Systemic activity of a juvenile hormone analog

The peptidic analog of insect juvenile hormone, ethyl pivaloyl-L-alanyl-p-aminobenzoate with enormous biological activity on the red cotton bug, Dysdercus cingulatus, has pronounced systemic effect in sunflower plants. The compound is absorbed by the plant tissues and appears to be translocated throughout the plant system in active form. There is some evidence that juvenile hormone analogs of other types also have similar systemic effects. The discovery of systemic action should aid in the possible utilization of juvenile hormone analogs in insect control programs.     

Transition state analogs as ligands for affinity purification of juvenile hormone esterase

Insect juvenile hormones are metabolized in numerous species of caterpillars by low abundance, highly specific esterases. Because of their role in regulating and possibly disrupting juvenile hormone titer and thus insect metamorphosis, they are of interest to developmental biologists as well as scientists interested in selective insect control. However, the enzymes have defied attempts to purify and characterize them. Juvenile hormone esterase activity can be inhibited by a variety of 3-substituted 1,1,1-trifluoropropanone sulfides. These apparent transition state analogs were used as ligands and eluting agents to purify juvenile hormone esterase from four insect species from 500-fold to over 1000-fold in high yield. After elution from the affinity column, the enzymes were radiolabeled with paraoxon and analyzed by electrophoresis, and the results demonstrate a high degree of purity. Transition state analogs may be useful for the affinity purification of other enzymes.     

Peptides with juvenile hormone activity

Peptide derivatives of juvenile hormone analogs which show substantial hormonal activity for certain insects were prepared. The most active compound, L-isoleucyl-L-alanyl-p-aminobenzoic acid ethyl ester, was up to twice as active as juvabione. Like juvabione, the peptide analog showed selective action on pyrrhocorid bugs.     

化学放射法测定蜜蜂保幼激素酯酶活性

蜜蜂保幼激素(JH)是由蜜蜂咽侧体(CA)合成和分泌的一种氧化物。保幼激素酯酶是对蜜蜂体内呈游离态或结合态的保幼激素进行专化性降解的特异性酯酶。采用放射化学法(RC)测定了西方蜜蜂(Apis mellifera L．)不同日龄工蜂体内保幼激素酯酶(JHE)的活性。结果表明,工蜂体内保幼激素酯酶活性随着日龄的增大而下降。     

Juvenile hormone: activity of natural and synthetic synergists

A group of nonsesquiterpenoid compounds currently used commercially as insecticide synergists possesses a high order of juvenile hormone activity and species specificity.     

Juvenile hormone analogs: a possible case of mistaken identity?

Many synthetic compounds that exhibit activity in juvenile hormone assays have limited structural resemblance to natural juvenile hormones. The observed morphogenic action of many of the compounds considered to be biologically analogous to juvenile hormones is probably synergistic rather than intrinsically hormonal.     

Juvenile hormone action mediated in male accessory glands of Drosophila by calcium and kinase C

In an in vitro system for the Drosophila melanogaster male accessory gland, it was found that 10(-9)M juvenile hormone III could accurately mimic the copulation-induced response of increased protein synthesis in glands from virgin flies. Stimulation by this hormone required calcium in the medium. Experiments with tumor-promoting phorbol esters indicated that activation of protein kinase C can also cause the glands to increase protein synthesis. Stimulation of protein synthesis by juvenile hormone did not occur in mutants deficient in kinase C activity. These results suggest a membrane-protein-mediated effect of juvenile hormone that involves calcium and kinase C.     

Insect juvenile hormones: highly potent synthetic mimics

The substitution of a 7-alkoxy group for the 6,7-epoxy moiety in aryl terpenoid ethers having high juvenile hormone activity has produced several compounds exceptionally active against Tenebrio molitor. The most potent compound [7-ethoxy-1-(p-ethylphenoxy)-3,7-dimethyl-2-octene, called JH-25] is active at the level of 10 picograms per insect, or about 100 times more active than other promising juvenile hormone mimics so far reported. Compound JH-25 was also active against Tribolium confusum.     

昆虫保幼激素及其类似物的应用研究进展

介绍了昆虫保幼激素及其类似物应用于杀虫剂和昆虫生长调节剂的研究情况,并展望了昆虫保幼激素及其类似物的应用前景。     

Juvocimenes: potent juvenile hormone mimics from sweet basil

Two compounds with highly potent juvenile hormone activity were isolated and identified from the oil of sweet basil, Ocimum basilicum L., Labiatae.     

JH Zero: New Naturally Occurring Insect Juvenile Hormone from Developing Embryos of the Tobacco Hornworm

A new insect juvenile hormone was isolated from developing embryos of the tobacco hornworm moth, Manduca sexta. The new hormone was found with juvenile hormone I and is a 1-carbon homolog of this substance. The assigned structure is methyl (2E,6E,10-cis)-10,11-epoxy-3,7-diethyl-11-methyl-2,6-tridecadienoate, which constitutes a trishomosesquiterpenoid skeleton. This is the first chemical idetification of any juvenile hormone from insect eggs.     

