• Bulletin of the Korean Chemical Society
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• 제8권5호
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• pp.372-376
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• 1987

Acetone solution of quinoline-8-carbaldehyde reacts with $[Rh(cod)(PPh_3)_2] PF_6$and $[Ir(cod)(PPh_3)_2] PF_6$ to yield $[Rh(NC_9H_6CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (1) and $[Ir(NC_9H_6CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (2), respectively. The compound $[Ir(cod)(PPh_3)_2] PF_6$ also reacts with $Ph_2PC_6H_4-o-CHO$ in the acetone / $H_2O$ mixture to give $[Ir(Ph_2PC_6H_4-o-CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (3). Compounds 1, 2, and 3 were characterized by infrared, $^1H$ NMR, $^{31}P$ NMR spectra and conductivity measurement. The $^1H$ NMR spectra of 1, 2, and 3 support the presence of a terminal hydride that is cis to the phosphine. The IR band of 3 at 2185 $cm^{-1}$, which is assigned to $\nu$(Ir-H), and the hydride cleavage reaction of 3 with $CCl_4$, provide evidence for the Ir-H bond.

• Journal of Ginseng Research
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• 제32권4호
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• pp.291-299
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• 2008

수삼으로부터 용매추출, 용매분획 및 silica gel column chromatography를 반복하여 ginsenoside $Rg_1$을 분리하였다. Ginsenoside $Rg_1$의 결정특성, 녹는점, 비선광도, IR 데이터, FAB/MS 데이터, TLC에서의 Rf 값, HPLC에서의 r.t. 및 NMR 데이터를 표준화한 조건으로 측정하여 문헌 값과 비교 고찰하였다. 특히 ginsenoside $Rg_1$의 $^{1}H-$ 및 $^{13}C$-NMR 데이터를 HSQC 및 HMBC와 같은 2D-NMR 실험을 통하여 정확하게 동정하였다.

• 한국자기공명학회논문지
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• 제15권2호
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• pp.90-103
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• 2011

Cornus officinalis (Cornaceae) is primarily grown in Asian countries. The pericarp of C. officinalis (Corni Fructus) is a well-known traditional medicine with tonic, analgesic, and diuretic properties. We analyzed methanolic extracts of Corni Fructus (grown in Korea and China) by $^1H$ NMR spectroscopy. Metabolite profiling was performed to characterize the metabolic difference between different Corni Fructus origins (Korea or China). Principal components analysis revealed significant separation between Comus Fructus from different origins. The metabolites responsible for differences were identified using loading plots, coefficients plots, and variable influence on projection followed by t-tests. As a result, 16 metabolites were identified and quantified; tyrosine, acetate, sucrose, and malate differed the most between origins. These data suggest that NMR-based metabolomics can be used to identify differences between Corni Fructus samples obtained from different regions.

• Archives of Pharmacal Research
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• 제14권3호
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• pp.237-241
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• 1991

The tautomerism in 3-phenyl-4-arylazo-5-isoxazolones 1 was examined by $^1H-NMR$ spectra of $^15N-labeled$ compound and by HMO method. Both spectra data $(^1H-NMR\;and\;IR)$ and bonding energies are in support of the assignment of the hydrazone structure to such compounds. It is further shown that intermolecular and intramolecular hydrogen bondings favor the hydrazone tautomer.

• Bulletin of the Korean Chemical Society
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• 제20권10호
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• pp.1145-1148
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• 1999

1H NMR spectra of methyl-, ethyl-, propyl-, isopropyl-, butyl-, N-methylethyl-, N-methylpropyl-, and N-methylisopropylamine coordinated to the paramagnetic 11-tungstocobalto(II)silicate anion (SiW11Co) in dimethylsulfoxide-d6 or dimethylformamide-d7 are reported. For these complexes the ligand exchange is slow on the NMR time scale and pure 1H NMR signals have been observed at room temperature. No complex is detected in D2O. From the pseudocontact shifts of the CH2 and CH3 groups in ethylamine the energy of the gauche conformers with respect to the anti conformer is estimated. Two diastereotopic protons in the CH2 group of N-methylethylamine have quite different chemical shifts especially at low temperatures (e.g. 48.5 vs. 19.4 ppm at -10℃). This may be attributed mainly to the different positions of the two protons in the most stable (gauche) conformer.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.825-828
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• 2010

