Odor blend

The main by-products of this synthesis type are sulfides and the isomer resulting from the Markownikoff addition to the alkene. For example, in the synthesis of 1-butanethiol (eq. 4), 5-thianonane, C H SC H, and 2-butanethiol are produced as by-products. The 2-butanethiol has uses as a herbicide intermediate and a gas odorant blend component and is further processed. The 5-thianonane is incinerated or reprocessed for fuel value. Sulfides account for up to 10% of the thiols produced. Another 2—5% is the Markownikoff addition product. 

Moreover, many parasitoids and predators, whether they are generalists or not, can find their hosts or prey on a variety of plant species and each of these has its own characteristic basic odor blend. Therefore, natural enemies that use plant odors to locate their prey will need to determine which odors are most reliably associated with a certain prey at a certain time. 

How does pathogen infestation affect odor emissions and does it interfere with emissions induced by insect herbivores So far, only one study has specifically looked at this cross-effect (Cardoza et al, 2002). It showed that insect feeding (beet armyworm, S. exigua) and fungus infection (white mold, Sclerotium rolfsii) resulted in distinctly different odor blends in peanut plants, whereas plants that were simultaneously infested by these two antagonists released a mix of both blends. 

Table 22.1 Functional analysis of complex odor blends, considering various sources and definitions of signal and noise ...

Vickers N. J., Christensen T. A. and Hildebrand J. G. (1998) Combinatorial odor discrimination in the brain attractive and antagonist odor blends are represented in distinct combinations of uniquely identifable glomeruli. J. Comp. Neurol. 400(1), 35-56. 

Terpenoid alcohols appeared early in the history of synthetic perfumery because several were readily available from inexpensive essential oils. Alpha-terpineol, citronellol and linalool shown in Figure 7 are important constituents of pine stump oil, citro-nella oil and rosewood oil, respectively. The fourth material listed, hydroxycitronellal, is a hydroxy aldehyde which perhaps has a questionable place in this discussion. It is included because it is one of the most important fragrance chemicals used today. "Hydroxy" is almost a perfume unto itself. Its soft flowery, linden blossom odor blends very well in many floral perfumes. 

J. E. CUek et al.. Evaluation of several novel aUcynols, alkenols, and selected host odor blends as attractants to female Aedes albopictus and Culex quinquefasciatus, J. Am. Mosq. Control Assoc., 28,199, 2012. 

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