Cecropia moths

FIGURE 10.36 Adult (left) and caterpillar (right) stages of the cecropia moth,... 

Scheme 14 illustrates Linstrumelle s synthesis of (9Z,11 )-9,11,13-tetradeca-trienyl acetate (8), the pheromone of the pyralid moth, Stenoma cecropia [25]. The key steps were palladium and copper-catalyzed Sonogashira couplings (A+B and C+D). Another noteworthy feature in this synthesis was the use of activated zinc dust in aqueous methanol for the reduction of the triple bonds of E to give two double bonds of 8. 

CO the Cecropia moth, they could induce the synthesis of more than a dozen antibacterial ... 

A number of compounds important to animal physiology have been identified as isoprenoid compounds. Notable examples are vitamin A, retinal (Section 28-7), and squalene (Table 30-1). Also, terpene hydrocarbons and oxygenated terpenes have been isolated from insects and, like famesol, show hormonal and pheromonal activity. As one example, the juvenile hormone isolated from Cecropia silk moths has the structure shown in 3 ... 

Looking first at the C-2, C-3 double bond of the cecropia moth s growth hormone... 

Strong electric fields and currents have been measured in a number of multicellular systems ranging from Fucus at the two cell state, a Cecropia moth oocyte-nurse cell cyncytum, amphibianand rodent limbs in regeneration and man (8, 22, 28, 3) Thus it is imperative to develop a formulation of multicellular phenomena. 

C. M. Williams ( 1) prepared the first active extract from the cecropia moth and showed that this extract prevented adult development when applied to insect pupae. Treated pupae molted into morphogenetic monsters and died. Treatment of other stages produced no ill effects. From these studies it became clear that during the transformation of the immature insect into the adult (during the pupal stage) the juvenile hormones must be absent. This short developmental period is completely deranged when supplied with JH. 

Phvtoluvenolds. Wigglesworth (JL) demonstrated that a hormone secreted by the insect corpora allata was responsible for the control of differentiation in immature insects and reproduction in adult female insects. Williams (3) prepared an active extract of this hormone from adult male cecropia moths and called it "juvenile hormone". We were able to derive sufficient knowledge of the chemistry of the juvenile hormone from the study of the active cecropia extract to synthesize JH III Q). Seven years later its presence as a natural hormone in the tobacco hornworm was confirmed Ci). Three other analogous juvenile hormones (JH 0, I, II) have been found to occur only in lepidoptera (5, ., 2.) (Figure 1). Juvenile hormone III is the principal juvenile hormone of insects and has been demonstrated in all of the insect taxa investigated. 

A cecropia moth Hyahphora cecropia) in Royal Oak, Michigan. Adults of this species are seen increasingly in urban areas, and often during the day. Photograph by Robert J. Huffman. Field Mark Publications. Reproduced by permission. 

The structure of the juvenile hormone of the moth Hyalophora cecropia was confirmed by the following synthesis. (At each stage where geometric isomers were obtained, these were separated and the desired one—(Z) or ( )—was selected on the basis of its nmr spectrum.)... 

As early as 1934 Wigglesworth showed that the evolutionary differentiation of insects is regulated by a centre in the brain. In 1956 Williams obtained from Cecropia moth a highly active extract which produced anomalies in the metamorphosis of experimental insects. Following this first description of the action of juvenile hormone, Gilbert and Schneiderman (1958), then Williams et al. (1959) described the juvenile hormone action of lipid extracts obtained from different mammalian organs. The pure active substance was isolated first by Schmialek (1961) from feces of the yellow mealworm, Tenebrio Molitor, and identified as famesol (1), known as an intermediate product in steroid biosynthesis. Six years later, Roeller and co-workers (1967) elucidated the structure of the juvenile hormone isolated from the male of Cecropia. The hormone was ascribed the structure methyl ( , )-3,11-dimethyl-10,ll-epoxy-7-ethyl-2,6-tridecadienoate (2), and was called C,g-JH. Independent of these workers, Meyer et al. (1968) isolated also from Cecropia another juvenile hormone, ( , )-10,11-epoxy farnesenate (3), called C,g-JH. 

Antifungal compounds in insects are not limited to small molecules. For example, the larvae of many insects have been found to contain antimicrobial proteins, notably in cecropia moths [147]. Because these types of compounds have been shown to be ubiquitous, occurring in vertebrates as well as plants and insects, their discussion is relegated to a subsequent section. 

Cecropins. Cecropins (169) were isolated from the larval hemolymph of the giant silkworm moth, Hyalophora cecropia, on the basis of their antibacterial activity subsequent to bacterial injection. Cecropins are also produced by Drosophila (170) and the larva of the tobacco homworm, Manduca sexta (110). Similar compounds called sarcotoxins (171) are produced by the flesh fly, Sarcophaga. Cecropins (169) are specific for prokaryotic cell lysis in contrast to melittin, which lyses eukaryotic cell membranes as well. Cecropins are characterized structurally by a concentration of basic... 

Figure 2 Oxygen uptake by a diapausing silk moth pupa (Hyalophora cecropia) in the chilled (undercooled) andfrozen states, showing the injurious effects of freezing...

A typical example of an application of ozonolysis in synthesis is the cleavage of the alkene unit in 351 to give aldehyde 352, with loss of formaldehyde, a part of Smith s synthesis of (+)-thiazinotrienomycin In this case, the reductive workup used triphenylphosphine. Ozonolysis of 353 gave aldehyde 354, an intermediate in Corey s synthesis of the Cecropia Moth Juvenile hormone, via a reductive workup with DMS. Note that the electron rich vinyl ether moiety reacted in preference to the simple alkene moiety. The ozonolysis product of the methyl vinyl ether was a methyl ester. This method is particularly useful for the preparation of protected acids. In general, electron rich alkenes are oxidized faster than electron-poor alkenes. 

Hyalophara cecropia (silk moth) flight muscle, (mem- trehalose 6.5 3.6 mAf 136... 

Cecropins, a group of insect-derived antimicrobial peptides first isolated from Drosophila and from the pupae of the giant silk moth Hyalophora cecropia, from which the name is derived. Cecropin A,... 

Paracentrotus lividus) silk moth pupae (Hyalophora cecropia) yes 111... 

Ozonolysis of an enol ether provides a carboxylic ester, as one of the two carbonyl products. For example, the enol ether 103 (formed by Birch reduction - see Section 7.2) was converted to the ester-alcohol 104, used in a synthesis of the Cecropia moth juvenile hormone (5.103). This example illustrates the preferential oxidation of the more electron-rich alkene by the electrophilic ozone. 

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