Synthesis and bioactivity of C-29 brassinosteroid analogues with different functional groups at C-6
In this paper, we report the synthesis and bioactivity of four synthetic analogues of 28-homobrassinosteroids, in order to evaluate the influence in bioactivity when the C-6 keto group is replaced by different functional groups. The synthetic analogues are 6-deoxo-28-homocastasterone [(22R,23R)-stig...
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| Autores principales: | , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00319422_v66_n5_p581_Ramirez |
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| Sumario: | In this paper, we report the synthesis and bioactivity of four synthetic analogues of 28-homobrassinosteroids, in order to evaluate the influence in bioactivity when the C-6 keto group is replaced by different functional groups. The synthetic analogues are 6-deoxo-28-homocastasterone [(22R,23R)-stigmasta- 2α,3α,22,23-tetraol], 6α-hydroxy-28-homocastasterone [(22R,23R)-stigmasta-2α,3α,6α,22,23-pentaol], 6β-hydroxy-28-homocastasterone [(22R,23R)-stigmasta-2α,3α, 6β,22,23-pentaol], and [(22R,23R)-6α-fluorostigmasta-2α, 3α,22,23-tetraol]. Results indicate that replacement of the 6-keto moiety by an β or α hydroxyl group led to a decrease in activity, whereas the 6-deoxo analogue showed a very low activity, confirming the importance of an electronegative moiety at C-6 to observe hormonal potency. The 6α-fluorinated analogue elicited a low activity, similar to that of the 6-deoxo analogue. © 2005 Elsevier Ltd. All rights reserved. |
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