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101. Probing the interactions of GlcNH2 with boric acid via NMR spectroscopy.

Author

Jia, Lingyu, Liu, Rui, Lv, Jiayu, Liu, Luqi, Zhang, Zhenzhou, Wang, Yingxiong, and Hou, Xianglin

Abstract

The essential role of boronic esters in controlling both the direction and selectivity of chemical reactions as well as their significant function in catalytic activity have been demonstrated for industrially important processes. The specific interaction analyses of the monosaccharide GlcNH2 with boric acid are of interest since monosaccharides serve as model systems for the more sophisticated carbohydrate molecules. The interaction of GlcNH2 with boric acid was systematically investigated by numerous NMR techniques. A 1 : 1 chelate boron complex coordinated at the cis-1,2 position of GlcNH2 was identified as the major species in DMSO-d6 solution via1H and 13C INEPT DOSY NMR spectroscopy. This specific boron nitrogen coordination mechanism was further supported by the 1H–15N HSQC spectra. Variations in the spin–lattice relaxation times (T1) of the 13C1 nucleus also provided quantitative data regarding this non-covalent interactions. This is an application of 1H, 13C INEPT DOSY, 1H–15N HSQC, and relaxation methods to study such aggregations in solutions. These methods have potential applications in the characterization of reactive intermediates in biomass conversions. [ABSTRACT FROM AUTHOR]

Published
2021
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105. Pre-Clinical Evaluation of CBD-NT3 Modified Collagen Scaffolds in Completely Spinal Cord Transected Non-Human Primates

Author

Han, Sufang, primary, Yin, Wen, additional, Li, Xing, additional, Wu, Shuyu, additional, Cao, Yudong, additional, Tan, Jun, additional, Zhao, Yannan, additional, Hou, Xianglin, additional, Wang, Lei, additional, Ren, Caiping, additional, Li, Juan, additional, Hu, Xia, additional, Mao, Yu, additional, Li, Gui, additional, Li, Bing, additional, Zhang, Haipeng, additional, Han, Jin, additional, Chen, Bing, additional, Xiao, Zhifeng, additional, Jiang, Xingjun, additional, and Dai, Jianwu, additional

Published
2019
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117. Purification and antioxidant activities of baicalin isolated from the root of huangqin (Scutellaria baicalensis gcorsi)

Author

Zhao MingQin, Duan Bin-bin, Deng Tiansheng, Hou Xianglin, Han FuGen, and Liu Pengfei

Subjects
chemistry.chemical_classification, Antioxidant, biology, Traditional medicine, business.industry, DPPH, Short Communication, medicine.medical_treatment, Flavonoid, biology.organism_classification, Ascorbic acid, chemistry.chemical_compound, chemistry, Medicine, Scutellaria baicalensis, business, Baicalin, Food Science
Abstract

Baicalin is a flavonoid from the root of huangqin (Scutellaria baicalensis gcorsi, a kind of Traditional Chinese Medicine and food condiment) with two pro phenolic hydroxyls. In this manuscript, high purity of baicalin (95.5 %) was isolated from the root of huangqin and its antioxidant activities were investigated. The antioxidant properties of baicalin were evaluated by scavenging of the diphenylpicrylhydrazyl radical (DPPH), reducing power, and iron-chelating assays, compared to ascorbic acid and BHT. The results of antioxidant activity showed that the activities of baicalin were significantly better than these of ascorbic acid and BHT, and the linear correlations were good in these three assays.

Published
2012
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121. Product Distribution Control for Glucosamine Condensation: Nuclear Magnetic Resonance (NMR) Investigation Substantiated by Density Functional Calculations

Author

Jia, Lingyu, primary, Zhang, Zhenzhou, additional, Qiao, Yan, additional, Pedersen, Christian Marcus, additional, Ge, Hui, additional, Wei, Zhihong, additional, Deng, Tiansheng, additional, Ren, Jun, additional, Liu, Xingchen, additional, Wang, Yingxiong, additional, and Hou, Xianglin, additional

Published
2017
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123. Collagen scaffold microenvironments modulate cell lineage commitment for differentiation of bone marrow cells into regulatory dendritic cells

Author

Fang, Yongxiang, primary, Wang, Bin, additional, Zhao, Yannan, additional, Xiao, Zhifeng, additional, Li, Jing, additional, Cui, Yi, additional, Han, Sufang, additional, Wei, Jianshu, additional, Chen, Bing, additional, Han, Jin, additional, Meng, Qingyuan, additional, Hou, Xianglin, additional, Luo, Jianxun, additional, Dai, Jianwu, additional, and Jing, Zhizhong, additional