To classify Glycyrrhiza species, samples of different species were analyzed by $^1H$ NMR-based metabolomics technique. Partial least squares discriminant analysis (PLS-DA) was used as the multivariate statistical analysis of the 1H NMR data sets. There was a clear separation between various Glycyrrhiza species in the PLS-DA derived score plots. The PLS-DA model was validated, and the key metabolites contributing to the separation in the score plots of various Glycyrrhiza species were lactic acid, alanine, arginine, proline, malic acid, asparagine, choline, glycine, glucose, sucrose, 4-hydroxy-phenylacetic acid, and formic acid. The compounds present at relatively high levels were glucose, and 4-hydroxyphenylacetic acid in G. glabra; lactic acid, alanine, and proline in G. inflata; and arginine, malic acid, and sucrose in G. uralensis. This is the first study to perform the global metabolomic profiling and differentiation of Glycyrrhiza species using $^1H$ NMR and multivariate statistical analysis.

• Natural Product Sciences
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• 제9권2호
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• pp.49-51
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• 2003

The underground part of Rosa rugosa Thunb. has been used in Korean folk medicine for treating diabetes. The $^{1}H-NMR$ signal of procyanidin B3 isolated from Rosa rugosa was fully assigned by utilizing $^{1}H-^{1}H$ COSY. Procyandin B3 showed a moderate inhibitory activity against HIV-1 protease.

• 대한화학회지
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• 제51권6호
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• pp.520-525
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• 2007

Thiourea/urea, 다양한 aromatic aldehydes, ammonium acetate의 세가지 요소를 가지고 마이크로파의 조 사하에서 무수조건의 활성화된 비산화재를 촉매로 사용하여 높은 수율의 6-aryl-1,2,4,5-tetrazinan-3-thiones/ones를 얻었 다. 6-aryl-1,2,4,5-tetrazinan-3-thiones/ones의 구조는 녹는점, MS, IR, 1H NMR, D2O 교환, 13C NMR, 이차원의 NMR 스펙트럼(HOMOCOR, HSQC)을 바탕으로 증명되었다.

• 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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• 제30권11호
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• pp.2535-2541
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• 2009

Prebiotic isomaltooligosaccharide preparations contain $\alpha$-D-glucooligosaccharides comprising isomaltooligosaccharides (IMOs) and non-prebiotic maltooligosaccharides (MOs). They are both glucose oligosaccharides characterized by their degree of polymerization (DP) value (from 2 to $\sim$10), linkages types and positions (IMOs: $\alpha$-(1$\rightarrow$2, 3, 6 and in a lower proportion internal 1$\rightarrow$4) linkages, MOs: α-(1$\rightarrow$4) linkages). Their structure is the key factor for their prebiotic potential. In order to determine and elucidate the exact structure of unknown IMOs and MOs, unambiguous assignments of $^{13}C$ and $^1H$ chemical shifts of commercial standards, representative of IMOs and MOs diversity, have been determined using optimized standard one and two-dimensional experiments such as $^1H$ NMR, $^{13}C$ NMR, APT and ${^1}H-{^1}H$ COSY, TOCSY, NOESY and <$^1H-{^{13}}C$ heteronuclear HSQC, HSQC-TOCSY, and HMBC. Here we point out the differential effect of substitution by a glucose residue at different positions on chemical shifts of anomeric as well as ring carbons together with the effect of the reducing end configuration for low DP oligosaccharides and diasteroisotopic effect for H-6 protons. From this study, structural $^{13}C$ specific spectral features can be identified as tools for structural analysis of isomaltooligosaccharides.