• 한국자기공명학회논문지
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• 제22권2호
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• pp.26-33
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• 2018

Xanthium sibiricum is used as a traditional folk medicine for the treatment of cancer, fever, headache, nasal sinusitis, and skin pruritus. This study aimed to identify components from Xanthium sibiricum extracts using an SPE-800MHz NMR-MS hyphenated system. The simultaneous acquisition of MS and NMR spectra from the same chromatographic peaks significantly increases the depth of information acquired for the compound and allows the elucidation of structures that would not be possible using MS or NMR data alone. LC -NMR analysis was conducted using a HPLC separation system coupled to 800 MHz spectrometer equipped with a cryoprobe, and a SPE unit was used to automatically trap chromatographic peaks using a HPLC pump. LC-MS analysis was conducted with a Q-TOF MS instrument using ESI ionization in the negative ion mode. Using the hyphenated analysis, several secondary metabolites were identified, such as 3',5'-O-dicaffeoylquinic acid, 1',5'-O-dicaffeoyl- quinic acid, and ethyl caffeate. These results demonstrate that the SPE-800MHz NMR-MS hyphenated system can be used to identify metabolites within natural products that have complex mixtures.

• 한국자기공명학회논문지
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• 제20권3호
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• pp.95-101
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• 2016

Apolipoprotein B-100 (Apo-B100) is a major component of low density lipoprotein (LDL). Apo B-100 protein has 4,536 amino acid sequence and these amino acids are classified into peptide groups A to G with subsequent 20 amino acids (P1-P302). The peptide groups were act as immunoglobulin (Ig) antigens which oxidized via malondialdehyde (MDA). The mimetic peptide P1 (EEEMLENVSLVCPKDAT RFK) out of D-group peptides carrying the highest value of IgG antigens were selected for structural studies that may provide antigen specificity. Circular Dichroism (CD) spectra were measured for peptide secondary structure in the range of 190-250 nm. Experimental results show that P1 exhibit partial of ${\beta}-sheet$ and random coil structure. Homonuclear (COSY, TOCSY, NOESY) 2D-NMR experiments were carried out for NMR signal assignments and structure determination for P1. On the basis of these completely assigned NMR spectra and distance data, distance geometry (DG) and Molecular dynamics (MD) were carried out to determine the structures of P1. The proposed structure was selected by comparisons between experimental NOE spectra and back calculated 2D NOE results from determined structure showing acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P1 obtained upon superposition of all atoms was in the range $0.33{\AA}$. The solution state P1 has mixed structure of ${\beta}-sheet$ (Glu[1] to Cys[12]) and random coil (Pro[13] to Lys[20]). These NMR results are well consistent with secondary structure from experimental results of circular dichroism. Structural studies based on NMR may contribute to the studies of atherosclerosis and observed conformational characteristics of apo B-100 in LDL using monoclonal antibodies.

• 식물조직배양학회지
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• 제25권6호
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• pp.507-514
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• 1998

자리공 엽절편에 Agrobacterium tumefaciens $A_4$T을 접종하여 암상태에서 초기 접종량의 139배로 분지능이 높고 성장률이 우수한 모상근 세포주인 PEH2를 선발하였다. 선발된 모상근으로부터 생리활성 물질인 Phytolaccoside G 및 D2를 IR, Mass, NMR등으로 동정하였다. 모상근 PEH2의 성장은 SH배지에서 가장 양호하였으며, 암상태 보다 광상태에서 배양하였을 때 40% 성장이 억제되었으며, betalain의 생성은 white 배지에서 가장 양호하였다. 배지별 Phytolaccoside G와 D2의 생성은 MS배지에서 암상태로 배양하였을 때 가장 양호하였으며, SH 및 . White 배지에서는 암상태보다 광상태에서 높은 생성을 나타내어 phytolaccoside G와 D2의 생성은 광에너지에 의하여 조절됨을 확인하였다. 자리공 모상근에서 betalain 및 phytolaccoside G와 D2의 생산성을 향상시키기 위한 방안으로 처리한 elicitor 을 처리하였던 바, 모상근의 성장은 억제되었으나, chitosan 및, yeast extract에 의하여 betalain 및 Phytolaccoside G와 D2의 생성이 촉진되어 적절한 elicitor와 광의 조합처리는 자리공 모상근으로부터 betalain 및 Phytolaccoside G와 D2의 생산성을 향상시킬 수 있음을 확인하였다.

• 한국자기공명학회논문지
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• 제22권3호
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• pp.54-63
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• 2018

Nymphaea tetragona, also known as waterlilies, is aquatic plant in the family of Nymphaeceae. Three flavonoids(3, 4, and 5) and one mixed flavonoids were separated from this plant. The mixed flavonoid consisted of two flavonoids; a well-known quercetin(1) and a new natural flavonoid(2). The latter also has two chiral centers and their configurations were established by ROESY experiment. Two glycoflavonoids were determined as isoquercetin and quercetin-3-O-${\beta}$-xyropyranosyl-($1{\rightarrow}2$)-${\beta}$-galactopyroside. The $^1H$ NMR spectra for 4 and 5 dissoloved in $DMSO-d_6$ solvent showed resonance proximity and and severely overlap in the glycoside region, hindering the determination of the configurations of the stereogenic centers of the sugar moieties. This problem was solved through the spin simulation. Here, the exact NMR parameters for the sugar moieties of 4 and 5 were listed.

