Juvenile hormone, structure

Kraker, J. J., Hawkins, D. M., Basak, S. C., Natarajan, R., Mills, D. Quantitative structure-activity relationship (QSAR) modebng of juvenile hormone activity Comparison of validation procedures. Chemometr. Intell. Lab. Syst. 2007, 87, 33M2. 

Draw the structure of Cecropia juvenile hormone and process it automatically. Save only the intermediate precursors which finally lead to the bicyclic compound B used by the Syntex group. 

Figure 5. Structures of the Insect Juvenile Hormone 3 and a Commercially Available Analog, Methoprene...

One of the insect neurohormones, the activation hormone, controls the secretion of the corpora allata, paired glands that synthesize the juvenile hormone (Fig. 22-4) in insect larvae. While the structure of the juvenile hormone varies somewhat with species, it is usually a polyprenyl ester. A specific binding protein provides the hormone with protection from degrada-tive enzymes. However, in the tobacco homworm an esterase, able to hydrolyze the protein-bound juvenile hormone, is produced at the start of pupal differentiation.354 The exact mechanism of action of juvenile hormones has been difficult to determine. However, it affects polyamine synthesis.355 356... 

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 ... 

The structure was established by an impressive combination of chemical, spectroscopic, and synthetic methods with about 200/xg of pure compound isolated from the abdomens of a myriad of male moths.1 (Some aspects of synthetic work on juvenile hormone are incorporated in Exercise 30-9.)... 

Exercise 30-9 The synthesis of Cecropia juvenile hormone outlined below was designed by E. J. Corey and co-workers. Draw in the structure of the product (as i, ii, etc.) at each stage where this has been omitted, and write above the arrows the reagents and conditions necessary to accomplish reactions where these have been omitted. (To save space, the abbreviation R and R are used to designate parts of the structure that do not change in later steps.)... 

Structure of /3-ecdysone and juvenile hormone. These hormones play major roles in the growth and maturation of insects by controlling the timing for molting of the insect exoskeleton. 

Tittiger C., Barkawi L. S., Bengoa C. S., Blomquist G. J. and Seybold S. J. (2003) Structure and juvenile hormone-mediated regulation of the HMG-CoA reductase gene from the Jeffrey pine beetle, Dendroctonus jejfreyi. Mol. Cell. Endocrin. 199, 11-21. 

Several authors have investigated the role of juvenile hormone (JH) in hydrocarbon signatures. Sledge et al. (2004) performed one such study based on measuring the size of the corpora allata as an indicator of JH levels. Since caste determination depends strictly on the colony social structure, it can be assumed that topical JH application mimics natural caste development and thus modifies the cuticular caste-specific odor. Based on this assumption,... 

Another developmental hormone is the juvenile hormone, which predominates early in larval life later ecdysone predominates. It is a methyl ester of the epoxide of a fatty acid derivative, and there is some evidence that its structure differs in different groups of insects. By a series of coincidences, it was discovered that certain paper toweling prevented the European bug, Pyrrhocoris apterus, from developing into sexually mature adults. Instead, an extra one or two larval molts ensued, and all eventually died without being able to complete metamorphosis. The juvenility factor was traced to particular conifers used in American paper pulp, mainly Abies balsamea, Tsuga canadensis, Taxus brevifolia, and Larix laricina. The active principle was isolated and characterized. It... 

In the next examples, formaldehyde makes a primary alcohol from two deprotonated alkynes. The second reaction here (for which we have shown organolithium formation, reaction, and quench simply as a series of three consecutive reagents) forms one of the last steps of the synthesis of Cecropia juvenile hormone whose structure you met right at the beginning of the chapter. 

You may think that this method is rather too trivial to be called a method for controlling the geometry of double bonds, as it s only of any use for making cyclic alkenes. Well, chemists are more ingenious than that Corey needed this as-alkene as an intermediate in his synthesis of the juvenile hormone we talked about above (it forms the left-hand end of the structure as shown there),... 

The existence of a cytosolic epoxide hydrolase was first indicated by its ability to hydrolyze analogs of insect juvenile hormone not readily hydrolyzed by microsomal epoxide hydrolase. Subsequent studies demonstrated a unique cytosolic enzyme catalytically and structurally distinct from the microsomal enzyme. It appears probable that the cytosolic enzyme is peroxisomal in origin. Both enzymes are broadly nonspecific and have many substrates in common. It is clear, however, that many substrates hydrolyzed well by cytosolic epoxide hydrolase are hydrolyzed poorly by microsomal epoxide hydrolase and vice versa. For example, l-(4 -ethylphenoxy)-3,7-dimethy I -6,7-epoxy-//7//i,v-2-octene, a substituted geranyl epoxide insect juvenile hormone mimic, is hydrolyzed 10 times more rapidly by the cytosolic enzyme than by the microsomal one. In any series, such as the substituted styrene oxides, the trans configuration is hydrolyzed more rapidly by the cytosolic epoxide hydrolase than is the cis isomer. At the same time, it should remembered that in this and other series,... 

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