Synthesis and crystal structure of [26,27-2H6] 24-epi-cathasterone

Kolbe, A.; Fuchs, Petra; Porzel, Andrea; Baumeister, Ute; Kolbe, Alfred; Adam, Günter

doi:10.1039/b203323b

Cited by 6 publications

(4 citation statements)

References 12 publications

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“…From x-ray diffraction analysis of the crystals of the epicastasterone derivative, whose structure has only two OH groups, intermolecular hydrogen bonds are formed in them between atoms of the group on the A ring of one molecule and the OH group of the side chain of another molecule. The carbonyl group does not participate in the association [8]. In the studied brassinosteroids, intermolecular hydrogen bonds are formed both between the OH groups and with the C=O groups, since in the spectra of the solid phase of the brassinosteroids we observe bands not only for free carbonyl groups but also for ones bound to an OH group.…”

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confidence: 91%

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

et al. 2007

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UDC 547;535.34;543.42.We have analyzed the IR spectra obtained for steroidal phytohormones 24-epibrassinolide, 24-epicastasterone, 28-homobrassinolide, and 28-homocastasterone. The characteristic frequencies of the stretching vibrations of the hydrocarbon groups CH 3 , CH 2 , and CH and also the C=O groups in the spectra of brassinolides are higher than in the spectra of castasterones, which makes it possible to identify them from the IR spectra. Study of the spectra of these brassinosteroids in different media (pressed samples in KBr, films, solutions in CHCl 3 and CDCl 3 ) allowed us to establish the presence of intermolecular interactions in which C=O and OH groups, OH-OH groups participate, and also the possible formation of intramolecular hydrogen bonds between the OH groups of the molecules.Introduction. Brassinosteroids are a new class of natural and synthetic steroidal phytohormones [1] which play a key role in regulation of the growth and development of plants, and also have good prospects for use in medicine and veterinary practice as new pharmacological agents. A condition for high biological activity of brassinosteroids is the presence in the B ring of a 6-keto (castasterone and related compounds) or 7-oxa-6-keto (brassinolide and other lactones) structural moiety, and also a 2α,3α-diol group on the A ring and a trans fusion for the A/B rings (see structural formulas). Along with these structural features, the biological activity of brassinosteroids is determined by the structure of the side chain: the presence and configurations of hydroxyl groups at the carbon atoms C 22 and C 23, and also the nature of the substituent at the carbon atom C 24 [2][3][4]. It has been established that the greatest biological activity in many test systems is shown by brassinolide, first obtained from pollen of the plant Brassica napus [5]. However, a clear interconnection between the structure and the biological properties of brassinosteroids has not yet been established. This makes large-scale use of brassinosteroids in agriculture as plant growth stimulators difficult, and limits their advance into other areas of application.Despite the fact that the IR spectra provide considerable information about the structure and interactions of molecules, in study of brassinosteroids, IR spectroscopy methods have been used mainly to confirm the course of chemical reactions in synthesis of new compounds in this class.In this work, we used IR spectroscopy methods to study the structure and intermolecular interactions of 24-epibrassinolide (1), 24-epicastasterone (2), 28-homobrassinolide (3), and 28-homocastasterone (4), the structural formulas of which have the form:

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confidence: 91%

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

et al. 2007

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“…The side-chain unit 3-½ 2 H 3 methyl-but-1-yne-½4; 4; 4-2 H 3 , 9 11, was synthesized in three steps starting from sodium acetylide and ½ 2 H 6 acetone in a similar manner to that described for the unlabelled compound. 10; 11; 12 Because acetylene in the steel flask is dissolved in acetone, the isotopic incorporation of the 3-½ 2 H 3 methyl-but-1-yne-½4; 4; 4-2 H 3 was somewhat reduced (88%).…”

Section: Resultsmentioning

confidence: 99%

A new synthesis of [26,28‐²H₆]brassinolide and [26,28‐²H₆]castasterone via an unusual methyl migration

Kolbe

Porzel

Schmidt

et al. 2003

Labelled Comp Radiopharmac

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SummaryDeuterium-labelled brassinosteroids, namely ½26; 28-2 H 6 castasterone, 8, and ½26; 28-2 H 6 brassinolide, 9, were synthesized starting from 6; 6-ethylenedioxy-20-formyl-2a; 3a-isopropylidenedioxy-5a-pregnane, 1, and 3-½ 2 H 3 methyl-but-1-yne-½4; 4; 4-2 H 3 , 11. Upon alkylating cleavage of the epoxide 6 with trimethylaluminium-n-butyllithium an unusual migration of a neighbouring ½ 2 H 3 methyl group takes place to afford deuteriation at positions 26 and 28.

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“…The key step of the synthesis of [26,27-2 H 6 ]24-epi-cathasterone (109) by Kolbe et al [53] (Scheme 6.21) was alkylation of the aldehyde (106) with labeled lithium butyldimethyl-(E)-2,3-dimethylbutenylaluminate (107). The key step of the synthesis of [26,27-2 H 6 ]24-epi-cathasterone (109) by Kolbe et al [53] (Scheme 6.21) was alkylation of the aldehyde (106) with labeled lithium butyldimethyl-(E)-2,3-dimethylbutenylaluminate (107).…”

Section: Isotopically Labeled Bsmentioning

confidence: 99%

Synthetic Aspects of Brassinosteroids

Хрипач

Жабинский

Ermolovich

2015

Studies in Natural Products Chemistry

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Synthesis and crystal structure of [26,27-2H6] 24-epi-cathasterone

Cited by 6 publications

References 12 publications

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

A new synthesis of [26,28‐²H₆]brassinolide and [26,28‐²H₆]castasterone via an unusual methyl migration

Synthetic Aspects of Brassinosteroids

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Synthesis and crystal structure of [26,27-2H6] 24-epi-cathasterone

Cited by 6 publications

References 12 publications

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

Manifestation of structure and intermolecular interactions of biologically active brassinosteroids in infrared spectra

A new synthesis of [26,28‐2H6]brassinolide and [26,28‐2H6]castasterone via an unusual methyl migration

Synthetic Aspects of Brassinosteroids

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A new synthesis of [26,28‐²H₆]brassinolide and [26,28‐²H₆]castasterone via an unusual methyl migration