Chain Ketones Research Articles

Upgrade of Acetone-Butanol-Ethanol Mixture to High-Value Biofuels over Ca-Doped Ni-CaO-SiO2 catalyst.

The selective conversion of biomass fermentation derived from an acetone-butanol-ethanol (ABE) mixture into high-value biofuels is of paramount importance for industrial applications. However, challenges persist in effectively controlling the selectivity of long carbon chain ketones in elevated ABE conversion. In this research, a Ca-doped Ni-CaO-SiO2 catalyst was designed and employed to achieve a remarkable conversion of 89.9% into ketone products from the extracted ABE mixture. The selectivity for C8+ ketones reaches 41.8%, demonstrating exceptional performance. The reversible phase transition between Ca2SiO4 and CaCO3 enhances the recyclability, thereby improving the sustainability of the process. Additionally, the trace intermediate 3-hepten-2-one was successfully detected using two-dimensional GC×GC-MS, elucidating the conversion pathway in the catalytic upgrading of the ABE mixture. This finding offers a potential route for the efficient utilization of biomass and the highly selective production of value-added chemicals.

Lignosulphonates in zinc pressure leaching: Decomposition behaviour and effect of lignosulphonates’ characteristics on leaching performance

Lignosulphonate (LS) is the most commonly used surfactant in zinc pressure leaching (ZPL). In this work, the performance of LS obtained from several producers in ZPL was comparatively studied, the differences in LS characteristics were evaluated in terms of composition, structure, surface tension, etc., and the decomposition behaviour of a typical LS in ZPL was investigated. The results indicated that the leaching performances of these LS varied and depended on the LS characteristics, purity and molecular weight in particular; the differences in the LS characteristics were distinct, and the LS surface activity was the fundamental reason for their diverse leaching performances; softwood and hardwood LS showed superior performances, and three main steps could be concluded for LS decomposition: LS→aromatic compounds (guaiacol, vanillin, vanillic acid, apocynin, etc.)→low molecular organics (short chain ketone, acids, etc.)→CO2+H2O. The results will help the selection and development of LS dedicated to ZPL, and further promote the efficiency, clean, and stability of zinc production.

Understanding cellulose pyrolysis under hydrogen atmosphere

The product distributions of cellulose pyrolysis under different pressures, temperatures, and atmospheres were investigated using a high-pressure micropyrolyzer to clarify the pyrolysis reaction mechanism of cellulose decomposition with hydrogen. EGA-MS results shows that the increase in hydrogen pressure prolonged the second stage of cellulose pyrolysis, which was dominated by decarboxylation. Pyrolysis products of cellulose under helium mainly included levoglucosan, furfural, and acids, while cellulose hydropyrolysis mainly produced C5-C7 ketones, besides small amount of alcohols, aromatics and aliphatic hydrocarbons, and even small amount of phenolics. Carbon yield of ketones was as high as 27.2% from cellulose hydropyrolysis under 2.5 MPa hydrogen and 500 °C. The yield of liquid products and non–condensable hydrocarbons increased with elevated hydrogen pressure. The formation mechanisms of aromatics, phenolics, aliphatic hydrocarbons, aldehydes, ketones, and alcohols under hydrogen atmosphere were discussed. Acetaldehyde was produced by acids through a HDO reaction. C5-C7 chain ketones and cyclic ketones were generated by furfural through HDO and hydrocracking reactions. The Diels–Alder reaction to generate aromatics was enhanced by increasing pyrolysis temperature under hydrogen atmosphere. The reaction network of cellulose hydropyrolysis was also proposed.

Fast Catalytic Pyrolysis of Tetradecanoic Acid: Formation of Ketones as Intermediate Compounds in the Production of Hydrocarbons

This work aimed to compare two different catalysts in the production of a long chain ketone, intermediate in the production of hydrocarbons, during pyrolysis of tetradecanoic acid as a model fatty acid. The studied variables were the temperature, 450 and 600 ºC, and catalysts, γ-Al2O3 and Nb2O5, the latter has never been studied under such conditions. Pyrolysis experiments were performed in a micro-pyrolyzer coupled to a gas chromatograph with mass spectrometry detector (GC-MS). In all pyrolysis conditions, 14-heptacosanone was formed in varied amounts. Under the best conditions, for pyrolysis at 600 ºC, using γ-Al2O3 as catalyst, the yield of 14-heptacosanone was 18% and the yield of hydrocarbons 24%. The major hydrocarbon product obtained was 1-dodecene. Among the partially deoxygenated compounds, the main products were the ketones 14-heptacosanone and 2-pentadecanone. The present experimental work confirmed also the possibility to obtain hydrocarbons having a chain length longer than the chain length of the original fatty acid reagent, due to a ketonization route followed by decarbonylation.

