EXTRACTION, ISOLATION AND STRUCTURE DETERMINATION OF MADECASSOID FROM CENTELLA ASIATICA

2012 ◽  
pp. 47-52
Author(s):  
Thi Hoai Nguyen ◽  
Thi Diem Phuc Le
Keyword(s):  
Physical Properties ◽  
Spectral Data ◽  
Structure Determination ◽  
Centella Asiatica ◽  
Pure Substance ◽  
Structural Determination ◽  
Coordination Structure ◽  
Nmr Spectrum

Background: Research on extraction, isolation and structural determination of a chemical saponin extracted from Centella asiatica (L.) Urb. - Apiaceae. Materials and method: Centella asiatica is collected in Quang Dien district - Thua Thien Hue. Extracts isolated by chromatography coordination. Structure determination based on the physical properties and spectral data. Results: From species Centella asiatica (L.) Urb. - Apiaceae collected at Quang Dien, Thua Thien Hue has isolated one pure substance. Based on NMR spectrum identified the compound as madecassoid.

SEVERAL COMPOUNDS ISOLATED FROM CENTELLA ASIATICA

2011 ◽  
pp. 92-97
Author(s):  
Thi Hoai Nguyen ◽  
Thi Thao Trang Dang
Keyword(s):  
Physical Properties ◽  
Structure Determination ◽  
Centella Asiatica ◽  
Liquid Extraction ◽  
Structural Determination ◽  
Uv Spectrum ◽  
Pure Substances ◽  
Solid Liquid Extraction ◽  
Solid Liquid

Objectives: Research on extraction, isolation and structural determination of several chemical flavonoids extracted from Centella asiatica (L.) URB. - Apiaceae. Materials and method: Centella asiatica is collected in Phong Dien district - Thua Thien Hue. Extracts isolated by solid-liquid extraction and chromatography coordination. Structure determination based on the physical properties and spectral data. Results: From species Centella asiatica (L.) URB. - Apiaceae collected at Phong Dien, Thua Thien Hue has isolated two pure substances. Based on UV spectrum, IR, MS, NMR identified the compound as Quercetin and Kaempferol.

21,22-Disubstituted 18α,19βH-Ursane Derivatives with Oxabicyclooctane System in Ring E

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca
Keyword(s):  
Spectral Data ◽  
Spin Systems ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
Proton Proton ◽  
H Nmr ◽  
Proton Coupling ◽  
C Nmr

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.

Structural Determination of a Metastable Ag27 Nanocluster and Its Transformations into Ag8 and Ag29 Nanoclusters

2021 ◽  
Author(s):  
Chen Zhu ◽  
Tenfei Duan ◽  
Hao Li ◽  
Xiao Wei ◽  
Xi Kang ◽  
...  
Keyword(s):  
Structure Determination ◽  
Structural Determination ◽  
To Receive

Research on nanocluster transformation has generally focused on stable nanoclusters, while analysis on structure evolutions of metastable nanoclusters just began to receive attention recently. Herein, we reported the structure determination...

scholarly journals Metallation of Isatin (2,3-Indolinedione). X-Ray Structure and Solution Behavior of Bis(Isatinato)Mercury(II)

1995 ◽  
Vol 2 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Angel Garcia-Raso ◽  
Juan J. Fiol ◽  
Elies Molins ◽  
Antonia M. Calafat ◽  
Patricia A. Marzilli ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Metal Complex ◽  
Bond Length ◽  
Spectral Data ◽  
Structure Determination ◽  
Monoclinic System ◽  
Heterocyclic Nitrogen ◽  
X Ray

