• Journal of Ginseng Research
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• v.40 no.3
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• pp.245-250
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• 2016

Background: Ginsenosides are the major effective ingredients responsible for the pharmacological effects of ginseng. Malonyl ginsenosides are natural ginsenosides that contain a malonyl group attached to a glucose unit of the corresponding neutral ginsenosides. Methods: Medium-pressure liquid chromatography and semipreparative high-performance liquid chromatography were used to isolate purified compounds and their structures determined by extensive one-dimensional- and two-dimensional nuclear magnetic resonance (NMR) experiments. Results: A new saponin, namely malonyl-ginsenoside Re, was isolated from the fresh flower buds of Panax ginseng, along with malonyl-ginsenosides Rb1, Rb2, Rc, Rd. Some assignments for previously published $^1H$- and $^{13}C$-NMR spectra were found to be inaccurate. Conclusion: This study reports the complete NMR assignment of malonyl-ginsenoside Re, $Rb_1$, $Rb_2$, Rc, and Rd for the first time.

• YAKHAK HOEJI
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• v.40 no.3
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• pp.293-299
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• 1996

The $^1H$- and $^{13}C$-NMR signals of (20R)-panaxadiol and (20R)-panaxatriol were completely assigned by the extensive application of modern 2D-NMR techniques, $^1H-^1H$ COSY, HMQC and HMBC.

• Molecules and Cells
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• v.27 no.4
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• pp.493-496
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• 2009

Hypoxia-inducible factor $1{\alpha}$ ($HIF1{\alpha}$) is a transcription factor that plays a key role in the adaptation of cells to low oxygen stress and oxygen homeostasis. The oxygen-dependent degradation (ODD) domain of $HIF1{\alpha}$ responsible for the negative regulation of $HIF1{\alpha}$ in normoxia is intrinsically unfolded. Here, we carried out the backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignment of a proteolysis-resistant fragment (residues 404-477) in the $HIF1{\alpha}$ ODD domain using NMR spectroscopy. About 98% (344/352) of all the $^1HN$, $^{15}N$, $^{13}C{\alpha}$, $^{13}C{\beta}$, and $^{13}CO$ resonances were unambiguously assigned. The results will be useful for further investigation of the structural and dynamic states of the $HIF1{\alpha}$ ODD domain and its interaction with binding partners.

• Natural Product Sciences
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• v.12 no.1
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• pp.62-66
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• 2006

A steroidal saponin, $3-O-{\alpha}-L-rhamnopyranosyl-(1{\rightarrow}2)-[{\alpha}-L-rhamnopyranosyl-(1{\rightarrow}3)]-{\beta}-D-glucopyranosylpennogenin$ ;(1, spiroconazole A) was isolated from the tubers of Dioscorea bulbifera L. var sativa and $^1H-and\;^{13}C-NMR$ assignment was completed using HMBC correlation. In addition, four phenolic substances, 2,7-dihydroxy-4-methoxyphenanthrene (2), quercetin (3), $quercetin-3-O-{\beta}-D-glucopyranoside$ (4), and $quercetin-3-O-{\beta}-D-galactopyranoside$ (5) were also isolated.

• Natural Product Sciences
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• v.15 no.2
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• pp.76-82
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• 2009

Phytochemical investigation of the EtOAc and n-BuOH fractions obtained from the crude methanol extract of the seeds of Butyrospermum parkii led to the isolation of seven compounds including 1${\beta}$,2${\alpha}$,3${\alpha}$-trihydroxyurs-12-en-28-oic acid (1${\beta}$-hydroxyeuscaphic acid) which full NMR assignment is herein reported for the first time. The above extract, fractions and some of the isolated compounds were screened for antimicrobial and antioxidant activities; 1${\beta}$-hydroxyeuscaphic acid was the more potent.

• Journal of the Korean Magnetic Resonance Society
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• v.27 no.4
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• pp.23-27
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• 2023

Hoxc, or the Homeobox C cluster, is a group of genes that play a crucial role in embryonic development, particularly in patterning the body along the anterior-posterior axis. These genes encode transcription factors, which are proteins that bind to DNA and regulate the expression of other genes. Hoxc9 is specifically involved in the development of the skeletal system, nervous system, and adipose tissue. Hoxc9 overexpression has been linked to the development of various cancers such as leukemia and breast cancer. Here, we assigned the chemical shifts Hoxc9 DNA binding domain (DBD) using heteronuclear NMR techniques. The helical regions of Hoxc9 DBD correspond to the residues T200 - F213 (Helix I), T218 - L229 (Helix II), and T232 - K249 (Helix III). Our result would be helpful for studing the molecular interactions of the Hoxc9 DBD and other proteins.

• Journal of the Korean Magnetic Resonance Society
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• v.15 no.1
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• pp.69-79
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• 2011

HP0827 has two RNP motif which is a very common protein domain involved in recognition of a wide range of ssRNA/DNA.We acquired 3D NMR spectra of HP0827 which shows well dispersed and homogeneous signals which allows us to assign 98% of all $^1H_N$, $^{15}N$, $^{13}C_{\alpha}$, $^{13}C_{\beta}$ and $^{13}C$=O resonances and 90% of all sidechain resonances. The sequence-specific backbone resonance assignment of HP0827 can be used to gain deeper insights into the nucleic acids binding specificity of HP0827 in the future study. Here, we report secondary structure prediction of HP0827 derived from NMR data. Additionally, ssRNA/DNA binding assay studies was also conducted. This study might provide a clue for exact function of HP0827 based on structure and sequence.

• Korean Journal of Pharmacognosy
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• v.28 no.2
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• pp.88-92
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• 1997

The full NMR assignment of hispidulin 7-0-neohesperidoside (1) isolated from Cirsium japonicum var. ussuriense was made with the aid of 2D correlation NMR techniques such as HMQC and HMBC. To investigate detoxification of bromobenzene-induced hepatic lipid peroxidation by compound 1, hepatic lipid peroxide level and the activities of enzymes responsible for production and removal of epoxide were studied. The level of lipid peroxide elevated by bromobenzene was significantly reduced by compound 1. This compound administered daily over one week before intoxication with bromobenzene did not affect the activities of aminopyrine N-demethylase, aniline hydroxylase, glutathione S-transferase. Epoxide hydrolase activity was decreased significantly by bromobenzene, which was restored to the control level by pretreatment of persicarin. The results suggest that the bromobenzene-induced hepatic lipid peroxidation by compound 1 is reduced by enhancing the activity of epoxide hydrolase, an enzyme removing bromobenzene epoxide.

• Korean Journal of Pharmacognosy
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• v.12 no.1
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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.

• Natural Product Sciences
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• v.26 no.2
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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.