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At least 19 recordsLinked to original sources
PubMed2002

Developmental profiles of ecdysteroids, ecdysteroid receptor mRNAs and DNA binding properties of ecdysteroid receptors in the Ixodid tick Amblyomma americanum (L.).

Total body ecdysteroid titers were determined at specific stages during the larval and nymphal life of Amblyomma americanum (L.). One ecdysteroid peak was observed following the completion of larval apolysis. However, two distinct ecdysteroid peaks occurred at a comparable stage in the nymphal molting cycle. The first occurred following apolysis and the second peak occurred at about the time of ecdysis. When whole body profiles of EcR and RXR mRNAs were examined during the molting cycle using RT-PCR, the expression of both AamEcR and AamRXR mRNAs was shown to be correlated with the ecdysteroid titer. Using an electrophoretic gel mobility shift assay, it was demonstrated that AamEcR*AamRXR1, but not AamEcR*AamRXR2, exhibits broad DNA binding specificity, forming complexes with a variety of synthetic direct repeat and palindromic nuclear response elements with the half-site consensus AGGTCA. These data suggest that functional differences may exist between the AamRXR1 and AamRXR2 proteins.

Animals↗
PubMed1998

Hemolymph ecdysteroid titer and ecdysteroid-dependent developmental events in the last-larval stadium of the silkworm, Bombyx mori: role of low ecdysteroid titer in larval-pupal metamorphosis and a reappraisal of the head critical period.

The endocrine regulation of larval-pupal metamorphosis was studied in the silkworm, Bombyx mori, by measuring the following changes: hemolymph ecdysteroid titer, the secretory activity of prothoracic glands and the responsiveness of larvae to ecdysteroids and prothoracicotropic hormone (PTTH), with regard to developmental events such as the occurrence of spinneret pigmentation, initiation of cocoon spinning and onset of wandering stage as indicated by gut purge. These measurements were concentrated especially on the time before and after the head critical period (HCP) which falls 3-4 days before the gut purge ([Sakurai, 1984]). A small increase in the hemolymph ecdysteroid titer was first found during the HCP, and then the titer increased with daily fluctuations. Small but significant titer peaks were found prior to the occurrence of both spinneret pigmentation and gut purge, indicating that an individual titer peak could possess a specific role in development. Responsiveness of larvae to exogenous 20-hydroxyecdysone (20E) after the HCP was markedly higher than that before the HCP. The sensitivity of the prothoracic gland to PTTH also changed during the HCP. The results thus showed that the HCP is not the period after which an additional PTTH release is not required for the developmental events occurring on schedule, but rather it is the period during which complex events occur not only in the endocrine glands but also in the peripheral tissues. In addition, various developmental phenomena before gut purge are brought about by the hemolymph ecdysteroid whose concentration gradually increased with daily fluctuations, and these precise changes in the titer appeared to be important for the sequential occurrence of developmental events in the larval-pupal metamorphosis.

Journal Article↗
PubMed2006

Ecdysteroid titers and developmental expression of ecdysteroid-regulated genes during metamorphosis of the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae).

Ecdysteroid titers and expression profiles of ecdysone-regulated genes were determined during the last instar larval and during the pupal stages of Aedes aegypti (Diptera: Culicidae). Three peaks of ecdysteroids occurring at approximately 24, 30-33 and 45-48h after ecdysis to the fourth instar larval stage were detected. In the pupa, a large peak of ecdysteroids occurred between 6 and 12h after ecdysis to the pupal stage. A small rise in ecdysteroids was also detected at the end of the pupal stage. Quantitative reverse transcriptase polymerase chain reaction analyses of the expression of ecdysone receptors and ecdysone-regulated genes showed that the peaks of expression of most of these genes coincided with the rise in ecdysteroid levels during the last larval and pupal stages. In the last larval stage, ecdysteroid titers and mRNA expression profiles of ecdysone-regulated genes are similar to those observed for Drosophila melanogaster. However, in the early pupal stage, both ecdysteroid titers and the expression of ecdysone-regulated genes are somewhat different from those observed in D. melanogaster, probably because the duration of the pupal stage in D. melanogaster is 84h while in Ae. aeqypti the duration is only 48h. These data which describe the relationship between ecdysteroid titers and mRNA levels of Ae. aegypti ecdysteroid-regulated genes lay a solid foundation for future studies on the hormonal regulation of development in mosquitoes.

