Allomone

The co-occurring marine allomones 2- and 9-isocyanopupukeanane have been synthesized from a common intermediate. This condition along with topologically based strategic disconnection had a major impact on the retrosynthetic analysis. 

The regiochemical course reacting saturated ketones depended on the substitution pattern of the a-positions. In most cases, the intermediate oxime had an anti N-OH function with respect to the chain branched a-position. Consequently, the more substituted alkyl group preferentially migrates. This advantage was utilized for synthesizing the spiro a-amino-e-caprolactam (202 203, Scheme 38) [12c], the Mexican bean beetle azamacrolide allomone (205 206, Scheme 39) [44 a], in a key step of the chiral synthesis of benzomorphanes... 

The first volume ends with a chapter by G. Pohnert on chemical defence in the marine environment. Defense compounds, which can be regarded as allomones, are often, but not always, more complex than other semiochemicals and may have unique modes of action. The biological mechanisms are not always easy to unravel, which is shown by some of examples. The reader may be tempted to compare the chemical complexity with that of terrestrial insect defence, which can be found in the second volume chapter by D. Daloze and J.-C. Braekman. Insects thus do not only produce interesting pheromones, but also complex allelochemicals for their own protection. 

Labelled mevalonic acid dibenzylethylenediamine (DBED) salt (14 pCi) was injected into the digestive glands of D. limbata [90]. After 24 h, the animals were sacrificed and labelled polygodial (30) was recovered from the skin of the mollusc. After two subsequent chromatographic purifications, the dialdehyde was reduced to the corresponding diol (35) which was significantly labelled. The ability of D. limbata to synthesize de novo its own defensive allomone raised a series of questions linked to... 

Another example of a nudibranch, which probably modifies dietary metabolites to obtain more effective allomones, is seen in Aldisa cooperi (= A. sanguinea cooperi) [155]. It elaborates two fish antifeedant bile acids (104,105) that are absent in its prey, the sponge Anthoarcuata graceae, where the main steroid is 4-cholesten-3-one (106). Biosynthetic experiments starting from both labelled mevalonic acid and labelled 4-eholesten-3-one would definitely clarify, whether, the two allomones (104-105) are biosynthetized de novo by the mollusc, or if they are derived from a food source. 

Agilent ChemStation software, 29-31, 33 Alkylquinaxolines, in Phodopus roborovskii, 19 Allomones, 13 2-Aminoacetophenon, 155 2-Amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid, see Felinine Amniotic fluid, odour of, 194 Amphetamine, 266... 

Secondary chemicals can be said to be defensive in function only if they protect their producers from the life-threatening activities of another organism. Distinguishing between offensive and defensive use of chemicals is difficult, and present terminology does little to assist in making that distinction. The term "allomone" is frequently used synonymously with "chemical defense," yet allomones are not necessarily defensive in function. An allomone has been defined as a chemical substance beneficial to its producer and detrimental to its recipient (15), so chemicals used... 

All-in dyeing method, 9 177 Allinger force fields, 26 744, 745 All-in paste, 9 216 Allocation methods, in life cycle assessment, 24 815 Allomone, 24 473 Allo-ocimene, 24 490, 495 oxidation of, 24 491 Allo-ocimene diepoxide, 24 491 Allo-ocimene epoxide, 24 491 Allo-ocimenols, isomeric, 24 490 All-organic transistors, 22 222-223 D-Allose, 4 698... 

The terminology used in this research area is not well established in the chemical community while the term pheromone is widely known, semio-chemical is not. Nevertheless, chemicals used in the communication between individuals are correctly called semiochemicals recently the equivalent term infochemicals was introduced. These compounds can be further divided into pheromones, compounds used in communication between individuals of the same species, while allelochemicals serve interspecific communication. Most pheromones are releasers, i.e. they provoke a behavioral change in the receiver. More rare are primers, which provoke physiological changes. Allelochemicals can be divided into kairomones, which are advantageous for the receiver, while the emitter benefits from allomones. Synomones are advantageous for both the emitter and the receiver. 

Keywords Heteroptera Pheromone Allomone Semiochemical Chemical defenses... 

Abstract This chapter reviews chemical structures of biologically active, volatile compounds in beetles. Techniques used for structure elucidation are briefly discussed as well as facts and speculations on the biosynthesis of target compounds. Syntheses of selected substances are cursorily presented. The order of sections follows taxonomic classifications. Depending on the biological significance of relevant compounds in certain taxa, the corresponding sections are again subdivided into attractive compounds (mostly intraspecifically active pheromones) and defensive compounds (mostly interspecifically active allomones). 

Allomones are interspecific semiochemicals that primarily benefit the sender. Animals as well as plants defend themselves chemically against predators. Myriads of ways to deter predation have evolved. Many chemicals have more than one function, being aimed not only at predators but also at parasites, prey, or conspecific competitors. As common denominator of allomones we assume that the inclusive fitness of the sender - rather than the receiver - is enhanced. Chapter 10 deals with defenses by animals, and Chapter 11 with plant defenses against herbivores. 

Invertebrate allomones that deter vertebrate predators 10.7.1 Taste aversion to invertebrate prey... 

Table 10.3 Allomones invertebrate compounds that deter vertebrate predators...

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