Published
2017
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124. Binary scaffold facilitates in situregeneration of axons and neurons for complete spinal cord injury repairElectronic supplementary information (ESI) available. See DOI: 10.1039/d0bm02212h

Author

Liu, Dingyang, Shu, Muya, Liu, Weiyuan, Shen, Yeyu, Long, Ge, Zhao, Yannan, Hou, Xianglin, Xiao, Zhifeng, Dai, Jianwu, and Li, Xing

Abstract

The limited regrowth of transected axons and insufficient regeneration of lost neurons in adult mammals collectively hinder complete spinal cord injury (SCI) repair. Hence, designing an ideal bio-scaffold which could coordinate the regeneration of axons and neurons in situmight be able to effectively facilitate the reconstruction of neural circuits and the recovery of nerve function after complete SCI. In this study, a sponge-like collagen scaffold with good drug release characteristics and good nerve cell compatibility was prepared and used as a drug delivery platform. When doubly modified with Taxol liposomes and collagen-binding neurotrophic factor 3, the scaffold dually alleviated myelin-derived inhibition on neurite outgrowth of neurons and neuronal differentiation of neural stem cells in vitro. Meanwhile, the binary-drug modified scaffold was also able to simultaneously promote both axonal and neuronal regeneration when implanted into a complete transected SCI model. Additionally, the regenerated axons and neurons throughout the lesion site formed extensive synaptic connections. Finally, complete SCI rats that received binary scaffold implantation exhibited optimal neuroelectrophysiological recovery and hindlimb locomotor improvement. Taken together, implantation of the binary scaffold can establish neural bridging networks for functional recovery, representing a clinically promising strategy for complete SCI repair.

Published
2021
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125. Product Distribution Control for Glucosamine Condensation:Nuclear Magnetic Resonance (NMR) Investigation Substantiated by Density Functional Calculations

Author

Jia, Lingyu, Zhang, Zhenzhou, Qiao, Yan, Pedersen, Christian Marcus, Ge, Hui, Wei, Zhihong, Deng, Tiansheng, Ren, Jun, Liu, Xingchen, Wang, Yingxiong, Hou, Xianglin, Jia, Lingyu, Zhang, Zhenzhou, Qiao, Yan, Pedersen, Christian Marcus, Ge, Hui, Wei, Zhihong, Deng, Tiansheng, Ren, Jun, Liu, Xingchen, Wang, Yingxiong, and Hou, Xianglin

Published
2017

126. Mechanism of the self-condensation of GlcNH2:insights from in situ NMR spectroscopy and DFT study

Author

Jia, Lingyu, Liu, Xingchen, Qiao, Yan, Pedersen, Christian Marcus, Zhang, Zhenzhou, Ge, Hui-Juan, Wei, Zhihong, Chen, Yanyan, Wen, Xiaodong, Hou, Xianglin, Wang, Yingxiong, Jia, Lingyu, Liu, Xingchen, Qiao, Yan, Pedersen, Christian Marcus, Zhang, Zhenzhou, Ge, Hui-Juan, Wei, Zhihong, Chen, Yanyan, Wen, Xiaodong, Hou, Xianglin, and Wang, Yingxiong

Abstract

A combined experimental and computational study on the imidazolium ionic liquid-promoted conversion of d-Glucosamine (GlcNH2) to deoxyfructosazine (DOF) and fructosazine (FZ) was performed. The pathways for the formation of DOF and FZ via self-condensation of GlcNH2 were investigated by in situ13C NMR using site-selectively 13C-labeled GlcNH2. The structural characterization of the reactive species by ESI–MS spectrometry combined with NMR analysis of [13C-1]GlcNH2 indicates that the first carbon (C-1) of GlcNH2 maps onto the corresponding ring carbons of the intermediate, called dihydrofructosazine [2,5-bis(d-arabino-tetrahydroxybutyl)dihydropyrazine], which subsequently is converted to the corresponding pyrazine ring carbons of DOF and FZ respectively. The isotopic-labelling experiments disclose that there are two parallel reaction pathways open to the intermediate dihydrofructosazine, when the reaction takes place in DMSO with [C2C1Im][OAc] as catalyst. The theoretical results from DFT calculation indicate that the role of the imidazolium based ILs [C2C1Im][OAc] can be envisaged as an acid-base dual activation in catalyzing DOF and FZ formation. It turns out that the acidic cation center exerted significant influences on the energy barriers associated with dehydration reaction. In addition, a critical role of counteranion AcO− is to facilitate dehydrogenation process, leading to the formation of hydrogen. A comparison between the two reaction channels, after the formation of intermediate dihydrofructosazine, indicates that both pathways are plausible and that the pathway to DOF is thermodynamically more favorable than that to FZ. The theoretical results are consistent with the experimental observations, and therefore, a detailed and reasonable reaction mechanism was proposed

