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Thomas Hummel - One of the best experts on this subject based on the ideXlab platform.
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The Presentation of Olfactory–Trigeminal Mixed Stimuli Increases the Response to Subsequent Olfactory Stimuli
Journal of agricultural and food chemistry, 2017Co-Authors: Ute Walliczek-dworschak, Johan Poncelet, Daniel Baum, Ramona Baki, Charlotte Sinding, Jonathan Warr, Thomas HummelAbstract:The aim of this study was to evaluate the effect of (1) the addition of trigeminal stimuli to an olfactory stimulus and (2) the congruence in the odorous mixture after repeated odor presentation. Twenty-five normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition, orange odor; congruent condition, orange odor + CO2; incongruent condition, orange odor + l-Isopulegol), and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D; peak to peak N1P2 at electrode positions Cz, Fz, and Pz; response amplitudes between H3 and DH). The addition of CO2 modified the perception of orange odor, pronouncing a fruity note, whereas the addition of l-Isopulegol as a DH pronounced the l-Isopulegol note. This study provides evidence that incongruent trigeminal-olfactory stimulants increase the response to subsequent olfactory stimulus.
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The Presentation of Olfactory–Trigeminal Mixed Stimuli Increases the Response to Subsequent Olfactory Stimuli
Journal of agricultural and food chemistry, 2017Co-Authors: Ute Walliczek-dworschak, Johan Poncelet, Daniel Baum, Ramona Baki, Charlotte Sinding, Jonathan Warr, Thomas HummelAbstract:The aim of this study was to evaluate the effect of (1) the addition of trigeminal stimuli to an olfactory stimulus and (2) the congruence in the odorous mixture after repeated odor presentation. Twenty-five normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition, orange odor; congruent condition, orange odor + CO2; incongruent condition, orange odor + l-Isopulegol), and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D; peak to peak N1P2 at electrode positions Cz, Fz, and Pz; response amplitudes between H3 and DH). The addition of CO2 modified the perception of orange odor, pronouncing a fruity note, whereas the addition of l-Isopulegol as a DH pronounced the l-Isopulegol note. This study provides evidence that incongruent trigeminal-olfactory stimulant...
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The presentation of olfactory-trigeminal mixed stimuli increases the response to subsequent olfactory stimuli
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Ute Walliczek-dworschak, Johan Poncelet, Daniel Baum, Ramona Baki, Charlotte Sinding, Jonathan Warr, Thomas HummelAbstract:The aim of this study was to evaluate the effect of 1) the addition of trigeminal stimuli to an olfactory stimulus and 2) the congruence in the odourous mixture after repeated odor presentation. 25 normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition: orange odor; congruent condition: orange odor + CO2; incongruent condition: orange odor + L-Isopulegol) and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D ; peak to peak N1P2 at electrode positions Cz, Fz and Pz; response amplitudes between H3 and DH) . The added DH modified perception of orange odor-pronouncing a fruity note by addition of CO2 respectively L-Isopulegol note by addition of L-Isopulegol. This study provides evidence that incongruent trigeminal-olfactory stimulants increase the response to following olfactory stimulus.
Jayesh J. Nair - One of the best experts on this subject based on the ideXlab platform.
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isomerization of citronellal to Isopulegol using eclectically engineered sulfated zirconia carbon molecular sieve composite catalysts udcat 2
Langmuir, 2000Co-Authors: Ganapati Yadav D And, Jayesh J. NairAbstract:Sulfated zirconia (S−ZrO2) is a well-known solid superacid used as a catalyst in various reactions of commercial importance such as isomerization, Friedel−Crafts alkylation and acylation, nitration, cracking, esterification, etc. S−ZrO2, per se, is not a shape-selective catalyst. The selectivity toward the formation of the desired product can be greatly enhanced by eclectically designing a shape-selective catalyst by a synergistic combination between S−ZrO2 and carbon molecular sieves (CMS). The paper presents the novelty of the combination of S−ZrO2 and CMS, designated as UDCaT-2, as a shape-selective catalyst in the cyclization of citronellal to Isopulegol which has industrial value. UDCaT-2 was found to be the best catalyst, among others, for the selective cyclization of citronellal to Isopulegol wherein the shape selectivity can be tailored by proper pretreatment. The conversion and selectivity were found to be the maximum at 95 °C. The formation of Isopulegol was found to be dependent on the average ...
