Botanical insecticides have long been touted as attractive alternatives to synthetic chemical insecticides for pest management because botanicals reputedly pose little threat to the environment or to human health. The body of scientific literature documenting bioactivity of plant derivatives to arthropod pests continues to expand, yet only a handful of botanicals are currently used in agriculture in the industrialized world, and there are few prospects for commercial development of new botanical products. Pyrethrum and neem are well established commercially, pesticides based on plant essential oils have recently entered the marketplace, and the use of rotenone appears to be waning. A number of plant substances have been considered for use as insect antifeedants or repellents, but apart from some natural mosquito repellents, little commercial success has ensued for plant substances that modify arthropod behavior. Several factors appear to limit the success of botanicals, most notably regulatory barriers and the availability of competing products (newer synthetics, fermentation products, microbials) that are cost-effective and relatively safe compared with their predecessors. In the context of agricultural pest management, botanical insecticides are best suited for use in organic food production in industrialized countries but can play a much greater role in the production and postharvest protection of food in developing countries.

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Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world

Privileged substructures are of potentially great importance in medicinal chemistry. These scaffolds are characterized by their ability to promiscuously bind to a multitude of receptors through a variety of favorable characteristics. This may include presentation of their substituents in a spatially defined manner and perhaps also the ability to directly bind to the receptor itself, as well as exhibiting promising characteristics to aid bioavailability of the overall molecule. It is believed that some privileged substructures achieve this through the mimicry of common protein surface elements that are responsible for binding, such as β- and gamma;-turns. As a result, these structures represent a promising means by which new lead compounds may be identified.

The combinatorial synthesis of bicyclic privileged structures or privileged substructures

The biochemistry and medical significance of the flavonoids.

Continued growth and intensi¢cation of aquaculture production depends upon the development of sustainable protein sources to replace ¢sh meal in aquafeeds. This document reviews various plant feedstuis, which currently are or potentially may be incorporated into aquafeeds to support the sustainable production of various ¢sh species in aquaculture. The plant feedstuis considered include oilseeds, legumes and cereal grains, which traditionally have been used as protein or energy concentrates as well as novel products developed through various processing technologies. The nutritional composition of these various feedstuis are considered along with the presence of any bioactive compounds that may positively or negatively aiect the target organism. Lipid composition of these feedstuis is not speci¢cally considered although it is recognized that incorporating lipid supplements in aquafeeds to achieve proper fatty acid pro¢les to meet the metabolic requirements of ¢sh and maximize human health bene¢ts are important aspects. Speci¢c strategies and techniques to optimize the nutritional composition of plant feedstuis and limit potentially adverse eiects of bioactive compounds are also described. Such information will provide a foundation for developing strategic research plans for increasing the use of plant feedstuis in aquaculture to reduce dependence of animal feedstuis and thereby enhance the sustainability of aquaculture.

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Expanding the utilization of sustainable plant products in aquafeeds: a review

Dietary phenolics: chemistry, bioavailability and effects on health.

Revised structure of a flavonoid from the fern notholaena aschenborniana

Flavonoids from Brickellia scoparia

Flavonoids from Ageratina saltillensis

Sesquiterpene lactones from Gaillardia pulchella

The pheromone produced by females of Manduca sexta (L.) (Lepidoptera: Sphingidae) was identified as a blend of the 16-carbon aliphatic aldehydes hexadecanal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (E)-11-hexadecenal, (E,Z)-10,12-hexadecadienal, (E,E)-10,12-hexadecadienal, (E,E,Z)-10,12,14- hexadecatrienal, and (E,E,E)-10,12-14-hexadecatrienal (Starratt et al. 1979; Christensen et al. 1989a; Tumlinson et al. 1989). Subsequently, we showed that fatty acyl analogs of the pheromone aldehydes are present in the pheromone glands of females from about 3 or 4 days prior to adult eclosion until the adults are 8 days old or until death (Fang et al. 1992). By determining the fate of deuterium-labeled fatty acids applied to the gland, we also found that hexadecanoate is the precursor of the 16-carbon unsaturated pheromone aldehydes and fatty acids produced in the gland. Hexadecanoate is converted to (Z)-11-hexadecenoic acid and (E)-11-hexadecenoic acid by All-desaturases, and (Z)-11-hexadecenoic acid is further desaturated and isomerized to the conjugated diene and triene 16-carbon fatty acids (Fang et al. 1995a). The deuterium labeling studies also showed quite clearly that the fatty acids in the gland were the precursors of the aldehydic pheromones. Normally, the aldehydes are produced and released only during the scotophase when the female is calling. However, injection of pheromone biosynthesis activating neuropeptide (PBAN) at any time of the photoperiod into the abdomens of females of any age resulted in production of the pheromone aldehydes after about an hour (Fang et al. 1992). Our labeling studies indicated, but did not prove, that the role of PBAN in regulating pheromone biosynthesis in this species was to activate the enzymes that convert the fatty acids stored in the gland into the analogous aldehydes.

Nianbai Fang

Papers

Revised structure of a flavonoid from the fern notholaena aschenborniana

Flavonoids from Brickellia scoparia

Flavonoids from Ageratina saltillensis

Sesquiterpene lactones from Gaillardia pulchella

The Effect of PBAN on Conversion of Fatty Acyls to Pheromone Aldehydes in Female Manduca sexta