Effects of temperature and urea concentration on nitrogen-rich pyrolysis: Pyrolysis behavior and product distribution in bio-oil

Nitrogen-rich pyrolysis is an important means of biomass utilization. In this paper, the effects of urea concentration and pyrolysis temperature on the composition of various nitrogen- and oxygen-containing compounds in bio-oil produced during the pyrolysis of pine powder (PP) were studied. The results showed that A-type (a benzene ring with one methoxy group) and B-type (a benzene ring with two methoxy groups) phenols were only detected in the bio-oil derived from conventional biomass pyrolysis. After nitrogen-rich pyrolysis, the total phenolic content in the bio-oil increased significantly, and all four types of phenols (A, B, C (a benzene ring featuring an alkyl group that is not a methoxy group), and D (other types of phenols)) were detected. In addition, the aldehyde and linear chain ketone contents in the bio-oil significantly decreased after nitrogen-rich pyrolysis compared to after conventional biomass pyrolysis. When the urea concentration was 10 wt%, only cyclic ketones were detected in the bio-oil. Furthermore, the content of nitrogenous heterocyclic compounds in the bio-oil significantly increased after nitrogen-rich pyrolysis when the urea concentration increased from 5 wt% to 10 wt%, with pyridine being the most abundantly produced.

Plasma Carboxyl-Metabolome Is Associated with Average Daily Gain Divergence in Beef Steers.

Simple SummaryIn this study, we analyzed the plasma carboxyl-metabolome in beef steers with divergent average daily gain (ADG). Several short chain fatty acids were greater in beef steers with greater ADG. Conversely, several long chain fatty acids were greater in beef steers with lower ADG. Pathway analysis of the differential metabolites revealed alterations in abundance/activities of enzymes involved in fatty acid metabolism in the liver. The results of this study demonstrated that beef steers with divergent ADG had altered plasma carboxyl-metabolome, which is possibly caused by altered abundances and/or activities of enzymes involved in fatty acid oxidation and biosynthesis.We applied an untargeted metabolomics technique to analyze the plasma carboxyl-metabolome of beef steers with divergent average daily gain (ADG). Forty-eight newly weaned Angus crossbred beef steers were fed the same total mixed ration ad libitum for 42 days. On day 42, the steers were divided into two groups of lowest (LF: n = 8) and highest ADG (HF: n = 8), and blood samples were obtained from the two groups for plasma preparation. Relative quantification of carboxylic-acid-containing metabolites in the plasma samples was determined using a metabolomics technique based on chemical isotope labeling liquid chromatography mass spectrometry. Metabolites that differed (fold change (FC) ≥ 1.2 or ≤ 0.83 and FDR ≤ 0.05) between LF and HF were identified using a volcano plot. Metabolite set enrichment analysis (MSEA) of the differential metabolites was done to determine the metabolic pathways or enzymes that were potentially altered. In total, 328 metabolites were identified. Volcano plot analysis revealed 43 differentially abundant metabolites; several short chain fatty acids and ketone bodies had greater abundance in HF steers. Conversely, several long chain fatty acids were greater in LF steers. Five enzymatic pathways, such as fatty acyl CoA elongation and fatty-acid CoA ligase were altered based on MSEA. This study demonstrated that beef steers with divergent ADG had altered plasma carboxyl-metabolome, which is possibly caused by altered abundances and/or activities of enzymes involved in fatty acid oxidation and biosynthesis in the liver.

A bimodular PKS platform that expands the biological design space

Traditionally engineered to produce novel bioactive molecules, Type I modular polyketide synthases (PKSs) could be engineered as a new biosynthetic platform for the production of de novo fuels, commodity chemicals, and specialty chemicals. Previously, our investigations manipulated the first module of the lipomycin PKS to produce short chain ketones, 3-hydroxy acids, and saturated, branched carboxylic acids. Building upon this work, we have expanded to multi-modular systems by engineering the first two modules of lipomycin to generate unnatural polyketides as potential biofuels and specialty chemicals in Streptomyces albus. First, we produce 20.6 mg/L of the ethyl ketone, 4,6 dimethylheptanone through a reductive loop exchange in LipPKS1 and a ketoreductase knockouts in LipPKS2. We then show that an AT swap in LipPKS1 and a reductive loop exchange in LipPKS2 can produce the potential fragrance 3-isopropyl-6-methyltetrahydropyranone. Highlighting the challenge of maintaining product fidelity, in both bimodular systems we observed side products from premature hydrolysis in the engineered first module and stalled dehydration in reductive loop exchanges. Collectively, our work expands the biological design space and moves the field closer to the production of “designer” biomolecules.

