Sesquiterpene lactones of Cephalophora aromatica (HOOK.) SCHRADER and their deterrent activity. The stereostructure of geigerinin

1989 ◽  
Vol 54 (7) ◽  
pp. 1903-1918 ◽  
Author(s):  
Ełżbieta Błoszyk ◽  
Aleksandra Dudek ◽  
Zofia Kosturkiewicz ◽  
Urszula Rychłewska ◽  
Włodzimierz M. Daniewski ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Sesquiterpene Lactones ◽  
Cd Spectra ◽  
Antifeedant Activity ◽  
Crop Pests ◽  
X Ray ◽  
Main Crop ◽  
Deterrent Activity

From species Cephalophora aromatica (HOOK.) SCHRADER the authors isolated a series of previously described sesquiterpene lactones I-V and newly the lactone geigerinin (VI). Its structure was confirmed by X-ray analysis and its absolute configuration was determined on the basis of the CD spectra of its complex with Pr(thd)3. The lactones I-VII were tested for antifeedant activity against main crop pests.

Sesquiterpene Lactones of Ambrosia artemisiifolia L. and Ambrosia trifida L. Species

1992 ◽  
Vol 57 (5) ◽  
pp. 1092-1102 ◽  
Author(s):  
Ełżbieta Błoszyk ◽  
Urszula Rychłewska ◽  
Beata Szczepanska ◽  
Miloš Buděšínský ◽  
Bohdan Drożdż ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Aerial Part ◽  
Sesquiterpene Lactones ◽  
Ambrosia Artemisiifolia ◽  
Cd Spectra ◽  
Ambrosia Trifida ◽  
X Ray ◽  
Aerial Parts ◽  
Full Structure

In addition to the already described peruvin (I), two further lactones, 3α-hydroxy-11αH,13-dihydrodamsin (II) and, 3α-acetoxy-11αH,13-dihydrodamsin (III), were isolated from aerial parts of species Ambrosia artemisiifolia L. The full structure of these lactones was derived from their NMR and CD spectra and the X-ray structural analysis of compound III. In the aerial part of Ambrosia trifida L. species coronopilin (V) and ivoxanthin (VI) were also identified.

Sesquiterpenoids from Dittrichia viscosa (L.) GREUTER. Their structure and deterrent activity

1986 ◽  
Vol 51 (8) ◽  
pp. 1710-1721 ◽  
Author(s):  
Włodzimierz M. Daniewski ◽  
Wojciech Kroszczyṅski ◽  
Ełżbieta Błoszyk ◽  
Bohdan Drożdż ◽  
Jan Nawrot ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Activity ◽  
Insect Pests ◽  
Antifeedant Activity ◽  
X Ray ◽  
Dittrichia Viscosa ◽  
Deterrent Activity

In addition to the earlier described inuviscolide (II), the sesquiterpenic vachanic (V) and 2α-hydroxyisocostic (VII) acids, as well as carabron (VIII) and the so far undescribed sesquiterpenic lactone 11αH,13-dihydroconfertin were also isolated from Dittrichia viscosa (L.) GREUTER. For the last mentioned lactone the structure IX has been derived. The structure of vachanic acid (V) was confirmed by X-ray structural analysis. Compounds V to VII were tested for their deterrent (antifeedant) activity against selected insect pests living in corn stores, and they generally had a high activity.

Molecular Structure of cis- and trans-Tergurides

1998 ◽  
Vol 63 (3) ◽  
pp. 425-433 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Petr Sedmera ◽  
Vladimír Havlíček ◽  
Hana Votavová ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Absolute Configuration ◽  
Catalytic Hydrogenation ◽  
Ergot Alkaloid ◽  
Cd Spectra ◽  
X Ray ◽  
Relative Stereochemistry ◽  
Cis And Trans

Four isomers of terguride, a semisynthetic ergot alkaloid derivative, have been prepared by catalytic hydrogenation of (5R,8S)- and (5S,8S)-lisuride [1,1-diethyl-3-(6-methyl-8-ergolenyl)urea]. Relative stereochemistry of the isomers is based on NMR and CD spectra. Absolute configuration of all the series has been confirmed by the X-ray crystal structure determination of (5R,8S,10S)-terguride 2-bromobenzoate [1,1-diethyl-3-(6-methyl-8-isoergolenyl)urea, cis-dihydrolisuride].

