• Journal of Ginseng Research
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• 제38권3호
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• pp.194-202
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• 2014

Background: Ginsenosides, the major ingredients of Panax ginseng, have been studied for many decades in Asian countries as a result of their wide range of pharmacological properties. The less polar ginsenosides, with one or two sugar residues, are not present in nature and are produced during manufacturing processes by methods such as heating, steaming, acid hydrolysis, and enzyme reactions. $^1H$-NMR and $^{13}C$-NMR spectroscopic data for the identification of the less polar ginsenosides are often unavailable or incomplete. Methods: We isolated 21 compounds, including 10 pairs of 20(S) and 20(R) less polar ginsenosides (1-20), and an oleanane-type triterpene (21) from a processed ginseng preparation and obtained complete $^1H$-NMR and $^{13}C$-NMR spectroscopic data for the following compounds, referred to as compounds 1-21 for rapid identification: 20(S)-ginsenosides Rh2 (1), 20(R)-Rh2 (2), 20(S)-Rg3 (3), 20(R)-Rg3 (4), 6'-O-acetyl-20(S)-Rh2 [20(S)-AcetylRh2] (5), 20(R)-AcetylRh2 (6), 25-hydroxy-20(S)-Rh2 (7), 25-hydroxy-20(S)-Rh2 (8), 20(S)-Rh1 (9), 20(R)-Rh1 (10), 20(S)-Rg2 (11), 20(R)-Rg2 (12), 25-hydroxy-20(S)-Rh1 (13), 25-hydroxy-20(R)-Rh1 (14), 20(S)-AcetylRg2 (15), 20(R)-AcetylRg2 (16), Rh4 (17), Rg5 (18), Rk1 (19), 25-hydroxy-Rh4 (20), and oleanolic acid 28-O-b-D-glucopyranoside (21).

• 생명과학회지
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• 제11권1호
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• pp.93-96
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• 2001

n-BuOH fraction obtained from MeOH extracts of Allium monanthum was applied to repeated silica gel column chromatographies to give a glycosylglyceride. The chemical structure of the compound was determined to be 1-O-linolenoyl-2-O-linolenoyl-3-O-$\beta$-D-galactopyranosyl-누-glycerol on the basis of NMR data and by the adaptation of chemical methods.

• 대한화학회지
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• 제54권6호
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• pp.701-706
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• 2010

우리나라 동해안에 서식하는 염생식물인 갯방풍으로부터 2개의 polyacetylene 화합물인 falcarindiol(1)과 falcarinol(2), 4개의 coumarin 화합물인 bergapten(3), xanthotoxin(4), umbelliferone(5), scopoletin(6) 및 1개의 sesquiterpene 화합물인 $(5\beta,10\alpha)$-lasidiol angelate(7)가 분리되었다. 이들 화합물 중 scopoletin(6)과 $(5\beta,10\alpha)$-Lasidiol angelate(7)는 갯방풍으로부터 처음 분리되어진 것이다. 분리된 화합물의 구조결정은 $^1H$ COSY, HMQC 그리고 HMBC와 같은 2D NMR 분광학적 실험과 문헌에 보고 된 값을 비교하여 이루어졌다.

• Food Science and Biotechnology
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• 제17권5호
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• pp.1060-1065
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• 2008

A novel benzoyl glucoside (4) and 13 known phenolic compounds were isolated from the leaves of Camellia japonica by a guided 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The structure of 4 was determined to be 4-hydroxy-2-methoxyphenol 1-O-$\beta$-D-(6'-O-p-hydroxylbenzoyl)-glucopyranoside (camelliadiphenoside). The 13 known compounds were identified as (E)-coniferyl alcohol (1), (-)-epicatechin (2), 4-hydroxyphenol 1-O-$\beta$-D-(6-O-p-hydroxybenzoyl) glucopyranoside (3), naringenin 7-O-$\beta$-D-glucopyranoside (5), quercetin 3-O-$\beta$-L-rhamnopyranosyl(1$\rightarrow$6)-$\beta$-D-glucopyranoside (6), kaempferol 3-O-$\beta$-L-rhamnopyranosyl(1$\rightarrow$6)-$\beta$-D-glucopyranoside (7), (+)-catechin (8), 1,6-di-O-p-hydroxybenzoyl-$\beta$-D-glucopyranoside (9), phloretin 2'-O-$\beta$-D-glucopyranoside (10), quercetin 3-O-$\beta$-D-glucopyranoside (11), quercetin 3-O-$\beta$-D-galactopyranoside (12), kaempferol 3-O-$\beta$-D-galactopyranoside (13), and kaempferol 3-O-$\beta$-D-glucopyranoside (14). Their chemical structures were determined by the spectroscopic data of fast atom bondardment mass spectrometry (FABMS) and nuclear magnetic resonance (NMR). Flavonoids having the catechol moiety showed significantly higher DPPH radical scavenging activity than other isolated compounds having monohydroxy phenyl group.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.254-258
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• 2007

Five flavonoids, isorhamnetin 3-O-${\beta}$-D-galactosyl-4'-O-${\beta}$-D-glucoside (1), isorhamnetin 3,4'-di-O-${\beta}$-D-glucoside (2), isorhamnetin 3-O-${\beta}$-D-(6-O-${\alpha}$-L-rhamnosyl)glucosyl-4'-O-${\beta}$-D-glucoside (3), isorhamnetin 3-O-${\beta}$-D-(6-O-${\alpha}$-L-rhamnosyl)glucoside (4), and isorhamnetin 3-O-${\beta}$-D-(6-O-${\alpha}$-L-rhamnosyl) galactoside (5) were isolated from the stems of Opuntia humifusa (Raf.) Raf. and their structures were identified based on LC-MS and NMR data.

