• Korean Journal of Pharmacognosy
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• v.31 no.4
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• pp.434-437
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• 2000

Two sinapic acid esters were isolated from the methanol extract of Raphani Semen. The structures were elucidated on the basis of spectroscopic methods $(^1H-NMR,\;^{13}C-NMR,\;HMQC,\;^1H-^1H\;COSY\;and\;HMBC)$ and were identified as methyl sinapate (1) and ${\beta}-D-(3-O- sinapoyl)fructofuranosyl-{\alpha}-D-(6-O-sinapoyl)glucopyranoside$ (2). Compound 1 was first isolated from the genus of Raphanus.

• Natural Product Sciences
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• v.27 no.2
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• pp.122-127
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• 2021

A new steroidal saponin, (23S,24S)-spirosta-5,25(27)-diene-1𝛽,3𝛽,23,24-tetrol 1-O-((2,3-diacetyl-α-L-rhamnopyranosyl)-(1→2)-[𝛽-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside)-24-O-𝛽-D-glucopyranoside (humilisoside) together with the known 𝛽-sitosterol 3-O-glucopyranoside, adenosine, dioscin, and methylprotodioscin were isolated from the leaves of Dracaena humilis. Their structures were elucidated by spectral techniques including mass spectrometry (ESIMS, HRESIMS, tandem MS-MS), 1D NMR (¹H, ¹³C NMR), 2D NMR (HSQC, ¹H-¹H COSY, HMBC, NOESY), chemical method as well as by comparison with spectroscopic data reported in the literature. The chemotaxonomic significance of the isolation of these compounds is discussed. This is the first report on the phytochemical investigation of D. humilis.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.136-139
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• 2018

The inhibitory compound (Compound S) against Ralstonia solanacearum and its conversion product (Compound S') were isolated from the culture filtrate of Bacillus subtilis JW-1 using a series of chromatography procedures. The structures were elucidated as alanyl-L-${\beta}$-(2,3-epoxycyclohexyl-4-one)alanine and alanyl-L-${\beta}$-(2,3-dihydroxycyclohexyl-4-one)alanine, respectively on the basis of nuclear magnetic resonance spectral data, including $^1H$, $^{13}C$, $^1H-^1H$ correlation spectroscopy and heteronuclear multiple bond correlation spectroscopy. The compound S exhibited a broad antimicrobial activity against $G^+$, $G^-$ bacteria, Saccharomyces cerevisiae and Candida albicans. The activity loss of the conversion product revealed that the epoxy function was essential for activity of Compound S.

• Natural Product Sciences
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• v.28 no.1
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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 Magnetic Resonance Society
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• v.10 no.2
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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.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.144-149
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• 2003

Extracts were obtained from the flower of Rhododendro yedoense var. poukhanense. (7 kg) in 80% aqueous MeOH and successively fractionated with solvent of EtOAc, n-BuOH and $H_2O$, successively. Silica gel and ODS column chromatographies of the EtOAc and n-BuOH fractions were repeatedly carried out by using the various solvent systems to give five terpenoids. Chemical structures of the isolated terpenoids were determined as $2{\alpha},3{\beta}-dihydroxylolean-12-ene$ (1), ursolic acid (2), grayanotoxin IV (3), grayanotoxin I (4) and grayanotoxin III (5) based on the interpretation of several spectral data including 2D-NMR such as $^1H-^1H\;COSY$, HMQC and HMBC.

• Natural Product Sciences
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• v.17 no.4
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• pp.350-353
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• 2011

A new daucosteryl derivative, verticilloside (1), was isolated from the seeds of Malva verticillata L. (Malvaceae). The structure was determined to be 3-O-[${\beta}$-D-(6'-linoleoyl)glucopyranosyl]-${\beta}$-sitosterol based on spectroscopic analyses ($^1H$ and $^{13}C$-NMR, DEPT, COSY, HMQC, and HMBC) and chemical reactions.

• Analytical Science and Technology
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• v.9 no.1
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• pp.112-117
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• 1996

Three active compounds were isolated from the culture of a plant pathogenic fungus, Bipolaris cynodontis. The structure elucidation of these compounds was accomplished by 2D NMR techniques, such as $^1H-^1H$ and $^{13}C-^1H$ COSY, COLOC, HMBC and rotating frame NOE(ROESY). Compounds were found as derivatives of cochlioquinone and cochlioquinol that were previously isolated as phytotoxins from B. bicolor and B. cynodontis, respectively. The compounds showed phytotxicity against Italian ryegrass, one of the host plants of B. cynodontis.

• Journal of Microbiology and Biotechnology
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• v.5 no.1
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• pp.36-40
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• 1995

Valistatin, a new inhibitor of aminopeptidase M(AP-M) was discovered in the culture broth of Streptomyces sp. SL20209 isolated from a soil sample. The inhibitor was purified by extraction with n-butanol and the various column chromatographies, and then isolated as whitish powder. The $^1 H-and ^1 H, ^1 H-COSY$ NMR studies, amino acid analysis, and fragmentation patterns by FAB-MS suggested the presence of one 3-amino-2-hydroxy-4-phenylbutanoic acid and two valine residues in the inhibitor. Thus, the structure of valistatin was determined as 3-amino-2-hydroxy-4-phenylbutanoyl-valyl-valine. Valistatin has the molecular formular $C_20H_31N_3 O_5$ (MW 394), and its $IC_50$ value against hog kidney AP-M was determined to be 3.12 $mu g/ml$.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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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.