• The Korean Journal of Mycology
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• v.43 no.1
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• pp.68-70
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• 2015

Mushrooms are valued as a nutritional food and also as an important source of useful medicinal components. They produce various secondary metabolites which have interesting biological activities and unique chemical structures. As part of our ongoing investigation on chemical constituents and bioactive components of Korean native mushrooms, compound 1, an indole alkaloid, was isolated from the fruiting body of Boletus umbriniporus. B. umbriniporus is characterized by its yellow flesh, which changes to pallid blue when exposed to air, and its chemical constituent has not been reported. Chemical structure of compound 1 was determined to be flazin on the basis of ESI-mass, $^1H$ NMR, $^{13}C$ NMR, $^1H-^1H$ COSY, HMQC, and HMBC analysis. This compound was isolated from the fruiting body of B. umbriniporus for the first time.

• Natural Product Sciences
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• v.23 no.2
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• pp.113-118
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• 2017

A new tetracyclic triterpenoid [4,4,24-trimethylcholesta-${\Delta}^{8,9;14,5;24,28}$-trien-$3{\beta},11{\beta},12{\alpha}$-triol-12-acetate, 3-sulfate] sodium salt (1), together with eight known compounds including ergosterol $5{\alpha},8{\alpha}$-endoperoxide (2), 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (3), 3-O-${\beta}$-D-2-acetyl-amino-2-deoxyglucopyranoxyloleanoic acid (4), hydnocarpin (5), derrone (6), isovitexin (7), erythrinin C (8), and 5,4'-dihydroxy-2"-hydroxyisopropyldihydrofurano [4,5:7,8]-isoflavone (9), were isolated from the EtOAc soluble fraction of the methanol extract of aerial part of Desmodium uncinatum collected in the western highland of Cameroon. The structures of these compounds were established by comprehensive interpretation of their spectral data mainly including 1D- ($^1H$ and $^{13}C$), 2D-NMR($^1H$-$^1H$ COSY, HMQC, HMBC) spectroscopic and ESI-TOF-MS mass spectrometric analysis. The isolation of an integracide-like compound from plant origin is a very unusual finding.

• Microbiology and Biotechnology Letters
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• v.25 no.6
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• pp.592-597
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• 1997

During the screening of inhibitors against phospholipase C (PLC) and the formation of inositol phosphates (IP$_{t}$) at NIH3T3${\gamma}$1 cells from microbial secondary metabolites, we selected a fungal strain MT60109 which was capable of producing an inhibitor. By the taxonomic studies, this fungus was identified as Pseudallescheria sp. MT60109 and an inhibitor of PLC was purified by BuOH extraction and chromatographic techniques from the culture broth of Pseudallescheria sp. MT60109. The inhibitor was identified as thielavin B by the physico-chemical properties and spectroscopic analysis of UV, FAB-MS, $^{1}$H, $^{13}$C-NMR, $^{1}$H-$^{1}$H COSY and HMBC. Thielavin B showed potent inhibitory activity against PLC purified from bovine brain with an IC$_{50}$ of 20 $\mu$M. And it also inhibited the formation of inositol phosphates in platelet-derived growth factor (PDGF) -stimulated NIH3T3${\gamma}$1 cells with an IC$_{50}$ of 20 $\mu$M.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.271-276
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• 1999

Several Streptomyces strains were tested for potent antifungal agents active against phytopathogenic fungi. Among the tested, S. hygroscopicus MJM1004 showed a potent antifungal activity when assayed using Candida albicans as indicator organism. With the strain of MJM1004, fermentation medium for the production of an antifungal agent was developed with varying carbon sources, nitrogen sources, and mineral elements, which resulted in the highest productivity in the medium containing 2% soybean meal, 1% glucose, 2% starch, 0.3% $CaCO_3$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $K_2HPO_4$. The active compound showed a broad spectrum of antifungal activity against several plant pathogenic fungi. The antifungal compound was purified and showed the physicochemical characteristics similar to azalomycin F complex in NMR and MS analysis.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.69-79
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• 2012

In an ongoing survey of the bioactive potential of microorganisms from Ladakh, India, the culture medium of a bacterial strain of a new Pseudomonas sp., strain ICTB-745, isolated from an alkaline soil sample collected from Leh, Ladakh, India, was found to contain metabolites that exhibited broad-spectrum antimicrobial and biosurfactant activities. Bioactivity-guided purification resulted in the isolation of four bioactive compounds. Their chemical structures were elucidated by $^1H$ and $^{13}C$ NMR, 2D-NMR (HMBC, HSQC, $^1H$,$^1H$-COSY, and DEPT-135), FT-IR, and mass spectroscopic methods, and were identified as 1-hydroxyphenazine, phenazine-1-carboxylic acid (PCA), rhamnolipid-1 (RL-1), and rhamnolipid-2 (RL-2). These metabolites exhibited various biological activities like antimicrobial and efficient cytotoxic potencies against different human tumor cell lines such as HeLa, HepG2, A549, and MDA MB 231. RL-1 and RL-2 exhibited a dose-dependent antifeedant activity against Spodoptera litura, producing about 82.06% and 73.66% antifeedant activity, whereas PCA showed a moderate antifeedant activity (63.67%) at 60 ${\mu}g/cm^2$ area of castor leaf. Furthermore, PCA, RL-1, and RL-2 exhibited about 65%, 52%, and 47% mortality, respectively, against Rhyzopertha dominica at 20 ${\mu}g/ml$. This is the first report of rhamnolipids as antifeedant metabolites against Spodoptera litura and as insecticidal metabolites against Rhyzopertha dominica. The metabolites from Pseudomonas sp. strain ICTB-745 have interesting potential for use as a biopesticide in pest control programs.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2945-2949
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• 2014

