18. Triterpenoids. Part V. Some relative configurations in rings<scp>C</scp>,<scp>D</scp>, and<scp>E</scp>of the β-amyrin and the lupeol group of triterpenoids

Barton, D. H. R.; Holness, N. J.

doi:10.1039/jr9520000078

Cited by 63 publications

(23 citation statements)

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“…5 3-ˇ-Hydroxyolean-11-oxo-12-en-28-oic acid (11-oxooleanolic acid) (2) was obtained as described in the literature. 6 3-ˇ-Hydroxyolean-12-en-18˛-28-oic acid (18˛-oleanolic acid) (3) was obtained by a reported procedure, but characterization was not reported by the authors: 7 3-ˇ-Hydroxyolean-11-oxo-12-en-18˛-28-oic acid (11-oxo-18˛-oleanolic acid) (4) was prepared by the reported alkaline process. 7 3-ˇ-Hydroxyurs-12-en-28-oic acid (ursolic acid) (5) was isolated from powdered bearberry leaves.…”

Section: Preparation Of Triterpene Acidsmentioning

confidence: 99%

Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Seebacher

Simić

Weis

et al. 2003

Magnetic Reson in Chemistry

444

246

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One way to increase the rate of an electrochemical process is to increase the area of the interface between the electrode and the electrolyte. A novel polymer electrode, with a very high effective surface area and a nanometer‐scale continuous conducting network that extends into a large volume, is presented and its preparation from a commercially available aqueous dispersion of a conducting polymer described. An application to supercapacitors is detailed, as a demonstration of the properties that are a consequence of the unique structure of the material.

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Section: Preparation Of Triterpene Acidsmentioning

confidence: 99%

Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Seebacher

Simić

Weis

et al. 2003

Magnetic Reson in Chemistry

444

246

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“…β-Amyrin has perhydropicene skeleton with a trisubstituted double bond in ring C. The relation of β-amyrin with oleanolic acid is shown in Fig. 10.21, which elucidates the stereochemistry at C17 and C18 [73]. Barton [74] has elegantly shown that C17 COOH in oleanolic acid is β-axial in ring D, and D/E rings are cis-fused as is evident from the following facts: the C17-CO and C13-O bonds in the lactone (A) are in 1,3-diaxial relationship in ring D (Fig.…”

Section: Stereochemistrymentioning

confidence: 98%

Triterpenes (C30)

Talapatra

2014

Chemistry of Plant Natural Products

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“…These data are consistent with the structure and properties of the compound we report. The stereochemistry and reactions of several related compounds have been reported (Barton & Holness, 1952;Halsall, Jones & Meakins, 1952;Ames, Halsall & Jones, 1951).…”

Section: Discussionmentioning

confidence: 99%

The molecular structure of 3β-acetoxy-20-hydroxylupane, C32H54O3

Watson¹,

Ting²,

Domínguez³

1972

Acta Crystallogr Sect B

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The structure of the monoacetate derivative of lupane-3fl,20-diol, C32H5403, was determined by the symbolic-addition procedure and-tangent formula method. The space group is P21 and cell dimensions are a= 15"198 (8), b= 8.260 (7), c= 12.226 (5) A and fl= 108"6 (3) °. The triterpene lupane-3fl,20-diol, C30Hs202, was extracted from Thelocactus bicoior, and a monoacetate derivative was prepared. The relative molecular configuration was found to beThe molecule is composed of four trans fused six-membered rings and one trans fused five-membered ring. All six-membered rings are in the chair conformation. The absolute configuration of the 3-position is known, and the absolute configuration of the remainder of the molecule can be established.

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18. Triterpenoids. Part V. Some relative configurations in ringsC,D, andEof the β-amyrin and the lupeol group of triterpenoids

Cited by 63 publications

References 0 publications

Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Triterpenes (C30)

The molecular structure of 3β-acetoxy-20-hydroxylupane, C32H54O3

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18. Triterpenoids. Part V. Some relative configurations in ringsC,D, andEof the β-amyrin and the lupeol group of triterpenoids

Cited by 63 publications

References 0 publications

Complete assignments of 1H and 13C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Complete assignments of 1H and 13C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Triterpenes (C30)

The molecular structure of 3β-acetoxy-20-hydroxylupane, C32H54O3

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Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives

Complete assignments of ¹H and ¹³C NMR resonances of oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives