Twofold Deprotonated Citric Acid as a Bidentate Ligand of Pentacoordinate Silicon: Synthesis and Structural Characterization of the Zwitterionic λ5Si-Spirosilicate Bis[citrato(2–)-O3,O4][(dimethylammonio)methyl]silicate Hydrate

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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Molybdenum(VI) complex with citric acid: synthesis and structural characterization of 1:1 ratio citrato molybdate K2Na4[(MoO2)2(cit)2]·5H2O

Polyhedron ◽

10.1016/0277-5387(96)00260-4 ◽

1997 ◽

Vol 16 (1) ◽

pp. 75-79 ◽

Cited By ~ 30

Author(s):

Zhao-Hui Zhou ◽

Hui-Lin Wan ◽

Khi-Rui Tsai

Keyword(s):

Citric Acid ◽

Structural Characterization ◽

Acid Synthesis

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Synthesis and Structural Characterization of Lanthanum(III) Complexes of 4-Nitrosoantipyrine

Asian Journal of Chemistry ◽

10.14233/ajchem.2021.23047 ◽

2021 ◽

Vol 33 (3) ◽

pp. 617-621

Author(s):

Meera Gopal ◽

Sreesha Sasi

Keyword(s):

Magnetic Susceptibility ◽

Spectral Data ◽

General Formula ◽

Structural Characterization ◽

Bidentate Ligand ◽

Bidentate Ligands ◽

Nitroso Group ◽

Physico Chemical ◽

Chemical Studies

A new series of La(III) complexes of the ligand with the general formula [La(L)2(a)3] and [La2(L)4(aa)3], (a = nitrate (1), thiocyanate (2), acetate (3) and propionate (4) ions, aa = sulphate (5), thiosulphate (6), oxalate (7) and malonate (8) ions with the ligand 4-nitrosoantipyrine (L) were synthesized and characterized using various physico-chemical studies. The primary ligand L acts as a bidentate ligand utilizing the carbonyl group and the nitroso group for bonding. The nitrate, thiocyanate, acetate and propionate ions are monovalent unidentate ligands, whereas sulphate, thiosulphate, oxalate and malonate ions are divalent bidentate ligands in the complexes 1-8. Based on spectral data and magnetic susceptibility measurements, geometry of the lanthanum(III) complexes were also proposed.

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Structural characterization of pentacoordinate silicon in a calcium silicate

Nature ◽

10.1038/384441a0 ◽

1996 ◽

Vol 384 (6608) ◽

pp. 441-444 ◽

Cited By ~ 58

Author(s):

R. J. Angel ◽

N. L. Ross ◽

F. Seifert ◽

T. F. Fliervoet

Keyword(s):

Structural Characterization ◽

Calcium Silicate ◽

Pentacoordinate Silicon

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Structural characterization of oligomers from the polycondensation of citric acid with ethylene glycol and long-chain aliphatic alcohols

Journal of Applied Polymer Science ◽

10.1002/app.11664 ◽

2003 ◽

Vol 88 (2) ◽

pp. 302-306 ◽

Cited By ~ 35

Author(s):

Fabienne Barroso-Bujans ◽

Ricardo Martínez ◽

Pedro Ortiz

Keyword(s):

Citric Acid ◽

Ethylene Glycol ◽

Structural Characterization ◽

Aliphatic Alcohols ◽

Long Chain

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New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100160467 ◽

1990 ◽

Vol 48 (3) ◽

pp. 582-583

Author(s):

S. F. Hayes ◽

M. D. Corwin ◽

T. G. Schwan ◽

D. W. Dorward ◽

W. Burgdorfer

Keyword(s):

Lyme Disease ◽

Borrelia Burgdorferi ◽

Structural Characterization ◽

Negative Staining ◽

Low Speed ◽

Thin Sectioning ◽

Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

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