Aedes↗
PubMed2002

Ecdysteroid 7,9(11)-dien-6-ones as potential photoaffinity labels for ecdysteroid binding proteins.

Three ecdysteroid 7,9(11)-dien-7-ones (dacryhainansterone, 25-hydroxydacryhainansterone and kaladasterone) were prepared by dehydration of the corresponding 11a-hydroxy ecdysteroids (ajugasterone C, turkesterone and muristerone A, respectively). The biological activities of the dienones in the Drosophila melanogaster B(II) cell bioassay, which reflect the affinity for the ecdysteroid receptor complex, showed that the dienones retain high biological activity. Irradiation at 350 nm of the ecdysteroid dienones (100 nM) with bacterially-expressed dipteran and lepidopteran ecdysteroid receptor proteins (DmEcR/DmUSP or CfEcR/CfUSP), followed by loading with [(3)H]ponasterone A revealed that irradiation of dacryhainansterone or kaladasterone resulted in blocking of >70% of the specific binding sites. Thus, ecdysteroid dienones show considerable potential as photoaffinity analogues for ecdysteroid binding proteins.

Animals↗
PubMed1988

Ecdysteroid receptors of the blowfly Calliphora vicina: partial purification and characterization of ecdysteroid binding.

A macromolecule with high affinity for the ecdysteroid analogue ponasterone A was isolated from nuclei of larvae of the blowfly Calliphora vicina. The ecdysteroid-binding molecule revealed characteristics of the moulting hormone receptor. It was sensitive towards protease but not towards nucleases. The nuclear protein had a limited binding capacity (0.2 pmol ponasterone A/mg protein), showed hormone analogue specificity and high affinity for ecdysteroids. Enzyme activities were present in the nuclear extract that metabolized ecdysteroids and thereby interfered with the binding assay. After their removal by DEAE-cellulose chromatography the ecdysteroid receptor preparation was stable at 20 degrees C for hours. This allowed a reliable determination of dissociation constants at equilibrium conditions. The hormone receptor complex had a KD of 1 nM, 30 nM, and 2000 nM with ponasterone A, 20-hydroxyecdysone, and ecdysone, respectively. The apparent molecular mass of the ecdysteroid receptor was 105,000 as determined by gel filtration.

Animals↗
PubMed1999

Ecdysteroid biosynthesis in crayfish Y-organs: feedback regulation by circulating ecdysteroids

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 (20E) levels in the hemolymph. The present study asks the question whether the 20E peak in premoult stages D2/D3 is explained solely bythe cessation of MIH release or whether positive feedback mechanisms are also involved. Ecdysteroid production by the Y-organ of the crayfish Orconectes limosus was found to be under negative feedback control by circulating ecdysteroids. Exogenous 20-hydroxyecdysone (20E) as well as RH-5849, a non-steroidal ecdysteroid agonist, reduced ecdysteroid synthesis significantly when injected into intermoult animals. A direct, short loop inhibitory feedback effect was demonstrated by in vitro incubations of Y-organs with RH-5849. Thus, the results presented here do not point to a stimulatory effect of 20E on Y-organ activity but suggest that during intermolt a negative feedback by ecdysteroids plays a role in addition to MIH. Arch. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗
PubMed1997

Induction of enzymes involved in molting hormone (ecdysteroid) inactivation by ecdysteroids and an agonist, 1,2-dibenzoyl-1-tert-butylhydrazine (RH-5849).

Molting in insects is regulated by molting hormones (ecdysteroids). The major active hormone, 20-hydroxyecdysone, is formed by ecdysone 20-monooxygenase-catalyzed hydroxylation of ecdysone. During times of decreasing hormone titers, inactivation occurs by several routes including (i) 26-hydroxylation and further oxidation to the 26-oic acid, (ii) formation of various conjugates (e.g. phosphates), and (iii) in Lepidoptera in particular, ecdysone oxidase-catalyzed formation of 3-dehydroecdysteroid, which is reduced to 3-epiecdysteroid, followed by phosphotransferase-catalyzed formation of phosphate conjugates. Administration of the nonsteroidal ecdysteroid agonist RH-5849 (1,2-dibenzoyl-1-tert-butylhydrazine), but not 20-hydroxyecdysone, to tobacco hornworm (Manduca sexta) resulted in induction of midgut cytosolic ecdysone oxidase and ecdysteroid phosphotransferase activities. In addition, both 20-hydroxyecdysone and RH-5849 caused induction of ecdysteroid 26-hydroxylase activity in midgut mitochondria and microsomes, whereas 20-hydroxylase was induced to a lesser extent by 20-hydroxyecdysone in mitochondria and by either RH-5849 or 20-hydroxyecdysone in microsomes. Commensurate with induction of the enzymes by ecdysteroid and RH-5849 is a requirement for RNA and protein synthesis, without precluding indirect mechanisms. These results indicate that molting hormone stimulates at least one universal route of its own inactivation by inducing ecdysteroid 26-hydroxylase activity and are discussed in relation to an analogous phenomenon observed for vitamin D inactivation in vertebrates.

