Farnesenes

Aerial parts of N. sintenisii yielded 0.3% of a clear yellowish oil. Forty constituents (96.5% of the total oil) were identified. The main components were 4aP,7a,7aP-nepetalactone (23.4%), elemol (16.1%), E- -farnesene (9.5%), 1,8-cineole (8.2%), cw-sabinene hydrate (6.5%), P-bisabolene (4.2%), germacrene-D (3.5%), P-sesquiphellandrene (2.8%), P-bourbonene (1.5%) and a-epi-cadinol (1.3%). According to available data, Nepeta species can be divided into two groups of nepetalactone-containing and nepetalactone-free species. The results of this study indicate that the compositions of volatile oil of N. sintenisii are similar to the other Nepeta genus and this plant could be classified in the group which 4aP,7a,7aP-nepetalactone is the major component of their oils. 

PALLADIUM-CATALYZED SYNTHESIS OF 1.4-DIENES BY ALLYLATION OF ALKENYLALANES a-FARNESENE... 

When dehydrated with potassium hydrogen sulpnate, farnesol yields a sesquiterpene, which has been named farnesene, and is a colourless oil having the following characters —... 

In order to establish the primary character of farnesol, farnesenic acid was prepared from farnesal oxime and the corresponding nitrile. Saponification of the farnesene-nitrile with caustic soda solution yields farnesenic acid and acetic acid, and also a ketone which was identified as a dihydropsewdoionone. The semi-carbazone melts between 95° and 96°. The dihydropmtdoionone from farnesene nitrile proved to be... 

Alpha farnesene, structure of, 207 Alpha helix (protein), 1038 Alpha-keratin, molecular model of, 1039... 

Aphidius uzbekistanicus Aphidius sp. Host alarm signal [attraction] (E)-p-Farnesene 48 [88]... 

When the intact seedlings were placed in the vicinity of wounded seedlings, pyrethrin content in the leaves of the intact seedlings increased significantly. Also, exposing the intact seedlings to a mixture of (Z)-3-hexenal (27), ( )-2-hexenal (28), (Z)-3-hexen-l-ol (29), (Z)-3-hexen-l-yl acetate (30), and ( )-p-farnesene (31) at the same concentrations at which they were emitted in response to wounding resulted in enhanced pyrethrins. Thus, the effects of each component as well as... 

Adults of some species also produce 4-oxo-( )-2-alkenals. Other types of simple compounds that have been found in the defensive secretions of true bugs include common terpenoids such as a- and (3-pinenes, limonene, linalool, and Z, -oc-farnesene, and simple aromatic compounds such as benzyl alcohol, ben-zaldehyde,p-hydroxybenzaldehyde, methyl p-hydroxybenzoate,phenylethanol, and guaicol. In general, although a number of species may share particular components, each species does appear to produce its own particular blend. In at least one species, the blend of defensive compounds is reported to vary with season and/or diet [36]. 

Schnee C, Kollner TG, Gershenzon J, Degenhardt J (2002) The maize gene terpene synthase 1 encodes a sesquiterpene synthase catalyzing the formation of ( )-P-farnesene, ( )-nerolidol, and ( , )-famesol iter herbivore damage. Plant Physiol 130 2049-2060... 

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