https://repository.kopri.re.kr/handle/201206/9768 2026-04-12T00:57:22Z 2026-04-12T00:57:22Z Ha Manh Tuan Le Thi Thanh Lee Da Yeong Kim Chung Sub Youn, Ui Joung Kim, Sanghee Kim Jeong Ah Min Byung Sun https://repository.kopri.re.kr/handle/201206/16439 2025-11-06T08:26:06Z 2025-01-01T00:00:00Z

Title: Chemical constituents of Himantormia lugubris collected from Antarctica and their PTP1B and α-glucosidase inhibitory activities Authors: Ha Manh Tuan; Le Thi Thanh; Lee Da Yeong; Kim Chung Sub; Youn, Ui Joung; Kim, Sanghee; Kim Jeong Ah; Min Byung Sun Abstract: A phytochemical investigation of an Antarctic endemic species [Himantormia lugubris (Hue) M. Lamb] led to the isolation and structural elucidation of three new compounds including one lanostane-type triterpenoid (1, himanlugubrol A), one ergostane-type sterol (2, himanlugubrol B), one benzyl orsellinate derivative (3, himanlugubrin A), along with ten known compounds (4-13). The chemical structures of new compounds were determined using diverse NMR techniques, HRESIMS data analysis, and computational approaches supported by advanced statistics (DP4+). The anti-diabetic potential of all isolated compounds was investigated by evaluating their inhibitory effects on PTP1B and alpha-glucosidase enzymes. As a result, compound 3 moderately inhibited PTP1B with an IC50 value of 43.86 mu M and significantly inhibited alpha-glucosidase (IC50 = 73.46 mu M) in comparison to the positive controls, ursolic acid (IC50 = 5.92 mu M) and acarbose (IC50 = 210.11 mu M), respectively. Enzyme kinetic analysis revealed that compound 3 demonstrated noncompetitive inhibition of PTP1B and mixed-type inhibition of alpha-glucosidase. Additionally, molecular docking results supported these in vitro findings, showing that compound 3 had strong binding affinities for the active sites of both PTP1B and alpha-glucosidase, indicated by the key H-bond and van der Waals interactions and negative binding energies.

2025-01-01T00:00:00Z Tran, Huynh Nguyen Khanh Youn, Ui Joung Kim, Jeong Ah Chae, Hyunsik Kim, Sanghee Min, Byung Sun https://repository.kopri.re.kr/handle/201206/12048 2022-03-24T07:14:59Z 2020-04-01T00:00:00Z

Title: Glycerols and fatty acids isolated from Micractinium sp. KSF0031 Authors: Tran, Huynh Nguyen Khanh; Youn, Ui Joung; Kim, Jeong Ah; Chae, Hyunsik; Kim, Sanghee; Min, Byung Sun Abstract: From the collected extract from King Sejong Antarctic Station, strain Micractinium sp. KSF0031, led to the isolation of one new monoacyldigalactosyl glycerol (1) and seven known compounds (2-8). Their chemical structures were established using extensive spectroscopic techniques, including 1D, 2D-NMR, and MS, and compared with the published data. To the best of our knowledge, this is the first report to investigate the secondary metabolites from genus Micractinium. The monoacyldigalactosyl glycerol in Micractinium could serve as its chemotaxonomic markers.

2020-04-01T00:00:00Z Tran, Huynh Nguyen Khanh Youn, Ui Joung Kim, Minji Cao, Thao Quyen Kim, Jeong Ah Woo, Mi Hee Kim, Sanghee Min, Byung Sun https://repository.kopri.re.kr/handle/201206/10626 2022-03-24T07:14:17Z 2020-03-01T00:00:00Z

Title: Biological Activity of Chemical Constituents Isolated from Strain Chlamydomonas sp. KSF108 (Chlamydomonadaceae) Authors: Tran, Huynh Nguyen Khanh; Youn, Ui Joung; Kim, Minji; Cao, Thao Quyen; Kim, Jeong Ah; Woo, Mi Hee; Kim, Sanghee; Min, Byung Sun Abstract: This study focused on investigation of the immunosuppressive inhibitory effect through determination of IL-2 production of nine compounds (1 ？ 9) isolated from Chlamydomonas sp. KSF108. Among them, compounds 1, 5, and 6 displayed moderately inhibitory effects on IL-2 production at a concentration of 100 μM. In addition, the related ones including cytotoxic, anti-inflammatory, and anti-oxidant activities were also elucidated. 6 further displayed cytotoxic activity against the MCF-7 cell line, with an IC50 value of 17.2 μM and 4, 6 ？ 7, and 9 possessed significant DPPH radical scavenging activity, with IC50 values ranging from 3.1 to 4.4 μM. To the best of our knowledge, this is the first report on the bioactivity of isolated chemical constituents from the genus Chlamydomonas. Compounds 1 and 5 investigated for the first time in the activity of immunosuppressivity and 6 may come to serve as the most important marker in broad-spectrum activities of the secondary metabolites identified from C. sp. KSF108.

2020-03-01T00:00:00Z Kim, Eun Jae Kim, Jung Eun Hwang, J. S. Kim, Il-Chan Lee, Sung Gu Kim, Sanghee Lee, Jun Hyuck Han, Se Jong https://repository.kopri.re.kr/handle/201206/10402 2022-03-24T07:14:35Z 2019-09-01T00:00:00Z

Title: Increased Productivity and Antifreeze Activity of Ice-binding Protein from Flavobacterium frigoris PS1 Produced using Escherichia coli as Bioreactor Authors: Kim, Eun Jae; Kim, Jung Eun; Hwang, J. S.; Kim, Il-Chan; Lee, Sung Gu; Kim, Sanghee; Lee, Jun Hyuck; Han, Se Jong Abstract: Ice-binding proteins (IBPs) inhibit the growth and recrystallization of intracellular ice, enabling polar organisms to survive at subzero temperatures. IBPs are promising materials in biomedical applications such as cryopreservation and the hypothermic storage of cells, tissues, and organs. In this study, recombinant IBP from the antarctic bacterium Flavobacterium frigoris PS1 (FfIBP) was produced by Escherichia coli used as bioreactor, to examine the feasibility of scale-up. Oxygen transfer was the most important factor influencing cell growth and FfIBP production during pilot-scale fermentation. The final yield of recombinant FfIBP produced by E. coli harboring the pET28a-FfIBP vector system was 1.6 g/L, 3.8-fold higher than that from the previously published report using pCold I-FfIBP vector system, and its thermal hysteresis activity was 2.5°C at 9.7 μM. This study demonstrates the successful pilot-scale production of FfIBP.

2019-09-01T00:00:00Z