Animals↗
PubMed2002

Ecdysteroid titer and reproduction in queens and workers of the honey bee and of a stingless bee: loss of ecdysteroid function at increasing levels of sociality?

Evidence from field wasps and bumblebees appoints the endocrine system as a mediator between dominance status and ovarian activity in primitively social Hymenoptera. In this comparative study on ecdysteroid titers in the highly social honey bee, Apis mellifera, and a stingless bee, Melipona quadrifasciata, we focussed on the relationship between the ecdysteroid titer, social conditions (presence or absence of the queen), and ovary activity. In contrast to bumblebees, ecdysteroid titers in honey bee and stingless bee workers were either not altered, or dropped to even lower levels after the queen was removed. We also did not detect differences between virgin queens and mated, egg laying queens. These results suggest that ecdysteroids may have lost most of their reproductive functions - yet gained functions in larval caste differentiation - as higher levels of social organization were attained in the evolution of social insects. The observation that ecdysteroid titers are transiently elevated in young workers adds a new, yet functionally still speculative facet to hormonal regulation in insect societies.

Animals↗
PubMed2004

[Ecdysteroids of Silene italica ssp. nemoralis, novel approaches of ecdysteroid therapy].

Ecdysteroids are known as insect moulting hormones. They have the basic steroid structure, although their physiological effects on mammalians do not show the thymolytic and androgenic side effects of vertebrate type steroid hormones. At the same time, phytoecdysteroids can be used utilizing their anabolic and adaptogenic effects. Ecdysteroids also have a tremendous potential in the most modern therapy. Recently, the biotechnology started to employ ecdysteroids as powerful inducers for gene-switch systems with insertion of modified insect receptor into the malignant cells. Nineteen ecdysteroids were isolated with combined chromatographic methods from the herbs of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman. The chemical structure of the isolated compounds have been elucidated using spectroscopic methods (x-ray, UV, CD, IR, MS, 1D-, 2D-NMR, HMQC, HMBC, COSY, TOCSY, NOESY, ROESY). Structural determination of two of the five new ecdysteroids is detailed here.

Ecdysteroids↗
PubMed1999

Titres of biogenic amines and ecdysteroids: effect of octopamine on the production of ecdysteroids in the silkworm Bombyx mori.

At day two, a sharp peak of octopamine (OA) was observed in last instar female Bombyx mori larvae. This peak also appeared in male larvae a day later than in females at day three. An OA peak was also observed before the 3rd ecdysis. However, no OA peaks were observed in 4th instar larvae. At day eight and nine of the 5th instar, another OA peak was observed for male and female, respectively. A peak of tyramine (TA) was found at day one followed by a peak of OA at day two in 3rd instar larvae. At day two, a day before OA peak, a peak of TA was observed for male insects and before the 2nd peak of OA, TA titre was also high in 5th instar larvae. Immediately after 3rd ecdysis, a high titre of DL-beta-(3,4-dihydroxyphenyl)alanine (DOPA) was observed, followed by a peak of dopamine (DA) at day five. A peak of DOPA was found at day one followed by a peak of DA at day two in 3rd instar larvae. Similarly, a small peak of DOPA was observed at day two, followed by an increase of DA at days eight and nine after the 4th ecdysis. Ecdysteroid peaks were observed just before the 3rd and 4th ecdysis and an ecdysteroid titre increased after the start of spinning. The effects of OA and JH on production of ecdysteroids by prothoracic glands (PGs) were examined in order to identify neuromediators responsible for triggering pupation in B. mori larvae. Exogeneous OA (10-100 mM) reduced and 10 &mgr;M OA stimulated the production of ecdysteroids in the presence and absence of brain extracts by PGs in the final instar (day five) of B. mori in vitro. Meanwhile, exogeneous JHI (10 &mgr;g/ml) stimulated and at 5 &mgr;g/ml it reduced production of ecdysteroids in the presence of brain extracts. Gramine, an OA antagonist, delayed pupation when applied in the diet. Thus, OA may produce some biological effects on the programming of larval-pupal development.