The first X-ray structure of an isatin (2,3-indolinedione, isaH) metal complex, bis(isatinato)memury(II) (C16H8N2O4Hg) (1), was determined. (1) was obtained from the reaction of isaH with mercury(II) acetate in methanol. Analogously, treatment of sodium saccharinate and mercury(II) acetate in methanol yielded Hg(saccharinato)2•0.5CH3OH (3). (1) crystallizes in the monoclinic system, space group P21/a with a = 7.299(1) Å, b = 8.192(1) Å, c = 11.601(1) Å , β = 105.82(1)°, V = 667.4 Å3, Z = 2, Dcalc = 2.452 g cm−3, MoKα radiation(λ = 0.71073 Å), μ = 115.5 cm-1, F(000) = 460, 21(1) °C. The structure was refined on the basis of 2023 observed reflections to R= 0.044. The two deprotonated, non coplanar isa ligands are trans to each other in a head to tail orientation and bound to the Hg through the nitrogen in a linear N-Hg-N arrangement. The Hg atom is at the center of symmetry of the complex and displaced by 0.62 Å from the two planes of the isa ligands (τ Hg-N1-C2-O2= -16°). The Hg-N bond length is 2.015 Å. Noπ-aryl-memury(ll)-π-aryl stacking interaction was observed either in the solid state or in the solution state. The IR, electronic, and H1 and C13NMR spectral data of (1) and (3) suggest binding of the memury to the heterocyclic nitrogen, in agreement with the crystal structure determination of (1).

Tables of Spectral Data for Structure Determination of Organic Compounds

1983 ◽  
Author(s):  
Ernö Pretsch ◽  
Thomas Clerc ◽  
Joseph Seibl ◽  
Wilhelm Simon
Keyword(s):  
Spectral Data ◽  
Organic Compounds ◽  
Structure Determination

Some Physical Properties and Structure Determination of Vinyl Monomer-Grafted Antheraea assama Silk Fiber

2009 ◽  
Vol 48 (20) ◽  
pp. 9338-9345 ◽  
Author(s):  
A. M. Das ◽  
P. K. Chowdhury ◽  
C. N. Saikia ◽  
P. G. Rao
Keyword(s):  
Physical Properties ◽  
Structure Determination ◽  
Vinyl Monomer ◽  
Silk Fiber ◽  
Antheraea Assama

Metallkomplexe mit funktionalisierten Schwefelliganden, V Ruthenium(II)-Alkyl- und -Arylthiosulfinato-Komplexe. Kristallstrukturanalyse von CpRu(PPh3)(CO)[S-S(O)-CH2-C6H5] / Metal Complexes of Functionalized Sulfur Containing Ligands, V Ruthenium(II)-Alkyl-and -Arylthiosulfinato Complexes. X-Ray Structure Determination of CpRu(PPh3)(CO)[S-S(O)-CH2-C6H5]

1993 ◽  
Vol 48 (5) ◽  
pp. 627-635 ◽  
Author(s):  
Wolfgang Weigand ◽  
Gabriele Bosl ◽  
Christian Robl ◽  
Jürgen Kroner
Keyword(s):  
Bond Length ◽  
Structure Determination ◽  
Spectroscopic Data ◽  
Structural Determination ◽  
Chiral Complexes ◽  
X Ray ◽  
Extended Hückel Calculations ◽  
Sulfur Containing ◽  
Sulfur Bond

Compounds of the type CpRu(PPh3)(L)(SH) [L = PPh3 (2), CO (4)] react with N-alkyl and -arylsulfinyl phthalimides 3a-f to give the chiral complexes CpRu(PPh3)(L)[S-S(O)-R] (L = PPh3, 5a: R = C4H9,5b: R = C12H25,5d: R = C18H37,5e: R = Tol; L = CO, 6a: R = C4H9,6b: R = C12H25,6c: R = C16H33,6d: R = C18H37,6f: R = CH2Ph). With 6a-c diastereoselectivities of 5:2, with 6d 5:1, and with 6f 10:3, respectively, are observed. The compounds 5,6 are characterized by their spectroscopic data; the X-ray structural determination of u-6f shows a sulfur-sulfur bond length of 208,6 (3) pm, the dihedral angle Ru-S(1)-S(2)-C(25) is 170,8°. Extended Hückel calculations give information about the rotational barrier around the S-S(O) axis.

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