scholarly journals Trimacoside A, a High Molecular Weight Antioxidant Phenylpropanoid Glycoside from Tricyrtis maculata

2021 ◽  
Vol 15 (3) ◽  
pp. 194-201
Author(s):  
Yunze Wang ◽  
Wei Zhang ◽  
Li Ren ◽  
Jing Sun ◽  
Dongbo Zhang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Spectroscopic Data ◽  
Structure Elucidation ◽  
Antioxidant Activities ◽  
2D Nmr ◽  
Phenylpropanoid Glycoside

Trimacoside A (1), a new phenylpropanoid glycoside, together with nine known compounds (2−10) was isolated from Tricyrtis maculata. All compounds, except for 8, were firstly isolated from this plant. The structure elucidation of the new compound was carried out by the analysis of spectroscopic data, including 1D, 2D NMR, and HRESIMS. Compounds 1, 4, 5, 7, 8, and 10 showed significant antioxidant activities by DPPH and ABTS assays.

Isolation, Structure Elucidation and Activity of Anthracycline Acetates from a Terrestrial Streptomyces sp.

2003 ◽  
Vol 58 (12) ◽  
pp. 1242-1246 ◽  
Author(s):  
Serge Fotso ◽  
Rajendra P. Maskey ◽  
Iris Grün-Wollny ◽  
Hartmut Laatsch
Keyword(s):  
Molecular Weight ◽  
Natural Product ◽  
Structure Elucidation ◽  
Ethyl Acetate Extract ◽  
2D Nmr ◽  
Streptomyces Sp ◽  
Naturally Occurring ◽  
Nmr Data ◽  
New Antibiotics ◽  
First Time

The red coloured ethyl acetate extract of the Streptomyces sp. isolate GW37/3236 delivered the two new antibiotics 13-O-acetyl-bisanhydro-13-dihydrodaunomycinone (3c) and 4,13-O-diacetylbisanhydro- 4-O-demethyl-13-dihydrodaunomycinone (3d) and additionally several known compounds. The quinones 3c and 3d are the first naturally occurring quinone acetates. Their structures were derived by comparison of the NMR data with those of bisanhydro-13-dihydrodaunomycinone (3b) and by interpretation of the 2D NMR data accompanied by the molecular weight and formula. 2-Acetamido-3-hydroxybenzamide (5) was also isolated from the extract and was identified by comparison of the NMR data with those of 2-acetamidobenzamide and by 2D NMR correlations. 6,9,11- Trihydroxy-4-methoxy-5,12-naphthacenedione (4) is isolated for the first time as a natural product.

scholarly journals Antibacterial and Antioxidant Activities of Polyeugenol with High Molecular Weight

2020 ◽  
Vol 20 (3) ◽  
pp. 722
Author(s):  
Erwin Abdul Rahim ◽  
Nur Istiqomah ◽  
Gilang Almilda ◽  
Ahmad Ridhay ◽  
Ni Ketut Sumarni ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Antibacterial Activity ◽  
High Molecular Weight ◽  
Antioxidant Activities ◽  
Diffusion Method ◽  
E Coli ◽  
Ic50 Value ◽  
Inhibition Zones ◽  
Escherichia Coli Bacteria

This study was aimed to prepare polyeugenol with high molecular weight and to evaluate its antibacterial and antioxidant activities. First, polyeugenol was synthesized from eugenol in the presence of H2SO4-CH3COOH (4:1) as catalyst. The synthesized polyeugenol was weighed by using viscometer, revealing its high molecular weight of (7.76–21.9) × 105 g/mol. Furthermore, the antibacterial activity of the polyeugenol was conducted against Staphylococcus aureus and Escherichia coli bacteria. It was conducted by applying well diffusion method at 1, 2, 3, 4 and 5% concentrations to observe inhibition zones, in which the tests showed that the antibacterial activity of the polyeugenol against S. aureus were 17.42, 17.76, 18.79, 21.42 and 22.55 mm, while those against E. coli were 15.87, 17.23, 17.56, 18.24 and 19.21 mm, respectively. In short, these results indicated a strong antibacterial activity. Then, tests on antioxidant activity against free radical DPPH (2,2-diphenyl-1-pycrylhydrazyl) gave the IC50 value of 80.47 µg/mL, indicating a strong antioxidant activity. Therefore, the polymer synthesized in this work has a high potential to be applied in various biomedical applications.

scholarly journals Structure elucidation of a complex CO2-based organic framework material by NMR crystallography

2016 ◽  
Vol 7 (7) ◽  
pp. 4379-4390 ◽  
Author(s):  
Julien Leclaire ◽  
Guillaume Poisson ◽  
Fabio Ziarelli ◽  
Gerard Pepe ◽  
Frédéric Fotiadu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
Solid State Nmr ◽  
Structure Elucidation ◽  
Structural Model ◽  
De Novo ◽  
Three Dimensional ◽  
Nmr Crystallography ◽  
Organic Framework

A three-dimensional structural model of a complex CO2-based organic framework made from high molecular weight, self-assembled, flexible and multi-functional oligomeric constituents has been determined de novo by solid-state NMR including DNP-enhanced experiments.

scholarly journals A new Butenolide Derivative from the Brown Alga Sargassum micracanthum

2022 ◽  
Vol 17 (1) ◽  
pp. 1934578X2110686
Author(s):  
Ji-Yul Kim ◽  
Jeong Min Lee ◽  
Hyun-Soo Kim ◽  
Dae-Won Ki ◽  
Mi-Jin Yim ◽  
...  
Keyword(s):  
Brown Alga ◽  
Sulfonic Acid ◽  
Spectroscopic Data ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
2D Nmr ◽  
Dpph Radical ◽  
Meoh Extract ◽  
Dpph Radical Scavenging

A new butenolide derivative (1), along with three known compounds (2-4) were isolated from the MeOH extract of brown alga Sargassum micracanthum. The structures of 1 to 4 were determined by the analyses of 1D and 2D NMR and mass spectroscopic data. The known compounds (2-4) were identified as (5 E,10 Z)-6,10,14-trimethylpentadeca-5,10-dien-2,12-dione (2), (5 E,9 E)-6,10,14-trimethylpentadeca-5,9-dien-2,12-dione (3), and (-)-loliolide (4) by comparing with their published spectroscopic data. The antioxidant activities of compounds 1 to 4 were evaluated based on using 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities. Compounds 1 to 4 were inactive at the concentration of 200 μM.

Structural characterization of the O-chain polysaccharide from Proteusmirabilis strain 7570

1995 ◽  
Vol 73 (10) ◽  
pp. 1600-1604 ◽  
Author(s):  
Dušan Uhrín ◽  
Vandana Chandan ◽  
Eleonora Altman
Keyword(s):  
Molecular Weight ◽  
Nmr Spectroscopy ◽  
Chemical Analysis ◽  
High Molecular Weight ◽  
Structural Characterization ◽  
Galacturonic Acid ◽  
2D Nmr ◽  
Chain Structure ◽  
2D Nmr Spectroscopy

The O-chain polysaccharide produced by Proteusmirabilis strain 7570 was shown by chemical analysis and 1D and 2D NMR spectroscopy to be a high molecular weight acidic linear polymer of tetrasaccharide repeating units, composed of D-galacturonic acid, 2-acetamido-2-deoxy-D-galactose, and 2-acetamido-2-deoxy-D-glucose (2:1:1). In addition, native O-chain was randomly substituted by O-acetyl groups. Keywords: Proteus, lipopolysaccharide, O-chain, structure, NMR.

Microtubule motors and other maps

1990 ◽  
Vol 48 (3) ◽  
pp. 1-1
Author(s):  
Richard B. Vallee
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cytoplasmic Dynein ◽  
Organelle Transport ◽  
Structural Components ◽  
Microtubule Associated Proteins ◽  
Microtubule Motors ◽  
Associated Proteins ◽  
The Subject ◽  
Intracellular Motility

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.

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