[Show abstract][Hide abstract] ABSTRACT: Background:
c-Met signaling has been implicated in oncogenesis especially in cells with c-met gene amplification. Since 20 % of gastric cancer patients show high level of c-Met expression, c-Met has been identified as a good candidate for targeted therapy in gastric cancer. Herein, we report our newly synthesized c-Met inhibitor by showing its efficacy both in vitro and in vivo.
Compounds with both triazolopyrazine and pyridoxazine scaffolds were synthesized and tested using HTRF c-Met kinase assay. We performed cytotoxic assay, cellular phosphorylation assay, and cell cycle assay to investigate the cellular inhibitory mechanism of our compounds. We also conducted mouse xenograft assay to see efficacy in vivo.
KRC-00509 and KRC-00715 were selected as excellent c-Met inhibitors through biochemical assay, and exhibited to be exclusively selective to c-Met by kinase panel assay. Cytotoxic assays using 18 gastric cancer cell lines showed our c-Met inhibitors suppressed specifically the growth of c-Met overexpressed cell lines, not that of c-Met low expressed cell lines, by inducing G1/S arrest. In c-met amplified cell lines, c-Met inhibitors reduced the downstream signals including Akt and Erk as well as c-Met activity. In vivo Hs746T xenograft assay showed KRC-00715 reduced the tumor size significantly.
Our in vitro and in vivo data suggest KRC-00715 is a potent and highly selective c-Met inhibitor which may have therapeutic potential in gastric tumor with c-Met overexpression.
[Show abstract][Hide abstract] ABSTRACT: Eleven new abietane-type diterpenes, holophyllins D-N (1-11), and 17 known analogues (12-28), were isolated from a MeOH extract of the trunk of Abies holophylla. The chemical structures of 1-11 were determined through spectroscopic data analysis, including NMR ((1)H and (13)C NMR, DEPT, (1)H-(1)H COSY, HMQC, HMBC, and NOESY) and HRFABMS methods. All isolated compounds (1-28) were evaluated for their cytotoxicity against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-116), for their potential neuroprotective effects through induction of nerve growth factor in C6 glioma cells, and for their effects on nitric oxide levels in lipopolysaccharide-stimulated murine microglia BV2 cells.
Full-text · Article · Jan 2016 · Journal of Natural Products
[Show abstract][Hide abstract] ABSTRACT: Investigation of the MeOH extract of Chaenomeles sinensis twigs resulted in the isolation of seven biphenyl compounds (1-7) including a new compound, chaenomin (1). The chemical structures of the isolated compounds were elucidated by extensive NMR data ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC), specific optical rotation, and chemical reaction. Compounds 2 and 6 showed potent cytotoxic activities against four cancer cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15), and compound 7 exhibited potent anti-neuroinflammatory and NGF-potentiating activity.
[Show abstract][Hide abstract] ABSTRACT: A new N-glucosylated indole alkaloid, 1-(1-β-glucopyranosyl)-3-(hydroxymethyl)-1H-indole (1) and a new O-serine glycoside, 3-O-α-Dxylopyranosyl-L-serine methyl ester (2), along with five known compounds (3-7) were isolated from the trunk of Berberis koreana. The structures of the new compounds were elucidated by 1D and 2D NMR data analysis and chemical reaction. Compounds 1, 2, 4, 5, and 7 reduced nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, a microglial cell line. In addition, compounds 4 and 5 showed moderate anti-proliferative activity against A549 and HCT-15 cell lines.
[Show abstract][Hide abstract] ABSTRACT: As part of our ongoing search for bioactive constituents of natural Korean medicinal resources, a bioassay-guided fractionation and chemical investigation of the MeOH extract of Raphanus sativus (Brassicaceae) seeds resulted in the isolation and identification of fifteen compounds, including a new phenolic compound. The structure of the new compound was determined by extensive spectroscopic analysis and the Mosher's method. One of the compounds has been recently reported as a synthetic product. Some compounds showed moderate antiproliferative activities against the tumor cell lines A549, SK-OV-3, SK-MEL-2, and HCT-15 with IC50 values in the range of 5.62 to 28.88 μM. Moreover, the anti-neuroinflammatory activities of the isolates were determined by measuring the nitric oxide (NO) levels in the medium using murine microglia BV-2 cells. With exception of one specific compound, all the others inhibited the lipopolysaccharide (LPS)-stimulated NO production (IC50 values < 200 μM).