Journal Article↗
PubMed2003

Comparative effects of some ecdysteroid agonists in mealworms: ecdysteroid amounts and protein analysis in developing ovaries under in vivo conditions.

Some ecdysteroid agonists (RH-0345, RH-5849, RH-5992) were tested topically (10 microg/female) on newly emerged adult females of mealworms under in vivo conditions. In a first series of experiments the compounds were assayed on ovarian ecdysteroid production measured at day 2 and 4 following treatment, corresponding to the beginning and the end of vitellogenesis. All tested compounds resulted in a significant increase in ovarian ecdysteroid amounts. RH-5992 and RH-0345 were more active than RH-5849. In a second series of experiments, the activity of the compounds was investigated on ovarian proteins. The ecdysteroid agonists caused a significant reduction of protein amounts in the ovaries, and electrophoretic separation of ovary extracts from treated series showed that one or two bands were missing. These observations may an interference with the vitellogenesis process.

Animals↗
PubMed1997

The effects of several ecdysteroids and ecdysteroid agonists on two Drosophila imaginal disc cell lines.

Two Drosophila imaginal disc cell lines, C18+ (sensitive to 20-hydroxyecdysone, 20HE) and C18R (resistant to 20HE) were exposed to the ecdysteroid agonists RH5849 and RH5992 and the ecdysteroids inokosterone, makisterone A and muristerone A. All compounds tested were found to have similar effects on the cells, comparable to the effects of 20HE, although at different concentrations. C18R showed resistance to all compounds, again at varying concentrations. We conclude that it is likely that all the compounds tested use the same receptors as 20HE, but show maximum effectiveness at different concentrations.

Animals↗
PubMed2004

A new ecdysteroid with unique 9beta-OH and four other ecdysteroids from Silene italica ssp. nemoralis.

A new natural ecdysteroid, 9beta,20-dihydroxyecdysone (1) and four related compounds 5alpha-20-hydroxyecdysone (2), 5alpha-2-deoxy-integristerone A (3), integristerone A (4) and 22-deoxy-integristerone A (5) were isolated from the herb of Silene italica ssp. nemoralis. Compound 1 is the C-9 epimer of the known 9alpha,20-dihydroxyecdysone (6) and represents a peculiar steroid skeleton. The structures of the compounds were elucidated by 1D and 2D NMR, IR and MS spectroscopy.

Ecdysteroids↗
PubMed1997

26-hydroxylation of ecdysteroids is catalyzed by a typical cytochrome P-450-dependent oxidase and related to ecdysteroid resistance in an insect cell line.

The epithelial cell line from the dipteran Chironomus tentans responds to the insect steroid hormone 20-hydroxyecdysone and the non-steroidal analogue tebufenozide by undergoing a morphogenetic and biochemical differentiation program. Long-term culture in the presence of 20-hydroxyecdysone has resulted in the selection of subclones that are resistant to the steroid but respond normally to the non-steroidal analogue. In the present study, several subclones that were resistant to the steroid hormone have been compared with steroid-sensitive subclones with respect to their capability to metabolize 20-hydroxyecdysone. Homogenates of both types of cells, when incubated with 3H-labelled steroid in the presence of NADPH, producecd 20,26-dihydroxyecdysone, which was further metabolized to two compounds, which behaved less polar than 20-hydroxyecdysone on reverse-phase HPLC. Ecdysone, a less-active hormone precursor, provided 26-hydroxyecdysone as the only product. The metabolites were identified by mass spectrometry coupled to HPLC, chromatography with authentic samples, and formation of acetonides. The structure of 20,26-dihydroxyecydsone was confirmed by 1H-NMR. The enzyme responsible for the synthesis of 20,26-dihydroxyecdysone in the Chironomus cell preparations has been characterized as a typical cytochrome P-450-dependent monooxygenase. It was a strictly microsomal enzyme, sensitive to inhibition by carbon monoxide and imidazole/triazole-based fungicides, and required NADPH for maximal activity. NADH could partly replace NADPH. The Michaelis constant (Km) for 20-hydroxyecdysone was 0.96 microM, and the maximal enzyme velocity (Vmax) was 50 pmol substrate metabolized x mg protein(-1) x min(-1). 26-Hydroxylation of 20-hydroxyecdysone was inhibited by ecdysone, an alternative substrate, and by inokosterone, a product analogue, to 50% at 1.4 microM and 0.73 microM, respectively. When various subclones were compared with respect to their in vitro rate of 20-hydroxyecdysone metabolization, those clones known to be resistant to the steroid were 'high metabolizers' (> 70% relative rate), whereas the sensitive clones were 'poor metabolizers' (< 30% relative rate). Hence, it is tempting to conclude that ecdysteroid resistance of the Chironomus cell clones is due to metabolic inactivation of the steroid hormone.

