The Experts below are selected from a list of 420 Experts worldwide ranked by ideXlab platform
Jens Christoffers - One of the best experts on this subject based on the ideXlab platform.
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an unprecedented ring transformation of a 4 aminomethyl Oxazoline Derivative to a 4 hydroxymethyl imidazoline
ChemInform, 2014Co-Authors: Marvin Schulz, Jens ChristoffersAbstract:An optically active 4-(azidomethyl)-2-(2-pyridyl)Oxazoline (III) is prepared starting from L-serine methyl ester and picolinic acid via a 7-step sequence.
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an unprecedented ring transformation of a 4 aminomethyl Oxazoline Derivative to a 4 hydroxymethyl imidazoline
Synthesis, 2013Co-Authors: Marvin Schulz, Jens ChristoffersAbstract:An optically active 4-(azidomethyl)-2-(2-pyridyl)Oxazoline was prepared starting from l -serine and picolinic acid. Reduction of the azide moiety gave the corresponding 4-(aminomethyl)-2-(2-pyridyl)Oxazoline, which is not a stable compound but readily undergoes ring-transformation rearrangement to furnish a 4-(hydroxymethyl)-2-(2-pyridyl)imidazoline. After Boc protection of the amidine function, the material could be further converted into the 4-(aminomethyl)-2-(2-pyridyl)imidazoline via the respective azidomethyl compound.
Marvin Schulz - One of the best experts on this subject based on the ideXlab platform.
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an unprecedented ring transformation of a 4 aminomethyl Oxazoline Derivative to a 4 hydroxymethyl imidazoline
ChemInform, 2014Co-Authors: Marvin Schulz, Jens ChristoffersAbstract:An optically active 4-(azidomethyl)-2-(2-pyridyl)Oxazoline (III) is prepared starting from L-serine methyl ester and picolinic acid via a 7-step sequence.
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an unprecedented ring transformation of a 4 aminomethyl Oxazoline Derivative to a 4 hydroxymethyl imidazoline
Synthesis, 2013Co-Authors: Marvin Schulz, Jens ChristoffersAbstract:An optically active 4-(azidomethyl)-2-(2-pyridyl)Oxazoline was prepared starting from l -serine and picolinic acid. Reduction of the azide moiety gave the corresponding 4-(aminomethyl)-2-(2-pyridyl)Oxazoline, which is not a stable compound but readily undergoes ring-transformation rearrangement to furnish a 4-(hydroxymethyl)-2-(2-pyridyl)imidazoline. After Boc protection of the amidine function, the material could be further converted into the 4-(aminomethyl)-2-(2-pyridyl)imidazoline via the respective azidomethyl compound.
Masashi Ohmae - One of the best experts on this subject based on the ideXlab platform.
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reaction specificity of keratanase ii in the transglycosylation using the sugar Oxazolines having keratan sulfate repeating units
Carbohydrate Research, 2018Co-Authors: Yuji Yamazaki, Shunsaku Kimura, Masashi OhmaeAbstract:Abstract The reaction specificity of the transglycosylation catalyzed by keratanase II from Bacillus circulans KsT202 (KSase II) was studied by using the Oxazoline Derivatives having keratan sulfate repeating units. The addition of 10% organic cosolvent reduced the activity for the enzymatic transglycosylation. The Oxazoline Derivative of 6-O-sulfonato-N-acetyllactosamine (su-LacNAc) was processively oligomerized to the corresponding hexamer or longer by the enzyme. This result strongly implies that the enzyme has the large positively numbered subsites. In contrast, the transglycosylation of the su-LacNAc Oxazoline donor with the 6-O-sulfonato-Lewis X (su-LeX) acceptor solely gave the su-LacNAc-su-LeX pentasaccharide. In addition, both the Oxazoline Derivatives of su-LeX and 6,6′-di-O-sulfonato-LacNAc have been exclusively oligomerized to the corresponding dimers respectively. These results strongly suggest that the steric hindrance exists around the (+3)(+4) subsites in KSase II. Furthermore, KSase II-catalyzed reaction of the excess su-LeX Oxazoline with the su-LacNAc gave the su-LeX-su-LacNAc pentasaccharide as the sole transglycosylation product, also implying the steric hindrance at the catalytic center hampering processive shift of this pentasaccharide. Thus, KSase II has the sterically crowded structures at the catalytic center and around the (+3)(+4) subsites, which are all expected to be tunnel-like.
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enzymatic polymerization to an alternating n l cysteinyl chitin Derivative a novel class of multivalent glycopeptidomimetics
Carbohydrate Research, 2013Co-Authors: Masashi Ohmae, Sanae Koide, Yuki Fujita, Shunsaku KimuraAbstract:Abstract A novel chitin Derivative with an alternating N - l -cysteinyl group was successfully prepared. The precursor chitin Derivative with an alternating N - l -thioprolinyl group could be obtained via chitinase-catalyzed polymerization of the N ′- l -thioprolinyl chitobiose Oxazoline Derivative as a transition state analog substrate monomer under weak alkaline conditions. Conversion of the l -thioprolinyl group to an l -cysteinyl group in the product chitin Derivative proceeded in a dose-dependent manner by methoxyamine hydrochloride, and the reaction could be completed almost quantitatively. The obtained chitin Derivative is a uniformly amino acid-branching polysaccharide, which is categorized into a novel class of multivalent glycopeptidomimetics.
