Learning secondary metabolites

Most studies in marine chemical ecology examine the effects of secondary metabolites on consumers as the initial payability of whole organisms, crude extracts, or isolated metabolites. Although the effectiveness of chemical defenses can depend on the experiences of the consumer, especially when the consumer has repeated experience with chemical defenses,210,213,255-257 only a few studies in marine chemical ecology have examined the ability of consumers to learn about chemical defenses.206,210,213,258-260 In addition to constantly rejecting foods of low palatability, consumers may increase their acceptance of initially unpalatable foods that have positive post-ingestive... 

In retrospect, neither of these important antimicrobial agents could have been developed if Lilly did not have a fully integrated natural products discovery group that included scientists dedicated to bioconversions of natural products and medicinal chemists dedicated to modifying complex cyclic peptides and other secondary metabolites. This may be a lesson learned to help guide antibiotic discovery and development in the 21st century. 

We will now examine, in Experiment [IIC], a third class of secondary metabolites the essential of/s.The majority of these materials are high-boiling liquids that can be extracted from plant material via steam distillation techniques. The value of codisfilling high-boOing substances was learned early in the days of alchemy. Because fhese oils often gave pleasant odors and flavors, they were considered to be the "essence"of the original plant material. Eventually, they became known as essential oils. 

One of the most instructive examples related to the mystery of chemical-mediated relations between plants and animals was described by Meinwald. Alkaloids (natural compounds traditionally referred to as secondary , i.e. non-important, metabolites) are amply produced by various plants. In many cases, alkaloids have been shown to be part of a defense system against various herbivores. However, some plant-eating insects learned to break through this... 

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