• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
• /
• pp.134-134
• /
• 1998

The modulation of glycosidase activity by inhibitors is of great interest. Such compounds have been shown to be important tools in mechanistic studies on glycohydrolase as well as having promising therapeutic application. An ${\alpha}$-glucosidase inhibitor was isolated from culture filterates of Penicillium sp. The inhibitor was active against ${\alpha}$-glucosidase isolated from yeast and porcine small intestine. However, it showed no inhibition to Aspergillus ${\alpha}$-galactosidase, Escherichia coli ${\beta}$-galactosidase, and jack bean ${\alpha}$-mannosidase. The inhibitor was highly soluble in ether, methanol and chloroform. The inhibitor was purified using silica gel, Sephadex LH-20 column chromatography and reverse-phase HPLC. The inhibitory compound designated PA-7(IC$\sub$50/=35$\mu\textrm{g}$) was obtained as white powder. The structure of PA-7 was determined with spectroscopic data of EI-MS, FAB-MS, $^1$H, and $\^$13/C NMR. The inhibitor has a diketopiperazine moiety.

• Journal of Applied Biological Chemistry
• /
• 제50권3호
• /
• pp.144-147
• /
• 2007

Dried, unripe fruits of Cornus kousa Burg. were extracted with 80% aqueous MeOH and the concentrated extracts were partitioned between EtOAc and $H_2O$. From the EtOAc fraction, four flavonoids were isolated through repeated silica gel, ODS and Sephadex LH-20 column chromatographies followed by a preparative HPLC. Based on the spectroscopic data including NMR, MS and IR, the chemical structures of the compounds were determined as kaempferol (1), astragalin (2), hyperin (3) and isoquercitrin (4). These compounds were isolated for the first time from the fruits of this plant.

• Applied Biological Chemistry
• /
• 제45권2호
• /
• pp.114-118
• /
• 2002

점액세균의 대사산물을 대상으로 새로운 항암활성물질을 탐색하는 과정에서 해양퇴적물에서 분리한 균주 JW111의 균체 추출액이 인체유래의 각종 암세포에 대해 강한 활성을 나타냄을 발견하고, 먼저 생산균주인 JW111이 Myxococcus stipitatus임을 확인한 후 그 대사산물을 분리, 정제하여 구조결정한 결과, Phenalamide $A_1$, $A_2E, $A_3$임을 밝혔다. 이들은 공시된 감수성 암세포에 대해 모두 우수한 활성을 나타내었으며, $IC_50$의 값은 $0.23{\sim}0.50{\mu}g/ml$이었다. 또한 이들은 Adriamycin의 내성 세포주에 대해서도 감수성 세포주와 동일한 활성을 나타내어 내성을 나타내지 않음이 확인되었다.

• Journal of Microbiology and Biotechnology
• /
• 제15권3호
• /
• pp.532-536
• /
• 2005

In the course of our screening for small molecules to inhibit apoptosis of U937 human leukemia cells induced by etoposide ($10\;{\mu}g/ml$), Penicillium sp. F020150 with potent inhibitory activity was selected. The active compound was purified from ethyl acetate extract of the microorganism by Sephadex LH-20 column chromatography and HPLC, and was identified as gentisyl alcohol (2,5-dihydroxybenzyl alcohol) by spectroscopic methods. The compound inhibited caspase-3 induction with $IC_{50}$ value of $3.0\;{\mu}g/ml$ after 8 h of etoposide treatment. The expression levels of caspase-3 and PARP were dose-dependently inhibited by the compound, suggesting that gentisyl alcohol inhibits etoposide-induced apoptosis via downregulation of caspases.

• Food Science and Biotechnology
• /
• 제14권1호
• /
• pp.147-151
• /
• 2005

Purified compound with intestinal immune system-modulating properties, GWE-2c, was isolated from methanol extract of Gelidium amansii by sequential procedures with silica gel column, LH-20 Sephadex gel column, and thin-layer chromatographies. In the presence of GWE-2c, strong immunoactivity in Peyers patch cell-mediated bone marrow cells was observed in vitro. In vivo intestinal immune-modulating activity was also enhanced by crude phenolic compound (GWE) of G. amansii in a dose-dependent manner. Investigation of production of several cytokines in Peyer's patch cells upon stimulation with GWE in vivo revealed the levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-6 increased. Results suggest that the phenolic compound from G. amansii represents immunopotentiator and biological response modifier at in vitro and in vivo levels.

• 약학회지
• /
• 제42권6호
• /
• pp.607-612
• /
• 1998

In the course of our search for anti-Herpes simplex virus type I (HSV 1) substances from natural sources, we screened crude drugs for their antiviral activity using SRB assay. T he methanol extract from herb of Brassica rapa (Cruciferae) was found to inhibit HSV-1. Though bioassay-directed fractionation of the extract, anti-HSV-1 agent was isolated by chromatographic separation using Amberlite XAD-4 and Sephadex LH-20. The structure of compound I was elucidated by spectral means including $^1H-^1H$ COSY, HMQC and HMBC to be isorhamnetin 3-O-${\beta}$-D-glucopyranoside (compound I). Compound I was active against HSV-1 with the 50% effective concentration of O.42mg/ml and the 50% cytotoxicity of 5.0mg/ml.