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enzymatic polymerization to an alternating n phthaloyl chitin Derivative catalyzed by chitinase
Chemistry Letters, 2011Co-Authors: Masashi Ohmae, Kazuhiro Kurosaki, Akira Makino, Shiro KobayashiAbstract:A chitin Derivative with an alternating N-phthaloyl group was prepared via chitinase-catalyzed polymerization. A chitobiose Oxazoline Derivative with a N-phthaloyl group at the C2′ position was des...
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chitinase catalyzed synthesis of an alternatingly n sulfonated chitin Derivative
Biomacromolecules, 2007Co-Authors: Akira Makino, Masashi Ohmae, Hideaki Nagashima, Shiro KobayashiAbstract:An alternatingly N-sulfonated chitin Derivative (2) was synthesized via ring-opening polyaddition of an N-sulfonated chitobiose Oxazoline Derivative (1) catalyzed by chitinases from Bacillus sp. and Serratia marcescens. The polymerization proceeded homogeneously, providing 2 as a water-soluble polysaccharide in good yields with total control of regioselectivity and stereochemistry. Mn of 2 reached 1900 and 4180 by use of chitinases from Bacillus sp. and Serratia marcescens, which correspond to 8−10 (n = 4−5) and 18−20 (n = 9−10) saccharide units, respectively. These results indicate that Mn of 2 is controllable by selecting chitinases from different origins. It is considered that the C-2 position of the nonreducing unit in the Oxazoline-type monomer is not deeply involved in the catalysis of chitinase.
H. M. Schulte - One of the best experts on this subject based on the ideXlab platform.
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comparison of the pharmacodynamic effects of deflazacort and prednisolone in healthy subjects
European Journal of Clinical Pharmacology, 1996Co-Authors: G Babadjanova, Bruno Allolio, Martin Reincke, M. Vollmer, H. M. SchulteAbstract:Objective: Deflazacort, a synthetic Oxazoline Derivative of prednisolone, has been suggested as having major advantages over other glucocorticoids, as it is claimed to cause fewer adverse effects at equivalent antiinflammatory potency. The assumed equipotency ratio of deflazacort versus other glucocorticoids is critical for this assumption.
Shunsaku Kimura - One of the best experts on this subject based on the ideXlab platform.
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reaction specificity of keratanase ii in the transglycosylation using the sugar Oxazolines having keratan sulfate repeating units
Carbohydrate Research, 2018Co-Authors: Yuji Yamazaki, Shunsaku Kimura, Masashi OhmaeAbstract:Abstract The reaction specificity of the transglycosylation catalyzed by keratanase II from Bacillus circulans KsT202 (KSase II) was studied by using the Oxazoline Derivatives having keratan sulfate repeating units. The addition of 10% organic cosolvent reduced the activity for the enzymatic transglycosylation. The Oxazoline Derivative of 6-O-sulfonato-N-acetyllactosamine (su-LacNAc) was processively oligomerized to the corresponding hexamer or longer by the enzyme. This result strongly implies that the enzyme has the large positively numbered subsites. In contrast, the transglycosylation of the su-LacNAc Oxazoline donor with the 6-O-sulfonato-Lewis X (su-LeX) acceptor solely gave the su-LacNAc-su-LeX pentasaccharide. In addition, both the Oxazoline Derivatives of su-LeX and 6,6′-di-O-sulfonato-LacNAc have been exclusively oligomerized to the corresponding dimers respectively. These results strongly suggest that the steric hindrance exists around the (+3)(+4) subsites in KSase II. Furthermore, KSase II-catalyzed reaction of the excess su-LeX Oxazoline with the su-LacNAc gave the su-LeX-su-LacNAc pentasaccharide as the sole transglycosylation product, also implying the steric hindrance at the catalytic center hampering processive shift of this pentasaccharide. Thus, KSase II has the sterically crowded structures at the catalytic center and around the (+3)(+4) subsites, which are all expected to be tunnel-like.
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enzymatic polymerization to an alternating n l cysteinyl chitin Derivative a novel class of multivalent glycopeptidomimetics
Carbohydrate Research, 2013Co-Authors: Masashi Ohmae, Sanae Koide, Yuki Fujita, Shunsaku KimuraAbstract:Abstract A novel chitin Derivative with an alternating N - l -cysteinyl group was successfully prepared. The precursor chitin Derivative with an alternating N - l -thioprolinyl group could be obtained via chitinase-catalyzed polymerization of the N ′- l -thioprolinyl chitobiose Oxazoline Derivative as a transition state analog substrate monomer under weak alkaline conditions. Conversion of the l -thioprolinyl group to an l -cysteinyl group in the product chitin Derivative proceeded in a dose-dependent manner by methoxyamine hydrochloride, and the reaction could be completed almost quantitatively. The obtained chitin Derivative is a uniformly amino acid-branching polysaccharide, which is categorized into a novel class of multivalent glycopeptidomimetics.