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Isomerization of Citronellal to Isopulegol Using Eclectically Engineered Sulfated Zirconia−Carbon Molecular Sieve Composite Catalysts, UDCaT-2
Langmuir, 2000Co-Authors: Ganapati D. Yadav And, Jayesh J. NairAbstract:Sulfated zirconia (S−ZrO2) is a well-known solid superacid used as a catalyst in various reactions of commercial importance such as isomerization, Friedel−Crafts alkylation and acylation, nitration, cracking, esterification, etc. S−ZrO2, per se, is not a shape-selective catalyst. The selectivity toward the formation of the desired product can be greatly enhanced by eclectically designing a shape-selective catalyst by a synergistic combination between S−ZrO2 and carbon molecular sieves (CMS). The paper presents the novelty of the combination of S−ZrO2 and CMS, designated as UDCaT-2, as a shape-selective catalyst in the cyclization of citronellal to Isopulegol which has industrial value. UDCaT-2 was found to be the best catalyst, among others, for the selective cyclization of citronellal to Isopulegol wherein the shape selectivity can be tailored by proper pretreatment. The conversion and selectivity were found to be the maximum at 95 °C. The formation of Isopulegol was found to be dependent on the average ...
Ute Walliczek-dworschak - One of the best experts on this subject based on the ideXlab platform.
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The Presentation of Olfactory–Trigeminal Mixed Stimuli Increases the Response to Subsequent Olfactory Stimuli
Journal of agricultural and food chemistry, 2017Co-Authors: Ute Walliczek-dworschak, Johan Poncelet, Daniel Baum, Ramona Baki, Charlotte Sinding, Jonathan Warr, Thomas HummelAbstract:The aim of this study was to evaluate the effect of (1) the addition of trigeminal stimuli to an olfactory stimulus and (2) the congruence in the odorous mixture after repeated odor presentation. Twenty-five normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition, orange odor; congruent condition, orange odor + CO2; incongruent condition, orange odor + l-Isopulegol), and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D; peak to peak N1P2 at electrode positions Cz, Fz, and Pz; response amplitudes between H3 and DH). The addition of CO2 modified the perception of orange odor, pronouncing a fruity note, whereas the addition of l-Isopulegol as a DH pronounced the l-Isopulegol note. This study provides evidence that incongruent trigeminal-olfactory stimulants increase the response to subsequent olfactory stimulus.
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The Presentation of Olfactory–Trigeminal Mixed Stimuli Increases the Response to Subsequent Olfactory Stimuli
Journal of agricultural and food chemistry, 2017Co-Authors: Ute Walliczek-dworschak, Johan Poncelet, Daniel Baum, Ramona Baki, Charlotte Sinding, Jonathan Warr, Thomas HummelAbstract:The aim of this study was to evaluate the effect of (1) the addition of trigeminal stimuli to an olfactory stimulus and (2) the congruence in the odorous mixture after repeated odor presentation. Twenty-five normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition, orange odor; congruent condition, orange odor + CO2; incongruent condition, orange odor + l-Isopulegol), and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D; peak to peak N1P2 at electrode positions Cz, Fz, and Pz; response amplitudes between H3 and DH). The addition of CO2 modified the perception of orange odor, pronouncing a fruity note, whereas the addition of l-Isopulegol as a DH pronounced the l-Isopulegol note. This study provides evidence that incongruent trigeminal-olfactory stimulant...
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The presentation of olfactory-trigeminal mixed stimuli increases the response to subsequent olfactory stimuli
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Ute Walliczek-dworschak, Johan Poncelet, Daniel Baum, Ramona Baki, Charlotte Sinding, Jonathan Warr, Thomas HummelAbstract:The aim of this study was to evaluate the effect of 1) the addition of trigeminal stimuli to an olfactory stimulus and 2) the congruence in the odourous mixture after repeated odor presentation. 25 normosmic volunteers were enrolled and presented stimulation blocks, consisting of three habituation stimuli (H) (orange odor), one dishabituation (DH) (control condition: orange odor; congruent condition: orange odor + CO2; incongruent condition: orange odor + L-Isopulegol) and one dishabituated stimulus (D) (orange odor). Olfactory event-related potentials were analyzed. Response amplitudes differed significantly in the incongruent condition (N1P2 between H3 and D ; peak to peak N1P2 at electrode positions Cz, Fz and Pz; response amplitudes between H3 and DH) . The added DH modified perception of orange odor-pronouncing a fruity note by addition of CO2 respectively L-Isopulegol note by addition of L-Isopulegol. This study provides evidence that incongruent trigeminal-olfactory stimulants increase the response to following olfactory stimulus.
Karunanithi Kalaivani - One of the best experts on this subject based on the ideXlab platform.