• Journal of Photoscience
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• 제9권2호
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• pp.344-346
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• 2002

Eight intact bacteriochlorophyll (BChl)-d homologs and isomers were isolated from a strain of green sulfur bacterium Chlorobium vibrioforme. All the molecular structures of the BChl-d components were fully determined by a combination of mass spectrometry and $^1$H-NMR spectroscopy. The aggregation behavior of the isomerically pure BChls-d in hydrophobic organic solvents was examined with respect to the stereoisomeric configuration at the C3$^1$ position as well as the bulkiness of the C8 and C12 side-chains by using electronic- absorption spectroscopy.

• Biomolecules & Therapeutics
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• 제2권1호
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• pp.28-33
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• 1994

In order to obtain insight into the repair mechanism of DNA containing thymine photo-dimer, the conformation of the duplex d(GCGGTTGGCG).d(CGCCAACCGC) with a thymine dimer incorporated has been studied by proton NMR. NOE data show that, although the local environment around the thymine dimer is altered, the gross structural changes are relatively small. T$_4$endonuclease V exhibited a conformational change on complex formation with DNA. This conformational change occurred around histidine 16 which was close to tyrosine 129 located in the aromatic segment (WYKYY) near the C-terminus. It is likely that the interaction between T$_4$endonuclease V and DNA is strong since the complex was not dissociated up to 1.6 M NaCl.

• Bulletin of the Korean Chemical Society
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• 제15권8호
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• pp.673-679
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• 1994

$^1H$ NMR spectra of imidazole, 2-and 4(5)-methylimidazole, histamine, L-histidine, L-histidine methyl ester, N${\alpha}$-acetyl-L-histidine, and L-carnosine coordinated to the paramagnetic undecatungstocobalto(II)silicate ($SiW_{11}Co$) and undecatungstonickelo(II)silicate ($SiW_{11}Ni$) anions are reported. For these complexes the ligand exchange is slow on the NMR time scale and the pure resonance lines of the free ligand and the complexes have been observed separately at room temperature. Two different complexes are formed, depending upon which nitrogen atom of the imidazole ring is coordinated to the cobalt or nickel ion of $SiW_{11}M$. Thus the NMR spectrum of a $D_2O$ solution containing a ligand and $SiW_{11}M$ consists of three sets of lines originating from the free ligand and two complexes. All NMR lines of the $SiW_{11}Co$ complexes have been assigned unequivocally using the saturation transfer technique. The temperature dependence of some spectra are also reported. The NMR spectra of some complexes show that the internal rotation of the substituent on the imidazole ring is hampered by the heteropolyanion moiety even at room temperature.

• Natural Product Sciences
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• 제10권2호
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• pp.59-62
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• 2004

A novel chlorinated diterpene quinone methide; chlorosmaridione (7-chloro-11-hydroxy-abeita-7,9(11),13-triene-6,12-diode) was isolated from petroleum ether extract of the stems of Rosemarinus officinalis L. growing in Egypt. In addition, ${\beta}-sitosterol$, stigmasterol, lupeol acetate, ${\alpha}-amyrin,\;{\beta}-amyrin$, lupeol, acetyloleanolic acid, acetylursolic acid taxodione, horminone, and cryptotanshinone were also identified. Chemical structures of the isolated compounds have been elucidated on the bases of physical, chemical, and spectral data including IR, UV, MS, 1D-and 2D-NMR spectra.

• Bulletin of the Korean Chemical Society
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• 제8권2호
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• pp.96-101
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• 1987

2-Ethoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyran (1_a$), 2-n-butoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyr an (1b), 2-isobutoxy-6-methoxy-5-cyano-3,4-dihydro-2H-py ran ($1_c$), and 2-ethoxy-6-methoxy-3-methyl-5-cyano-3,4-dihydro -2H-pyran ($1_d$) were prepared by (4 + 2) cycloaddition reaction of methyl $\alpha$-cyanoacrylate with the corresponding alkyl vinyl ethers. Compounds $1_{a-d}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, head-to-tail (H-T) copolymer $3_a$ was also prepared by free radical copolymerization of the corresponding monomers. The H-H copolymer exhibited minor differences in its $1_H% NMR and IR spectra, but in the $^{13}C$ NMR spectra significant differences were observed between the H-H and H-T copolymers. Glass transition temperature ($T_g$) of H-H copolymer was higher than that of the H-T copolymer, but thermal decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. Compounds $1_a$, $a_b$, and $1_c$, copolymerized well with styrene by cationic catalyst, but compound 1d failed to copolymerize with styrene. All of the H-H and H-T copolymers were soluble in common solvents and the inherent viscosities were in the range 0.2-0.4 dl/g.