The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Nagatoshi Nishiwaki - One of the best experts on this subject based on the ideXlab platform.
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Substrate switchable Suzuki–Miyaura coupling for Benzyl Ester vs. Benzyl halide
RSC Advances, 2018Co-Authors: Masato Ohsumi, Nagatoshi NishiwakiAbstract:Two reaction conditions were developed to accomplish the substrate switchable Suzuki–Miyaura coupling of Benzyl derivatives and arylboronic acid derivatives. Under conditions for Esters, Benzyl Esters such as carbonates and acetates reacted with arylboronic acids to afford the corresponding diarylmethanes. However, the Benzyl halides did not react under the same conditions. On the other hand, Benzyl halides such as bromides and chlorides furnished diarylmethanes under conditions for halides, under which Benzyl Ester substrates did not react, in which water was found to play an important role. This switching system was tested using the intermolecular/intramolecular competitive reactions, during which the desired products could be synthesized by selecting the appropriate reaction conditions.
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substrate switchable suzuki miyaura coupling for Benzyl Ester vs Benzyl halide
RSC Advances, 2018Co-Authors: Masato Ohsumi, Nagatoshi NishiwakiAbstract:Two reaction conditions were developed to accomplish the substrate switchable Suzuki–Miyaura coupling of Benzyl derivatives and arylboronic acid derivatives. Under conditions for Esters, Benzyl Esters such as carbonates and acetates reacted with arylboronic acids to afford the corresponding diarylmethanes. However, the Benzyl halides did not react under the same conditions. On the other hand, Benzyl halides such as bromides and chlorides furnished diarylmethanes under conditions for halides, under which Benzyl Ester substrates did not react, in which water was found to play an important role. This switching system was tested using the intermolecular/intramolecular competitive reactions, during which the desired products could be synthesized by selecting the appropriate reaction conditions.
Andreas Seidelmorgenstern - One of the best experts on this subject based on the ideXlab platform.
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occurrence and consequences of differences in the cation anion ratios during classical resolution d l serine Benzyl Ester 2 3 toluyl d tartrate
Crystal Research and Technology, 2014Co-Authors: V. S. Sistla, Von Langermann, Heike Lorenz, Andreas SeidelmorgensternAbstract:Differences in physical-chemical properties of diaste-reomeric salts allow the separation into the respective salts and subsequently into enantiomers by crystallization. Within this study unusual deviations in the cation-/anion-ratio of a diastereomeric salt pair were observed and characterized. While the n-salt (L-serine Benzyl Ester 2,3-toluyl-D-tartrate) crystallizes in a ratio of two cations and one anion, the p-salt (D-serine Benzyl Ester 2,3-toluyl-D-tartrate) consists of only one cation and one anion. Consequently the classical definition of a diastereomeric salt pair does not apply. In this contribution all differences in relevant thermodynamic properties of the unusual resulting diastereomeric salt pair are presented and discussed.
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crystallization based resolution process for the 2 3 dibenzoyl d l tartrate salts of d l serine Benzyl Ester
Crystal Growth & Design, 2013Co-Authors: V. S. Sistla, Heike Lorenz, Andreas SeidelmorgensternAbstract:It is shown that the 2,3-dibenzoyl-d-/l-tartrate salts of d-/l-serine Benzyl Ester (salt pair 1, l-d,d-d; salt pair 2, d-l,l-l) behave like simple eutectic systems in their binary (melting) and ternary (solubility) systems. Due to this essential thermodynamic property, these salts are separable via crystallization. Metastable zone width data for primary nucleation of both salts were measured to support a rational process design. Resolution processes for both salt pairs were designed and executed successfully delivering diastereomeric salts in high purity. The presence of excesses of resolving agents, previously not considered, was systematically studied and found to possess the potential to further improve the performance of the selective crystallization processes.
Masato Ohsumi - One of the best experts on this subject based on the ideXlab platform.
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Substrate switchable Suzuki–Miyaura coupling for Benzyl Ester vs. Benzyl halide
RSC Advances, 2018Co-Authors: Masato Ohsumi, Nagatoshi NishiwakiAbstract:Two reaction conditions were developed to accomplish the substrate switchable Suzuki–Miyaura coupling of Benzyl derivatives and arylboronic acid derivatives. Under conditions for Esters, Benzyl Esters such as carbonates and acetates reacted with arylboronic acids to afford the corresponding diarylmethanes. However, the Benzyl halides did not react under the same conditions. On the other hand, Benzyl halides such as bromides and chlorides furnished diarylmethanes under conditions for halides, under which Benzyl Ester substrates did not react, in which water was found to play an important role. This switching system was tested using the intermolecular/intramolecular competitive reactions, during which the desired products could be synthesized by selecting the appropriate reaction conditions.
