Feeding deterrence

Marine corals secrete organohalogen compounds that act as a feeding deterrent to Starfish. 

A cyclobutene ROCM sequence was also used in a synthesis of racemic sporochnol (410), a naturally occurring feeding deterrent toward herbivorous fish (Scheme 80) [170]. Exposing cyclobutene 406 (0.01 M in boiling 1,2-dichloroethane) in the presence of ethylene to second-generation catalyst C (8 mol%) led to 1,5-diene 407 in 73% yield, along with 9% of the homodimer derived from 407 by involving the less hindered double bond. Site-selective hy-... 

Chauhan, K.R. et al.. Feeding deterrent effects of catnip oil components compared with two synthetic amides against Aedes aegypti, J. Med. EntomoL, 42, 643, 2005. 

Flavonoids and other phenolic compounds released by plant roots have important functions in plant-pathogenic interactions, feeding deterrence, nematode resistance, and allelopathic interactions they also serve as signal molecules for the establishment of symbiotic associations (72,149). However, a detailed analysis of signaling pathways involved in these interactions is currently available in only a limited number of cases (see also Chap. 7). 

The role of antiproliferative effects of an activated defense reducing the next generation of herbivores compared with the straightforward action of toxins or feeding deterrent metabolites in the evolutionary arms race is still under discussion. The proposed mechanism suggests natural selection at the group level,... 

One example for a chemically defended zooplankton species is the Antarctic pteropod Clione antarctica. This shell-less pelagic mollusk offers a potentially rich source of nutrients to planktivorous predators. Nonetheless fish do not prey on this organism, due to its efficient chemical defense. In a bioassay-guided structure elucidation, pteroenone 37 could be isolated and characterized as the main defensive principle of C. antarctica [82,83]. If embedded in alginate, this compound is a feeding-deterrent in nanomolar concentrations. This unusual metabolite is likely to be produced by C. antarctica itself and not accumulated from its food, since its major food sources did not contain any detectable quantities of 37. 

Faulkner DJ (1988) Feeding deterrents in molluscs. In Fautin DG(ed) Biomedical importance of marine organisms, California Academy of Sciences, San Francisco, p 29... 

Cronin G, Paul VJ, Hay ME, Fenical W (1997) Are tropical herbivores more resistant than temperate herbivores to seaweed chemical defenses Diterpenoid metabolites from Dictyota acutiloba as feeding deterrents for tropical versus temperate fishes and urchins. J Chem Ecol 23 289-302... 

Most of the species that produce DMSP can also cleave it, suggesting that DMSP is produced in order to be able to rapidly generate its breakdown products or to use the cleavage reaction as a means of regulating intracellular concentrations of DMSP, carbon, or sulfur (Stefels 2000). The cleavage products of DMSP have been hypothesized to function as antioxidants (Sunda et al. 2002 Ross and Van Alstyne 2007), antibiotics (Sieburth 1960, 1961), and herbivore feeding deterrents (Wolfe et al. 1997 Van Alstyne et al. 2001b Van Alstyne and Houser 2003). A more detailed description of each of these functions is described in what follows. 

Only a few compounds or mixtures of compounds have been shown beyond doubt to be mammalian pheromones. This is the main reason why the subject matter of this chapter is not restricted to pheromones and why exocrine secretions and other mammalian excretions in general will be discussed as possible sources of pheromones, even though their role in the chemical communication of the species under discussion has not yet been established. Feeding deterrents are not discussed. In general defensive secretions are also not discussed, but the anal sac secretions of the mustelids are included, because it is possible that these secretions could also fulfill a semiochemical role, in addition to being used for defense. 

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