Published
2017

128. NMR Insights into the Unexpected Interaction of SnCl4 with D-Glucosamine and Its Effect on 5-HMF Preparation in ZnCl2 Molten Salt Hydrate Medium

Author

Chen, Chunyan, Ge, Wenzhi, Jia, Lingyu, Pedersen, Christian Marcus, Yan , Qiao, Jia, Shiyu, Xiaoya , Guo, Wang, Yingxiong, Hou, Xianglin, Chen, Chunyan, Ge, Wenzhi, Jia, Lingyu, Pedersen, Christian Marcus, Yan , Qiao, Jia, Shiyu, Xiaoya , Guo, Wang, Yingxiong, and Hou, Xianglin

Abstract

SnCl4, a versatile Lewis acid catalyst in the biomass conversion, plays a positive role for the cellulose biomass conversion but negative for chitin biomass conversion as realized in our previous research. In this report, the unexpected effects of SnCl4 on the conversion of d-glucosamine (GlcNH2) to 5-hydroxymethylfurfural (5-HMF) in ZnCl2 molten salt hydrate medium were investigated. The strong interaction between SnCl4 and GlcNH2 in ZnCl2 molten salt hydrate medium was examined by nuclear magnetic resonance (NMR) techniques. Additionally the d-glucose and N-acetyl-d-glucosamine were also utilized in NMR titration experiments to reveal the complexation of amino group with Sn4+ ions during the catalytic process. The observed drifts of chemical shifts and signal broadening of the C2 position of GlcNH2 in 13C NMR spectra indicates that the amino group in GlcNH2 is probably the Sn4+ ion complexation site. The correlations in the 1H-15N HSQC NMR spectra provide the direct evidence and further confirm that the amino group is the complexation site between SnCl4 and GlcNH2. This very specific complex between the amino group and the Sn4+ ion inhibit the conversion of GlcNH2 to 5-HMF in ZnCl2 molten salt hydrate medium

Published
2016

129. Glycosylation intermediates studied using low temperature 1H- and 19F-DOSY NMR:new insight into the activation of trichloroacetimidates

Author

Qiao, Yan, Ge, Wenzhi, Jia, Lingyu, Hou, Xianglin, Wang, Yingxiong, Pedersen, Christian Marcus, Qiao, Yan, Ge, Wenzhi, Jia, Lingyu, Hou, Xianglin, Wang, Yingxiong, and Pedersen, Christian Marcus

Abstract

Low temperature 1H- and 19F-DOSY have been used for analyzing reactive intermediates in glycosylation reactions, where a glycosyl trichloroacetimidate donor has been activated using different catalysts. The DOSY protocols have been optimized for low temperature experiments and provided new insight into acid catalyzed glycosylation chemistry. From the study a new glycosylation intermediate was characterized.

Published
2016

146. Pyrolysis of chitin biomass:TG-MS analysis and solid char residue characterization

Author

Qiao, Yan, Chen, Shuai, Liu, Ying, Sun, Haizhen, Jia, Shiyu, Shi, Junyan, Pedersen, Christian Marcus, Wang, Yingxiong, Hou, Xianglin, Qiao, Yan, Chen, Shuai, Liu, Ying, Sun, Haizhen, Jia, Shiyu, Shi, Junyan, Pedersen, Christian Marcus, Wang, Yingxiong, and Hou, Xianglin

Abstract

The thermal degradation of chitin biomass with various molecular structures was investigated by thermogravimetric analysis (TG), and the gaseous products were analyzed by connected mass spectroscopy (MS). The chemical structure and morphology of char residues collected at 750°C using the model substrates GlcNH2 and GlcNAc, were characterized systematically. The experimental results disclosed that one main mass loss stage was observed for each substrate. Chitosan samples with high molecular weight shown the more thermal stability, and chitin showed the highest thermal stability. Additionally, it was found that catalysts play a significant role during the pyrolysis. The gaseous evolution components, including NH3, H2O, CO, and CO2 were observed by on line MS. The experimental results disclosed that the obtained carbonaceous materials had lost the original hydrocarbon structure totally, and transformed into an aromatic structure with high carbon and nitrogen content, which was identified by XPS and solid state NMR.

Published
2015

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