As a part of ongoing phytochemical research on Euonymus alatus leaves and twigs, we have isolated one new reissantane-type triterpene (1), together with eight known triterpenes, isoarborinol (2), friedelin (3), abruslactone A (4), $3{\beta},22{\alpha}$-dihydroxyolean-12-en-29-oic acid (5), $3{\alpha},22{\alpha}$-dihydroxyolean-12-en-29-oic acid (6), $3{\alpha},22{\beta}$-dihydroxyolean-12-en-29-oic acid (7), $22{\alpha}$-hydroxy-3-oxoolean-12-en-29-oic acid (8), demethylregelin (9). The structure of 1 has been elucidated as 24,24-dimethyl-reissant-7(8),25-dien-$3{\alpha}$-ol, by extensive 1D and 2D spectroscopic methods including $^1H$-NMR, $^{13}C$-NMR, $^1H-^1H$ COSY, HSQC, HMBC and NOESY. Anti-inflammatory activities of the isolated compounds were determined as potential regulating excessive inflammatory responses in RAW264.7 macrophage cells. Particularly, abruslactone A (4) and demethylregelin (9) showed the most potent activity, which effectively reduced the expression of iNOS protein and subsequent nitric oxide production induced by lipopolysaccharide in RAW264.7 cells.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.39-44
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• 2002

Recently, we have reported that 2-bromopropane might have an immunotoxic potential in rats when exposed for 28 days. In the present studies, the possibility of 2i-deoxyguanosine abduct formation by 2- bromopropane was investigated in vitro to elucidate molecular mechanism of 2-bromopropane-induced immunosuppression. $N^7-Guanine adduct$ of 2'-bromopropane (i.e., $N^7-isopropyl$ guanine) was chemically synthesized and structurally characterized by analysis of UV,$^1H-NMR,{\;}^{13}C-NMR$, COSY and fast atom bombardment mass spectrometry to use as a reference material. Incubation of 2'-deoxyguanosine with an excess amount of 2-bromopropane in PBS buffer solution, pH 7.4, at $37^{\circ}C$ for 16 h, followed by a thermal hydrolysis, produced a detectable amount of $N^7-isopropyl$ guanine by an HPLC and UV analysis. The present results suggest that 2-bromopropane might form a DNA adduct in $N^7-position$ of 2'-deoxyguanosine at 3 Physiological condition.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.153-159
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• 1996

A new streptothricin family antibiotic producing Streptomyces spp. SNUS 8810-111 was isolated from a soil sample. Study of its morphological and physiological characters indicated that the antibiotic producing organism was a Streptomyces spp. Taxonomical studies suggested that the organism might belong to the genus streptomyces gougeroti. The organism produced antibiotics most in calcium carbonate-tryptic soy broth. The active principles were recovered from the broth with a cation exchange resin and eluted from the resin with HCI. Cellulose column chromatography gave two active principles.$^1H-^1H$ Homo-COSY study on the first compound revealed four structural components. Total hydrolysis of the antibiotic with HCI allowed isolation of $\beta-lysine$. From these data the antibiotic was found to be streptothricin D. The other compound showed one additional signal in the .$^1H$NMR and the $^{13}C$ NMR spectra. The signal was from a methyl group attached to a nitrogen atom. Comparison of the NMR signals with those of streptothricin D suggested that the compound was N-methyl-streptothricin D which was a new compound in the family of streptothricin antibiotics.

• Journal of the Korean Magnetic Resonance Society
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• v.23 no.4
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• pp.87-92
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• 2019

Allium hookeri (Liliaceae) has been received the increasing attention as a bioactive resource due to its potent biological activities including anti-oxidant, anti-obesity, anti-microbial and lipid-regulating activities. The beneficial effects of A. hookeri are known contributed from the high content of organosulfur compounds in A. hookeri. Though a variety of articles demonstrated that A. hookeri contains 'saponin' as a bioactive constituent, the scientific evidence to prove it was limited. In the present study, we have attempted to identify saponin contained in A. hookeri through chromatographic isolation and NMR spectroscopic methods. As a result, a spirostane-type steroidal saponin (1) has been successfully isolated from the methanolic extract of A. hookeri roots. The structure of 1 was elucidated by extensive 1D and 2D spectroscopic methods including ¹H-NMR, ¹³C-NMR, ¹H-¹H COSY, HSQC, HMBC and NOESY; identified as (3β, 22R, 25S)-spirost-5-en-3yl O-6-deoxy-α-L-mannopyranosyl-(1→4)-O-6-deoxy-α-L-mannopyranosyl-(1→4)-O-[6-deoxy-α-L-mannopyranosyl-(1→2)]-β-D-gluco pyranoside. 1 showed the significant inhibitory activity on mushroom tyrosinase with IC₅₀ values of 248.7 μM while the inhibition on alpha-glucosidase was not significant.

• Natural Product Sciences
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• v.28 no.1
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• pp.6-12
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• 2022

Five sesquiterpenoids, 7-epi-eudesm-4(15)-ene,1β,6α-diol (1), 7-epi-eudesm-4(15)-ene,1β,6α-diol (2), saniculamoid D (3), aphanamol I (4), and 4β,10α-dihydroxyaromadendrane (5), were isolated from the stem bark of Aglaia grandis. The compounds' (1-5) chemical structures were identified by spectroscopic data including, IR, NMR (¹H, ¹³C, DEPT 135°, HMQC, HMBC, ¹H-¹H COSY), and HRTOFMS, as well as by comparing with the previously reported spectral data. Therefore, this study described the structural elucidation of compounds 1-5 and evaluated their cytotoxic effects against Hela cervical and B16F10 melanoma cells for the first time, but no significant result was discovered.