Poststerone increases muscle fibre size partly similar to its metabolically parent compound, 20-hydroxyecdysone.

In mice, poststerone is a major in vivo metabolite of the worldwide popular anabolic food supplement 20-hydroxyecdysone (20E). Here we present the first study on this ecdysteroid in view of the in vivo anabolic effect of its parent compound, 20E in mammals. We have monitored muscle fibre type cross sectional areas (CSA) of developing rats after treatment with poststerone as we did in a previous study with 20E.

Side-chain cleaved phytoecdysteroid metabolites as activators of protein kinase B.

Phytoecdysteroids exert their non-hormonal anabolic and adaptogenic effects in mammals, including humans, through a partially revealed mechanism of action involving the activation of protein kinase B (Akt). We have recently found that poststerone, a side-chain cleaved in vivo metabolite of 20-hydroxyecdysone, exerts potent anabolic activity in rats. Here we report the semi-synthetic preparation of a series of side-chain cleaved ecdysteroids and their activity on the Akt phosphorylation in murine skeletal muscle cells.

Backstabbing P-gp: Side-Chain Cleaved Ecdysteroid 2,3-Dioxolanes Hyper-Sensitize MDR Cancer Cells to Doxorubicin without Efflux Inhibition.

P-glycoprotein (P-gp, ABCB1) over-expression, causing a multi-drug resistant (MDR) phenotype, is a major problem in cancer chemotherapy that urgently requires novel approaches. Our previous studies showed certain ecdysteroid derivatives as promising chemo-sensitizers against MDR and non-MDR cancer cell lines while also exerting mild to moderate inhibition of P-gp function. Here we report the preparation of a set of substituted 2,3-dioxolane derivatives of poststerone, a known in vivo metabolite of 20-hydroxyecdysone (20E).

BBB penetration-targeting physicochemical lead selection: Ecdysteroids as chemo-sensitizers against CNS tumors.

The anticancer potential of ecdysteroids, especially their chemo-sensitizing activity has recently gained a substantial scientific interest. A comprehensive physicochemical profiling was performed for a set of natural or semi-synthetic ecdysteroids (N=37) to identify a lead compound against central nervous system (CNS) tumors. Calculated properties, such as lipophilicity (clogP), topological polar surface area (TPSA), brain-to-plasma ratio (clogBB) along with the measured blood-brain barrier specific in vitro permeability (logP) were evaluated in parallel.

Oxidized Metabolites of 20-Hydroxyecdysone and Their Activity on Skeletal Muscle Cells: Preparation of a Pair of Desmotropes with Opposite Bioactivities.

Increasing the activation of protein kinase B (Akt) has been suggested as a key signaling step in the nonhormonal anabolic activity of the phytoecdysteroid 20-hydroxyecdysone (20E) in mammals. Base-catalyzed autoxidation of this compound was shown previously to yield interesting B-ring-modified analogues. Herein is reported a thorough study on this reaction, resulting in the preparation and complete NMR spectroscopic assignments of calonysterone (5) and its previously overlooked desmotropic pair (7), along with two new sensitive metabolites of 20E.

Ecdysteroids sensitize MDR and non-MDR cancer cell lines to doxorubicin, paclitaxel, and vincristine but tend to protect them from cisplatin.

Ecdysteroids, analogs of the insect molting hormone, are known for their various mild, nonhormonal bioactivities in mammals. Previously, we reported that less-polar ecdysteroids can modulate the doxorubicin resistance of a multidrug resistant (MDR) mouse lymphoma cell line expressing the human ABCB1 transporter. Here, we describe the ability of 20-hydroxyecdysone (1) and its mono- (2) and diacetonide (3) derivatives to sensitize various MDR and non-MDR cancer cell lines towards doxorubicin, paclitaxel, vincristine, or cisplatin.

Rapid, laser-induced conversion of 20-hydroxyecdysone - a follow-up study on the products obtained.

We have recently reported the set-up of an experimental system for the laser-induced photochemical modification of bioactive substances, where two ecdysteroids, 20-hydroxyecdysone (20E) and its diacetonide derivative served as probes. As a direct continuation of our previous work, three new compounds together with five other ecdysteroid derivatives, have been identified from the novel, laser-induced photo-transformation reaction of 20E. The structures and NMR signal assignment were established by comprehensive one- and two-dimensional NMR spectroscopy supported by mass spectroscopy.

Synthesis and structure-activity relationships of novel ecdysteroid dioxolanes as MDR modulators in cancer.

Ecdysteroids, molting hormones of insects, can exert several mild, non-hormonal bioactivities in mammals, including humans. In a previous study, we have found a significant effect of certain derivatives on the ABCB1 transporter mediated multi-drug resistance of a transfected murine leukemia cell line. In this paper, we present a structure-activity relationship study focused on the apolar dioxolane derivatives of 20-hydroxyecdysone.

1H and 13C NMR investigation of 20-hydroxyecdysone dioxolane derivatives, a novel group of MDR modulator agents.

The synthesis, structure elucidation and the complete (1)H and (13)C signal assignment of a series of dioxolane derivatives of 20-hydroxyecdysone, synthesized as novel modulators of multidrug resistance, are presented. The structures and NMR signal assignment were established by comprehensive one-dimensional and two-dimensional NMR spectroscopy supported by mass spectrometry.