Animals↗
PubMed1992

Hemolymph concentrations of host ecdysteroids are strongly suppressed in precocious prepupae of Trichoplusia ni parasitized and pseudoparasitized by Chelonus near curvimaculatus.

Regulation of ecdysteroid production in lepidopteran prepupae was studied using a parasitic wasp (C. near curvimaculatus) which specifically suppresses host prepupal ecdysteroid production after the induction of precocious host metamorphosis. At the developmental stage at which the hemolymph of the unparasitized metamorphosing host has its maximum titer of prepupal ecdysteroids, the hemolymph of 4th instar "truly parasitized" hosts (hosts with a surviving endoparasite) had a strongly reduced ecdysteroid titer. However, during the photophase about 12 h later, just prior to emergence of the parasite larva, an ecdysteroid peak was observed in the host hemolymph. Fourth instar pseudoparasitized prepupal hosts (in which the endoparasite was not present or died early in development) exhibited a sustained suppression in the hemolymph ecdysteroid titer. Small 5th instar pseudoparasitized hosts, which normally would molt to a 6th instar prior to metamorphosis, but which precociously attained the prepupal stage, also had a strongly reduced ecdysteroid titer. The late increase observed in truly parasitized hosts could be completely prevented by surgical removal of the parasite 24 h earlier, resulting in a titer similar to that in pseudoparasitized hosts. HPLC analysis of ecdysteroids in normal, truly parasitized, and 4th or 5th instar pseudoparasitized prepupae showed that both ecdysone and 20-OH ecdysone* were suppressed in truly and pseudoparasitized prepupae, with ecdysteroid levels being lowest in pseudoparasitized hosts. These data, and those of Brown and Reed-Larsen (Biol Contr 1, 136 [1992]), showing endoparasite secretion of ecdysteroids just prior to its emergence from the host, strongly indicate that: (1) the prepupal peak in truly parasitized hosts originates from the endoparasite, and (2) the low level of ecdysteroids in pseudoparasitized hosts results from the host's intrinsic inability to express a normal level of prepupal ecdysteroid titer. While precocious 4th or 5th instar prepupae of similar size had similarly suppressed ecdysteroid titers, smaller 4th instar prepupae had a lower ecdysteroid titer than larger, precocious 5th instar prepupae. Rare 5th instar pseudoparasitized prepupae that were of nearly normal size showed a prepupal ecdysteroid titer distinctly greater than those of the usual smaller, precocious 5th instar prepupae. The data suggest that the competence of the host to express a normal hemolymph titer of prepupal ecdysteroids is more closely correlated with the size of the prepupae than with the instar attained.

Animals↗
PubMed2005

Release of ecdysteroid-phosphates from egg yolk granules and their dephosphorylation during early embryonic development in silkworm, Bombyx mori.

Newly laid eggs of many insect species store maternal ecdysteroids as physiologically inactive phosphoric esters. In the silkworm Bombyx mori, we previously reported the presence of a specific enzyme, called ecdysteroid-phosphate phosphatase (EPPase), which catalyzes the dephosphorylation of ecdysteroid-phosphates to increase the amount of free ecdysteroids during early embryonic development. In this study, we demonstrated that (1) EPPase is found in the cytosol of yolk cells, (2) ecdysteroid-phosphates are localized in yolk granules, being bound to the yolk protein vitellin (Vn), and (3) Vn-bound ecdysteroid-phosphates are scarcely hydrolyzed by EPPase, although free ecdysteroid-phosphates are completely hydrolyzed by EPPase. Thus, we investigated the mechanism by which ecdysteroid-phosphates dissociate from the Vn-ecdysteroid-phosphate complex, and indicated that the acidification of yolk granules causes the dissociation of ecdysteroid-phosphates from the Vn-ecdysteroid-phosphate complex and thereby ecdysteroid-phosphates are released from yolk granules into the cytosol. Indeed, the presence of vacuolar-type proton-translocating ATPase in the membrane fraction of yolk granules was also verified by Western blot analysis. Our experiments revealed that Vn functions as a reservoir of maternal ovarian ecdysteroid-phosphates as well as a nutritional source during embryonic development. This is the first report showing the biochemical mechanism by which maternal Vn-bound ecdysteroid-phosphates function during early embryonic development.