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substrate switchable suzuki miyaura coupling for Benzyl Ester vs Benzyl halide
RSC Advances, 2018Co-Authors: Masato Ohsumi, Nagatoshi NishiwakiAbstract:Two reaction conditions were developed to accomplish the substrate switchable Suzuki–Miyaura coupling of Benzyl derivatives and arylboronic acid derivatives. Under conditions for Esters, Benzyl Esters such as carbonates and acetates reacted with arylboronic acids to afford the corresponding diarylmethanes. However, the Benzyl halides did not react under the same conditions. On the other hand, Benzyl halides such as bromides and chlorides furnished diarylmethanes under conditions for halides, under which Benzyl Ester substrates did not react, in which water was found to play an important role. This switching system was tested using the intermolecular/intramolecular competitive reactions, during which the desired products could be synthesized by selecting the appropriate reaction conditions.
V. S. Sistla - One of the best experts on this subject based on the ideXlab platform.
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occurrence and consequences of differences in the cation anion ratios during classical resolution d l serine Benzyl Ester 2 3 toluyl d tartrate
Crystal Research and Technology, 2014Co-Authors: V. S. Sistla, Von Langermann, Heike Lorenz, Andreas SeidelmorgensternAbstract:Differences in physical-chemical properties of diaste-reomeric salts allow the separation into the respective salts and subsequently into enantiomers by crystallization. Within this study unusual deviations in the cation-/anion-ratio of a diastereomeric salt pair were observed and characterized. While the n-salt (L-serine Benzyl Ester 2,3-toluyl-D-tartrate) crystallizes in a ratio of two cations and one anion, the p-salt (D-serine Benzyl Ester 2,3-toluyl-D-tartrate) consists of only one cation and one anion. Consequently the classical definition of a diastereomeric salt pair does not apply. In this contribution all differences in relevant thermodynamic properties of the unusual resulting diastereomeric salt pair are presented and discussed.
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Occurrence and consequences of differences in the cation/anion ratios during classical resolution: D-/L-serine Benzyl Ester 2,3-toluyl-D-tartrate
Crystal Research and Technology, 2014Co-Authors: V. S. Sistla, Von Langermann, Heike Lorenz, Andreas Seidel-morgensternAbstract:Differences in physical-chemical properties of diaste-reomeric salts allow the separation into the respective salts and subsequently into enantiomers by crystallization. Within this study unusual deviations in the cation-/anion-ratio of a diastereomeric salt pair were observed and characterized. While the n-salt (L-serine Benzyl Ester 2,3-toluyl-D-tartrate) crystallizes in a ratio of two cations and one anion, the p-salt (D-serine Benzyl Ester 2,3-toluyl-D-tartrate) consists of only one cation and one anion. Consequently the classical definition of a diastereomeric salt pair does not apply. In this contribution all differences in relevant thermodynamic properties of the unusual resulting diastereomeric salt pair are presented and discussed.
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crystallization based resolution process for the 2 3 dibenzoyl d l tartrate salts of d l serine Benzyl Ester
Crystal Growth & Design, 2013Co-Authors: V. S. Sistla, Heike Lorenz, Andreas SeidelmorgensternAbstract:It is shown that the 2,3-dibenzoyl-d-/l-tartrate salts of d-/l-serine Benzyl Ester (salt pair 1, l-d,d-d; salt pair 2, d-l,l-l) behave like simple eutectic systems in their binary (melting) and ternary (solubility) systems. Due to this essential thermodynamic property, these salts are separable via crystallization. Metastable zone width data for primary nucleation of both salts were measured to support a rational process design. Resolution processes for both salt pairs were designed and executed successfully delivering diastereomeric salts in high purity. The presence of excesses of resolving agents, previously not considered, was systematically studied and found to possess the potential to further improve the performance of the selective crystallization processes.
Jianyu Li - One of the best experts on this subject based on the ideXlab platform.
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Scutellarin Benzyl Ester partially secured the ischemic injury by its anti-apoptosis mechanism in cardiomyocytes of neonatal rats.
