A fast microfluidic mixer enabling rapid preparation of homogeneous PEG and bicelle media for RDC in NMR analysis

Glucosylation of the cis- and trans-isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a/1b, 2a/2b, 1a or 2a) was performed to prepare the corresponding alkyl β-D-glucopyranosides, mainly to get analytical data of pure enantiomers of the glucosides (3a-6b), required for subsequent investigations of related compounds with biological activity. One of the employed modifications of the Koenigs-Knorr synthesis resulted in achieving 85-95% yields of pure β-anomers 3a/3b, 4a/4b, 3a or 4a of protected intermediates, with several promoters and toluene as solvent, yielding finally the deprotected products 5a/5b, 6a/6b, 5a or 6a as pure β-anomers. To obtain enantiomerically pure β-anomers of the target structure (3a, 4a, 5a and 6a) for unambiguous structure assignment, an enzymic reduction of 2-(4-methoxybenzyl)cyclohexan-1-one by Saccharomyces cerevisiae whole cells was performed to get (1S,2S)- and (1S,2R)-enantiomers (1a and 2a) of 2-(4-methoxybenzyl)cyclohexan-1-ol. The opposite enantiomers of alkyl β-D-glucopyranosides (5b and 6b) were obtained by separation of the diastereoisomeric mixtures 5a/5b and 6a/6b by chiral HPLC. All stereoisomers of the products (3a-6b) were subjected to a detailed 1H NMR and 13C NMR analysis.

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High Resolution NMR Analysis of the Composition of Copolymer and Mixture of 6-Nylon and 66-Nylon

The Journal of the Society of Chemical Industry Japan ◽

10.1246/nikkashi1898.70.4_460 ◽

1967 ◽

Vol 70 (4) ◽

pp. 460-465

Author(s):

Mitsuru YAMAZAKI ◽

Tsugio TAKEUCHI

Keyword(s):

High Resolution ◽

Nmr Analysis ◽

High Resolution Nmr

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Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

Molecules ◽

10.3390/molecules26154443 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4443

Author(s):

Jiangyan Huo ◽

Min Lei ◽

Feifei Li ◽

Jinjun Hou ◽

Zijia Zhang ◽

...

Keyword(s):

Molecular Weight ◽

Citric Acid ◽

Gut Microbiota ◽

Structural Characterization ◽

Hot Water ◽

Nmr Analysis ◽

Gastrodia Elata ◽

Hot Water Extraction ◽

Hydroxybenzyl Alcohol

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

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Mono- and Dinitro-BN-Naphthalenes: Formation and Characterization

Molecules ◽

10.3390/molecules26144209 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4209

Author(s):

Mao-Xi Zhang ◽

Nathaniel B. Zuckerman ◽

Philip F. Pagoria ◽

Bradley A. Steele ◽

I-Feng Kuo ◽

...

Keyword(s):

Electron Density ◽

Nmr Analysis ◽

X Ray ◽

Boron Nitrogen

Mono- and dinitro-BN-naphthalenes, i.e., 1-nitro-, 3-nitro-, 1,6-dinitro-, 3,6-dinitro-, and 1,8-dinitro-BNN, were generated in the nitration of 9,10-BN-naphthalene (BNN), a boron–nitrogen (BN) bond-embedded naphthalene, with AcONO2 and NO2BF4 in acetonitrile. The nitrated products were isolated and characterized by NMR, GC-MS, IR, and X-ray single crystallography. The effects of the nitration on the electron density and aromaticity of BNN were evaluated by B-11 NMR analysis and HOMA calculations.

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