Hyalophora cecropia

Recently, a variety of natural peptides that form transmembrane channels have been identified and characterized. Melittin (Figure 10.35) is a bee venom toxin peptide of 26 residues. The cecropins are peptides induced in Hyalophora cecropia (Figure 10.36) and other related silkworms when challenged by bacterial infections. These peptides are thought to form m-helical aggregates in mem-... 

Proteins cecropins (induced from immune resprxise in Hyalophora cecropia L., Lepidoptera, and other Ins. frcm various regions MI). 

One of the most well-known examples of insect toxins is melittin, a bee venom peptide with potent haemolytic activity. Melittin adopts an a-helical conformation, and has been extensively characterised using a range of techniques, including both solution- and solid-state NMR spectroscopy.176 Some helical peptides with antimicrobial activity have also been found in wasps, such as eumenine mastroparan-AF (EMP-AF-NH2) from the venom of the solitary wasp Anterhynchium flavormarginatum micado,177 and the cecropins found in the haemolymph of Hyalophora cecropia.178 Several of these peptides have cytotoxic activity and are potential anticancer agents.179... 

Hyalophora cecropia Saturnidae Lepidopiera N-terminal sequence 14... 

Eggs from Hyalophora cecropia (Telfer, 1960), Samina cynthia (Chino et al., 1977), M. sexta (Kawooya et al., 1988), and R. prolixus (Gondim et al., 1989b) have been shown to contain a very high-density lipophorin, VHDLp-E, which is derived from HDLp-A in the hemolymph by a receptor-mediated process (Kawooya et al., 1988 Telfer and Pan, 1988 Kulakosky and Telfer, 1990) this represents the only known exception to the generalization that lipophorin delivers its lipids to tissues without internalization. The conversion of HDLp-A to VHDLp-E involves removal of DG, which is catalyzed by a lipoprotein lipase found in the yolk body of the egg (Van Antwerpen and Law, 1992). However, in spite of the presence of lipophorin in the egg, 90% of the lipid in the egg is... 

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.)... 

What is the structure of the juvenile hormone of Hyalophora cecropia Account for the fact that the synthesis yields a racemic modification. 

Synthesis of olefins1 (see Triethylphosphonoacetate, 1, 1217). The trimethyl ester was used in two key steps in the synthesis of the juvenile hormone of Hyalophora cecropia, methyl trans,trans,cj j-10,1 l-epoxy-7-ethyl-3,ll-dimethyl-2,6-tridecadieno-ate (formula I) the reagent was used in the preparation of ds-II and of trans,cis-Vll. 

This pathway or variations of it occur in other insect species. The ethyl branches of the higher JH homologs found in the Lepidoptera (Fig. (1)) are derived from isoleucine and valine which are first metabolized to propionate and then incorporated, instead of acetate, in the early steps of biosynthesis [72, 73], The sequence of the final steps of JH biosynthesis may also be different in these insect species. In the adult female CA of some Lepidoptera, epoxidation of famesoic acid to the JH acid occurs before the final methylation step [64,65, 71]. Interestingly, in larval stages of the tobacco homworm, M. sexta, and adult males of the silkworm, Hyalophora cecropia, the CA synthesize and release JH acids into the... 

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...

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... 

Another example of a sesquiterpene-derived insect juvenile hormone is that of the giant silkworm moth, Hyalophora cecropia (Fig. 21.18). Several juvenile hormone mimics have been found in plants (Bowers, 1985,1991,1992 Fraga, 1991 Menn and Beroza, 1972). 

Juvenile hormone, larval hormone, stalus-quo hormone insect hormone responsible for the control of molting. The first J.h. to be isolated and structurally elucidated was obtained from the abdomens of the male silk worm moth (Hyalophora cecropia) in 200 ig quantities. Homologs of this compound were discovered later, and other J.h. were postulated. Juva-bione (see) and famesol derivatives are among the... 

Scriber, J. M. (1977) Limiting effects of low leaf water content on the nitrogen utilization, energy budget and larval growth of Hyalophora cecropia (Lepidoptera Saturniidae). Oecologia, 28, 269-87. 

In many insects, for example in the large silk moth Hyalophora cecropia, a large amount of the juvenile hormone is stored. In most species it is inactive, or is so bound that it is no longer extractable. In Tenebrio, excretion in the faeces heis been observed" , the substance being identified as famesol. 

Juvenile hormone (JH) is a substance that controls metamorphosis in insects. It is produced by the male wild silk moth, Hyalophora cecropia L., and its presence delays the maturation of insect larvae until the appropriate... 

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