K S Im

Publications (16)40.78 Total impact

• Article: Cytotoxic polyacetylenic alcohols from the marine sponge Petrosia species.

  Y J Lim, C O Lee, J Hong, D K Kim, K S Im, J H Jung
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  ABSTRACT: New polyacetylenic alcohols (1-5) have been isolated as cytotoxic principles from the marine sponge Petrosia sp. The compounds were particularly cytotoxic against a human melanoma cell line (SK-MEL-2). The gross structures were established on the basis of NMR and MS data, and the absolute configuration was determined by the modified Mosher's method.
  Journal of Natural Products 01/2002; 64(12):1565-7. · 3.13 Impact Factor
• Article: New cytotoxic sesterterpenes from the sponge Sarcotragus species.

  Y Liu, B H Bae, N Alam, J Hong, C J Sim, C O Lee, K S Im, J H Jung
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  ABSTRACT: Five new (1-3, 5, and 7) and two known (4, 6) furanosesterterpene tetronic acids were isolated from the marine sponge Sarcotragus sp. by bioactivity-guided fractionation. These compounds showed cytotoxicity against a panel of five human tumor cell lines. The gross structures were established on the basis of NMR and MS analyses. The compounds showed interesting variations of geometry and absolute configuration.
  Journal of Natural Products 11/2001; 64(10):1301-4. · 3.13 Impact Factor
• Article: A triterpene glucosyl ester from the roots of Rubus crataegifolius.

  S W Jung, M H Shin, J H Jung, N D Kim, K S Im
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  ABSTRACT: Along with five known triterpene glycosides, a new triterpene glucosyl ester, named crataegioside, was isolated from the roots of Rubus crataegifolius Bunge. The structure was established as ilexosapogenin A 28-O-beta-D-glucopyranosyl ester by chemical and spectroscopic methods.
  Archives of Pharmacal Research 11/2001; 24(5):412-5. · 1.59 Impact Factor
• Article: Cytotoxic diacetylenes from the stony coral Montipora species.

  N Alam, B H Bae, J Hong, C O Lee, K S Im, J H Jung
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  ABSTRACT: Ten new (1, 4-6, 9-14) and four known (2, 3, 7, 8) diacetylenes have been isolated from a brine shrimp active fraction of the methanolic extract of the stony coral Montipora sp. The structures were determined by combined spectroscopic methods. The compounds exhibited significant cytotoxicity against a small panel of human solid tumor cell lines. Montiporyne A (15), a previously reported congener, was also found to induce apoptosis in human colon tumor cell.
  Journal of Natural Products 09/2001; 64(8):1059-63. · 3.13 Impact Factor
• Article: Montipyridine, a new pyridinium alkaloid from the stony coral montipora species.

  N Alam, J Hong, C O Lee, K S Im, B W Son, J S Choi, W C Choi, J H Jung
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  ABSTRACT: A new pyridinium alkaloid, montipyridine (1), has been isolated from the stony coral Montipora sp. The structure was established from spectroscopic data.
  Journal of Natural Products 08/2001; 64(7):956-7. · 3.13 Impact Factor
• Article: Additional bioactive Lyso-PAF congeners from the sponge Spirastrella abata.

  N Alam, B H Bae, J Hong, C O Lee, B A Shin, K S Im, J H Jung
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  ABSTRACT: A known (1) and four new (2--5) lyso-PAF (platelet activating factor) derivatives were isolated from the sponge Spirastrella abata. Two of them are unprecedented in having a methoxy group at C-2'. The structures have been determined by combined spectroscopic methods. Their inhibitory effect on the biosynthesis of cholesterol and cytotoxicity against human solid tumor cell lines are reported.
  Journal of Natural Products 05/2001; 64(4):533-5. · 3.13 Impact Factor
• Article: New galactolipids from the marine bacillariophycean microalga Nitzschia sp.

