Sesquiterpenic lactones of Inula aschersoniana JANKA var. aschersoniana species

1990 ◽  
Vol 55 (6) ◽  
pp. 1562-1567 ◽  
Author(s):  
Ełżbieta Błoszyk ◽  
Miloš Buděšínský ◽  
Włodzimierz M. Daniewski ◽  
Eva Pešková ◽  
Bohdan Drożdż ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Cd Spectroscopy ◽  
H Nmr ◽  
Aerial Parts ◽  
The Absolute

Aerial parts of species Inula aschersoniana JANKA var. aschersoniana have been shown to contain parthenolide (I), costunolide diepoxide (III) and the hitherto undescribed inusoniolide (IV) whose structure, including the absolute configuration, was determined using 1H NMR and CD spectroscopy.

scholarly journals A New Bisabolene from Stevia tomentosa

2011 ◽  
Vol 6 (9) ◽  
pp. 1934578X1100600
Author(s):  
Alejandro Valdez-Calderón ◽  
J. Martín Torres-Valencia ◽  
J. Jesús Manríquez-Torres ◽  
René Velázquez-Jiménez ◽  
Mario A. Gómez-Hurtado ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Coupling Constants ◽  
Spectral Studies ◽  
Dihedral Angles ◽  
Model Compounds ◽  
H Nmr ◽  
Aerial Parts ◽  
The Absolute

The new sesquiterpene (1 R,2 R,3 R,6 R,7 S)-1-acetoxy-2,3-dmydroxy-2,3-dihydrobisabolene (3) together with ten known terpenes and three known flavonoids were isolated from the aerial parts and from the roots of Stevia tomentosa. The structure of 3 follows from spectral studies, the relative chirality at C-3 follows from 1H NMR coupling constants comparison with the corresponding calculated values obtained by applying a generalized Karplus-type relationship to the dihedral angles of model compounds, and the absolute configuration is assumed in analogy to known (2 R,3 R,6 R,7 S)-2,3-epoxy-2,3-dihydrobisabolen-1-one (2).

Alkaloids of Rauvolfia salicifolia GRISEB species

1982 ◽  
Vol 47 (11) ◽  
pp. 2912-2921 ◽  
Author(s):  
Patricia Sierra ◽  
Ladislav Novotný ◽  
Zdeněk Samek ◽  
Miloš Buděšínský ◽  
Ladislav Dolejš ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Cd Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Absolute

From the endemic Cuban species Rauvolfia salicifolia GRISEB nine alkaloids were isolated of which the following seven had been already described: (+)-ajmalidine (I), (-)-reserpiline (II), (-)-isoreserpiline (III), (-)-isocarapanaubine (IV), (-)-ajmalicine (V), (+)-vellosimine (VI), and (+)-yohimbine (VII). The structure of (-)-raucubaine (VIII) had been previously determined by X-ray diffraction and the structure of the alkaloid (-)-raucubainine (IX) was suggested on the basis of its conversion to (-)-raucubaine (VIII). The absolute configuration of (-)-raucubaine and (-)-raucubainine was elucidated by CD spectroscopy.

scholarly journals Sesquiterpene Lactones from Calea pinnatifida: Absolute Configuration and Structural Requirements for Antitumor Activity

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3005
Author(s):  
Lhaís Araújo Caldas ◽  
Mariana T. Rodrigues ◽  
Andrea N. L. Batista ◽  
João M. Batista ◽  
João H. G. Lago ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Absolute Configuration ◽  
Sesquiterpene Lactones ◽  
Carcinoma Cells ◽  
Spectrometric Data ◽  
Aerial Parts ◽  
Antitumor Potential ◽  
The Absolute ◽  
The Michael Addition

This work describes the chromatographic fractionation of the aerial parts of Calea pinnatifida and the structural characterization and determination of the absolute configuration of the isolated compounds as well as their antitumor potential. The HPLC fractionation of the CH2Cl2 phase of the MeOH extract from the leaves of C. pinnatifida led to the isolation of two related sesquiterpene lactones (STLs): calein C (1) and calealactone B (2). Additionally, during the purification process, a derivative of calein C (3) was formed as a product of the Michael addition of MeOH. The structures of Compounds 1–3 were established based on spectroscopic and spectrometric data, while the absolute stereochemistry was established by vibrational circular dichroism. In order to evaluate the effect of the conjugated double bonds on the cytotoxic activity of STLs, Compounds 1–3 were tested against anaplastic (KTC-2) and papillary (TPC-1) thyroid carcinoma cells. Calein C was the most active of the STLs, and displayed activity against both KTC-2 and TPC-1. On the other hand, the calein C derivative (3) was the least cytotoxic of all the compounds tested. These results are promising and suggest the importance of studying sesquiterpene lactones isolated from C. pinnatifida in terms of antitumor activity, especially considering the effects of α,β-unsaturated carbonyl systems.

