Aggregation compounds

Pheromones are used as sex attractants in courtship, warning substances, or aggregation compounds (to cause members of their species to congregate). 

The protocols to aggregate compound-specific PAF values to a single risk estimate for a mixture of compounds are derived from common toxicological theories on joint effects of compounds. As already proposed by van Straalen and Bergema (1995), these protocols may be applied after corrections for differences in bioavailability among test media and the actual field conditions have been made, if the necessary information is available. This adaptation to reflect actual exposure is conceptually motivated by the common theory of molecule-receptor interactions, which... 

M.W. and stereoregularlty)of the resulting polymers d end critically on their structural characteristics these Include not only the composition, but also the size (degree of association) and the shape (coordination nunher and geometry around the metals) of these coordlnatlvely aggregated compounds. These pareuneters, obviously difficult to determine directly and Independently, depend in a very sensitive manner on slight variations in the synthesis conditions, as shown by changes in kinetic data and product characteristics. 

Among the well-known offenders with nonleadlike properties are protein-reactive compounds, warhead-containing agents, frequent hitters, and aggregator compounds (Table 1.1) [18]. Computationally, the elimination of reactive and... 

Although pheromones are secreted by insects in extremely small amounts, they can cause profound and varied biological effects. Some insects use pheromones in courtship as sex attractants. Others use pheromones as warning substances, and still others secrete chemicals called aggregation compounds to cause members of fheir species to congregate. 

Figure 4.11 Two possibilities for the formation of a Carpophilus beetle aggregation compound suggested by the investigators knowing that the last step is not decarboxylation. The broad lines indicate the individual acid units for clarity. Reduction of carbonyl groups and dehydration of the resulting alcohols are requiredfrom the intermediates to give the final products...

Figure 4.12 Structures of some other aggregation compounds from Carpophilus beetles.

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