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.

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.

Antifeedant activity of xanthohumol and supercritical carbon dioxide extract of spent hops against stored product pests

2015 ◽  
Vol 105 (4) ◽  
pp. 456-461 ◽  
Author(s):  
J. Jackowski ◽  
M. Hurej ◽  
E. Rój ◽  
J. Popłoński ◽  
L. Kośny ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Potential Application ◽  
Insect Pests ◽  
Sitophilus Granarius ◽  
Antifeedant Activity ◽  
Stored Product Pests ◽  
Spent Hops ◽  
Deterrent Activity ◽  
Supercritical Carbon

AbstractXanthohumol, a prenylated flavonoid from hops, and a supercritical carbon dioxide extract of spent hops were studied for their antifeedant activity against stored product insect pests: Sitophilus granarius L., Tribolium confusum Duv. and Trogoderma granarium Everts. Xanthohumol exhibited medium deterrent activity against the adults of S. granarius L. and larvae of T. confusum Duv. The spent hops extract was more active than xanthohumol towards the adults of T. confusum Duv. The potential application of the crude spent hops extract as a feeding deterrent against the stored product pests is proposed.

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Endocarp Structural Components of Insect Resistance in Almond

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 526d-526
Author(s):  
M. Freeman ◽  
C. Walters ◽  
M.A. Thorpe ◽  
T. Gradziel
Keyword(s):  
Insect Resistance ◽  
Insect Pests ◽  
Stone Fruit ◽  
Structural Components ◽  
Insect Infestation ◽  
Insect Feeding ◽  
Kernel Development ◽  
X Ray ◽  
Seal Integrity ◽  
Structural Barrier

Almond, as with other stone fruit, possesses a highly lignified endocarp or shell. The dominant hard-shelled trait (D-) is positively associated with greater resistant to insect infestation than nuts expressing the paper-shelled (dd) trait. Hard-shelled genotypes have undesirable effects, including a lower kernel meat-to-nut crack-out ratio, greater kernel damage during mechanical shelling, and a reduction in plant energy available to kernel development. Histogenic analysis shows that the almond endocarp, unlike peach, has a tri-partite structure. Insect feeding studies have subsequently demonstrated that the inner endocarp layer, which is similar in both hard and paper-shelled types, is the most important structural barrier to insect infestation. Shell-seal integrity and X-ray studies have confirmed that discontinuities at the inner endocarp suture seal are the primary, though not the sole site of entry for insect pests. Paper-shelled almond selections with highly lignified and well-sealed inner endocarps show resistance levels comparable to hard shelled types but with crack-out ratios 30% to 40% higher. Pseudo-paper-shelled types have also been selected, in which a highly lignified outer endocarp is formed, but is retained by the fruit hull at dehiscence. An understanding of endocarp morphology and development is thus important in breeding for insect resistance as well as the commercial utilization of both kernel and hull.

The crystal and molecular structure of tris(pentamethylenedithiocarbamate) chromium(III)-chloroform (1 : 2)

1981 ◽  
Vol 46 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Viktor Kettman ◽  
Ján Garaj ◽  
Jaroslav Majer
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Crystal And Molecular Structure ◽  
Analysis Method ◽  
Complex Molecules ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Cell Dimensions ◽  
Crustal Density ◽  
Unit Cell Dimensions

The crystal and molecular structure of [Cr(S2CN(CH2)5)3].2 CHCl3 was found by the X-ray structural analysis method. The value R 0.090 was found for 1 131 observed independent reflections. The substance crystallizes in a space group of symmetry P212121 with the following unit cell dimensions: a = 0.8675 (6), b = 1.815(2), c = 2.155(3) nm. The experimentally observed crustal density was 1.48 Mgm-3 and the value calculated for Z = 4 was 1.51 Mgm-3. The CrS6 coordination polyhedron has the shape of a trigonally distorted octahedron, where the D3 symmetry is a approximately retained. The degree of trigonal distortion expressed as the projection of the chelate S-Cr-S angle onto the plane perpendicular to the C3 pseudo axis is Φ = 41.7° (Φ = 60° for an octahedron). The skeleton of the structure formed by the complex molecules contains channels filled with chloroform molecules. The specific type of complex-chloroform interaction consists of the formation of hydrogen bonds of the chloroform protons with the fully occupied pπ-orbitals of the sulphur atoms in the coordination polyhedra. The low stability and crystal decomposition can be explained by loss of chloroform from the channels.