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Isopulegol Mitigates Hyperglycemia Mediated Oxidative and Endoplasmic Reticulum Stress in HFD/STZ Induced Diabetic Rats.
Archives of medical research, 2020Co-Authors: Chandrasekaran Sankaranarayanan, Karunanithi KalaivaniAbstract:Background Oxidative and endoplasmic reticulum stresses contribute to the pathogenesis of β-cell dysfunction in diabetes mellitus. This study investigates the effect of Isopulegol on the above stresses in HFD/STZ induced diabetic rats. Methods Animals in group I and II were placed in normal pellet diet and group II was treated with Isopulegol at 200 mg/kg b.w. Animals in groups III–V were placed in HFD for 4 weeks and made diabetic with single intraperitoneal injection of STZ (35 mg/kg b.w) in 0.1 M citrate buffer (pH 4.5). Group III served as diabetic control while animals in group IV and V were treated with Isopulegol (100 mg/kg b.w) and metformin (25 mg/kg b.w) respectively for 28 d. Results The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione sulphur transferase (GST), glutathione reductase (GR) and the levels of vitamin-E, vitamin-C, reduced glutathione (GSH) were significantly (p Conclusions Isopulegol a naturally occurring monoterpene alcohol attenuated oxidative and ER stress in HFD/STZ induced diabetic rats.
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Isopulegol mitigates hyperglycemia mediated oxidative and endoplasmic reticulum stress in hfd stz induced diabetic rats
Archives of Medical Research, 2020Co-Authors: Chandrasekaran Sankaranarayanan, Karunanithi KalaivaniAbstract:Background Oxidative and endoplasmic reticulum stresses contribute to the pathogenesis of β-cell dysfunction in diabetes mellitus. This study investigates the effect of Isopulegol on the above stresses in HFD/STZ induced diabetic rats. Methods Animals in group I and II were placed in normal pellet diet and group II was treated with Isopulegol at 200 mg/kg b.w. Animals in groups III–V were placed in HFD for 4 weeks and made diabetic with single intraperitoneal injection of STZ (35 mg/kg b.w) in 0.1 M citrate buffer (pH 4.5). Group III served as diabetic control while animals in group IV and V were treated with Isopulegol (100 mg/kg b.w) and metformin (25 mg/kg b.w) respectively for 28 d. Results The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione sulphur transferase (GST), glutathione reductase (GR) and the levels of vitamin-E, vitamin-C, reduced glutathione (GSH) were significantly (p Conclusions Isopulegol a naturally occurring monoterpene alcohol attenuated oxidative and ER stress in HFD/STZ induced diabetic rats.
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Modulatory effect of Isopulegol on hepatic key enzymes of glucose metabolism in high-fat diet/streptozotocin-induced diabetic rats.
Archives of physiology and biochemistry, 2019Co-Authors: Karunanithi Kalaivani, Chandrasekaran SankaranarayananAbstract:To investigate the antidiabetic effect of Isopulegol in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic rats. Animals were made diabetic by feeding HFD for 4 weeks followed by single intr...
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modulatory effect of Isopulegol on hepatic key enzymes of glucose metabolism in high fat diet streptozotocin induced diabetic rats
Archives of Physiology and Biochemistry, 2019Co-Authors: Karunanithi Kalaivani, Chandrasekaran SankaranarayananAbstract:To investigate the antidiabetic effect of Isopulegol in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic rats. Animals were made diabetic by feeding HFD for 4 weeks followed by single intr...
Dmitry Yu. Murzin - One of the best experts on this subject based on the ideXlab platform.
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Catalytic synthesis of bioactive 2H-chromene alcohols from (−)-Isopulegol and acetone on sulfonated clays
Reaction Kinetics Mechanisms and Catalysis, 2020Co-Authors: Mathias Laluc, Konstantin Volcho, Nariman F. Salakhutdinov, Päivi Mäki-arvela, Andreia F. Peixoto, Nikolai Li-zhulanov, Thomas Sandberg, Cristina Freire, Alexander Yu. Sidorenko, Dmitry Yu. MurzinAbstract:Condensation of (−)-Isopulegol with acetone was investigated at 25–40 °C over clay based materials (K10, cloisite Na^+ and halloysite nanotubes) modified with sulfonic acid groups by one-pot sulfonation with chlorosulfonic acid or via organosilylation with 2-(4-chlrosulfonylphenyl)-ethyltrimethoxysilane. The target product was the R diastereomer of dimethyl-substituted octahydro-2 H -chromen-4-ol with exhibits antiviral activity. The catalysts were characterized by a range of physico-chemical methods. The effect of the initial Isopulegol concentrations on the yield of ketone-derived chromenols and the R/S isomers ratio was studied for the first time. The best catalyst was a highly acidic, large pore K10-clay modified by sulfonic acid. Varying the initial concentration of the reagents allows to find a balance between dehydration by-products and a side etherification reaction. A high yield (73%) of the desired chromenols was reached using 0.52 mol/l initial (−)-Isopulegol concentration after 240 min at 87% substrate conversion and reaction temperature 25 °C. The yield exceeded that of other previously reported in the open literature catalysts.