Soldier determination in ants: new role for juvenile hormone

Topical application of juvenile hormone analog induces soldier development in the ant Pheidole bicarinata. Soldier induction takes place if the juvenile hormone analog is present during a period of sensitivity that occurs during the last larval instar. Control of worker dimorphism seems to be accomplished through control of timing of metamorphosis. The smallest size at which metamorphosis can be initiated is shifted upwardfrom 1.2 to 1.7 millimeters by exposure to the juvenile hormone analog during the sensitive period.     

网目缩结对盘锦海域桁杆虾拖网网囊的选择性影响

为研究盘锦海域桁杆虾拖网网囊结构的调整,掌握网囊网目在不同缩结系数0.99、0.95、0.91时对桁杆虾拖网捕获葛氏长臂虾Palaemon gravieri和脊尾白虾Palaemon carinicauda的选择性影响,采用套网法对不同缩结系数的网囊网目进行了选择性试验。结果表明:随着网囊网目缩结系数的减小,两种虾的选择性曲线向右偏移,较小体长范围内虾的选择率变小,说明可以释放一定数量的幼虾;但当所捕获的葛氏长臂虾和脊尾白虾体长达到某一值时,缩结系数的减小对两种虾的选择性已无明显影响,当缩结系数为0.95、0.91时,对应葛氏长臂虾体长分别为42.5、52.5 mm,对应脊尾白虾体长均为47.5 mm。研究表明,缩结系数降低后,两种虾的选择范围均变小,选择性尖锐度变强,本研究结果可为桁杆拖网过渡期的合理利用和保护渤海海域幼虾类资源提供科学依据,也可为过渡期后的桁杆虾拖网归属问题提供一些理论参考。     

Juvenile hormone induction of biting behavior in culex mosquitoes

Juvenile hormone deprivation caused by surgical removal of corpora allata shortly after adult emergence blocked the initiation of biting behavior in Culex. pipiens and Culex quinquefasciatus. Reimplantation of corpora allata or injection of a synthetic juvenile hormone (JH-I) corrected the juvenile hormone deficiency and restored biting behavior. Ovariectomy experiments demonstrated that this behavioral effect of juvenile hormone was independent of ovarian involvement.     

Insect juvenile hormone: activity of selected terpenoid compounds

A nuimber of compounds with terpenoid skeletons attached to various functional groups were prepared and tested for their effects as a juvenile hormone in the yellow mealworm Tenebrio molitor. Several of these compounds showed high activity.     

Juvenile hormone: identification of an active compound from balsam fir

A sesquiterpenoid ester with high juvenile hormone activity for Pyrrhocoris apterus (L.) was isolated from balsam fir, Abies balsamea (L.) Miller, and identified as the methyl ester of todomatuic acid.     

Antiallatotropins: inhibition of corpus allatum development

Treatment of newly eclosed adult milkweed bug (Oncopeltus fasciatus) females with precocene 2 prevents secretion of juvenile hormone by inhibition of postimaginal development of the corpus allatum. Ovarian development which is dependent upon juvenile hormone is prevented or reversed, depending upon the timing of precocene treatment. Juvenile hormone secretion is shown to be related to the development of the corpus allatum.     

Juvenile hormone mimics: effect on cirriped crustacean metamorphosis

A synthetic juvenile hormone mimic has been shown to cause premature metamorphosis of the cyprid larva of an acorn barnacle in concentrations as low as 10 parts per billion in filtered seawater. The effect of a juvenile hormone mimic on a crustacean has not previously been demonstrated.     

Juvenile Hormone Activity: Effects of Isoprenoid and Straight-Chain Alcohols on Insects

A wide variety of alcohols, applied topically or injected into pupae of the yellow mealworm, Tenebrio niolitor L., exhibit juvenile hormone activity. Inclulded among these comipounds are saturated and unsaturated alcohols with 8 to 15 carbon atoms, in straight-or branched-chains. Ether derivatives of several of these alcohols fuirther enhance the activity.     

Prevention of metamorphosis by exposure of insect eggs to juvenile hormone analogs

Metamorphosis of the bugs Pyrrhocoris apterus and Oncopeltus fasciatus is blocked by the application of juvenile hormone analogs to the eqgs 4 weeks earlier. One or more supernumerary larval molts occur to form "giant" larvae which routinely die without undergoing netamorphosis. When the corpora allatta were excised at the outset of the fifth larval stage, the entire phenomenon vanished and all individuals underwent normal metamorphosis. The inhibition of metamorphosis can therefoore be attributed to a continuation of the secretion of endogenous juvenile hormone by the corpora allata of mature larvae deried from eggs treated with juvenile hormone.