Methyl 3α,6α-diacetoxy-10-oxo-(7α)-kemp-11-en-20-oate: The revised structure for the kempane derivative from the frontal gland secretion of Nasutitermes costalis soldiers

1987 ◽  
Vol 52 (3) ◽  
pp. 707-713 ◽  
Author(s):  
Silvio Cerrini ◽  
Doriano Lamba ◽  
Irena Valterová ◽  
Miloš Buděšínský ◽  
Jan Vrkoč ◽  
...  
Keyword(s):  
Gland Secretion ◽  
Frontal Gland ◽  
X Ray ◽  
Nasutitermes Costalis ◽  
Suggested Structure ◽  
Defense Compound

The structure of methyl 3α,6α-diacetoxy-10-oxo-(7α)-kemp-11-en-20-oate (II) was established by X-ray analysis for a defense compound of termites Nasutitermes costalis. The previously suggested structure I with 7β-kempane skeleton is revised.

Defensive substances from the frontal gland secretion of Nasutitermes nigriceps termite soldiers

1991 ◽  
Vol 56 (12) ◽  
pp. 2969-2977 ◽  
Author(s):  
Irena Valterová ◽  
Miloš Buděšínský ◽  
Jan Vrkoč
Keyword(s):  
Detailed Analysis ◽  
Infrared Spectra ◽  
Nmr Spectra ◽  
Gland Secretion ◽  
Volatile Fraction ◽  
Termite Species ◽  
Frontal Gland ◽  
Derivatives Of ◽  
Termite Soldiers ◽  
C Nmr

The components of the defence secretion of the soldiers of Nasutiterms nigriceps termite species (Isoptera: Termitidae: Nasutitermitinae) have been identified. In the volatile fraction the following components were found: α- and β-pinene, camphene, myrcene, α-terpinene, p-cymene, limonene and terpinolene. Ten diterpenic compounds (I - X), mostly derivatives of the tricyclic trinervitane, were found in the non-volatile fraction. The structure of the so far undescribed 1(15),8(19)-trinervitadiene-2β,3α,14α-triol triacetate (X) was determined on the basis of its mass and infrared spectra and a detailed analysis of 1H and 13C NMR spectra. Considerable differences were found in the composition of the non-volatile fraction of the secretion of the species of termites studied from various localities.

Impact of a juvenile hormone analogue on the anatomy and the frontal gland secretion of Prorhinotermes simplex (Isoptera: Rhinotermitidae)

2010 ◽  
Vol 56 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Jan Šobotník ◽  
Robert Hanus ◽  
Rafal Piskorski ◽  
Klára Urbanová ◽  
Zdeněk Wimmer ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Gland Secretion ◽  
Hormone Analogue ◽  
Frontal Gland ◽  
Juvenile Hormone Analogue

Chemical composition of the frontal gland secretion from soldiers of nasutitermes lujae (termitidae, nasutitermitinae)

Tetrahedron ◽  
1983 ◽  
Vol 39 (24) ◽  
pp. 4237-4241 ◽  
Author(s):  
J.C. Braekman ◽  
D. Daloze ◽  
A. Dupont ◽  
J.M. Pasteels ◽  
P. Lefeuve ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gland Secretion ◽  
Frontal Gland

4,11-Epoxy--eudesmane, a novel oxygenated sesquiterpene in the frontal gland secretion of the termite, silvestri

1974 ◽  
Vol 15 (18) ◽  
pp. 1697-1700 ◽  
Author(s):  
Lester J. Wadhams ◽  
Raymond Baker ◽  
Philip E. Howse
Keyword(s):  
Gland Secretion ◽  
Frontal Gland

Chemical composition of the frontal gland secretion ofSyntermes soldiers (Isoptera, Termitidae)

1981 ◽  
Vol 7 (1) ◽  
pp. 135-145 ◽  
Author(s):  
Raymond Baker ◽  
Helen R. Coles ◽  
Michael Edwards ◽  
David A. Evans ◽  
Philip E. Howse ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gland Secretion ◽  
Frontal Gland

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

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