Results 121 to 130 of about 2,178 (156)

Ecdysteroid biosynthesis in crayfish Y‐organs: Feedback regulation by circulating ecdysteroids

Archives of Insect Biochemistry and Physiology, 1999
In crustaceans, ecdysteroid synthesis in the Y-organs is negatively regulated by the molt-inhibiting hormone (MIH). Reduction or cessation of MIH release from the sinus gland in the eyestalk, probably due to environmental cues, is one of possibly several signals for an increase of edysteroid production and subsequently enhancement of 20-hydroxyecdysone
, Dell, , Sedlmeier, , Bocking, , Dauphin-Villemant   +3 more
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Ecdysteroids and Ecdysteroid Signaling Pathways During Insect Oogenesis

2009
During insect oogenesis, the oocyte acquires nutrients and genetic determinants to support embryonic development (previtellogenesis and vitellogenesis) and subsequently becomes surrounded by a protective eggshell (choriogenesis). In many insects, ecdysteroids are synthesized during ovarian growth which is often followed by the accumulation of ...
Luc Swevers, Kostas Iatrou
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Ecdysteroids inLimulus larvae

Experientia, 1979
Free ecdysteroids were extracted from intermolt and premolt larvae ofLimulus polyphemus in the first posthatch stage, purified by TLC and HRLC, and assayed by RIA and theLimulus bioassay 20-hydroxyecdysone appears to be a principal ecdysteroid and occurs at least 3 times higher a concentration in premolt vs intermolt animals.
T. C. Jegla, J. D. Costlow
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New ecdysteroid and ecdysteroid glycosides from the roots of Serratula chinensis

Journal of Asian Natural Products Research, 2016
Three new ecdysteroid glycosides (1-3) and one new ecdysteroid (4), were isolated from the roots of Serratula chinensis. Their structures were established on the basis of extensive spectroscopic analysis and chemical methods.
Zhang, Zi Yue, Yang, Wei Qun, Fan, Chun Lin, Zhao, Hui Nan, Huang, Xiao Jun, Wang, Ying, Ye, Wencai   +6 more
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Ecdysteroid Chemistry and Biochemistry

2005
Ecdysteroids are arthropod steroid hormones controlling development and reproduction. Their main representative is 20-hydroxyecdysone synthesized from cholesterol, but some species produce slightly different molecules using phytosterols as starting material.
Lafont, René, Dauphin-Villemant, C., Warren, J.T., Rees, H.H.   +3 more
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Ecdysteroid metabolism in crustaceans

The Journal of Steroid Biochemistry and Molecular Biology, 2011
The molting gland, or Y-organ (YO), is the primary site for ecdysteroid synthesis in decapod crustaceans. Ecdysteroid biosynthesis is divided into two stages: (1) conversion of cholesterol to 5β-diketol and (2) conversion of 5β-diketol to secreted products.
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The ecdysteroid receptor

Invertebrate Reproduction & Development, 1990
Summary The steroid molting hormone of insects and other arthropods regulates gene activity in target tissues through its association with a specific, high affinity receptor protein. In this review we summarize recent advances in several areas of ecdysteroid receptor research, including efforts to characterize and purify the receptor protein ...
HANS J. BIDMON, TIMOTHY J. SLITER
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New Ecdysteroids fromSerratula tinctoria

Planta Medica, 1992
Six new ecdysteroids have been isolated from SERRATULA TINCTORIA; these are: the 2,22- and 3,22-diacetates of 20-hydroxyecdysone, 5beta-hydroxyrubrosterone, 3-epi-poststerone, 3-epi-rubrosterone, and 22-oxo-20-hydroxyecdysone. These minor compounds were found together with the known ecdysteroids, 20-hydroxyecdysone, its 2-, 3-, and 22-monoacetates ...
Rudel D, Báthori Mária, Gharbi J, Girault J-P, Racz I, Melis K, Szendrei Kálmán, Lafont R   +7 more
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Ant Ecdysteroid Extraction and Radioimmunoassay

Cold Spring Harbor Protocols, 2009
INTRODUCTIONEcdysteroids are a group of steroid compounds present in many plant and invertebrate species. In arthropods, they function primarily as hormones involved in the regulation of molting. This protocol describes how to extract ecdysteroid hormones from ant specimens and subsequently quantify circulating levels of the hormone. The hormone can be
Colin, Brent, Adam, Dolezal
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Dimeric Ecdysteroid Analogues and Their Interaction with the Drosophila Ecdysteroid Receptor

Collection of Czechoslovak Chemical Communications, 2006
Three structurally related specific ecdysteroid derivatives, 7,7'-dimers of 14-deoxy-8(14)-ene transformed 20-hydroxyecdysone, ponasterone A and ajugasterone C, were obtained by photochemical transformation. The structures of the dimeric ecdysteroids were identified mainly by NMR spectroscopy supported by MS and IR spectroscopy.
Juraj Harmatha, Miloš Buděšínský, Karel Vokáč, Laurence Dinan, René Lafont   +4 more
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