The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Anup Kumar Misra - One of the best experts on this subject based on the ideXlab platform.
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a generalized procedure for the one pot preparation of glycosyl azides and thioglycosides directly from unprotected Reducing Sugars under phase transfer reaction conditions
European Journal of Organic Chemistry, 2006Co-Authors: Rishi Kumar, Pallavi Tiwari, Prakas R Maulik, Anup Kumar MisraAbstract:Per-O-acetylated glycosyl azides and thioglycosides were prepared in excellent yield directly from unprotected Reducing Sugars through in situ generation of per-O-acetylated glycosyl bromides by a generalized one-pot procedure under phase-transfer conditions. Stereoselective products were formed with complete inversion at the anomeric centers of the glycosyl bromides to provide a general high-yielding procedure for the preparation of 1,2-trans-glycosyl azides and thioglycosides.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
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one pot synthesis of per o acetylated thioglycosides from unprotected Reducing Sugars
Carbohydrate Research, 2005Co-Authors: Geetanjali Agnihotri, Pallavi Tiwari, Anup Kumar MisraAbstract:Abstract A sequential per- O -acetylation and thioglycosidation of unprotected Reducing Sugars using a stoichiometric quantity of acetic anhydride and alkyl- or arylthiols is reported. These reactions, which are catalyzed by BF 3 ·OEt 2 , together constitute an efficient one-pot method for the synthesis of acetylated thioglycosides.
Fuping Zheng - One of the best experts on this subject based on the ideXlab platform.
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analysis of Reducing Sugars organic acids and minerals in 15 cultivars of jujube ziziphus jujuba mill fruits in china
Journal of Food Composition and Analysis, 2018Co-Authors: Haiyan Fu, Fuping Zheng, Weizheng Wang, Yaqi Wang, Lina Wang, Hui NiAbstract:Abstract Ziziphus jujuba Mill. has been used as both an edible fruit and Chinese medicine for a long time. In this study, the chemical profiles in terms of Reducing Sugars, organic acids, and minerals of 15 cultivars of jujube were analyzed. The Reducing Sugars and organic acids were measured by HPLC-UV (high performance liquid chromatography with ultraviolet detection). Minerals were detected by ICP-OES (inductively coupled plasma-optical emission spectrometry). Glucose (85.9–1005 mg/100 g FW), malic acid (120–509 mg/100 g FW), citric acid (29.4–181 mg/100 g FW), iron (5.27–12.5 mg/100 g DW), calcium (16.2–30.2 mg/100 g DW) and magnesium (51.2–70.0 mg/100 g DW) were found to be the major components in the fruits. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used, in order to classify these cultivars based on the aforementioned chemical profiles. According to the PCA, classification based on the content of Reducing Sugars is more reasonable and reliable than other parameters. In this classification, 15 cultivars were categorized into 6 groups.
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optimization of reactions between Reducing Sugars and 1 phenyl 3 methyl 5 pyrazolone pmp by response surface methodology
Food Chemistry, 2018Co-Authors: Haiyan Fu, Fuping Zheng, Weizheng Wang, Yaqi Wang, Lina Wang, Feng ChenAbstract:Abstract Reducing Sugars have strong reactivity with 1-phenyl-3-methyl-5-pyrazolone (PMP) to form the sugar-PMP derivatives, which can be more accurately analyzed by HPLC-UV at 248 nm. Glucose and glucosamine reacted with the PMP based on the response surface methodology within a range of temperature between 60 °C and 80 °C, and time between 60 and 180 min. The optimal conditions for the glucose-PMP and glucosamine-PMP reactions were obtained at 71 °C for 129 min, and 73 °C for 96 min, respectively. Subsequently, other Sugars and their derivatives, including xylose, ribose, fructose, galactose, mannose, lactose, maltose, sucrose, glucuronic acid, sorbitol, mannitol, xylitol, and cyclodextrins were investigated and compared under the optimized condition for glucose. All of the above compounds, except the fructose, sugar alcohols and non-Reducing Sugars, could form the sugar-PMP derivatives. This study demonstrated that different chemical structures of Sugars and their derivatives could significantly influence the rate and yield of the PMP derivatization.
