Side-chain cleaved phytoecdysteroid metabolites as activators of protein kinase B
摘要:
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. Twelve C-21 ecdysteroids including 8 new compounds were obtained through the oxidative side-chain cleavage of various phytoecdysteroids, or through the base-catalyzed autoxidation of poststerone. The complete H-1 and C-13 NMR spectroscopic assignments of the new compounds are presented. Among the tested compounds, 9 could activate Akt stronger than poststerone revealing that side-chain cleaved derivatives of phytoecdysteroids other than 20-hydroxyecdysone are valuable bioactive metabolites. Thus, our results suggest that the expectable in vivo formation of such compounds should contribute to the bioactivity of herbal preparations containing ecdysteroid mixtures.
Oxidized Metabolites of 20-Hydroxyecdysone and Their Activity on Skeletal Muscle Cells: Preparation of a Pair of Desmotropes with Opposite Bioactivities
摘要:
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. The two isomers showed considerable stability in solution. Time dependency of the reaction for yield optimization is also presented; by means of analytical HPLC, the two desmotropes can reach a maximum combined yield of >90%. The activity of these compounds on Akt phosphorylation was tested in murine skeletal muscle cells. Compounds 2 and 5 showed more potent activity than 20E in increasing Akt activation, while compound 7 exerted an opposite effect. As such, the present study provides the first direct evidence for a pair of desmotropes exerting significantly different bioactivities.
Side-chain cleaved phytoecdysteroid metabolites as activators of protein kinase B
作者:Halima Meriem Issaadi、József Csábi、Tusty-Jiuan Hsieh、Tamás Gáti、Gábor Tóth、Attila Hunyadi
DOI:10.1016/j.bioorg.2018.10.049
日期:2019.2
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. Twelve C-21 ecdysteroids including 8 new compounds were obtained through the oxidative side-chain cleavage of various phytoecdysteroids, or through the base-catalyzed autoxidation of poststerone. The complete H-1 and C-13 NMR spectroscopic assignments of the new compounds are presented. Among the tested compounds, 9 could activate Akt stronger than poststerone revealing that side-chain cleaved derivatives of phytoecdysteroids other than 20-hydroxyecdysone are valuable bioactive metabolites. Thus, our results suggest that the expectable in vivo formation of such compounds should contribute to the bioactivity of herbal preparations containing ecdysteroid mixtures.
Oxidized Metabolites of 20-Hydroxyecdysone and Their Activity on Skeletal Muscle Cells: Preparation of a Pair of Desmotropes with Opposite Bioactivities
作者:József Csábi、Tusty-Jiuan Hsieh、Feria Hasanpour、Ana Martins、Zoltán Kele、Tamás Gáti、András Simon、Gábor Tóth、Attila Hunyadi
DOI:10.1021/acs.jnatprod.5b00249
日期:2015.10.23
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. The two isomers showed considerable stability in solution. Time dependency of the reaction for yield optimization is also presented; by means of analytical HPLC, the two desmotropes can reach a maximum combined yield of >90%. The activity of these compounds on Akt phosphorylation was tested in murine skeletal muscle cells. Compounds 2 and 5 showed more potent activity than 20E in increasing Akt activation, while compound 7 exerted an opposite effect. As such, the present study provides the first direct evidence for a pair of desmotropes exerting significantly different bioactivities.