• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.93-98
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• 2006

Two new compounds 1'-(stigmast-11,20(21),25-trien 3$\alpha$,9$\alpha$-diolyl)-3'-(pimara-11,15-dien-3$\alpha$-olyl) glycerol (1) and stigmast-5-en-3$\alpha$,26-diol (2) along with known fatty acids n-hexacosanoic acid (3) and hexadecanoic acid (4), have been isolated from the methanol extract of rice hulls of Oryza sativa. The structures of the compounds were elucidated using 1D and 2D NMR spectral methods, viz; $^1H, ^{13}C, ^{13}C$-DEPT, $^1H-^1H$ COSY, $^1H-^{13}C$ HETCOR, HSQC and HMBC aided by IR, EIMS, FABMS and HRFABMS. Compound (1) showed inhibition to radish germination, growth of shoot and root length.

• 미생물학회지
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• 제50권4호
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• pp.381-383
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• 2014

미생물 기원의 ${\alpha}$-glucosidase 저해제를 탐색하는 과정에서 토양에서 분리한 균주인 Bacillus sp. SKU31-1 배양액에서 강력한 저해제 compound K을 일련의 크로마토그래피 방법에 의해 분리 정제하였고 $^1H$ NMR, $^{13}C$ NMR, $^1H-^1H$ COSY spectra 분석과 문헌조사를 통해 5-amino-1-hydroxymethyl-1,2,3,4-cyclohexanetetrol로 동정되었다. Compound K의 ${\alpha}$-glucosidase 저해 활성은 $IC_{50}$값이 maltose 기질에서는 $1.9{\mu}M$이고, sucrose 기질 사용시 4.9 mM이었다. Lineweaver Burk plot에 의해 $K_i$값이 0.15 mM 로 강력한 경쟁적 저해제 임이 밝혀졌다.

• 미생물학회지
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• 제54권2호
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• pp.136-139
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• 2018

풋마름병 균에 대해 강한 저해활성을 갖는 활성물질 Compound S와 conversion product인 compound S'이 Bacillus subtilis JW-1 배양액에서 일련의 크로마토그래피 방법으로 분리 정제되었고, $^1H$ NMR, $^{13}C$ NMR, $^1H-^1H$ COSY와 HMBC 등의 spectra 분석에 의해 구조가 alanyl-L-${\beta}$-(2,3-epoxycyclohexyl-4-one)alanine와 alanyl-L-${\beta}$-(2,3-dihydroxycyclohexyl-4-one) alanine로 각각 동정되었다. Compound S는 $G^+$, $G^-$ bacteria, yeast와 Candida albicans 등에 대해 광범위한 antimicrobial activity를 나타내며, conversion product의 활성 상실을 통해 intact oxirane ring이 Compound S의 활성에 필수적임이 밝혀졌다.

• 한국자기공명학회논문지
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• 제10권2호
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• pp.163-174
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• 2006

Luteinizing Hormone Releasing Hormone(LHRH) is a decapeptide neurotransmitter known to be regulated by metal ions in the hyperthalamus. Zn-binding LHRH complex was systhesized, and zinc-LHRH complex was studied to understand what kinds of structural modifications would be critical in the LHRH releasing mechanism. Both nonexchangeable and exchangeable $^1H-NMR$ signal assignments were accomplished by pH-dependent and COSY NMR experiments. In addition, $^1H-NMR$ chemical shift changes of a-proton and peptide NH NMR signals at different pH condition, and $^1H-NMR$ signal differences between metal free and metallo-LHRH complex was monitored. NMR signals exhibit that primary metal-binding sites are nitrogens donor of imidazole ring and Arg, and peptide oxygen of Pro-His in the sequence. Structure obtained in this study has a cyclic conformation which is similar to that of energy minimized, and exhibits a specific a-helical turn with residue numbers $(2{\sim}7)$ out of 10 amino acids.

• 한국식품영양학회지
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• 제34권5호
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• pp.553-559
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• 2021

The aim of study to investigate the phytochemicals and biological activities the bark of Betula schmidtii. The studies consisted of the solvent extraction, followed by the isolation of phenolic components 1~3 from ethyl acetate-soluble fraction of Betula schmidtii Bark. Their chemical structures were identified as arbutin (1), ρ-coumaric acid (2) and ferulic acid (3) using Ultraviolet-Visible (UV-Vis) Spectrophotometer, Electrospray Ionization Mass Spectrometry (ESI-MS) (negative ion mode), ¹H-Nuclear Magnetic Resonance (NMR), ¹³C-NMR, ¹H-¹H Correlation Spectroscopy (COSY) and ¹H-¹³C Hetero Nuclear Multiple Quantum Correlation (HMQC) spectral data. Compounds 1~3 shows the anti-oxidant effect with IC₅₀ values of 29.74±1.52, 21.32±1.07 and 34.41±1.24 in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, respectively. Also, compounds 1~3 exhibited mushroom tyrosinase inhibitory activity with IC₅₀ values of 31.14±1.07, 42.54±1.46 and 69.22±1.43 µM, respectively.

