Chapter 2 Oxindole Alkaloids

Bindra, Jasjit S.

doi:10.1016/s1876-0813(08)60219-5

Cited by 24 publications

(29 citation statements)

References 46 publications

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“…The first isolated spirooxindole alkaloids were spirocycloalkyl-oxindole systems of type 1,2 (gelsemine 1a, gelsevirine 1b, gelsemicine 2a, gelsedine 2b), which were found in the roots of Gelsemium sempervirens and were classified as Gelsemium species [3,4]. The 3,3 -spirooxindole skeleton of these compounds is formed by the 2-oxindolic core linked to the cycloalkyl moiety [5] (Fig.…”

Section: Naturally Occurring S Spirooxindolesmentioning

confidence: 99%

“…Examples of 3-heteroatom-substituted spirooxindoles are also found in nature, e.g., spiroindoline [3,5 ]thiazolidinetype phytoalexins from some plants of the family Cruciferae, cultivated worldwide. Thus, in 1987 the first oxindole phytoalexin (S) − ( _ )-spirobrassinin 21 was isolated from Japanese radish (Raphanus sativus) by Monde et al [28,29].…”

Section: Naturally Occurring S Spirooxindolesmentioning

confidence: 99%

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Molecular diversity of spirooxindoles. Synthesis and biological activity

et al. 2015

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Spirooxindoles are important synthetic targets possessing extended biological activity and drug discovery applications. This review focuses on the various strategies for the enantioselective synthesis of spirocyclic oxindoles relying on reports over the past decade and from earlier work. The spirooxindoles in this review are separated into three structural classes, and then further categorized into the method type from which the spirocycle is generated.

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Section: Naturally Occurring S Spirooxindolesmentioning

confidence: 99%

Section: Naturally Occurring S Spirooxindolesmentioning

confidence: 99%

Molecular diversity of spirooxindoles. Synthesis and biological activity

et al. 2015

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“…-While epimerization at the spiro center of p -carboline oxindoles under comparatively mild conditions (usually a few hours reflux in pyridine or AcOH) is a long-standing phenomenon [20], which was rationalized by Wenkert et a/. [21] (for reviews, see [22]), the great ease with which compounds 2,12,13, and 22 epimerize, seems to be unprecedented. During the reductive decyanation of (+)-33 in a recent synthesis of (-)-horsfiline ((-)-34), e.g., less than 5% of racemization was observed [8] (Scheme 5), while (-)-11 racemized and epimerized completely under the same conditions.…”

mentioning

confidence: 99%

Total Synthesis of (+)‐Elacomine and (−)‐Isoelacomine, Two Hitherto Unnamed Oxindole Alkaloids from Elaeagnus commutata

Pellegrini¹,

Weber

Borschberg³

1996

Helvetica Chimica Acta

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Racemic elacomine ((%)-2), a hemiterpene spiro oxindole alkaloid from Elueagnus commutata, was synthesized in five steps from 6-methoxytryptamine (19) in 16% overall yield (Scheme 3 ) . The final oxidative rearrangement of the corresponding 8-carboline precursor (%)-21 furnished isoelacomine ((%)-22) as a by-product (6% overall yield). A more elaborate route that started from L-tryptophan furnished (+)-2 and (-)-22 with optical purities of 76% (Scheme 4 ) and established the absolute configuration of these compounds. A reinvestigation of the alkaloidal content of the roots of E. cornmututu showed that both elacomine and isoelacomine occur naturally in racemic form. ( [ a ] , = +174.8) hemiterpene oxindole alkaloid3) from the roots of the shrub Elaeagnus commutata (Elaegnaceae) [ 11. Chemical degradation studies and spectroscopic evidence led to structure proposal 1 which, however, left open the exact position of the phenolic OH group and the relative configuration at the two asymmetric centres C(3) and C(4')4). These questions were addressed subsequently by James and Williams by means of an X-ray diffraction study that allowed them to established formula 2 for this compound which they had obtained from Locock and Slywka [2]. Curiously enough, the sample investigated by X-ray crystallography must have been racemic, since the crystal was composed of alternating layers of both optical antipodes of 2, a fact that is consistent with the reported space group P2,lc. Surprisingly, the evident conflict concerning the enantiomeric purity of 2 was not commented by James and Williams, and in the context of our interest in the chemo-and diastereoselective transformation of indole alkaloids into their oxindole (1,3-dihydro-2H-indol-2-one) or pseudoindoxyl (1,2-dihydro-3H-indo1-3-one) derivatives [4-81, we decided to synthesize (+)-elacomine ((+)-2) in a way that would allow to delineate its hitherto unknown absolute configuration. Introduction. ~ In 1968, Slywka reported the isolation of a novel, optically active

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“…[1][2][3] For example, MI-219 is an inhibitor of the p53-MDM2 protein-protein interaction ( Figure 1). 4 A highly functionalized spiro cyclobutyloxindole, welwitindolinone A isonitrile isolated from bluegreen algae by Moore et al possesses antifungal activity.…”

mentioning

confidence: 99%

“…However, the reaction became sluggish, despite consumption of the diazooxindole (Table 1 entry 1). The use of the more electron-enriched ethyl vinyl ether also failed to give the desired product.…”

mentioning

confidence: 99%