87833-54-3Relevant academic research and scientific papers
An alternative brassinolide biosynthetic pathway via late C-6 oxidation
Choi, Yong-Hwa,Fujioka, Shozo,Nomura, Takahito,Harada, Atsushi,Yokota, Takao,Takatsuto, Suguru,Sakurai, Akira
, p. 609 - 613 (1997)
6-Deoxoteasterone and 6-deoxotyphasterol were identified in cultured cells of Catharanthus roseus. Feeding experiments with deuterium-labelled substrates revealed the conversions of 6-deoxoteasterone to 6- deoxotyphasterol, and of 6-deoxotyphasterol to 6-deoxocastasterone in cultured cells of C. roseus. Furthermore, the conversion of 3-dehydro-6- deoxoteasterone to 6-deoxotyphasterol was also demonstrated in the cells. These results, together with our previously published data, demonstrate an alternative biosynthetic pathway of brassinolide production: 6- deoxoteasterone→3-dyhydro-6-deoxoteasteronne→6-deoxotyphasterol→6- deoxocastasterone→castasterone→brassinolide. This is termed the late C-6 oxidation pathway, and it is operated in cultured cells of C. roseus in addition to the early C-6 oxidation pathway.
Synthesis of new naturally occurring 6-deoxo brassinosteroids
Takatsuto, Suguru,Watanabe, Tsuyoshi,Fujioka, Shozo,Sakurai, Akira
, p. 901 - 924 (2007/10/03)
New naturally occurring 6-deoxo brassinosteroids, 6-deoxoteasterone 1, 3-dehydro-6-deoxoteasterone 2 and 6-deoxotyphasterol 3 as well as 6-deoxocastasterone 4, have been synthesized from (20S)-20-formyl-6β-methoxy-3α,5-cyclo-5α-pregnane 5.The key reactions for the construction of the (22R,23R,24S)-side chain of these C28 brassinosteroids are the reaction of the 22-aldehyde 5 with a Grignard reagent derived from (Z)-1-bromo-1-propene, orthoester Claisen rearrangement of the resulting (22S,23Z)-allylic alcohol, and the asymmetric dihydroxylation of the crinosterol dide chain.Regeneration of a 5-en-3β-ol system in A/B-ring followed by catalytic hydrogenation provided 6-deoxoteasterone 1, which was converted to the methanesulfonate 11.Inversion of configuration of the 3β-hydroxyl group and introduction of the 2-ene functionality were achieved by reaction of the sulfonate 11 with potassium superoxide and with lithium carbonate, respectively.The inverted 3α-alcohol 12 was deprotected to afford 6-deoxotyphasterol 3.The alcohol 12 was oxidized to give, after deprotection, 3-dehydro-6-deoxoteasterone 2.Introduction of a 2α,3α-diol group into the 2-ene 14 with osmium tetroxide was followed by deprotection to afford 6-deoxocastasterone 4.
SYNTHESIS OF NATURALLY OCCURRING BRASSINOSTEROIDS EMPLOYING CLEAVAGE OF 23,24-EPOXIDES AS KEY REACTIONS. SYNTHESIS OF BRASSINOLIDE, CASTASTERONE, DOLICHOLIDE, DOLICHOSTERONE, HOMODOLICHOLIDE, HOMODOLICHOSTERONE, 6-DEOXOCASTASTERONE AND 6-DEOXODOLICHOSTERONE
Mori, Kenji,Sakakibara, Masayuki,Okada, Katsuhide
, p. 1767 - 1782 (2007/10/02)
Eight new plant growth-promoting steroids (brassinolide, castasterone, dolicholide, dolichosterone, homodolicholide, homodolichosterone, 6-deoxocastasterone and 6-deoxodolichosterone) were synthesized by the regio- and stereoselective ring-opening reactions of 23,24-epoxides prepared from stigmasterol.