Journal of Chinese Integrative Medicine, 2011Co-Authors: Jun Gu, Lingzhi Li, Limei Yang, Jianyu LiAbstract:OBJECTIVE: To investigate the protective effects of scutellarin Benzyl Ester on neonatal rats' cardiomyocytes injured by ischemia and its anti-apoptosis mechanism. METHODS: The cardiomyocytes in primary culture were prepared from ventricular tissue of 1- to 3-day-old Sprague-Dawley rats and the cells in good condition were assigned to five groups: control group, ischemic model group and three scutellarin Benzyl Ester groups (doses of 100, 50 and 25μmol/L, respectively). The model of ischemic injury was established in the primary culture of cardiomyocytes under glucose-free anoxic condition. After ischemia for 6 h, the metabolic ability of the cells was detected by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay and the activity of lactate dehydrogenase (LDH) in the media was measured by biochemistry approaches. The nuclear damage was revealed by Hoechst-propidium iodide staining. The percentage of apoptotic cells was monitored by flow cytometry. The expression levels of cytochrome c and caspase-3 mRNAs and proteins were determined by reverse transcription-polymerase chain reaction and WEstern blotting, respectively. RESULTS: After exposure to ischemic condition, the cell viability of the model group was degraded compared with that of the control group (P
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scutellarin Benzyl Ester partially secured the ischemic injury by its anti apoptosis mechanism in cardiomyocytes of neonatal rats
Journal of Chinese Integrative Medicine, 2011Co-Authors: Jun Gu, Lingzhi Li, Limei Yang, Jianyu LiAbstract:OBJECTIVE: To investigate the protective effects of scutellarin Benzyl Ester on neonatal rats' cardiomyocytes injured by ischemia and its anti-apoptosis mechanism. METHODS: The cardiomyocytes in primary culture were prepared from ventricular tissue of 1- to 3-day-old Sprague-Dawley rats and the cells in good condition were assigned to five groups: control group, ischemic model group and three scutellarin Benzyl Ester groups (doses of 100, 50 and 25μmol/L, respectively). The model of ischemic injury was established in the primary culture of cardiomyocytes under glucose-free anoxic condition. After ischemia for 6 h, the metabolic ability of the cells was detected by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay and the activity of lactate dehydrogenase (LDH) in the media was measured by biochemistry approaches. The nuclear damage was revealed by Hoechst-propidium iodide staining. The percentage of apoptotic cells was monitored by flow cytometry. The expression levels of cytochrome c and caspase-3 mRNAs and proteins were determined by reverse transcription-polymerase chain reaction and WEstern blotting, respectively. RESULTS: After exposure to ischemic condition, the cell viability of the model group was degraded compared with that of the control group (P<0.01) and scutellarin Benzyl Ester (high and medium doses) could attenuate the loss of cell viability induced by ischemia (P<0.01 and P<0.05). In addition, each dose of scutellarin Benzyl Ester could significantly reduce the release of LDH from cardiomyocytes injured by ischemia (P<0.01). In morphology, the injured nuclei presented significant changes such as condensation of chromatin, and shrinkage and fragmentation of nuclei, which could be attenuated remarkably by pretreatment with scutellarin Benzyl Ester. Furthermore, scutellarin Benzyl Ester could significantly decrease the percentage of apoptosis induced by ischemia (P<0.01) and inhibit the increased expression levels of cytochrome c and caspase-3 mRNAs and proteins (<0.01). CONCLUSION: Scutellarin Benzyl Ester has a remarkable protective effect against myocardial ischemic injury and the protective mechanism may associate with its anti-apoptosis effect by inhibiting cytochrome c release and caspase-3 activation.
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Effects of scutellarin Benzyl Ester on the expressions of Bcl-2 and Bax in cardiomyocytes injured by acute hypoxia
Chinese critical care medicine, 2011Co-Authors: Jianyu Li, Jun Gu, Lingzhi LiAbstract:OBJECTIVE: To investigate the effects of scutellarin Benzyl Ester on the expressions of Bcl-2 and Bax in cardiomyocytes after acute injury of hypoxia. METHODS: Cardiomyocytes harvested from neonatal Sprague-Dawley (SD) rats were cultured for 4 days. The cells of the primary culture were assigned randomly to five groups: control group, hypoxia model group (acute hypoxic injury was induced by exposing cells to anoxic condition with 95%N₂ and 5%CO₂) and high, moderate and low dose of scutellarin Benzyl Ester groups (pretreated with 100, 50 and 25 μmol/L scutellarin Benzyl Ester before hypoxia) with 6 wells in each group. After hypoxic injury for 6 hours, the activity of lactate dehydrogenase (LDH) and content of nitric oxide (NO) in media were measured by biochemical methods. The mRNA and protein expressions of Bcl-2 and Bax were determined by reverse transcription-polymerase chain reaction (RT-PCR) and WEstern blotting, respectively. RESULTS: After hypoxic injury, comparing with those in control group, the leakage of LDH (U/L) in hypoxia model group increased (288.10 ± 30.69 vs. 78.75 ± 12.85) and the release of NO (μmol/L) decreased (9.02 ± 1.55 vs. 24.11 ± 2.04, both P
