3MI vapor is also complemented here with newly obtained vapor phase infrared data and ab initio calculations to refine and extend previous vibrational assignments. The present results provide an improved basis for assessing the dependence of the indolyl Raman signature on the local environment of the tryptophan side chain of proteins. The principal conclusions of this work are the following. (i) The vapor phase 3MI molecule exhibits Raman bands at 3506, 1585, 1409, 1349/1341 (Fermi doublet) and 881cm-1, which differ greatly from their counterparts in the Raman spectrum of 3MI liquid and thus serve as spectral markers of the indolyl ring environment. (ii) The Fermi doublet relative intensity ratio (I1/I2, where I1 and I2 are, respectively, the Raman intensities of the higher and lower wavenumber components of the doublet) is highly sensitive to the state of 3MI condensation, consistent with the previously reported sensitivity of I1/I2 to solvent polarity. The maximum value of the intensity ratio (I1/I2=3.0) is observed for 3MI vapor, while the minimum value (I1/I2=0.43) is observed for 3MI in CHCl3 solution. Implications of the present results for Raman analysis of hydrogen bonding states, hydrophilic interactions and hydrophobic interactions of tryptophan residues in proteins are considered. [Copyright &y& Elsevier]

Chemiluminescence of 3-methylindole (3-MIH) based on electrogeneration of superoxide ion (O2−⋅) in air-saturated acetonitrile solutions containing no base was investigated by the use of spectroelectrochemical techniques for the first time. The emission spectrum was observed around −0.2 V versus Ag ∣ AgCl ∣ NaCl(sat) after the electrogeneration and the subsequent reoxidation of O2−⋅ (formal potential, E0′O2/O2−⋅=−0.86 V) on the electrode surface. This spectrum revealed maximum intensity around 475 nm. On the cyclic voltammogram obtained together with the chemiluminescence at the 475-nm curve, an oxidation peak apart from the reoxidation peak of O2−⋅ was observed at about −0.2 V. This oxidation process around −0.2 V had a close connection with the chemiluminescence, and was considered to be due to the electrooxidation of 3-MI− (i.e. a conjugate base of 3-MIH) to 3-MI⋅ (i.e. a one-electron oxidation product, a radical species of 3-MI−). The electrogenerated O2−⋅ could function as a proton acceptor to 3-MIH. This reaction generates 3-MI− and hydroperoxyl radical (HO2⋅). In the chemiluminescence observed around −0.2 V, the radical–radical coupling reaction between 3-MI⋅ and HO2⋅ was considered to result in the formation of a 1,2-dioxetane-like intermediate to lead to the emission of light. The chemiluminescent reaction mechanism of 3-MIH was discussed in detail in comparison with that of the MCLA (a Cypridina luciferin analogue)–O2−⋅ system. [Copyright &y& Elsevier]

Vapor-phase alkylation of indole with methanol was carried out over HZSM-5 (30), HY, CeHY, LaHY, CrHY and CuHY zeolites in a continuous fixed-bed reactor at atmospheric pressure. Rare earth metal cation-modified HY zeolites are found to be more active for the alkylation of indole than HY zeolites and transition metal-modified HY zeolites. The maximum of 33.6% yield of 3-methylindole at 72.6% indole conversion was obtained over 3 wt.% CeHY catalyst at 300 °C. Furthermore, the activity of pyridine-poisoned and calcined catalysts revealed that either Brønsted or Lewis acid sites of medium strength are the suitable sites for 3-methylindole formation. [Copyright &y& Elsevier]