  B W Son, Y J Cho, J S Cho, W K Lee, D S Kim, H D Choi, J S Choi, J H Jung, K S Im, W C Choi
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  ABSTRACT: Two new galactopyranosyldiacylglycerols have been isolated from the marine bacillariophycean microalga Nitzschia sp. and their structures were determined as (2S)-3-O-beta-D-galactopyranosyl-1,2-di-O-(9Z-hexadecenoyl)glycerol (1) and (2S)-3-O-beta-D-galactopyranosyl-1-O-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-O-(9Z-hexadecenoyl)glycerol (2) by physicochemical evidence.
  Natural Product Letters 02/2001; 15(5):299-306.
• Article: Additional cytotoxic polyacetylenes from the marine sponge Petrosia species.

  Y J Lim, H S Park, K S Im, C Lee, J Hong, M Lee, D Kim Dk, J H Jung
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  ABSTRACT: Ten new polyacetylenic alcohols (1-6, 8-11), along with a known compound, petrocortyne C (7), were isolated from the marine sponge Petrosia sp. The gross structures were established based on NMR and MS data, and the absolute configuration was determined by the modified Mosher's method. These compounds displayed considerable cytotoxicity against a small panel of human solid tumor cell lines. Compounds 1-11 were further evaluated for in vitro inhibitory activity on DNA replication.
  Journal of Natural Products 02/2001; 64(1):46-53. · 3.13 Impact Factor
• Article: New acetylenic compounds from the stony coral Montipora sp.

  B H Bae, K S Im, W C Choi, J Hong, C O Lee, J S Choi, B W Son, J I Song, J H Jung
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  ABSTRACT: Six new acetylenic compounds (1-6) with cytotoxic activities against human solid tumor cell lines (SK-OV-3, SK-MEL-2, XF498, and HCT15) have been isolated from the stony coral Montipora sp. Structures of the compounds 1-6 were elucidated based on analysis of the NMR and MS data.
  Journal of Natural Products 12/2000; 63(11):1511-4. · 3.13 Impact Factor
• Article: Activity of crude extract of Rubus crataegifolius roots as a potent apoptosis inducer and DNA topoisomerase I inhibitor.

  J H Lee, Y A Ham, S H Choi, E O Im, J H Jung, K S Im, D K Kim, Y Xu, M W Wang, N D Kim
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  ABSTRACT: The effects of methanol extract of Rubus crategifolius roots and its solvent fractions were investigated on the proliferation of MCF-7 human breast carcinoma cells. The methanol extract inhibited the proliferation of MCF-7 cells in a concentration dependent manner. Moreover, their methanol soluble (W-M) fraction had the greatest inhibitory effect on the growth of MCF-7 cells. To evaluate whether the W-M fraction affects on the cell cycle of MCF-7 cells, cells treated with this fraction were analyzed with flow cytometry. The W-M fraction increased G0/G1 phase after 24 h-treatment and induced apoptosis after 48 h-treatment. The hallmark of apoptosis, DNA fragmentation, also appeared by W-M fraction after 48 h-treatment. Furthermore, the methanol extract and its W-M fraction inhibited the activity of the topoisomerase I enzyme in the relaxation assay. From these results, their W-M fraction as well as methanol extract of R. crategifolius roots are necessary for further studies as a potent inhibitor of the growth of cancer cells.
  Archives of Pharmacal Research 09/2000; 23(4):338-43. · 1.59 Impact Factor
• Article: Lyso-PAF analogues and lysophosphatidylcholines from the marine sponge Spirastrella abata as inhibitors of cholesterol biosynthesis.

  B A Shin, Y R Kim, I S Lee, C K Sung, J Hong, C J Sim, K S Im, J H Jung
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  ABSTRACT: A series of phospholipids, including previously undescribed compounds 4-7, were isolated by a bioactivity-guided fractionation from the marine sponge Spirastrella abata as inhibitors of cholesterol biosynthesis in human liver cells. These compounds were identified as lyso-PAF analogues (1-5) and lysophosphatidylcholines (6, 7) based on NMR and MS analyses. Compounds 1-7 specifically blocked the conversion of lanosterol into cholesterol in the Chang liver cell.
  Journal of Natural Products 12/1999; 62(11):1554-7. · 3.13 Impact Factor
• Article: New cytotoxic polyacetylenes from the marine sponge Petrosia.