Reactivity of Sodium Hexaethyl-2,4-dicarba-nido-hexaborate(1-)

1999 ◽  
Vol 64 (6) ◽  
pp. 977-985 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz ◽  
Wolfgang Milius ◽  
Catherine McCammon
Keyword(s):  
Mössbauer Spectroscopy ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Hydrogen Atom ◽  
Mossbauer Spectroscopy ◽  
Sandwich Complex ◽  
X Ray ◽  
Bromo Derivative ◽  
Boron Tribromide ◽  
C Nmr

Sodium hexaethyl-2,4-dicarba-nido-hexaborate(1-) (6), available from hexaethyl-2,4-dicarba- nido-hexaborane(8) (4) by deprotonation, reacts with deuterated methanol, CD3OD, to give back 4 without H/D exchange of the B-H-B hydrogen atom. The reaction of 6 with diethylboron chloride, Et2BCl, affords hexaethyl-2,4-dicarba-closo-hexaborane(6) (7), the first example of a peralkylated carborane of this type. In contrast, the reaction of 6 with boron tribromide, BBr3, leads mainly to 2,3,4,5,6,7-hexaethyl-2,4-dicarba-closo-heptaborane(7) (8), together with the corresponding 1-bromo derivative (9) and the closo-carborane 7 as side products. The reaction of two equivalents of 6 with FeCl2 gives the air-stable sandwich complex bis[hexaethyl-2,4-dicarba-nido-hexaborate(1-)]iron 10 which was characterised by X-ray structural analysis. All products were characterised by 1H, 11B and 13C NMR spectroscopy, and 57Fe Mössbauer spectroscopy was used to study 10.

scholarly journals X-Ray Structural Analysis of Molten KF–KX(X=Cl, Br, and I) Systems

1987 ◽  
Vol 1987-7 (1) ◽  
pp. 165-174
Author(s):  
Yoshihiro OKAMOTO
Keyword(s):  
Structural Analysis ◽  
X Ray

scholarly journals Light-induced [2 + 2] Cycloaddition of 6-Methoxy-2-naphthonitrile to 2-Chloroacrylonitrile

1999 ◽  
Vol 23 (1) ◽  
pp. xiv-xiv
Author(s):  
Nader A. Al-Jalal ◽  
Robin G. Pritchard ◽  
Charles A. McAuliffe
Keyword(s):  
Structural Analysis ◽  
X Ray

6-Methoxy-2-naphthonitrile undergoes photocycloaddition to 2-chloroacrylonitrile to give [2 + 2] cyclobutane adducts (1a and 1b), the structure of one of which (1a) has been unambiguously confirmed by an X-ray structural analysis.

scholarly journals Toxicity and Biological Effects of Beauveria brongniartii Fe0 Nanoparticles against Spodoptera litura (Fabricius)

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 895
Author(s):  
Jing Xu ◽  
Kaihui Zhang ◽  
Andrew G. S. Cuthbertson ◽  
Cailian Du ◽  
Shaukat Ali
Keyword(s):  
Spodoptera Litura ◽  
Insect Pests ◽  
Growth Parameters ◽  
Uv Spectroscopy ◽  
Biological Effects ◽  
Fungal Treatment ◽  
Beauveria Brongniartii ◽  
Sem Images ◽  
X Ray ◽  
Infection Period

Nanotechnology has clear potential in the development of innovative insecticidal products for the biorational management of major insect pests. Metal-based nanoparticles of different microbial pest control agents have been effective against several pests. Synthesis of Beauveria brongniartii based Fe0 nanoparticles (Fe0NPs) and their bio-efficacy against Spodoptera litura was observed during this study. Beauveria brongniartii conidia were coated with Fe0NPs and characterized by applying a selection of different analytical techniques. Ultraviolet (UV) spectroscopy showed the characteristic band of surface plasmon at 430 nm; Scanning electron microscopy (SEM) images showed spherical shaped nanoparticles with a size ranging between 0.41 to 0.80 µm; Energy-dispersive X-ray (EDX) spectral analysis revealed characteristic Fe peaks at 6.5 and 7.1 Kev; the X-ray diffractogram showed three strong peaks at 2θ values of 45.72°, 64.47°, and 84.05°. The bioassay studies demonstrated that mortality of 2nd instar S. litura larvae following Fe0NPs treatment increased with increasing concentrations of Fe0NPs at different time intervals. The median lethal concentration (LC50) values of Fe0NPs against S. litura after seven days of fungal treatment was 59 ppm, whereas median survival time (LT50) values for 200 and 500 ppm concentrations of Fe0NPs against S. litura seven days post-treatment were 5.1 and 2.29 days, respectively. Beauveria brongniartii-Fe0NPs caused significant reductions in feeding and growth parameters (relative growth rate, relative consumption rate, and efficiency of conversion of ingested food) of S. litura. Beauveria brongniartii Fe0NPs induced reduction in glutathione-S-transferase activities throughout the infection period whereas activities of antioxidant enzymes decreased during later periods of infection. These findings suggest that B. brongniartii Fe0NPs can potentially be used in biorational S. litura management programs.

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