• Natural Product Sciences
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• 제25권2호
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• pp.130-135
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• 2019

The purification of the MeOH extract from Impatiens basamina by repeated column chromatography led to the isolation of one new tetrahydronaphthalene (1), together with eleven known compounds (2 - 12). The structure of the new compound (1) was determined by spectral data analysis ($^1H$ and $^{13}C$-NMR, $^1H-^1H$ COSY, HSQC, HMBC, NOESY, and HR-ESI-MS). Isolated compounds (1 - 12) were evaluated for their inhibitory effects on NO production in LPS-activated murine microglial BV-2 cells and their effects on NGF secretion from C6 glioma cells. Compounds 3, 7, and 10 reduced NO levels in LPS-activated murine microglial cells with $IC_{50}$ values of 26.89, 25.59, and $44.21{\mu}M$, respectively. Compounds 1, 5, and 9 upregulated NGF secretion to $153.09{\pm}4.66$, $156.88{\pm}8.86$, and $157.34{\pm}3.30%$, respectively.

• Natural Product Sciences
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• 제28권1호
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• pp.1-5
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• 2022

Two 2H-1-benzopyran derivatives, methyl 8-hydroxy-2,2-dimethyl-2H-1-benzopyran-5-carboxylate (1) and methyl 8-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carboxylate (2), including a new compound (1) were isolated from the twigs of Chaenomeles sinensis. Their chemical structures were characterized based on analysis of NMR data including ¹H and ¹³C, COSY, HSQC, and HMBC and HRMS data. The isolated compounds (1 and 2) were assessed for their anti-neuroinflammatory activity by measuring inhibition levels of nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells and for their neurotrophic activity by the secretion of nerve growth factor (NGF) in C6 cells. Compounds 1 and 2 exhibited powerful anti-neuroinflammatory effects with IC₅₀ values of 17.14 and 19.30 μM, respectively, without cell toxicity, and also showed moderate effects on the stimulation of NGF secretion levels with 113.15 ± 3.54 and 130.20 ± 8.03%, respectively. The biosynthetic pathway of 1 and 2 was proposed that they would be derived from a protocatechuic acid and an isoprenyl unit.

• Journal of the Korean Wood Science and Technology
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• 제34권2호
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• pp.95-100
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• 2006

This study is to isolate bio-active compounds from Alnus firma and evaluate their antioxidant activity. Dried wood powder of A. firma was extracted by organic solvents and fractionated in the sequential extraction steps. The isolated compounds were characterized by EI-MS, $^{13}C-$ and $^1H-NMR$ including COSY, DEFT, HMQC, and HMBC. Antioxidant activities of the isolated compounds were evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging effect. From the wood of A. firma, three kinds of diarylheptanoids, alnusodiol (1), alnusonol (2) and alnusone (3), and gallic acid (4) were isolated. Among these four compounds, compound 1, 2, and 3 are isolated from A. firma for the first time. The antioxidant activity of gallic acid was 93.5% at the concentration of 100 ppm. This compound showed stronger antioxidant activity than those of other isolated compounds and the reference BHT (butylated hydroxytoluene).

• Bulletin of the Korean Chemical Society
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• 제27권7호
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• pp.995-1000
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• 2006

Three new compounds orizaanthracenol (1-methoxyanthracen-2-ol, 1), 1-hydroxy-7-((2S,3R,4R,5S)-2'',3'',4''-trihydroxy-5''-(hydroxymethyl)tetrahydro-2H-pyran-1-yloxy)anthracen- 2-yl 3',7'-dimethyloctanoate (2) and 1-hydroxy-7-((2S,3R,4R,5S)-2'',3'',4''-trihydroxy-5''-(hydroxymethyl)tetrahydro-2H-pyran-1-yloxy)anthracen- 2-yl 3',7',11',15',19'-pentamethyltricosanoate (3) have been isolated and determined from the rice hulls of Oryza sativa. The structures of the compounds were elucidated using 1D and 2D NMR spectral methods, viz: 1H-NMR, 13C-NMR, DEPT, COSY and HSQC, and HMBC aided by IR, EIMS and FAB-MS. These isolated compounds were tested in bioassay on germination of radish to detect their inhibitory activities, in which compound 1 exhibited the most inhibition at the concentration of 40 ppm was 50.96% of total dry weight. Furthermore, germination and growth of radish were reduced by 27 to 48%, and dry weight of shoot and root were arranged from 50 to 52%, whilst compounds 2 and 3 exhibited weak inhibition than 1.

• 한국균학회지
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• 제43권1호
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• pp.68-70
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• 2015

우리나라 자생 버섯에 함유된 화학적 구성성분을 조사하던 중 암갈색그물버섯에서 indole alkaloid 화합물을 분리하고 mass 및 NMR 분석을 통하여 화학구조를 flazin으로 동정하였다. 비록 Flazin 화합물이 젖비단그물버섯에서 분리되어 보고된 적은 있으나 본 연구에 의하여 암갈색그물버섯에도 flazin 성분을 함유하고 있음이 처음으로 밝혀졌다.