Silk moth hormone

JUNVENILE HORMONES. One of several hormones, that retard the development of insects in the larval stage. So called because they prevent the insect from maturing by maintaining its juvenile characteristics. Obtained naturally from silk moths various syntheses indicate possible use as insecticides, especially for fire ants. Composition of one type is C18H30O3. 

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 ... 

Show how you would use a Suzuki reaction to synthesize Bombykol, the sex hormone of the silk moth, from cis-1-bromopent- 1-ene and the acetylenic alcohol shown below. 

Sterols. A considerable amount of work was devoted to the study of backbone rearrangements. - While partial syntheses of an insect moulting hormone, ecdysone, were announced by several groups, evidence is accumulating on the widespread occurrence in natxire of its hydroxylated derivatives. This year saw the isolation of 20-hydroxy-ecdysone - - from silkworm (ecdysterone), crayfish - (crustecdysone), oak-silk moth, tobacco hornworm, and from plants such as Podocarpus nakaii, Podocarpus elatus, and Achyranthis. The ready isolation of insect-moulting hormones from plants in contrast to -the extremely poor... 

A further hormonal factor, the diapause hormone is only indirectly related to the development. This substance is produced in the sub-esophageal ganglion and has been extracted therefrom . In the silk moth it determines the diapause in the development of the eggs. Similar arrests of development have been observed in the caterpillar and pupal stages their occurrence is often related to environmental conditions. How far the diapause factor of the sub-esophageal ganglion plays a part has not yet been determined. 

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... 

The biosynthesis of the insect juvenile hormone (19) continues to present incorporation problems. The acid 10-epoxy-7-ethyl-3,ll-dimethyltrideca-2,6-dienoic acid (20) acts as a substrate for the hormone in the giant silk moth, Hyalopkora cecropia. L-Methionine gave the ester methyl group. However, it did not contribute to the carbon skeleton whilst farnesol, farnesol pyrophosphate, propionate, and mevalonate were apparently not utilized for the biosynthesis of the hormone under the conditions of these experiments. There was a very low incorporation of [2- C]acetate into juvenile hormone. 

Polarimeters for measuring optical rotation are so sensitive that they can measure rotations to 0.001°, an important fact when only small amounts of sample are available. Ecdysone, for example, is an insect hormone that controls molting in the silk- j worm moth. When 7.00 mg ecdysone was dissolved in 1.00 mL chloroform and the solution was placed in a cel with a 2.00 cm pathlength, an observed rotation dT -I-0.087° was found. Calculate [a]n for ecdysone. 

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... 

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