Direct Solvent Liquefaction of Tropical Hardwood Bark and Characterization of the Resulting Bio-Oil

Ethanol, water and ethanol/water mix were used to directly liquefy Detarium senegalense bark at 500°C for 15 min. Ethanol/water mix at 50/50% weight by weight showed synergistic effect on biomass direct liquefaction, and was found to be the most effective solvent for the liquefaction of Detarium senegalense bark. Water was more active than Ethanol when both mono-solvents were evaluated. Liquefaction with 100% water yielded 46% by weight of the bio-oil, compared with 30% by weight of bio-oil yield when 100% ethanol was used. The result however, show that 50% ethanol/water showed a synergistic effect and work best to obtain 52% bio-oil on the liquefaction whereas water was found hence more active than ethanol as a single solvent with 46% and 30% bio-oil respectively.
 The GC-MS analysis of the obtained bio-oils from the three matrices confirmed the presence of phenolic compounds and aromatics such as benzenes, followed by aldehydes, long chain ketones and cyclic ketones and alcohol, esters, organic acids and ether compounds. The detected phenolic compounds were 4-ethyl-guaiacol, 2-methoxy-4-(2-propenyl)-phenol, 2-methoxy-phenol, and 2-methoxy-4-vinyl-phenol., formed from the cleavage of guaiacyl and hydroxyphenyl-type lignin with varying degrees of alcohol substitution. Understanding and evaluating the liquefied products obtained from hardwood barks, could offer valuable information on the utilization of the biomass-liquefaction products for chemical or energy production.

Comparison of the NMR and the Acid Value Determination Methods for Quality Control of Input Polysorbates

Polysorbates (PS) are the most common non-ionic surfactants used in protein formulations. Their degradation has been studied intensively in recent years. Ester bond hydrolysis is one of many pathways of PS degradation that can lead to accumulation of free fatty acids (FFAs) and particle formation. The distribution and quantity of FFAs in PSs impacts directly on product quality. Characterization of input PS is highly relevant, because the initial content of FFAs differs greatly between manufacturers. The purpose of this study was to set up a quick and simple analytical method for the quantitative evaluation of FFAs in PS. The content of FFAs was measured for selected PS 20 and 80, using two methods, 1H nuclear magnetic resonance spectroscopy (1H NMR) and the European pharmacopoeia method for determining acid value (IA). These methods have been evaluated using the method of standard addition and, based on the results, they are interchangeable. It was concluded that 1H NMR is a useful tool for quality control of input PS and a rapid method for indicating the rate of PS degradation by hydrolysis and oxidation. Further, a newly discovered impurity in PS raw material, the long chain ketone 12-tricosanone, can be identified using 1H NMR.

Facile synthesis of N’-(anthracen-9(10H)-ylidene)-4-(4-hydrophenyl)-6-methyl-2-oxo-1,2,3,4-tetra hydropyrimidine-5-carbohydrazide and other derivatives

Pyrimidine as vital constituents of nucleic acid is recognized for its role in the chemotherapy of AIDS. Hydrazide-hydrazones are important moieties with notable biological diversity in drug design. Thus, the aim of this present study is to synthetically couple these two frameworks together in order to achieve small molecular targets for possible development of improved therapeutic candidates. This was achieved in a domino reaction starting with one-pot three-component reaction to afford ethyl-4-(4-hydroxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate, 7 which upon treatment with hydrazine hydrate under acid-mediated condition gave 8, as an essential precursor and reactive intermediate. The expeditious condensation of intermediate 8 with various cyclic and straight chain ketones furnished N’-(anthracen-9(10H)-ylidene)-4-(4-hydrophenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5 -carbohydrazide 9a and other 9b-i scaffolds as envisaged. The reaction progress was monitored by thin layer chromatography (TLC) and upon reaction completion, the purification process was carried out with recrystallization and/or column chromatography. The authenticity of the prepared products 9a-i was confirmed by spectroscopic means including IR, UV, 1H-NMR, 13C-NMR and DEPT-135 as well as analytical data. These final products are good candidates for further study as regards anti-plasmodial activity which are been developed and examined.

