• Journal of the Korean Wood Science and Technology
• /
• v.30 no.1
• /
• pp.56-62
• /
• 2002

The air-dried bark of Salix rorida was extracted with acetone-water(7:3, v/v) and its extractives were concentrated with a vacuum evaporator. The extractives were fractionated with a series of n-hexane, chloroform, ethylacetate(EtOAc) and water on a separatory funnel. Each fraction was freeze-dried to give some dark brown powder. The EtOAc and water soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The isolated compounds were tested with a cellulose TLC developed with TBA and 6% acetic acid and then visualized on UV lamp or sprayed with vanillin-HCl-EtOH. The purified compounds were flavonoids and their glycosides as follows:(+)-catechin, naringenin, salipurposide, aromadendrin, isosalipurposide, aromadendrin-7-O-𝛽-D-glucopy- ranoside and taxifolin-7-O-𝛽-D-glucopyranoside. The structures of each compounds were confirmed by ¹H-NMR, ¹³C-NMR and mass spectra.

• Journal of Ginseng Research
• /
• v.34 no.2
• /
• pp.113-121
• /
• 2010

The fresh ginseng roots were extracted with aqueous methanol, and the obtained extracts were partitioned using ethyl acetate, n-butanol, and water, successively. The repeated silica gel and octadecyl silica gel column chromatogaraphy for n-butanol fraction afforded four diol ginseng saponins, ginsenosides $Rb_1$, $Rb_2$, $R_c$, and Rd. The physicochemical, spectroscopic, and chromatographic characteristics of these ginsenosides were measured and compared with those reported in the literature. Some of the peak assignments in previously published $^1H$- and $^{13}C$-nuclear magnetic resonance (NMR) spectra were inaccurate. This study employed two-dimensional NMR experiments, including $^1H-^1H$ correlation spectroscopy, heteronuclear single quantum correlation, and heteronuclear multiple bond connectivity, to determine exact peak assignments.

• Analytical Science and Technology
• /
• v.16 no.4
• /
• pp.283-291
• /
• 2003

Humic and fulvic acids present in soils of different depth were extracted and their acidic functional groups and structural characteristics were analyzed and compared. The purpose of this study was to present a basic data needed to evaluate the effect of humic substances on depth distribution and migrational behaviour of radioactive elements deposited on soil. Acidic functional groups of the humic and fulvic acids were analyzed by pH titration method, and their proton exchange capacity (PEC, $mq\;g^{-1}$) and average $pK_a$ values were obtained. Structural characteristics of the humic and fulvic acids were analyzed using their CPMAS $^{13}C$ NMR spectra and elemental composition data. pH titration data showed that fulvic acids have higher acidic functional group contents ranging from 5.5 to $7.0meq\;g^{-1}$ compared with that of humic acids ($3.8{\sim}4.8meq\;g^{-1}$). From depth profiles, it has been found that PEC values of humic acids in deeper soil (> 8 cm) were higher than those at the surface soils. Elemental compositions (H/C ratio) and spectral features ($C_{arom}/C_{aliph}$ ratio) obtained from CPMAS $^{13}C$ NMR spectra showed that the aromatic character in humic acids was a relatively higher than that of fulvic acids, while lower in carboxyl carbon content. The aromatic character and carboxyl carbon contents of humic acids tend to increase as soil depth increased, but those of fulvic acid showed little differences by the soil depth range.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.11-16
• /
• 2005

Humic substances(HS) from raw and process waters at a conventional water treatment plant were isolated and extracted by physicochemical fractionation methods to investigate their characteristics. They are characterized for their functionality, chemical composition, and spectroscopic characteristics using FT-IR(Fourier transform infrared) and $^1H-NMR$(proton nuclear magnetic resonance) spectroscopy. Humic fraction gradually decreased from 47.2% to 26.4%(from 0.97 to 0.54 mgC/L) through conventional water treatment processes. Concentration of phenolic groups in the HS fraction gradually decreased from 60.5% to 21.8%(from 12.2 to $6.0\;{\mu}M/L$ as phenolic-OH) through water treatment. In the case of carboxylic groups, the concentration increased from 39.5% to 46.9%(from 7.9 to $10.6\;{\mu}M/L$ as COOH) by pre-chlorination, but gradually decreased to 34.2%($9.4\;{\mu}M/L$ as COOH) through sedimentation and sand filtration. From the results of the FT-IR and $^1H-NMR$ spectra of HS, the content of carboxylic groups increased and ratio of aliphatic protons to aromatic protons($P_{Al}/P_{Ar}$) also increased through water treatment, which indicated the increase of aliphatic compounds.

