ChemInform Abstract: Improvement in the Synthesis of Epibrassinolide.

Хрипач, В. А.; Жабинский, В. Н.; Ol’khovik, V. K.; Иванова, Г. В.; Zhernosek, E. V.; Kotyatkina, A. I.

doi:10.1002/chin.199546203

Cited by 7 publications

(10 citation statements)

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“…Melting points were measured on a Kofler block. 24-Epicastasterone (1) and 24-epibrassinolide (6) were synthesized by the literature method [5]. Electronic absorption spectra of solutions of the studied compounds were recorded on a Cary-500 spectrophotometer.…”

Section: Methodsmentioning

confidence: 99%

Synthesis and spectral and luminescence properties of new conjugates of brassinosteroids for immunofluorescence analysis

et al. 2012

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Conjugates of 24-epibrassinolide and 24-epicastasterone with indoleacetic acid and nitrobenzofurazan were synthesized. It was shown that the prepared conjugates exhibited effective fluorescence properties and could be used as fluorescent-labeled antigens in immunochemical analysis of brassinosteroids of the 24-epibrassinolide class.Keywords: brassinosteroids, fluorescent-labeled antigens, synthesis, spectral and luminescence properties.Practical application of brassinosteroids in agriculture [1] and the prospects of application in medicine necessitate reliable analytical methods for their determination. In this respect, immunoenzyme analytical methods, which do not require multi-step sample preparation, are highly recommended [2]. A common step of these methods is the specific interaction of the determined enzyme-labeled steroid with antibodies. Therefore, the analytical results will be inaccurate under conditions where the steroid conjugate with the enzyme and the determined steroid can be destroyed (e.g., its enzymatic hydrolysis by plant proteinases).The solution to this problem could be the use of non-proteinaceous compounds as the label. The presence of a fluorescent group in the studied compounds enables them to be detected by instrumental methods based on luminescence measurements. Such a capability was demonstrated earlier using the conjugate of 24-epicastasterone and dansylhydrazine [3].Herein the synthesis and spectral and luminescence properties of new conjugates of brassinosteroids with various types of luminophores are reported as a continuation of research on the creation of fluorescent probes for immunochemical analysis of this class of compounds [3,4].Conjugate 5 of 24-epicastasterone 1 [5] with nitrobenzofurazan was prepared according to Scheme 1.

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Section: Methodsmentioning

confidence: 99%

Synthesis and spectral and luminescence properties of new conjugates of brassinosteroids for immunofluorescence analysis

et al. 2012

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“…The resulting oil was mixed with water and extracted with CHCl 3 . The organic layer was dried over Na 2 SO 4 H 3 ](22R,23R,24R)-24-Methy-5a-cholest-2-en-6-on-22,23-diol (10) Diacetate 9 (58 mg, 0.112 mmol) was dissolved in a solution of KOH in MeOH (5%, 3 ml). The mixture was heated under reflux for 1 h, then cooled down and acidified by adding a mixture AcOH-MeOH (1:4) to reach pH 7.…”

Section: Methodsmentioning

confidence: 99%

“…[2][3][4] As a result, now it is the most practically useful compound of this group; for a number of years preparations with 24-epibrassinolide ( Figure 1) as an active ingredient have been used in agriculture. 5,6 Research in the recent years has revealed its potential usefulness in medicine also.…”

Section: -Epibrassinolide Holds a Special Place Among Natural Brassmentioning

confidence: 99%

Synthesis of deuterium‐labeled (24R)‐methyl brassinosteroids

Хрипач

Жабинский

Gulyakevich

et al. 2011

Labelled Comp Radiopharmac

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Synthesis of labeled brassinosteroids (24-epibrassinolide and its biosynthetic precursors) containing three deuterium atoms in the terminal part of the side chain is reported. Labeling was achieved by three-step reductive transformation of carbethoxy group into methyl using lithium aluminium deuteride. The proposed method ensured high isotopic purity of (24R)-methyl brassinosteroids containing a label in a position which is not subjected to its loss.

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“…The compounds were synthesized by the literature methods [3,4]. * Samples were prepared for the study by triturating with anhydrous finely dispersed KBr and pressing in vacuo.…”

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Infrared spectra of brassinolide and castasterone steroid phytohormones and their 24-epi derivatives

Borisevich

Buslov

2010

J Appl Spectrosc

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Absorption bands in IR spectra of brassinolide, castasterone, and their 24-epi derivatives in the frequency range 3800-1000 cm -1 have been interpreted. A number of spectral features distinguishing brassinolide from castasterone have been found. The conducted analysis shows that the structural differences manifest themselves in IR spectra of the investigated brassinosteroids in the region of stretching vibrations of CO-H, C=O, C-OH, C-O-C, CH 3 , CH 2 , and CH groups. The main distinctions in IR spectra of brassinolides and castasterones are due to the B ring structure.All hydroxyl groups of brassinosteroids pressed in KBr are included in hydrogen bonds. Broad bands attributed to associated OH groups are observed in the IR spectra. Two possible kinds of hydrogen bonding exist. IR spectra of diluted solutions of the studied brassinosteroids contain two bands caused by vibrations of free hydroxyls and those associated by intramolecular hydrogen bonds.A fraction of the C=O groups of brassinosteroids pressed in KBr remains free. High-frequency bands in solid-state IR spectra are due to vibrations of free C=O groups whereas low-frequency bands are attributed to stretching vibrations of associated groups. The lack of low-frequency bands in solution spectra proves that the C=O⋅⋅⋅H-O hydrogen bond is intermolecular rather than intramolecular. Vibrational frequencies of brassinolide C=O groups are higher than the corresponding frequencies for castasterones because of the influence of oxygen in the seven-membered B ring.Introduction. IR spectra of 22R,23R-isomers of 24-epibrassinolide, 24-epicastasterone, 28-homobrassinolide, and 28-homocastasterone in the region of stretching vibrations of characteristic atomic groups [1] in addition to IR spectra of 22S,23S-and 22R,23R-isomers of 24-epibrassinolide, 24-epicastasterone, 28-homobrassinolide, and 28-homocastasterone over a broad spectral region including frequencies of bending vibrations [2] were studied previously.Herein we study IR spectra of brassinolide (1) and castasterone (2), which are key compounds of two series of biological phytohormones, in addition to their derivatives 24-epibrassinolide (3) and 24-epicastasterone (4), which differ from the key compounds only by the stereochemistry of the CH 3 group on C-24 of the side chain:

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ChemInform Abstract: Improvement in the Synthesis of Epibrassinolide.

Cited by 7 publications

References 0 publications

Synthesis and spectral and luminescence properties of new conjugates of brassinosteroids for immunofluorescence analysis

Synthesis and spectral and luminescence properties of new conjugates of brassinosteroids for immunofluorescence analysis

Synthesis of deuterium‐labeled (24R)‐methyl brassinosteroids

Infrared spectra of brassinolide and castasterone steroid phytohormones and their 24-epi derivatives

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