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Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Eugenol is a pale yellow to dark yellow clear liquid; its odor type is spicy and its odor at 10% in dipropylene glycol is described as ’sweet spicy clove woody’ (www.thegoodscentscompany.com). Eugenol is used in perfumery in clove and carnation compositions as well as for oriental and spicy notes. It is a common component of clove and other aroma compositions. Eugenol from clove leaf oil sources is used as a chemical raw material for conversion to several derivatives, the most important of which is isoeugenol, which in turn is used to produce vanillin. Zinc oxide-eugenol cements have many uses in dentistry; the admixture of powdered zinc oxide and liquid eugenol forms a bland, easily mixed paste having excellent working time but slow-setting antiseptic characteristics that is used in temporary luting and filling material, pulp capping and periodontal packs. Indeed, eugenol is found as a major ingredient in a variety of dental materials such as impression materials, filling materials, dental cements, endodontic sealers, periodontal dressing materials and dry socket dressings (94). In combination with geraniol, eugenol is applied as a kairomone insect attractant which is used widely for monitoring new infestations of the Japanese beetle Popillia japonica and for removal trapping in orchards. Eugenol may also be used as a denaturant for alcohol (U.S. National Library of Medicine).
Essential Oils as Lures for Invasive Ambrosia Beetles
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Paul E. Kendra, Nurhayat Tabanca, Wayne S. Montgomery, Jerome Niogret, David Owens, Daniel Carrillo
All known hosts of X. glabratus in the US are members of the Lauraceae family; therefore, research on kairomone attractants has focused on this taxonomic group. Kendra et al., (2014a) conducted a comparative study of nine lauraceous species (including avocado cultivars representative of each of the three botanical races) to determine boring preferences and in-flight attraction of X. glabratus as related to phytochemical emissions from host wood. Emissions of α-copaene, α-cubebene, α-humulene, and calamenene (all sesquiterpene hydrocarbons) were positively correlated with attraction to Lauraceae. Of these compounds, α-copaene and α-humulene had been correlated previously with attraction to three additional avocado cultivars, as well as to wood from lychee (Litchi chinensis Sonn.; Sapindaceae) (Kendra et al., 2011a). Lychee is not a reproductive host of X. glabratus, but particular cultivars will attract females and initiate boring behavior owing to sesquiterpene emission profiles similar to those of the Lauraceae (Kendra et al., 2011a, 2011b, 2013b). In addition, independent research identified eucalyptol (1,8 cineole; a monoterpene ether) as another host-based attractant (Kuhns et al., 2014).
Positive Selection of B-Cell Repertoire, Idiotype Networks and Immunological Memory
Published in Maurizio Zanetti, J. Donald Capra, The Antibodies, 2002
Maryse Brait, Georgette Vansanten, Annette Van Acker, Carl De Trez, Chantal Masungi Luko, Christian Wuilmart, Oberdan Leo, Robert Miller, Roy Riblet, Jacques Urbain
In fact, it has been shown recently that this learning can also take place for non-adaptive defense mechanisms. For example, when Agrawal et al. [18] exposed water fleas to kairomones from two invertebrate predators, the water fleas developed long helmets. Furthermore, offspring of kairomone-treated mothers produced longer helmets than offspring from control mothers, in whatever environment offspring were raised. The authors saw the same effects in successive broods produced later by kairomone-treated mothers in clean water. Thus, development of long helmets in embryonic stages resulted from maternal effects and did not need to be induced directly by the chemical cues called kairomones. Induced defenses can extend across generations. Similar observations were made in plant defenses. Transgenerational induction of defenses are a new level of phenotypic plasticity across generations that may be an important component of predator-prey interactions.
Plasticity of pheromone-mediated avoidance behavior in C. elegans
Published in Journal of Neurogenetics, 2020
YongJin Cheon, Hyeonjeong Hwang, Kyuhyung Kim
Pristionchus pacificus is a necromantic insect-dwelling nematode and a facultative predator of C. elegans (Serobyan, Ragsdale, & Sommer, 2014). It was reported that P. pacificus secreted a few ascarosides, indicating that C. elegans avoids this predator nematode (Choe et al., 2012). Interestingly, Liu et al., found that starved, but not well-fed, P. pacificus secreted additional non-volatile chemicals which elicited a strong avoidance behavior in C. elegans (Liu et al., 2018). They identified these chemical signals as a mixture of sulfolipids and found them to be similar to a known C. elegans repellent, sodium dodecyl sulfate (SDS) (Liu et al., 2018). These sulfolipids appeared to be detected redundantly by multiple chemosensory neurons, including the ADL, ASH, ASI, and ASJ neurons (Liu et al., 2018). Taken together, these results suggest that C. elegans ensures rapid and life-saving avoidance behavior against the predator by detecting predator-secreted ascaroside as a pheromone as well as sulfolipid as a kairomone (Brown, Eisner, & Whittaker, 1970; Stowe, Turlings, Loughrin, Lewis, & Tumlinson, 1995).