Structural Analysis of Proanthocyanidins Isolated from Fruit Stone of Chinese Hawthorn with Potent Antityrosinase and Antioxidant Activity

2013 ◽  
Vol 62 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Wei-Ming Chai ◽  
Chih-Min Chen ◽  
Yu-Sen Gao ◽  
Hui-Ling Feng ◽  
Yu-Mei Ding ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Structural Analysis ◽  
Fruit Stone

scholarly journals Structural analysis and antioxidant activity of an arabinoxylan from Malvastrum coromandelianum L. (Garcke)

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24267-24279 ◽  
Author(s):  
Shanti Devi ◽  
Ajeet K. Lakhera ◽  
Vineet Kumar
Keyword(s):  
Antioxidant Activity ◽  
Structural Analysis ◽  
Spectroscopic Methods ◽  
Malvastrum Coromandelianum

The structure of MAP was studied by degradative, derivatization and spectroscopic methods, and it was found to be an arabinoxylan comprising a backbone of →4)-β-d-linked Xylp(1→ with branching at O-2 by →3)-α-l-Araf(1→ and →3)-β-d-Xylp(1→ chains.

scholarly journals Structural analysis and antioxidant activity of the glycoside from Imperial Chrysanthemum

2018 ◽  
Vol 28 (9) ◽  
pp. 1581-1590 ◽  
Author(s):  
Zhen-Yuan Zhu ◽  
Li-Chao Pan ◽  
Yun-Tang ◽  
Yong-min Zhang
Keyword(s):  
Antioxidant Activity ◽  
Structural Analysis

scholarly journals Structural analysis of DNA and RNA interactions with antioxidant flavonoids

2009 ◽  
Vol 23 (1) ◽  
pp. 29-43 ◽  
Author(s):  
C. D. Kanakis ◽  
Sh. Nafisi ◽  
Mehdi Rajabi ◽  
Azadeh Shadaloi ◽  
P. A. Tarantilis ◽  
...  
Keyword(s):  
Dna Damage ◽  
Antioxidant Activity ◽  
Structural Analysis ◽  
Biomedical Applications ◽  
Binding Constants ◽  
Physiological Conditions ◽  
Dna And Rna ◽  
Rna Duplexes ◽  
Antiviral Activities ◽  
The Stability

Flavonoids are natural polyphynolic compounds with major antioxidant activity that can prevent DNA damage. The anticancer and antiviral activities of these natural products are attributed to their potential biomedical applications. In this review we are examining how the antioxidant flavonoids bind DNA and RNA and what mechanism of action is involved in preventing DNA damage. Detailed spectroscopic data on the interactions of morin (mor), apigenin (api), naringin (nar), quercetin (que), kaempferol (kae) and delphinidin (del) with DNA and transfer RNA in aqueous solution at physiological conditions were analysed. The structural analysis showed flavonoids mainly intercalate into DNA and RNA duplexes with minor external binding to the major or minor groove and the backbone phosphate group with overall binding constants for DNA adducts Kmor═5.99×103M–1, Kapi═7.10×104M–1, and Knar═3.10×103M–1, Kque═7.25×104M–1, Kkae═3.60×104M–1and Kdel═1.66×104M–1, and for tRNA adducts Kmor═9.15×103M–1, Kapi═4.96×104M–1, and Knar═1.14×104M–1, Kque═4.80×104M–1, Kkae═4.65×104M–1and Kdel═9.47×104M–1. The stability of adduct formation is in the order of que > api > kae > del >mor > nar for DNA and del > api > que > kae > nar > mor for tRNA. Low flavonoid concentration induces helical stabilization, whereas high pigment content causes helix opening. Flavonoids induce a partial B to A–DNA transition at high pigment concentration, while tRNA remains in A-family structure upon flavonoid complexation. The antioxidant activity of flavonoids changes in the order delphinidin > quercetin > kaempferol > morin > naringin > apigenin. The results show intercalated flavonoid molecule can act as an antioxidant and prevent DNA damage.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

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