Hui Ni - One of the best experts on this subject based on the ideXlab platform.
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analysis of Reducing Sugars organic acids and minerals in 15 cultivars of jujube ziziphus jujuba mill fruits in china
Journal of Food Composition and Analysis, 2018Co-Authors: Haiyan Fu, Fuping Zheng, Weizheng Wang, Yaqi Wang, Lina Wang, Hui NiAbstract:Abstract Ziziphus jujuba Mill. has been used as both an edible fruit and Chinese medicine for a long time. In this study, the chemical profiles in terms of Reducing Sugars, organic acids, and minerals of 15 cultivars of jujube were analyzed. The Reducing Sugars and organic acids were measured by HPLC-UV (high performance liquid chromatography with ultraviolet detection). Minerals were detected by ICP-OES (inductively coupled plasma-optical emission spectrometry). Glucose (85.9–1005 mg/100 g FW), malic acid (120–509 mg/100 g FW), citric acid (29.4–181 mg/100 g FW), iron (5.27–12.5 mg/100 g DW), calcium (16.2–30.2 mg/100 g DW) and magnesium (51.2–70.0 mg/100 g DW) were found to be the major components in the fruits. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used, in order to classify these cultivars based on the aforementioned chemical profiles. According to the PCA, classification based on the content of Reducing Sugars is more reasonable and reliable than other parameters. In this classification, 15 cultivars were categorized into 6 groups.
Pallavi Tiwari - One of the best experts on this subject based on the ideXlab platform.
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a generalized procedure for the one pot preparation of glycosyl azides and thioglycosides directly from unprotected Reducing Sugars under phase transfer reaction conditions
European Journal of Organic Chemistry, 2006Co-Authors: Rishi Kumar, Pallavi Tiwari, Prakas R Maulik, Anup Kumar MisraAbstract:Per-O-acetylated glycosyl azides and thioglycosides were prepared in excellent yield directly from unprotected Reducing Sugars through in situ generation of per-O-acetylated glycosyl bromides by a generalized one-pot procedure under phase-transfer conditions. Stereoselective products were formed with complete inversion at the anomeric centers of the glycosyl bromides to provide a general high-yielding procedure for the preparation of 1,2-trans-glycosyl azides and thioglycosides.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
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one pot synthesis of per o acetylated thioglycosides from unprotected Reducing Sugars
Carbohydrate Research, 2005Co-Authors: Geetanjali Agnihotri, Pallavi Tiwari, Anup Kumar MisraAbstract:Abstract A sequential per- O -acetylation and thioglycosidation of unprotected Reducing Sugars using a stoichiometric quantity of acetic anhydride and alkyl- or arylthiols is reported. These reactions, which are catalyzed by BF 3 ·OEt 2 , together constitute an efficient one-pot method for the synthesis of acetylated thioglycosides.
Yunhua Li - One of the best experts on this subject based on the ideXlab platform.
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Subcritical carbon dioxide-water hydrolysis of sugarcane bagasse pith for Reducing Sugars production
Bioresource Technology, 2017Co-Authors: Jiezhen Liang, Xiaojie Wei, Songzhou Lu, Huasheng Wang, Xiaopeng Chen, Linlin Wang, Yunhua LiAbstract:The aim of present study was to obtain total Reducing Sugars (TRS) by hydrolysis in subcritical CO2-water from sugarcane bagasse pith (SCBP), the fibrous residue remaining after papermaking from sugarcane bagasse. The optimum hydrolysis conditions were evaluated by L16(45) orthogonal experiments. The TRS yield achieved 45.8% at the optimal conditions: 200��C, 40�min, 500�r�min−1, CO2initial pressure of 1�MPa and liquid-to-solid ratio of 50:1. Fourier transform infrared spectrometry and two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance were used to characterize hydrolysis liquor, treated and untreated SCBP, resulting in the removal of hemicelluloses to mainly produce xylose, glucose and arabinose during hydrolysis. The severity factors had no correlation to TRS yield, indicating that the simple kinetic processes of biomass solubilisation cannot perfectly describe the SCBP hydrolysis. The first-order kinetic model based on consecutive reaction was used to obtain rate constants, activation energies and pre-exponential factors.