Preview · Article · Nov 2015 · Journal of the Brazilian Chemical Society
[Show abstract][Hide abstract] ABSTRACT: As part of our ongoing search for bioactive constituents of natural Korean medicinal resources, we found in a preliminary study that the methanol (MeOH) extract from the trunks of Tilia amurensis RUPR. showed an inhibitory effect on nitric oxide (NO) production in an activated murine microglial cell line. A bioassayguided fractionation and chemical investigation of the MeOH extract resulted in the isolation and identification of a new isoflavonoid glycoside, orobol 4'-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (1) and 16 known compounds (2-17). The structure of the new compound was determined by spectroscopic methods, i.e., one-dimensional (1D) and two-dimensional (2D)-NMR techniques and high resolution (HR)-MS, and chemical methods. The antineuroinflammatory activities of the isolated compounds were determined by measuring NO levels in the medium using murine microglial BV-2 cells. Among them, 12 compounds, including compound 1 (most active with an IC50 value of 23.42 μm), inhibited NO production in lipopolysaccharidestimulated BV-2 cells. Moreover, compounds 1-4 showed moderate antiproliferative activities against the SK-MEL-2 cell line, with IC50 values ranging from 12.31 to 19.67 μM.
Preview · Article · Oct 2015 · CHEMICAL & PHARMACEUTICAL BULLETIN
[Show abstract][Hide abstract] ABSTRACT: Two new salicin derivatives, saliglandin (1) and 6'-O-(Z)-p-coumaroylsalicin (2), along with fourteen known analogues (3-16) were isolated from the twigs of Salix glandulosa Seemen. The structures of 1-16 were characterized by the use of NMR methods ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC), chemical hydrolysis, and GC/MS. The full NMR data assignment of the known compounds 6, 13, and 14 are reported for the first time. Isolated compounds were evaluated for their nitric oxide (NO) inhibitory efficacy in lipopolysaccharide (LPS)-activated microglial cell (BV-2). Compounds 2, 5, 8-16 significantly inhibited NO production, compound 11 being the most efficacious (IC50 13.57μM) respectively. Moreover, compound 16 dramatically increased the nerve growth factor (NGF) production (165.24±11.1%) in C6 glioma cells. Taken together, these results revealed that salicin derivatives from Salix glandulosa might have potent effect as anti-neuroinflammatory agents.
[Show abstract][Hide abstract] ABSTRACT: From the MeOH extract of Ilex cornuta Lindley (Aquifoliaceae), four new triterpene saponins (I-IV) together with 13 known triterpenoids are isolated and their structures are elucidated via chemical and spectroscopic methods.
[Show abstract][Hide abstract] ABSTRACT: Two new aryl-tetralin lignan glycosides, linderanosides A and B (1 and 2, resp.), and a new dihydrobenzofuran neolignan glycoside, linderanoside C (3), together with five known lignan derivatives (4–8) were isolated from the trunk of Lindera glauca. The structures of these new compounds were determined through spectroscopic analyses, including extensive 2D-NMR data and acid hydrolysis. The absolute configurations of the compounds were clarified by circular dichroism (CD) spectroscopic studies. Compounds 1–8 were evaluated for their cytotoxicity against A549 (non-small cell lung adenocarcinoma), SK-OV-3 (ovarian cancer cells), A498 (human kidney epithelial cells), and HCT-15 (colon cancer cells) human tumor cell lines using sulforhodamine B assays in vitro.
No preview · Article · Aug 2015 · Helvetica Chimica Acta
[Show abstract][Hide abstract] ABSTRACT: Three new ursane triterpene saponins, together with twelve known ursane triterpenes were isolated from the stems of Firmiana simplex. The structures of the saponines were elucidated on the basis of spectroscopic and chemical methods. The cytotoxic activity of all compounds was evaluated in vitro against lung adenocarcinoma (A549), ovarian cancer (SK-OV-3), skin melanoma (SK-MEL-2), and colon cancer (HCT-15) human cell lines, using a sulforhodamine (SRB) assay. 23-Hydroxyursolic acid showed cytotoxicity against the tested cell lines with IC50 values ranging from 11.96 to 14.11 μM.
No preview · Article · Jul 2015 · Journal of the Brazilian Chemical Society
[Show abstract][Hide abstract] ABSTRACT: Phytochemical investigation of the twigs of Chaenomeles sinensis led to the isolation and identification of six new lignan glycosides, chaenomiside A-F (1-6), along with five known ones (7-11). Their chemical structures were determined by spectroscopic methods, including NMR, MS, ECD, and GC/MS analyses. All the isolated compounds (1-11) were tested for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide-activated murine microglial cells and the secretion of nerve growth factor (NGF) in a C6 rat glioma cell line. Compound 6 significantly reduced NO levels in the murine microglia BV2 cells with an IC50 value of 21.3 μM, and compounds 1, 3, and 6 were potent stimulants of NGF release with stimulation levels of 151.74 ± 6.77%, 144.31 ± 7.49%, and 167.61 ± 18.5%, respectively.
[Show abstract][Hide abstract] ABSTRACT: A new aliphatic alcohol, (2R,6R)-oct-7-ene-2,6-diol (1), and seven other known compounds (2-8) were isolated from Acorus gramineus rhizomes. The structure of 1 was elucidated by a combination of extensive spectroscopic analyses, including 2D NMR, HR-MS, and the modified Mosher's method. Compounds 3-8 displayed consistent antiproliferative activities against the cell lines tested with IC50 values ranging from 7 to 48 μm.
No preview · Article · Apr 2015 · Bioscience Biotechnology and Biochemistry