• Natural Product Sciences
• /
• v.13 no.3
• /
• pp.229-233
• /
• 2007

Chemical investigation of the crude extract of the Egyptian marine tunicate Eudistoma laysani led to the isolation of a new nucleoside; 3-deazainosine and four known ones; inosine, 2'-deoxyuridine, adenosine and 2'-deoxyadenosine. Structural elucidation of the isolated compounds was based on intensive studies of their spectral data including 1D ($^{1}H$ and $^{13}C$) and 2D ($^{1}H-^{1}H$ COSY, HMQC, HMBC) NMR together with mass spectra. The antioxidant effects of the isolated compounds were determined using DPPH, where they exhibited significant activities.

• Korean Journal of Pharmacognosy
• /
• v.18 no.3
• /
• pp.188-190
• /
• 1987

A triterpene glycoside was first isolated from berries of Rubus coreanus Miquel in the family of Rosaceae, which have been used as a tonic in chinese drug. The compound was identified as $28-{\beta}-D-glycopyranosyl$ ester of $2{\alpha},3{\beta},19{\alpha},23-tetrahydroxyurs-12-en-28-oic$ acid by IR, MS, $^{1}H-NMR$, $^{13}C-NMR$ spectra.

• Applied Biological Chemistry
• /
• v.29 no.4
• /
• pp.399-406
• /
• 1986

2-Acylaminobenzothiazole derivatives were synthesized from 2-aminobenzothiazole and acylchloride. Benzothiazolylurea derivatives were syntesized from 2-minobenzothiazole and phenylisocyanate. The products were identified by UV, IR, $^1H-NMR$, $^{13}C-NMR$ spectra with 2-acetamidobenzothiazole(I), 2-propionamidobenzothiazole(II), 2-butamidobenzothiazole(III), 2-benzamidobenzothiazole(IV). The compounds were tested for their phytotoxicity on the germination and seedling growth of rice, radish and green pea plants, It was found that treatment of 500ppm concentration each of 2-acetamidobentothiazole, 2-propionarmidobenzothiazole and 2-butamidobenzothiazole strongly inhibited of seedling growth of the radish and green pea.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.191-194
• /
• 2002

Humic acid, fulvic acid and humin present in volcanic ash soil were isolated by IHSS standard procedure and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of pollutants in contaminated surface soil. The volcanic ash soil contained 42.1 % of total organic matter based on the oven-dried soil, and humin, humic and fulvic acids corresponded to 67.5 %, 15.2 %, 7.6 % of TOM respectively. Structural informations of the humic fractions were obtained from their elemental analysis and IR, CPMAS C-13 NMR spectral analysis and the differences among them are discussed with their C/H, O/C ratios and distributions of carbon types in the molecules.

• Journal of the Korean Society of Tobacco Science
• /
• v.25 no.2
• /
• pp.120-127
• /
• 2003

Cyclodextrin glucanotransferase (CGTase) from Bacillus stearothermophilus synthesized vanillin and ethyl vanillin monoglucoside, with a series of its maltooligoglucosides by transglycosylation with dextrin as a donor, and vanillin or ethyl vanillin as an acceptor. The monoglucoside formed from reaction mixture of vanillin or ethyl vanillin by the successive actions of CGTase and Rhizopus glucoamylase was isolated by extraction with n-butanol saturated with water and silica gel column chromatography. The structure of the isolated monoglucoside was identified as vanillin- $\alpha$ -D-glucoside and ethyl vanillin- $\alpha$ -D-glucoside, respectively, by FAB-MS, UV, IR, 1H-NMR, 13C-NMR spectra and products by hydrolysis with acid, $\alpha$ - and $\beta$ -glucosidases.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.131-131
• /
• 1998

In the course of screening for new natural compounds having antioxidant activity from microbials, mushrooms as well as plants. We have isolated novel sesquiterpenoid and officinalic acid from methanolic extracts of Stereum ostrea. The dried fruit body( 450 g) of Stereum ostrea was extracted with methanol, then methanolic extract was partitioned between water and hexane, chloroform, and ethyl acetate, subsequently. The chloroform extract was subjected on silica gel, Sephadex LH-20 and RP-18 column chromatography, successively. And two compounds were isolated and identified as new triterpenoids and officinalic acid using $^1$H - NMR, $\^$13/C - NMR as well as Mass spectra.