The assignment of the configuration for α-hydroxy acid esters using a CEC strategy

2016 ◽  
Vol 14 (23) ◽  
pp. 5258-5262 ◽  
Author(s):  
Ruixue Peng ◽  
Lili Lin ◽  
Yuheng Zhang ◽  
Wangbin Wu ◽  
Yan Lu ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Hydroxy Acid ◽  
H Nmr ◽  
Nmr Method ◽  
The Absolute ◽  
Acid Esters

A simple and efficient 1H NMR method for determining the absolute configuration of chiral α-hydroxy acid esters using a CEC strategy with a chiral N,N′-dioxide-scandium(iii) complex was developed.

scholarly journals 5α-Hydroxyeudesm-4(15),11(13)-dien-8β,12-olide

2012 ◽  
Vol 68 (4) ◽  
pp. o1208-o1208 ◽  
Author(s):  
Xue Gao ◽  
Gang Chen
Keyword(s):  
Hydrogen Bonds ◽  
Sesquiterpene Lactone ◽  
Absolute Configuration ◽  
Title Compound ◽  
Aerial Parts ◽  
Compound C ◽  
Ring Junction ◽  
Twist Conformation ◽  
Cyclopentane Ring ◽  
The Absolute

The title compound, C15H20O3, a sesquiterpene lactone, was isolated from the aerial parts ofCarpesium minusHemsl. (Compositae). The molecule is composed of three rings, with the two cyclohexane rings in chair conformations and the cyclopentane ring adopting a twist conformation. TheA/Bring junction istrans-fused. The absolute configuration shown has been arbitrarily assigned. In the crystal, molecules are linked into [100] chains by O—H...O hydrogen bonds.

Synthesis and Determination of the Absolute Configuration of Fugomycin and Desoxyfugomycin: CD Spectroscopy and Fungicidal Activity of Butenolides

2004 ◽  
Vol 10 (18) ◽  
pp. 4584-4593 ◽  
Author(s):  
Manfred Braun ◽  
Andreas Hohmann ◽  
Jaykumar Rahematpura ◽  
Corinna Bühne ◽  
Stefan Grimme
Keyword(s):  
Absolute Configuration ◽  
Fungicidal Activity ◽  
Cd Spectroscopy ◽  
The Absolute

Structure of isosilerolide, relative and absolute configuration of silerolide and lasolide - Sesquiterpenic lactones of new stereoisomeric type of eudesmanolides

1986 ◽  
Vol 51 (4) ◽  
pp. 903-929 ◽  
Author(s):  
Miroslav Holub ◽  
Miloš Buděšínský ◽  
Zdenka Smítalová ◽  
David Šaman ◽  
Urszula Rychłewska
Keyword(s):  
Absolute Configuration ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Chemical Correlation ◽  
The Absolute

On the basis of spectroscopic, particularly 1H NMR data, isosilerolide was assigned structure I, including the absolute configuration. The structure was confirmed by X-ray diffraction. Isosilerolide represents a new stereoisomeric type of natural eudesmanolides, characterized as 5βH, 6αH, 7αH, 10αCH3-eudesman-6,12-olide. As shown by the chemical correlation of isosilerolide (I) with silerolide (III) and lasolide (X), the latter two natural lactones belong to this stereoisomeric group of eudesmanolides. Analysis of models and 1H NMR data shows that structures of some eudesman-6,12-olides, published by other authors, should be corrected.

scholarly journals Novel Bisabolane Sesquiterpenes from the Marine-derived Fungus Verticillium tenerum

2010 ◽  
Vol 5 (4) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Celso Almeida ◽  
Somaia Elsaedi ◽  
Stefan Kehraus ◽  
Gabriele M. König
Keyword(s):  
Absolute Configuration ◽  
Cd Spectroscopy ◽  
Mass Spectrometric ◽  
Planar Structures ◽  
The Absolute ◽  
New Compounds ◽  
Mass Spectrometric Techniques

Chemical investigations of the marine-derived fungus Verticillium tenerum yielded two new hydroxylated bisabolane-type sesquiterpenes verticinol A (1) and B (2). The planar structures of the new compounds were elucidated by employing spectroscopic (NMR, UV, and IR) and mass spectrometric techniques. The absolute configuration of the cyclohexenyl moiety was deduced by a combination of CD spectroscopy and NOESY measurements.

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