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catalytic synthesis of bioactive 2h chromene alcohols from Isopulegol and acetone on sulfonated clays
Reaction Kinetics Mechanisms and Catalysis, 2020Co-Authors: Mathias Laluc, K P Volcho, N F Salakhutdinov, Andreia F. Peixoto, Thomas Sandberg, Cristina Freire, Alexander Yu. Sidorenko, Paivi Makiarvela, Nikolai Lizhulanov, Dmitry Yu. MurzinAbstract:Condensation of (−)-Isopulegol with acetone was investigated at 25–40 °C over clay based materials (K10, cloisite Na+ and halloysite nanotubes) modified with sulfonic acid groups by one-pot sulfonation with chlorosulfonic acid or via organosilylation with 2-(4-chlrosulfonylphenyl)-ethyltrimethoxysilane. The target product was the R diastereomer of dimethyl-substituted octahydro-2H-chromen-4-ol with exhibits antiviral activity. The catalysts were characterized by a range of physico-chemical methods. The effect of the initial Isopulegol concentrations on the yield of ketone-derived chromenols and the R/S isomers ratio was studied for the first time. The best catalyst was a highly acidic, large pore K10-clay modified by sulfonic acid. Varying the initial concentration of the reagents allows to find a balance between dehydration by-products and a side etherification reaction. A high yield (73%) of the desired chromenols was reached using 0.52 mol/l initial (−)-Isopulegol concentration after 240 min at 87% substrate conversion and reaction temperature 25 °C. The yield exceeded that of other previously reported in the open literature catalysts.
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prins cyclisation of Isopulegol with benzaldehyde over zsm 5 based micro mesoporous catalysts for production of pharmaceuticals
Chinese Journal of Catalysis, 2019Co-Authors: Ekaterina Kholkina, Paivi Makiarvela, Chloe Lozachmeuer, Roman Barakov, Nataliya D. Shcherban, Dmitry Yu. MurzinAbstract:ABSTRACT Several ZSM-5 derived micro-mesoporous catalysts were investigated in Prins cyclisation of (–)-Isopulegol with benzaldehyde acting as a reactant and a solvent for production of heterocyclic oxygen containing 2H-chromene derivatives including the tetrahydropyran structure and exhibiting biological activity. The investigated catalysts were characterized by nitrogen adsorption, ammonia temperature programmed desorption, adsorption-desorption of pyridine and 2,6-di-tert- butylpyridine with Fourier transform infrared spectroscopic control. For the Prins reaction performed at 70 °C, the highest yield of the desired product, equal to 67% at complete conversion of (–)-Isopulegol, was obtained over a micro-mesoporous catalyst containing an optimum amount of strong acid sites and mesopores, being 12 fold larger than the size of the desired product.
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Prins cyclisation of (–)-Isopulegol with benzaldehyde over ZSM-5 based micro-mesoporous catalysts for production of pharmaceuticals
Chinese Journal of Catalysis, 2019Co-Authors: Ekaterina Kholkina, Päivi Mäki-arvela, Chloe Lozachmeuer, Roman Barakov, Nataliya D. Shcherban, Dmitry Yu. MurzinAbstract:ABSTRACT Several ZSM-5 derived micro-mesoporous catalysts were investigated in Prins cyclisation of (–)-Isopulegol with benzaldehyde acting as a reactant and a solvent for production of heterocyclic oxygen containing 2H-chromene derivatives including the tetrahydropyran structure and exhibiting biological activity. The investigated catalysts were characterized by nitrogen adsorption, ammonia temperature programmed desorption, adsorption-desorption of pyridine and 2,6-di-tert- butylpyridine with Fourier transform infrared spectroscopic control. For the Prins reaction performed at 70 °C, the highest yield of the desired product, equal to 67% at complete conversion of (–)-Isopulegol, was obtained over a micro-mesoporous catalyst containing an optimum amount of strong acid sites and mesopores, being 12 fold larger than the size of the desired product.