Synthesis of S-Containing Derivatives of the Sesquiterpene Lactone Britanin

Artemova, N. P.; Никитина, Л. Е.; Yushkov, D. A.; Shigabutdinova, O. G.; Племенков, В. В.; Клочков, В. В.; Хайрутдинов, Б. И.

doi:10.1007/s10600-005-0071-5

Cited by 7 publications

(8 citation statements)

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“…The IR spectrum exhibited absorptions at 3423 (OH), 1762 (C=O, γ-lactone), and 1718 cm −1 (C=O, ester). Compound 13 showed similar 1 H-and 13 C-NMR patterns to those of known britanin (15) [13]. The major difference was that the H-2 signal shifted upfield from δ H = 4.86 in 15 to δ H = 4.03 in 13 and an acetyl group (δ H = 2.04; δ C = 21.2 and δ C = 170.2) in 15 disappeared.…”

Section: Supporting Informationmentioning

confidence: 76%

“…The trans-attachment of the lactone ring was deduced from the allylic coupling pattern (J = 3.2 Hz) between H-7 and H a/b -13 based on Samekʼs rule [11]. Additionally, the relative configuration of britanlin I (13) was established by a molecular modeling study and a detailed comparison of the coupling pattern of protons with those of britanin (15) [13]. Furthermore, the relative configuration of britanin (15) was confirmed by X-ray single crystal diffraction analyses (l " Fig.…”

Section: Supporting Informationmentioning

confidence: 99%

“…As a result, nineteen sesquiterpenoids (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) were isolated from the flowers of I. britannica. Among these secondary metabolites, britanlins E -J (2,3,5,8,13, and 14, respectively) were reported for the first time. Additionally, the absolute configurations of compounds 12, 15, 17, and 19 were determined by X-ray single crystal diffraction analyses and chemical transformations.…”

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Sesquiterpenoids fromInula britannica

Yang¹,

Wang²,

Liu³

et al. 2010

Planta Med

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Phytochemical investigation of the flowers of Inula britannica led to the isolation of nineteen sesquiterpenoids (1- 19), including britanlins E-J ( 2, 3, 5, 8, 13, and 14, respectively) and known sesquiterpenoids (1, 4, 6, 7, 9- 12, and 15- 19). The structures of these isolates were elucidated by detailed spectroscopic analyses and comparison to the previously reported spectroscopic data. The absolute configurations of compounds 12, 15, 17, and 19 were determined by X-ray single crystal diffraction analyses and chemical transformations.

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Section: Supporting Informationmentioning

confidence: 76%

Section: Supporting Informationmentioning

confidence: 99%

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confidence: 99%

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Sesquiterpenoids fromInula britannica

Yang¹,

Wang²,

Liu³

et al. 2010

Planta Med

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“…The structure makes the molecule highly reactive and causes it to undergo various transformations [1][2][3][4]. Several novel organic transformations with alkynes have been explored to build valuable molecular skeletons in recent years [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Among these, difunctionalization of alkynes is an efficient and straightforward strategy for the synthesis of functionalized compounds, which can be transformed into diverse organic skeletons.…”

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confidence: 99%

Visible light promoted difunctionalization reactions of alkynes

Ren

2019

Chinese Journal of Catalysis

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Visible light promoted difunctionalization of alkynes is reviewed. The difunctionalization reaction is achieved by different reagents. Radicals such as carbon (sp 3), carbon (sp 2), and other heteroatom (P, S, N, Se, O, and halide) radicals initiated by visible light can undergo radical addition to a carbon-carbon triple bond. Upon further transformation, the desired difunctionalized products are obtained. Some organometallic complexes can be activated by visible light; the difunctionalization of alkynes is catalyzed by these species. Other reagents like 1,3-dipole precursors could also react with alkynes to give difunctionalization products; here, the 1,3-dipole derivatives are obtained by visible light photocatalysis. So far, the strategy has been succeeded in the formation of CC bonds and C-X bonds. Several valuable chemical skeletons have been constructed under mild conditions. However, high regio-and stereoselectivities in some direct difunctionalization methodologies are yet to be achieved.

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“…However, 1 and 2 also include a highly reactive electrophilic center as an exomethylene in the lactone ring that is susceptible to attack by nucleophiles. The reaction of 1 with methylmercaptoacetate (S-nucleophile) is known to occur at the lactone ring and to produce addition products at the C-11 and C-13 atoms in a 3:1 ratio [11]. Examples of the addition of N-nucleophiles to britanin isolated from I. caspica are known.…”

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Amination Products of Inula britannica Lactones and Their Antitumor Activity

et al. 2015

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The reactions with amines of the sesquiterpene lactones britanin and inuchinenolide C isolated from Inula britannica were studied. Migration of the acetyl group during the addition reaction was observed and depended on the nature of the amine and solvent. Compounds with antitumor activity were found among the new amine derivatives.The genus Inula (Asteraceae) comprises about 100 plants, many of which are widely used in folk medicine owing to a variety of biological activities [1] including anti-inflammatory, antitumor, and bactericidal [2]. Plants of this genus contain a large number of physiologically active compounds, e.g., sesquiterpene lactones, among which compounds with valuable biological properties were observed [3].The sesquiterpene lactone britanin (1) is frequently encountered in plants of the genus Inula and was isolated from I. caspica Blume, I. britannica L., and I. aspera Poir.[4]. Its pseudoguaianolide structure was first described over 50 years ago [5]. An x-ray crystal structure analysis [6] established the R-configuration for the 2-acetoxy group. ** We also obtained a significant quantity of a britanin isomer during its isolation by the previously described method [7]. This was inuchinenolide C (2), which was first isolated from I. britannica var. chinensis and differed in the position of the acetyl group [8]. Despite the similar structures, 1 and 2 were easily differentiated by the positions of the resonances for the 4-and 6-protons in the PMR spectrum.Chemical modifications of 1 that affected the five-and seven-membered rings included acylation and deacetylation [9] and oxidation [9, 10]. However, 1 and 2 also include a highly reactive electrophilic center as an exomethylene in the lactone ring that is susceptible to attack by nucleophiles. The reaction of 1 with methylmercaptoacetate (S-nucleophile) is known to occur at the lactone ring and to produce addition products at the C-11 and C-13 atoms in a 3:1 ratio [11]. Examples of the addition of N-nucleophiles to britanin isolated from I. caspica are known. According to some researchers [12][13][14], the reaction with secondary (diethylamine and morpholine) and primary (ethanolamine) amines in addition to bifunctional ethylenediamine occurred stereospecifically. However, the physicochemical properties of the products were not characterized in those studies. Furthermore, these reactions with 2 have not been reported. Recently, compounds with various biological activities, including antitumor activity, were observed among sesquiterpene lactone amine derivatives [15]. This is responsible for the heightened interest in such compounds.We studied the reaction of 1 with several primary aliphatic and secondary amines, including heterocyclic ones, in order to prepare new amine derivatives. The reaction proceeded readily in a polar protic (MeOH) or nonpolar aprotic (CH 2 Cl 2 ) solvent at room or slightly elevated temperature. The structures of the reaction products depended on the reaction conditions and the nature of the amine (basicity and nucleophil...

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Synthesis of S-Containing Derivatives of the Sesquiterpene Lactone Britanin

Cited by 7 publications

References 3 publications

Sesquiterpenoids fromInula britannica

Sesquiterpenoids fromInula britannica

Visible light promoted difunctionalization reactions of alkynes

Amination Products of Inula britannica Lactones and Their Antitumor Activity

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