  Y J Lim, J S Kim, K S Im, J H Jung, C O Lee, J Hong, D k Kim
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  ABSTRACT: New polyacetylenic alcohols with a C(45) carbon skeleton (2) and with an enone moiety in the alkyl chain (C(46), 1) were isolated from the marine sponge Petrosia sp. The gross structures of 1 and 2 were established by spectral methods, and the absolute stereochemistry was determined by the modified Mosher's method. Compounds 1 and 2 displayed considerable cytotoxicity against a small panel of human solid tumor cell lines. Significant inhibitions on DNA replication by 1 and 2 were also observed which could be explanative of their cytotoxicity.
  Journal of Natural Products 10/1999; 62(9):1215-7. · 3.13 Impact Factor
• Article: A cyclitol derivative as a replication inhibitor from the marine sponge Petrosia sp.

  D K Kim, Y J Lim, J S Kim, J H Park, N D Kim, K S Im, J Hong, J H Jung
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  ABSTRACT: A bioactive cyclitol derivative (1) was isolated from the marine sponge Petrosia sp. The chemical structure of 1 was determined as (2S)-1-O-(2',3',4',5'-tetrahydroxycyclopentyl)-3-O-(10' '-methylhexadecyl)glycerol. Compound 1 inhibited DNA replication in vitro at the level of initiation.
  Journal of Natural Products 06/1999; 62(5):773-6. · 3.13 Impact Factor
• Article: Cytotoxic polyacetylenes from the marine sponge Petrosia sp.

  J S Kim, Y J Lim, K S Im, J H Jung, C J Shim, C O Lee, J Hong, H Lee
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  ABSTRACT: Three C46 (1-3) and three C30 (4-6) polyacetylenic alcohols with cytotoxic activity against a small panel of human solid-tumor cell lines have been isolated from the marine sponge Petrosia sp. Although compound 1 was identified as the stereoisomer of petrocortyne A, the structures of compounds 2-5 have not been previously reported and were established by spectral methods. Compound 6 was identified as the known compound petrosiacetylene D. The stereochemistry of compounds 1-5 was determined by the modified Mosher's method.
  Journal of Natural Products 05/1999; 62(4):554-9. · 3.13 Impact Factor
• Article: Topoisomerase I inhibitors from the Streptomyces sp. strain KM86-9B isolated from a marine sponge.

  H K Lee, D S Lee, J Lim, J S Kim, K S Im, J H Jung
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  ABSTRACT: The crude extract of Streptomyces sp. strain KM86-9B, isolated from a marine sponge, displayed significant inhibition on topoisomerase I activity. Investigation of the causative components by bioactivity-directed fractionation resulted in the isolation of a series of iso- and anteiso-fatty acids.
  Archives of Pharmacal Research 01/1999; 21(6):729-33. · 1.59 Impact Factor
• Article: Cytotoxic constituents of Saussurea lappa.

  J H Jung, Y Kim, C O Lee, S S Kang, J H Park, K S Im
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  ABSTRACT: The crude extract of Saussurea lappa displayed significant lethality to brine shrimp larvae. Investigation of the causative components by bioactivity-directed fractionation resulted in the isolation of three C17-polyene alcohols. Based on various nmr spectral data, these compounds were identified as shikokiols which had been previously isolated from Cirsium nipponicum and/or Centaurea aegyptica. These C17-polyene alcohols exhibited moderate cytotoxicities against the human tumor cell lines, A549, SK-OV-3, SK-MEL-2, XF498, and HCT15.
  Archives of Pharmacal Research 05/1998; 21(2):153-6. · 1.59 Impact Factor