• 대한화학회지
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• 제36권5호
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• pp.685-691
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• 1992

디포스핀을 포함한 몇가지 $d^8$ 전이금속착물$(MCl_2PP)$은 출발물질 $K_nMCl_m$을 사용하여 합성하였다. 중심금속(M)은 Ni(II), Pd(II), Pt(II), Au(III)이며, 디포스핀(PP)은 bis(diphenylphosphino)methane(dppm), bis(diphenylphosphino)ethane(dppe), bis(diphenylphosphino)propane (dppp) 및 bis(diphenylphosphino)ethylene(dppety)이었다. 착물의 조성이나 특성은 원소분석과 $^1H-NMR$, $^{31}P-NMR$ 및 UV-Visible 스펙트럼을 이용하여 확인하였다. 이들 착물의 촉매적 활성은 3(2H)-furanone 및 cyclic carbonate 생성반응에 대하여 각각 조사하였다. 2-methyl-3-butyn-2-ol로부터 생성물 3(2H)-furanone을 얻은 반응 (1)에서 Ni(II)-, Pd(II)-diphosphine 착물은 좋은 촉매적 효과를 나타내었다. 그러나 이들 diphosphine 착물들은 cyclic carbonate 생성반응 (2)에 대해 촉매제로서의 활성을 거의 나타내지 않았다.

• Applied Biological Chemistry
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• 제50권4호
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• pp.344-347
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• 2007

비수리 지상부를 95% EtOH 용액으로 추출하고, 추출물을 n-hexane, $CH_2Cl_2$, EtOAc 및 $H_2O$로 용매 분획하였다. 이 중 EtOAc와 $H_2O$ 분획을 대상으로 Sephadex LH-20 column chromatography를 실시하여 4개의 화합물을 분리하였다. 화합물의 구조는 $^{1}H-NMR$, $^{13}C-NMR$, 2D-NMR 및 MS spectrum을 분석하여, quercetin (1), kaempferol (2), desmodin (3) 및 homoadonivernith (4)로 동정하였으며, 그 중 desmodin (3)과 homoadonivernith (4)는 비수리에서 처음으로 분리되었다.

• 공업화학
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• 제23권6호
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• pp.539-545
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• 2012

전자를 끌어당기는 benzotriazole을 vinylene으로 thiophene과 연결한 3-(2-benzo-triazolovinyl)thiophene (BVT)을 합성하고, FT-IR 및 $^1H$-NMR, $^{13}C$-NMR, 2D hetero-cosy spectra로 구조분석을 하였다. 합성한 BVT와 3-octylthiophene (OT)을 공중합 하였다. 공중합체들은 수평균 분자량 12000 (PDI 2.67)과 15000 (PDI 2.55)을 나타내었으며, THF, TCE와 chloroform 등의 유기용매에 잘 용해되었다. 공중합체들의 BVT와 OT의 공중합된 비율은 $^1H$-NMR spectra에 의하여 BVT : OT = 1 : 1.8과 1 : 2.8 (mol/mol)로 확인되었다. 파장 470 nm와 465 nm에서 UV-vis 최대 흡수를 나타내었고, photoluminescence (PL)는 각각 ${\lambda}_{max}$ = 662 nm와 641 nm로 나타나 적색계로 관찰되었다. 공중합체의 band gap은 각각 1.96 eV, 2.02 eV로 poly(3-octylthiophene)보다 더 증가하였다. 또한, poly(3-octylthiophene)에 비해서 HOMO 에너지 준위는 모두 낮아졌으나, LUMO 에너지 준위는 모두 높아졌다.

• 한국자원식물학회지
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• 제19권6호
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• pp.655-659
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• 2006

Two dineolignans (1,2) with nitric oxide inhibitory activities were isolated from Saururus chinensis (Saururaceae) using silica gel column chromatography. Although the structures, saucernetin-7 (1) and -8 (2), have been already reported, NMR assignment of the two compounds was completed aided by 2D-NMR spectroscopy including $^1H-^1H$ COSY, $^1H-^{13}C$ COSY, HMBC and NOESY NMR spectra. Compounds 1 and 2 exhibited significant nitride oxide inhibitory activity in LPS-induced RAW 264.7 cells with $IC_{50}$ values of $11.3{\mu}M\;and\;7.1{\mu}M$, respectively.

• Applied Biological Chemistry
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• 제43권2호
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• pp.136-140
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• 2000

방울비짜루의 MeOH 추출물 및 수포화 BuOH추출물로부터 항균활성을 확인하고 그 원인물질을 구명하던 중 두 종의 steroid saponin을 분리하였다. 이들의 구조확인을 위해 $^1H,\;^{13}C$ NMR 및 2D NMR 등 분광학적 방법을 사용하였으며 최종 이들의 구조가 25S-spirostane계의 steroid saponin인$3-O-[{\beta}-D-glucopyranosyl-(1{\rightarrow}2)-{\beta}-D-glucopyranosyl]-(25S)-spirostan-3{\beta}-ol$ 및 $3-O-{{\beta}-D-glucopyranosyl-(1{\rightarrow}2)-[{\beta}-D-xylopyranosyl-(1{\rightarrow}4)]-{\beta}-D-glucopyranosyl}-(25S)-spirostan-3{\beta}-ol$인 것으로 동정되었다. 이 두 화합물은 방울비짜루로부터는 처음으로 분리되었다. 이들 saponin의 항균활성 및 항균 스펙트럼을 검사하기 위하여 20개 균주에 대한 MIC를 실시하였다. 이들은 그중 10개 균주에 대해 $100\;{\mu}g/ml$의 농도에서 세균의 성장을 저지하는 항균력이 있었으며 광범위한 항균 스펙트럼을 나타내었다.

• 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.