Sterically Crowded Heterocycles. XIII. An Insight Into the Absolute Stereochemistry of Atropisomeric (Z)-3-(Imidazo[1,2-a]pyridin-3-yl)prop-2-en-1-ones

2000 ◽  
Vol 65 (10) ◽  
pp. 1643-1652
Author(s):  
Radek Pohl ◽  
Jan Sýkora ◽  
Petr Maloň ◽  
Stanislav Böhm ◽  
Bohumil Kratochvíl ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Heats Of Formation ◽  
Cd Spectra ◽  
X Ray ◽  
Space Analysis ◽  
The Absolute ◽  
Absolute Stereochemistry ◽  
Insight Into

The absolute configuration of the atropisomeric (Z)-3-(5-methyl-2-phenylimidazo[1,2-a]pyridin-3-yl)-1,3-diphenylprop-2-en-1-one was evaluated to be R for the dextrorotatory and S for the laevorotatory enantiomers. The assignment is based on their two-step syntheses via atropodiastereoisomeric carbamates prepared from the corresponding atropodiastereoisomeric alcohols with (R)-(+)-α-phenylethyl isocyanate and by a complete X-ray space analysis of the quaternary triiodide obtained from the (R)-(+)-enantiomer. CD spectra and PM3 calculated heats of formation for selected compounds are discussed in relation to the found molecular configurations.

Absolute Configuration of Chiral 1,3,4,5-Tetrahydro-2H-l,5-benzodiazepin-2-ones

1998 ◽  
Vol 53 (4) ◽  
pp. 485-487 ◽  
Author(s):  
Mashooda Hasan ◽  
Tanveer Ahmad Nizami ◽  
Abdul Malik ◽  
Claus Ohlendorf ◽  
Wolfgang Hiller ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Cd Spectra ◽  
X Ray ◽  
Cotton Effects ◽  
The Absolute

X-ray studies are carried out to correlate the Cotton effects in CD spectra with the absolute configuration of a series of previously reported chiral 1,3,4,5-tetrahydro-2H-1 ,5-benzodazepin-2-ones.

scholarly journals Diastereoselective Addition of Diazomethane to Zaluzanin A

2014 ◽  
Vol 9 (6) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Adriana Ortiz-León ◽  
J. Martín Torres-Valencia ◽  
J. Jesús Manríquez-Torres ◽  
José G. Alvarado-Rodríguez ◽  
Uvaldo Hernández-Balderas ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Absolute Configuration ◽  
Sesquiterpene Lactones ◽  
Addition Product ◽  
Vibrational Circular Dichroism ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Diastereoselective Addition ◽  
The Absolute

The diastereoselectivity of diazomethane addition to the conjugated double bond of α,β-unsaturated sesquiterpene lactones was explored using zaluzanin A (1) as a model. Thus, the absolute configuration of 1 was assured by X-ray diffraction analysis including evaluation of Flack and Hooft parameters, and by vibrational circular dichroism spectroscopy of its diacetyl derivative 2, while the absolute configuration of the diazomethane addition product, zaluzanin A pyrazoline (3), was determined by evaluation of the 1H NMR chemical shift changes with respect to 1, and confirmed by X-ray diffraction analysis, again including evaluation of Flack and Hooft parameters.

CD-Spectroscopic Confirmation of the Absolute Configuration of a Conformationally Flexible Aldehyde Ester Containing a Quarternary Stereogenic Center

1998 ◽  
Vol 53 (10-11) ◽  
pp. 891-895 ◽  
Author(s):  
Jörg Fleischhauer ◽  
Axel Koslowski ◽  
Jan Schiffer ◽  
Axel Wollmer ◽  
Dieter Enders ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Structure Determination ◽  
Matrix Method ◽  
Aldehyde Ester ◽  
Cd Spectra ◽  
Perfect Agreement ◽  
X Ray ◽  
The Absolute ◽  
Stereogenic Center

Abstract The absolute configuration of the conformationally flexible aldehyde ester methyl-2-formyl-2-(phe-nylsulfanyl)-3-(3,4,5-trimethoxyphenyl)-propanoate was determined by comparison of measured and calculated CD spectra.The spectra were calculated by means of the so-called matrix method assuming R configuration at the stereogenic center. Calculated and observed signs of the first three most intense CD bands agree. Therefore, it was concluded that the absolute configuration of the compound was also R, which is in perfect agreement with the results of an X-ray structure determination.

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