Steroids. CCCXI. Degradation of stigmasterol to 3.beta.-5.alpha.,6.beta.-trihydroxy-23,24-bisnorcholan-22-oic acid

Alvarez, Francisco S.; Watt, Alexander N.

doi:10.1021/jo01269a107

Cited by 25 publications

(7 citation statements)

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“…Therefore, compound 3 was established as 2,16-dihydroxyl-15-keto-2-acetoxy-ent-pimar-8(14)-ene-16-O-β-D-glucopyranoside. The known compounds sitost-5-en-3β-ol acetate (4) [12], β-sitosterol-3-O-β-D-glucopyranoside (5) [13], 3,5,6-trihydroxysitostane (6) [14], stigmastane-3β,5α,6β-triol-3,6-diacetate (7) [15] were identified by comparison of their spectroscopic data with the literature values.…”

Section: Resultsmentioning

confidence: 99%

Norditerpenoids from Flickingeria fimbriata and Their Inhibitory Activities on Nitric Oxide and Tumor Necrosis Factor-α Production in Mouse Macrophages

Chen

Zhong

et al. 2014

Molecules

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Bioassay-guided fractionation of the ethanolic extract of the leaves of Flickingeria flimbriata led to the isolation of two new degraded diterpenoids 1 and 2, a new ent-pimarane type diterpenoid 3, and four known steroids 4-7. The structures of 1-3 were elucidated by spectroscopic analysis, and their absolute configurations were determined by chemical methods, TDDFT quantum chemical calculations of ECD spectra, and CD exiton chirality method. Compounds 1 and 2, named flickinflimilins A and B, possess a rare 15,16-dinor-ent-pimarane skeleton. Compounds 1-7 were screened for the inhibitory activity against lipopolysaccharide (LPS)-induced NO and TNF-α production in RAW264.7 cells. Compounds 1-3 exhibited potent inhibitory activities, with IC 50 values of less than 10 µM.

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Section: Resultsmentioning

confidence: 99%

Norditerpenoids from Flickingeria fimbriata and Their Inhibitory Activities on Nitric Oxide and Tumor Necrosis Factor-α Production in Mouse Macrophages

Chen

Zhong

et al. 2014

Molecules

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“…The product was purified by column chromatography on silica gel using ethyl acetate to give the pure triol 9 (93 mg, 32%) as a white solid: mp 252-254°C (from ethyl acetate) [lit. (23) 3,6,-di-TMS Ether of 5r-Stigmasterol-3β,5r,6β-triol 23. 5R-Stigmasterol-3β,5R,6β-triol 9 (40 mg, 0.09 mmol) and pyridine (1 mL) were added under nitrogen, followed by hexamethyldisilizane (0.30 mL) and chlorotrimethylsilane (0.15 mL).…”

Section: Methodsmentioning

confidence: 99%

Synthesis and Characterization of Stigmasterol Oxidation Products

Foley¹,

O’Callaghan²,

O’Brien³

et al. 2010

J. Agric. Food Chem.

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The synthesis and structural characterization of a series of oxides of stigmasterol is described providing a valuable series of reference standards for these oxides, analogous to the cholesterol oxidation products (COPs) which have been shown to have detrimental biological effects. Biological evaluation of the oxides of phytosterols is significant in the context of increased dietary use of phytosterols in the drive to reduce cholesterol absorption.

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“…Diluted hydrochloric acid was added to the aqueous layer, adjusting the pH value to 2-3 before extraction of the carboxylic acids with diethyl ether. The products were esterified with methyl iodide and sodium hydrogen carbonate in dimethylformamide at 50 ЊC for 3 h. 21 These methyl esters were obtained with conversions of 100%. A Shimadzu GC17A/QP5000 MS spectrometer was used for isotopic analyses.…”

Section: Carbon-13 Nmr Spectramentioning

confidence: 99%

Carboxylations of alkali metal phenoxides with carbon dioxide

et al. 2003

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The reaction mechanism of the Kolbe-Schmitt reaction of phenol and 2-naphthol has been investigated. An alkali metal phenoxide-CO2 complex is not an intermediate that can be easily transformed into a carboxylic acid, such as salicylic acid (SA) and p-hydroxybenzoic acid (pHBA). A direct carboxylation of phenoxide with CO2 takes place even at room temperature, and is competitive with the formation of the CO2 complex. The resulting complex decomposes thermally (above ca. 100 degrees C) to phenoxide, which then undergoes further competitive reactions. Experiments using a carbon-13 labeled complex support a mechanism of direct carboxylation, and not the mechanism via a CO2 complex. The reactivity, C-13 NMR and MOPAC/PM3 calculations suggest a new carbonate-like structure for the CO2 complex.

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Steroids. CCCXI. Degradation of stigmasterol to 3.beta.-5.alpha.,6.beta.-trihydroxy-23,24-bisnorcholan-22-oic acid

Cited by 25 publications

References 0 publications

Norditerpenoids from Flickingeria fimbriata and Their Inhibitory Activities on Nitric Oxide and Tumor Necrosis Factor-α Production in Mouse Macrophages

Norditerpenoids from Flickingeria fimbriata and Their Inhibitory Activities on Nitric Oxide and Tumor Necrosis Factor-α Production in Mouse Macrophages

Synthesis and Characterization of Stigmasterol Oxidation Products

Carboxylations of alkali metal phenoxides with carbon dioxide

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