Animals↗
PubMed2003

Hemolymph ecdysteroids do not affect vitellogenesis in the lubber grasshopper.

The role of hemolymph ecdysteroids in the reproduction of non-dipteran insects is unclear. We examine the role(s) of hemolymph ecdysteroids during egg production in the lubber grasshopper, Romalea microptera. In all individuals, hemolymph ecdysteroids rose to a sharp peak with similar maxima and then fell to undetectable levels. The time from the adult molt to the maximum ecdysteroid titer (E(max) titer) varied in response to food availability, whereas the time from E(max) titer to oviposition was unrelated to food availability. Because both the timing of egg production and the timing of E(max) responded similarly to environmental changes, ecdysteroids may be involved in egg production. We hypothesized that this role is the stimulation of vitellogenesis. Ovariectomized females had vitellogenin but no ecdysteroids, so ecdysteroids are not necessary for vitellogenin production. In addition, treatment of females with ecdysteroids altered neither Vg titers nor ovarian growth. Ovarian ecdysteriods increased at the same age in development as hemolymph ecdysteroids. In contrast to hemolymph ecdysteroids, ovarian ecdysteroids persisted until oviposition. Despite this, [(3)H]ecdysone injected into the hemolymph was detected later only at very low levels in the ovary, suggesting that hemolymph ecdysteroids are not sequestered by the ovary. In summary, our studies indicate that hemolymph ecdysteroids in adult females of the lubber grasshopper are associated with the timing of egg production, but they neither regulate vitellogenesis nor act as a source of ecdysteroids for the ovary.

Analysis of Variance↗
PubMed2001

Identification and quantitative analysis of the phytoecdysteroids in Silene species (Caryophyllaceae) by high-performance liquid chromatography. Novel ecdysteroids from S. pseudotites.

Many species in the genus Silene (Caryophyllaceae) have previously been shown to contain ecdysteroids and this genus is recognised as a good source of novel ecdysteroid analogues. We have used ecdysteroid-specific radioimmunoassays and the microplate-based Drosophila melanogaster B(II) cell bioassay for ecdysteroid agonist and antagonist activities to identify further phytoecdysteroid-containing species in this genus. The main ecdysteroid components from 10 Silene species (S. antirrhina, S. chlorifolia, S. cretica, S. disticha, S. echinata, S. italica, S. portensis, S. pseudotites, S. radicosa, S. regia) were isolated and identified, mainly by normal-phase and reversed-phase high-performance liquid chromatography. The amount of each ecdysteroid was determined by comparing chromatogram peak areas with those for reference 20-hydroxyecdysone (20E) on reversed-phase HPLC. 20E is the most abundant ecdysteroid in each of the Silene extracts. Polypodine B, 2-deoxy-20-hydroxyecdysone and ecdysone are also common ecdysteroids in these Silene species, but the proportions of these ecdysteroids vary between the Silene species. HPLC proved to be a quick and effective way to screen Silene species, determine ecdysteroid profiles and, hence, identify extracts containing novel analogues. An extract of the aerial parts of S. pseudotites was found to contain several new ecdysteroids. These have been isolated and identified spectroscopically (by NMR and mass spectrometry) as 2-deoxyecdysone 22beta-D-glucoside, 2-deoxy-20,26-dihydroxyecdysone and 2-deoxypolypodine B 3beta-D-glucoside. Additionally, (5alpha-H)-2-deoxyintegristerone A (5alpha-2H 91%, 5alpha-1H 9%) was isolated as an artefact. This study contributes to the understanding of ecdysteroid distribution in Silene species and provides further information on the chemotaxonomic significance of ecdysteroids in Silene species.

Caryophyllaceae↗