Abstract MP59: The Differential Effects of Amount and Intensity of Aerobic Exercise Training on MVX, a Novel Mortality Risk Multimarker

Introduction: Metabolic Vulnerability Index (MVX) is a novel spectroscopic multimarker of mortality risk. MVX reflects components of nutrition and systemic inflammation status and is hypothesized to enhance disease and mortality risk stratification. As Studies Targeting Risk Reduction Interventions through Defined Exercise (STRRIDE) has previously demonstrated the ability of aerobic exercise training to improve traditional markers of cardiometabolic health, we hypothesized that aerobic exercise intervention also would result in beneficial changes in the components of MVX. Methods: Participants (n=222, previously sedentary, overweight men and women with mild to moderate dyslipidemia from STRRIDE) were randomized to either a 6-month control group or to one of three supervised aerobic exercise groups for 8-months: 1) low amount moderate intensity (LM): 14 kcal/kg/wk at 40-55% VO 2peak ; 2) low amount vigorous intensity (LV): 14 kcal/kg/wk at 65-80% VO 2peak ; 3) high amount vigorous intensity (HV): 21 kcal/kg/wk at 65-80% VO 2peak . Blood samples were obtained after an overnight fast at both baseline and study completion (16-24 hr after the final training bout for exercisers). Nuclear magnetic resonance spectroscopy was performed on the Vantera ® clinical analyzer at LabCorp to determine MVX score. MVX has two components: inflammation index [INFX; combined concentrations of GlycA and small HDL particle subspecies (diameters < 9 nm)] and metabolic malnutrition index (MALNX; combined concentrations of total branched chain amino acids and ketone bodies). MVX, INFX, and MALNX are all scaled from 1 (lowest risk) to 100 (highest risk). Paired t-tests determined whether the post- minus pre- intervention change scores within each group were significant (p<0.05). We used analysis of covariance accounting for baseline values to determine difference between groups. Results: The inactive control group did not exhibit significant changes in any of the multimarkers. After 8-months of exercise training, the LM group experienced significant decreases in all three scores: INFX (-2.1 ± 5.2), MALNX (-3.1 ± 11.3), and MVX (-3.9 ± 9.1). The LV group significantly decreased their INFX score (-1.5 ± 3.8), yet significantly increased MALNX (2.2 ± 6.8). The HV group significantly decreased their INFX (-1.6 ± 4.8) and MVX scores (-1.9 ± 5.6). For the LM group, the beneficial changes in MALNX and MVX were significantly greater than the LV group. Conclusion: Aerobic exercise improved components of the novel risk-prediction multimarker MVX, with the LM group displaying the best responses across all three scores. As ongoing research investigates the clinical utility of these mulitmarkers, this study provides evidence for the ability of exercise intervention to beneficially change MVX score.

Screening, expression, and characterization of Baeyer-Villiger monooxygenases for the production of 9-(nonanoyloxy)nonanoic acid from oleic acid

In this study, the production of 9-(nonanoyloxy) nonanoic acid from oleic acid was investigated. The whole cell biotransformation of oleic acid includes OhyA (hydratase), ADH (alcohol dehydrdogenase), and BVMO (Baeyer-Villiger Monooxygenase) enzymes consecutively. BVMOs are known to catalyze oxidative cleavage of long chain aliphatic ketones (e.g., 2-decanone, 10-ketooctadecanoic acid). However, the enzymes are difficult to overexpress in a soluble form in microorganisms. Thereby, this study has focused on screening and functional expression of the BVMOs in Escherichia coli. Initially BVMOs were selected by protein sequence analysis and were examined for their ability to express in soluble and active form to generate 9-(nonanoyloxy)nonanoic acid from oleic acid. Secondly various optimization strategies of inducer concentrations, co-expression with molecular chaperones, and different media conditions were investigated. Among the 9 BVMOs screened, three BVMOs were found to produce the target product and among these, Di_BVMO3 isolated from Dietzia sp. D5 was found to be best. Further, the soluble expression of Di_BVMO3 was enhanced by adding phosphoglycerate kinase as N-terminal fusion tag. The whole cell biotransformation with fusion enzyme resulted in 3 ~ 5-fold enhancement in product formation compared with the non-fusion counterpart. Final productivity up to 105.3 mg/L was achieved. Besides Di-BVMO3, other two new BVMOs of Rh_BVMO4 from Rhodococcus sp. RHA1 and AFL838 from Aspergillus flavus NRRL3357 were screened for production of 9-(nonanoyloxy)nonanoic acid and could be used for whole cell biotransformation reaction of other long chain ketones.

