• 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.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.381-383
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• 2014

In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

• 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.

• 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 $mu g/ml$.

• Advances in Traditional Medicine
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• v.8 no.1
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• pp.97-102
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• 2008

A total of five compounds namely, 2-methylanthracene-9, 10-dione (1), 1-hydroxy-6-methylanthracene-9,10-dione (2), $\beta$-sitosterol (3), stigmasterol (4) and sitosterone (5) were isolated from the stem extracts of Polygonum lanatum for the first time. The structures of the isolated compounds (1-5) were established by extensive spectroscopic studies, including 2D NMR such as $^{1}H-^{1}H$ COSY, HSQC and HMBC studies. The crude extracts and purified compound (1) were screened for antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria and fungi by the disc diffusion method. The n-hexane and dichloromethane soluble partitionates of the methanolic extract revealed mild to moderate inhibition of growth of the test organisms. The cytotoxic potential of the extractives and compound 1 was also determined by using brine shrimp lethality bioassay, where the extractives demonstrated significant cytotoxic activities.

• Natural Product Sciences
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• v.25 no.2
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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.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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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.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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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.

• KSBB Journal
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• v.15 no.6
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• pp.560-565
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• 2000

13-Deacetyl-taxchinin I, a taxoid having a rearranged 11(15\longrightarrow1)-abeo-taxane skeleton, has been isolated and identified from plant cell cultures of Taxus chinensis. The compound has not previously been encountered in nature. Its structure was elucidated by 1-and 2D NMR techniques including H-H COSY, HMQC, and HMBC experiments. This taxoid also provides information for better understanding of structure-activity relationships and biosynthesis, as well as improving the quality control of paclitaxel production.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.441-445
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• 2005

Tripterygium regelii has been used as an oriental medicine, especially antiparasitic, anti-inflammatory and detoxifying agents in East asia. During our research to develop new antitumor agents from natural products, MeOH ext. and CH2Cl2 ext. of Tripterygium regelii showed the potent antitumor activity. In order to purify active compounds from Tripterygium regelii, activity-guided fractionation was carried out. Silica gel and RP-18 column chromatography for the active fraction led to the isolation of two compounds and their antitumor activities were studied. Those two compounds didn't show potent antitumor activity against human tumor cell lines. The structure of two compounds were determined by $^1H-NMR$, $^{13}C-NMR$, DEPT, $^1H-^{13}C$ COSY and IR spectrum. Compound I and Compound II were turned out to be Celastrol, and ${\beta}-sitosteryl-3-o-{\beta}-D-glucopyranoside$ respectively.