Die relative Konfiguration der Chebulsäure

Schilling, Gerhard; Schweiger, Richard G.; Weis, Günter; Mayer, Walter; Weiβ, Johannes; Siegel, Rolf

doi:10.1002/jlac.198119810406

Cited by 6 publications

(6 citation statements)

References 5 publications

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“…The isolated materials actually consist of two epimers, ( S , S , S )‐ 1 and (3 S ,4 S ,9 R )‐ 1 (Figure 1). The relative trans ‐configuration at C3 and C4 was already earlier established by X‐ray structure of the triethylester of chebulic acid [9] …”

Section: Introductionmentioning

confidence: 62%

The First Total Synthesis of Racemic Chebulic Acid

Kieslich

Christoffers

2022

Eur J Org Chem

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The first total synthesis of racemic chebulic acid is reported, which is the aglycon of several antioxidant ingredients of the fruit of the Terminalia chebula tree. The route started with the straightforward preparation of an indanone‐based β‐oxoester from a benzaldehyde derivative (84 % over the first five steps). The side chain of the target compound was then introduced by conjugated addition of a cuprate reagent derived from dimethyl succinate, which was followed by the first key step of the synthesis: a cerium‐catalyzed α‐hydroxylation of an β‐oxoester. The second key step was the cyanide‐catalyzed ring transformation of the cyclic α‐hydroxy‐β‐oxoester to a δ‐lactone. Finally, chebulic acid was obtained after six‐fold demethylation of three methyl ester moieties and three phenolic ether functions. The overall synthetic route consists of nine consecutive steps and was accomplished in 15 % overall yield.

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Section: Introductionmentioning

confidence: 62%

The First Total Synthesis of Racemic Chebulic Acid

Kieslich

Christoffers

2022

Eur J Org Chem

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“…The small coupling constants (1.4 Hz) between H-3 and H-4 confirmed their trans-diequatorial relative configuration. 6,17 Euphorhirtins C−E (3−5) had the same molecular formula, C 18 H 18 O 11 , as determined by their positive-ion HRESIMS and 13 C NMR data. Analysis of their 1 H and 13 C NMR data (Table 1) revealed that the structures of 3−5 were similar to 15, the difference being the presence of only two ethoxy groups in 3− 5.…”

mentioning

confidence: 85%

“…Thus, the 2D structure of euphorhirtin A (1) was assigned and confirmed by analysis of its HMBC spectrum (Figure 1). The small 3 J 3,4 value of 2.0 Hz, 6,17 along with the NOESY correlation of H-3/H-4 indicated that H-3 and H-4 adopted a trans-diequatorial relative configuration with both hydrogens in an equatorial orientation. However, the configuration of the C-11−C-12 double bond could not be determined from the available data.…”

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confidence: 96%

Isolation, Absolute Configuration, and Biological Activities of Chebulic Acid and Brevifolincarboxylic Acid Derivatives fromEuphorbia hirta

Yang

Wang

et al. 2020

J. Nat. Prod.

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Twenty new chebulic acid and brevifolincarboxylic acid derivatives, including eight optically pure or achiral compounds (1–7 and 14) and six pairs of enantiomers (8a/8b–13a/13b), along with nine known analogues (15–23), were isolated from an EtOH extract of the aerial parts of Euphorbia hirta. The absolute configurations of the new compounds were assigned based on single-crystal X-ray diffraction analysis and comparison of the experimental and calculated ECD data. Racemic or scalemic mixtures of 8–13 were isolated, and their enantiomers were analyzed by chiral-phase HPLC-ECD measurements. Compound 12 possesses an unprecedented 2H-cyclopenta[de]chromene-2,5(4H)-dione scaffold. Compounds 12, 20, and 23 displayed moderate inhibitory effects against lipopolysaccharide-induced nitric oxide production in BV-2 microglial cells, while all the isolates exhibited significant DPPH radical scavenging activities with EC50 values of 2.2–15.8 μM.

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“…A skeleton of this type is reported in the literature for chebulic acid. 35,36 However, chebulic acid 2S, 3S, 4S 37 is the hydrolysis product of chebulinic and chebulagic acid 36 and is not a naturally occurring compound.…”

Section: Structure Elucidation Of B3ea-6mentioning

confidence: 98%

Modern drug development from traditional medicinal plants using radioligand receptor-binding assays

Misra

1998

Med. Res. Rev.

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Traditional medicinal plants in various countries, particularly in India have been used for centuries for various ailments; however, there has been little scientific effort to validate these anecdotal uses mentioned in the literature. A number of these traditionally used plant extracts and various “Ayurvedic medicines” that are highly valued in Ayurveda, the traditional system of medicine in India for antiaging, memory‐enhancing, nerve tonic, anxiolytic, anti‐inflammatory and immunopotentiation, have been screened using National Institutes of Mental Health (NIMH) Synthetic Screening Program for scientific validation and the development of new leads of psychotherapeutic compounds using Radioligand Receptor Binding Assays (RRA). Crude methanolic extracts of plants are screened using approximately 40 different in vitro RRA (primarily from rat brain homogenates) and 6 enzyme assays including acetylcholine esterase, choline acetyltransferase, and monoamine oxidase (MAO), A and B. The total crude extracts of many of these plants showed potent selectivity to various receptors, especially γ‐Amino Butyric Acid (GABAA), N‐Methyl‐D‐Aspartic Acid (NMDA), and MAO receptors, which are presumed to be involved in mental disorders. The focus was on plants showing the highest displacement of GABA, cholecystokinin (CCK), NMDA, MAO, and benzodiazopines. Bioassay guided fractionation of the most active extracts resulted in pure compounds which retained the original activity of the crude extract validating the folkloric use. A bioactivity‐guided fractionation of Terminalia bellerica fruit extract led to the isolation of several pure compounds which retained the original activity of the crude extract for CCK and GABA receptors, with the exception of compound B3EA‐6, which exhibited high affinity for Neurokinin receptor (Substance K ∼ NK‐1). The absolute structure of B3EA‐6 has been established by x‐ray crystallography. © 1998 John Wiley & Sons, Inc. Med Res Rev, 18, No. 6, 383–402, 1998.

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Die relative Konfiguration der Chebulsäure

Abstract: Entgegen früheren Aussagen besitzt die Chebulsäure 2 die relative Konfiguration 2R,3S,4R oder 2S,3R,4S. Dies wurde durch synthetische und NMR‐spektroskopisch Beweise sowie durch eine Röntgenstrukturanalyse festgestellt.

Cited by 6 publications

References 5 publications

The First Total Synthesis of Racemic Chebulic Acid

The First Total Synthesis of Racemic Chebulic Acid

Isolation, Absolute Configuration, and Biological Activities of Chebulic Acid and Brevifolincarboxylic Acid Derivatives fromEuphorbia hirta

Modern drug development from traditional medicinal plants using radioligand receptor-binding assays

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