• Journal of Ginseng Research
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• 제20권1호
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• pp.111-112
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• 1996

The chemical shifts of C-21 and C-23 in the $^{13}C$-NMR for (20R)-protopanaxatriol, (20R)-ginsenoside $Rh_1$ and (20R)-ginsenoside $Rg_3$ were revised by employing some extensive 2D-NMR techniques.

• 분석과학
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• 제7권1호
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• pp.91-102
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• 1994

일련의 polypropylene 계통의 공중합체 및 삼중합체 중에서 단량체의 조성에 관한 조성비를 $^{13}C-NMR$ 스펙트럼을 이용하여 정량하였다. 고온에서 얻어진 고분자의 $^{13}C-NMR$ 스펙트럼은 아주 높은 분해능을 보이며, 이는 모든 시그날을 명확하게 지정하는 것을 가능하게 하였으며, 또한 단량체의 조성비를 계산할 수 있도록 하였다. 따라서 단량체의 조성비를 계산하는 방법을 새롭게 제시하였으며, 고분자에서 dyad, triad, tetrad 및 pentad의 조성비도 계산할 수 있다는 것을 보여 주었다. 이러한 단량체 조성에 관한 NMR 분석 결과는 표준 물질을 이용하여 정량한 IR data와 잘 일치한다는 것을 보여 준다.

• 생약학회지
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• 제12권1호
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• pp.12-14
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• 1981

${\beta}-Sitosteryl-3-O-{\beta}-D-glucopyranoside$ was isolated from the seeds of Plantago asiatica (Plantaginaceae). The assignments of $^{13}C$ NMR spectra of ${\beta}-sitosterol$ and ${\beta}-sitosteryl-3-O-{\beta}-D-glucopyranoside$ were made by comparing with $^{13}C$ NMR spectra of cholesterol and $cholesteryl-3-O-{\beta}-D-glucopyranoside$. Our data indicate that the revision of previous $^{13}C$ NMR spectral assignment is needed.

• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.603-608
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• 2005

The $^1H\;and\;^{13}C$ chemical shifts of flavone and its five derivatives were determined completely using the basic 1D and 2D NMR experiments and molecular modeling. Of the six compounds used for our experiments, the NMR data of three compounds were published previously, but we found that the data of two compounds included wrong assignments. Therefore, we report the corrected data and the complete assignments of NMR data of the other three compounds.

• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.81-84
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• 2008

In the present study, we report 1H and 13C NMR data of 19 methoxyflavonol derivatives with different substitution patterns on A- and B-ring. In addition, the influence of the methoxy substituents in A- and B-ring on the 1H and 13C NMR chemical shifts is discussed: the 1H and 13C chemical shifts of and the number of methoxyl groups provided information allowing elimination of many structural isomers from consideration and in certain instances greatly simplified structural elucidation.

• Natural Product Sciences
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• 제26권2호
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• pp.171-175
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• 2020

Liriodendron tulipifera, belonging to the family Magnoliaceae, is commonly called tulip tree. Four N-acetylated aporphine alkaloids, N-acetylnornuciferine (1), N-acetylanonaine (2), N-acetyl-3-methoxynornuciferine (3), and N-acetyl-3-methoxynornantenine (4) were isolated from the roots of L. tulipifera. Although the purity of each compound (1 - 4) was determined to be 97, 96, 99, and 98%, respectively, the ¹H and ¹³C NMR spectroscopic data of the aporphine alkaloids 1 - 4 displayed all signals in duplicate, indicating the presence of two rotamers due to restricted rotation of N-COCH₃ functionality in solution status. The absolute configurations of 1 - 4 w ere established by measuring specific rotation and comparison with the reported data. This is the first report on the ¹H and ¹³C NMR assignments of N-acetyl-3-methoxynornuciferine (3) and N-acetyl-3-methoxynornantenine (4). This study provides advanced NMR spectroscopic data for the structure determination of rotameric aporphine alkaloids.

• 한국결정학회지
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• 제12권3호
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• pp.141-144
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• 2001

Na[Ga(N₃)₄]와 PPh₃의 반응으로부터 이온성 화합물 [Ph₃P(OH)]/sup +/[N₃]/sup -/ (1)이 분리되었다. 화합물1의 구조가 분광학적 방법(¹H-NMR, /sup 13/C{¹H-NMR, IR) 및 X-ray 회절법으로 규명되었다. 화합물1의 결정학 자료 : 사방정계 공간군 P2₁2₁2₁, a = 10.491(4)Å, b=11.603(5)Å, c=13.149(5)Å, Z=4, R(wR₂)=0.0547(0.0978).

• 약학회지
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• 제39권3호
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• pp.268-275
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• 1995

A novel polyacetylene was isolated from Cirsium spp., as well as five known ones, and its chemical structure was determined as heptadeca-1-en-11.13-diyne-8R, 9S, 10R-triol(1) on the basis of spectral data and chemical reactions. $^{1}$H-and $^{13}$C-NMR data of these polyacetylenes were completely assigned by the appfication of 2D-NMR techniques.

• 분석과학
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• 제14권1호
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• pp.1-7
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• 2001

6,6-Dichlorobicyclo[3, 1, 0]hexane-3carboxylic acid를 phase transfer catalyst(PTC)로 benzyl triethylamine chloride(BTEA.Cl)를 사용하여 3-cyclopentenecarboxylic acid로부터 합성하였다. $^1H$ NMR과 $^{13}C$ NMR 분석을 통하여 이 화합물은 boat-like conformation을 갖는 것으로 나타났고 carboxyl group은 trans로 존재하는 것으로 나타났다.

• Archives of Pharmacal Research
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• 제17권6호
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• pp.393-397
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• 1994

Rhomobifoline and 5,6-dehydrolupanine were isolated for the frist time from the leaves and stems of A. foetida L. indigenous to Saudil Arabia. In addition, five other alkaloids, previously identified in A, foetidia L., namely N-methylcytisine, sparteine, anagyrine, lupanine and cytisine, were isolated. The isolated alkaloids were characterized by UV, $^1-NMR,{\;}^{13}H-NMR,{\;}^{13}C-NMR{\;}and{\;}Mass{\;}spectral{\;}data.{\;}^{13}C-NMR$ data of rhombifoline and 5,6-dehydroupanine are reported for the first time.