Effect of Cp*Iridium(III) Complex and acid co-catalyst on conversion of furfural compounds to cyclopentanones or straight chain ketones

In this paper, Cp*Ir (III) Complex and acid co-catalyst system was developed. By using Cp*Ir and γ-Al2O3 (Lewis acid), 5-hydroxymethylfurfural (5-HMF) can be converted efficiently to 3-hydroxymethyl cyclopentanone (HCPN). Meanwhile, Cp*Ir and Brønsted acid can promote conversion of 5-HMF to 1-Hydroxy-2,5-hexanedione (HHD). The effect of Lewis acid and Brønsted acid on the hydrogenation of furan derivatives was studied. Mechanism of conversion of 5-HMF to HCPN was discussed in detail and mechanism proposed by our predecessors was revised. Instead of being an intermediate for the formation of HCPN, it is believed that, HHD is a product of another reaction pathway. HHD condensed via Aldol reaction to produce 3-methylcyclopenten-2-ol-1-one (MCP) instead of HCPN. Under the promotion of Lewis acid, 5-HMF firstly convert to the precursor of HHD. After that, the reaction is through 4 π-electrocyclic ring closure process and HCPN was formed ultimately. Furthermore, we found that our Cp*Ir and acid co-catalyst system is suitable for a variety of furfural compounds. By using Cp*Ir, Brønsted acid can promote conversion of furfural compounds to straight chain ketones and Lewis acid can promote the rearrangement of furfural compounds to cyclopentanone derivatives.

Synthesis and Antineoplastic Evaluation of Mitochondrial Complex II (Succinate Dehydrogenase) Inhibitors Derived from Atpenin A5.

Mitochondrial complex II (CII) is an emerging target for numerous human diseases. Sixteen analogues of the CII inhibitor natural product atpenin A5 were prepared to evaluate the structure-activity relationship of the C5 pyridine side chain. The side chain ketone moiety was determined to be pharmacophoric, engendering a bioactive conformation. One analogue, 1-(2,4-dihydroxy-5,6-dimethoxypyridin-3-yl)hexan-1-one (16 c), was found to have a CII IC50 value of 64 nm, to retain selectivity for CII over mitochondrial complex I (>156-fold), and to possess a ligand-lipophilicity efficiency (LLE) of 5.62, desirable metrics for a lead compound. This derivative and other highly potent CII inhibitors show potent and selective anti-proliferative activity in multiple human prostate cancer cell lines under both normoxia and hypoxia, acting to inhibit mitochondrial electron transport.

Non-catalytic and catalytic fast pyrolysis of Schizochytrium limacinum microalga

In this study, fast pyrolysis of lipid-rich microalga, Schizochytrium limacinum, is carried out to evaluate the potential of deriving valuable chemicals and fuel molecules from this algae variety. The alga was characterized for its proximate and elemental composition, and heating value. The pyrolytic mass loss profiles of the alga were obtained from thermogravimetric analyzer, and the apparent kinetic parameters of degradation were evaluated using advanced isoconversional method of Vyazovkin. Fast pyrolysis experiments were performed in analytical pyrolyzer coupled with gas chromatograph/mass spectrometer. Long chain carboxylic acids, primarily tetradecanoic and hexadecanoic acids, were observed as the major pyrolysates in the temperature range of 350–650°C in the absence of catalyst. A clear increase in production of aromatics and cyclic hydrocarbons was observed at high temperatures owing to the cracking of long chain hydrocarbon portion of the carboxylic acids. Catalytic fast pyrolysis was performed at 400°C using zeolite Y-hydrogen (ZYH), zeolite Y-sodium (ZYNa), and oxides like MgO, ZrO2 and TiO2. The production of polyaromatic hydrocarbons and nitriles increased, while that of long chain carboxylic acids decreased with increasing acidity of ZYH. Increasing the loading of ZYNa resulted in the formation of long chain ketones. The formation of ketones was more pronounced with MgO and ZrO2 catalysts. The major ketones obtained include 16-hentriacontanone and 14-heptacosanone, which were formed via ketonization reactions of palmitic and myristic acids present in the algae. This study demonstrates that selective production of valuable chemical intermediates can be achieved from complex feedstocks like microalgae via catalytic fast pyrolysis using zeolites and metal oxides.

Solvent induced supramolecular anisotropy in molecular gels

Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels.

Organic compound-mineral interactions: Using flash pyrolysis to monitor the adsorption of fatty acids on calcite

Fatty acids are near ubiquitous organic compounds in living organisms in the Earth’s biosphere. Following death of an organism in the marine environment its fatty acids may survive descent to the sea bed where they can be juxtaposed with minerals. The aim of this study was to investigate the interaction of fatty acids with the common marine mineral calcite. Adsorption of tetradecanoic acid (C14) on calcite results in a sigmoidal or “s” isotherm. Flash pyrolysis experiments were conducted on samples of fatty acid adsorbed onto calcite and were compared with similar experiments on pure fatty acid and on salts of a fatty acid. Flash pyrolysis of pure tetradecanoic acid generated unsaturated and saturated hydrocarbons and a series of unsaturated and saturated low molecular weight fatty acids. Flash pyrolysis of free tetradecanoic acid salt produced saturated and unsaturated hydrocarbons, an aldehyde and a homologous series of saturated and unsaturated ketones, one of which was a symmetrical mid chain ketone (14-heptacosanone). Flash pyrolysis data from adsorbed tetradecanoic acid samples suggested that adsorption is analogous to the formation of the calcium salt of tetradecanoic acid. A key characteristic of the flash pyrolysis products of adsorbed fatty acids and fatty acid salts was the production of ketones with higher molecular weights than the starting fatty acids. Ketonisation was not observed from the flash pyrolysis of pure acid which implied the catalytic significance of the calcite mineral surface. The abundance of hydrocarbons relative to ketones in the pyrolysates negatively correlated with the proportion of fatty acids adsorbed to the surface of calcite. The ability to use flash pyrolysis to diagnose the nature of fatty acid interactions with mineral surfaces provides a valuable tool for monitoring the fate of these important lipids at the Earth’s surface as they pass into the geosphere and are subjected to diagenetic processes.

Phytochemicals from Ruta graveolens Activate TAS2R Bitter Taste Receptors and TRP Channels Involved in Gustation and Nociception.

Ruta graveolens (rue) is a spontaneous plant in the Mediterranean area with a strong aroma and a very intense bitter taste, used in gastronomy and in folk medicine. From the leaves, stems and fruits of rue, we isolated rutin, rutamarin, three furanocoumarins, two quinolinic alkaloids, a dicoumarin and two long chain ketones. Bitter taste and chemesthetic properties have been evaluated by in vitro assays with twenty receptors of the TAS2R family and four TRP ion channels involved in gustation and nociception. Among the alkaloids, skimmianine was active as a specific agonist of T2R14, whereas kokusaginin did not activate any of the tested receptors. The furanocoumarins activates TAS2R10, 14, and 49 with different degrees of selectivity, as well as the TRPA1 somatosensory ion channel. Rutamarin is an agonist of TRPM5 and TRPV1 and a strong antagonist of TRPM8 ion channels.

A Highly Regioselective and Solvent-Free Sn(II)-Catalyzed Glycerol Ketals Synthesis at Room Temperature

Herein, an efficient and environmentally benign tin-based process who is a simple and available commercially catalyst, was used in the glycerol ketalization with different ketones at room temperature and solvent-free reactions. Although being a molecule highly functionalized, glycerol was selectively converted to ketal in all the SnCl2-catalyzed reactions. A high regioselectivity (ca. 78–99 % for 1,3-dioxolane derivatives) was achieved for ketones with straight or cyclic chain having up to six carbon atoms. Conversely, glycerol ketalization with branched carbon chain ketones containing six carbon atoms (i.e. 4-methyl-2-pentanone) resulted in the equimolar formation of two isomers products (i.e. cis and trans-1,3-dioxolane isomers glycerol derivatives). The main reaction parameters such as the ketone nature, reactants stoichiometry and catalyst concentration were assessed. The SnCl2 catalyst operate at mild and solvent-free reaction conditions and was successively recovered and reused without activity loss. Tin-catalyzed glycerol ketal synthesis

Silver-Catalyzed Highly Regioselective Synthesis of α-Carbonyl Furans from Enynones

A general and efficient method for the synthesis of a wide range of α-carbonyl furans is described here. The cyclization of enynone is catalyzed by AgBF4 in a fluorous biphasic system of perfluorodecalin and N,N-dimethylformamide. A variety of chain ketone and cyclic ketone substrates were used to investigate the scope of the reactions.