• 한국수산과학회지
• /
• 제30권6호
• /
• pp.909-915
• /
• 1997

The nitrite scavenging effect of methanol extracts of marine algae were evaluated to discover new natural nitrite scavengers. Among the tested seaweeds, Ecklonia stolonifera, an edible brown algae, showed the strongest scavenging effect. The MeOH extract was then sequentially partitioned into $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, EtOAc, n-BuOH, and $H_2O$ layers. The EtOAc and n-BuOH fraction demonstrated high levels of nitrite-scavenging activity while the $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, and $H_2O$ fractions were inactive. A column chromatography of the EtOAc fraction through silica gel and Sephadex LH-20 yielded phloroglucinol and a new compound tentatively named phlorotannin A. The nitrite scavenging activity of phloroglucinol $(IC_{50}=3.9{\mu}g/ml)$ was more potent than that of L-ascorbic acid $(IC_{50}=65.0{\mu}g/ml)$. However, phlorotannin A $(IC_{50}=193.2{\mu}g/ml)$ showed only low levels of activity. From the above results, it is possible to suggest that both the MeOH extract and their fractions and isolated phloroglucinol and phlorotannin A obtained from E. stolonifera may be applicable as scavengers of nitrite, which is a precursor for the formation of carcinogenic N-nitroso compounds.

• Journal of Microbiology and Biotechnology
• /
• 제3권1호
• /
• pp.12-18
• /
• 1993

Pseudomonas aeruginosa strain B5 with antagonistic activity against Phytophthora capsici and Magnaporthe grisea, was isolated from pepper-growing soil. From the culture of P. aeruginosa strain B5 grown on King's medium B, antibiotic substances were purified using XAD-2 column chromatography. XAD-2 eluates inhibited not only the mycelial growth of P. capsid and M. grisea, but also the development of Phytophthora blight on pepper plants. The crude antibiotic substances were further purified by using silica gel column chromatography, Sephadex LH-20 column chromatography, thin layer chromatography on silica gel plates, and high performance liquid chromatography. Silica gel column chromatogrphy gave good separation of the four antibiotic substances. The pure antibiotics P1, P2, and P3 finally purified by preparative HPLC inhibited the mycelial growth of P. capsici, at concentrations from 7 to 10 $\mu g/ml$. Only P1 and P2 had antifungal activity against M. grisea at 8 $\mu g/ml$. P1 and P3 were highly inhibitory to the mycelial growth of Botryosphaeria dothidea and Botrytis cinerea at relatively low concentrations. However, the three antibiotics had no antifungal activity against Rhizoctonia solani. The chemical structures of these antibiotics are being identified.

• 약학회지
• /
• 제40권3호
• /
• pp.262-272
• /
• 1996

The constituents of Sanguisorba hakusanensis leaves (Rosaceae), of which the roots have been used as an astringent, hemostatics and antiphlogistics, were studied phytoche mically. From water fraction of the MeOH extract, gallic acid 3-O-${\beta}$-D-(6'-O-galloyl)-glucopyranoside(I), quercetin-3-O-${\beta$-D-galactopyranoside(II), quercetin-3-O-${\alpha}$-L-arabinopyranoside(III) and $2{\alpha},\;3{\beta},\;19{\alpha}$, 23-tetrahydroxyurs-12-en-28-oic acid 28-O-${\beta}$-D-glucopyranoside(IV) were isolated by column chromatographic separation using Amberlite XAD-2, ODS-gel and Sephadex LH-20. The structure of these compounds were elucidated by spectroscopic parameters of $^1H$-NMR, $^{13}C$-NMR, $^1H-^1H$ COSY, $^{13}C-^1H$ COSY, EI-Mass, FAB-Mass, IR, UV and by comparison with authentic samples.

• Preventive Nutrition and Food Science
• /
• 제7권1호
• /
• pp.18-21
• /
• 2002

The extract of Ginkgo biloba leaves was measured for inhibitory activity against xanthine oxidase. Aceton extract of G. biloba leaves showed strong inhibitory activity. Inhibitory activities of the fractionated extract were in the order of water > ethyl acetate fractions. Two fractions exhibiting strong inhibitory activities ware further purified via repeated silica gel, Amberlite IRN-78, Polyclar AT, and Sephadex LH-20 column chromatographies. Active components were isolated and identified through $^1$H-NMR and $^{13}$ C-NMR. The compounds were characterized as kaempferol 3-Ο-$\alpha$-(6$^{"′}$-p-coumaroylglucosyl-$\beta$-1,4-rhamnoside), and quercertin 3-Ο-$\alpha$-(6$^{′}$-p-coumaroylglucosyl-$\beta$-1,4-rhamnoside).