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This study focused on the role of methionine (MET) in the autophagy of gastric cancer stem cells (GCSCs) and aims to elaborate its regulatory mechanism. In the present study, the GCSCs were isolated from human gastric cancer cell lines using an anti-CD44 antibody, and then cultured in MET+ homocysteine (HCY)− or MET−HCY+ medium. In MET+HCY–treated GCSCs, autophagy was suppressed, the methylation and phosphorylation of RAB37 were elevated, and miR-200b expression was down-regulated. Lentiviral vector (LV-) carrying methionine-γ lyase (an enzyme that could specifically lyse MET; Metase) promoted autophagy, reduced the methylation and phosphorylation of RAB37, and up-regulated miR-200b expression in MET+HCY–-treated GCSCs. Then, we found that miR-200b suppressed the expression of protein kinase C α (PKCα), a protein that could inactivate RAB37 through promoting its phosphorylation. LV-Metase down-regulated RAB37 phosphorylation via miR-200b/PKCα, thus promoting the RAB37-mediated autophagy and suppressing cell viability in MET+HCY–treated GCSCs. Finally, the in vivo study proved that LV-Metase treatment inhibited tumor growth through up-regulating RAB37 expression. In conclusion, MET suppressed RAB37 expression via enhancing its methylation and suppressed RAB37 activity via miR-200b/PKCα axis, thus repressing RAB37-mediated autophagy in GCSCs. The supplementation of Metase lysed MET, thus inducing the autophagy of GCSCs and inhibiting tumor growth. [ABSTRACT FROM AUTHOR]

Two new isoaurones derivatives were obtained from Callistephus chinensis flower. Their structures were elucidated on the basis of extensive spectroscopic analyses. Both of the new compounds were evaluated cytotoxic activity. Phytochemical investigation of Callistephus chinensis flower led to the isolation of two new isoaurones derivatives (Z)-4′,4,10-trihydroxy-siamaurone (1) and (E)-4′,4,10-trihydroxy-siamaurone (2). The structures of these new compounds were identified by the interpretation of spectroscopic data (mainly 1D and 2D NMR) and by comparison with data reported in the literature. Both of the new compounds were evaluated for their cytotoxicity. [ABSTRACT FROM AUTHOR]

A new dammarane-type triterpene saponin was isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. Its structural elucidation was accomplished mainly on the basis of the interpretation of spectroscopic data, such as IR, HR–TOF–MS and NMR. Its cytotoxic activity was evaluated against one human cancer cell line HL-60 using MTT assay. [ABSTRACT FROM PUBLISHER]

Four new dammarane-type triterpene saponins, 1-4, were isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. Their structural elucidations were accomplished mainly on the basis of spectroscopic methods, such as IR, HR-TOF-MS, and NMR. Compounds 1-4 showed moderate cytotoxic activities against cancer cell lines HL-60, Colon205, and Du145 in vitro. [ABSTRACT FROM AUTHOR]

From the dried petals of Carthamus tinctorius, a new flavonoid, (2R)-4',5-dihydroxyl-6,7-di-O-β-d-glucopyranosyl flavanone (1) and a new aromatic glucoside, methyl-3-(4-O-β-d-glucopyranosylphenyl) propionate (4) were isolated along with four known compounds (2S)-4',5-dihydroxyl-6,7-di-O-β-d-glucopyranosyl flavanone (2), 6-hydroxykaempferol-3,6-di-O-β-d-glucopyranoside (3), 4-O-β-d-glucosyl-trans-p-coumaric acid (5), and 4-O-β-d-glucosyl-cis-p-coumaric acid (6). Their structures were identified on the basis of chemical and spectroscopic methods. [ABSTRACT FROM AUTHOR]

A new bufadienolide named 16β-acetoxy-bufarenogin (1), together with six known bufadienolides, namely, 11α,12β-dihydroxy-bufalin (2), bufotalin (3), hellebrigenin (4), desacetylbufotalin (5), gamabufotalin (6), and resibufagin (7) were isolated from Chan'Su. Of these, 2 was a new natural product. Their structures were elucidated by spectral methods. The cytotoxic activities in vitro of these compounds have been assayed against HeLa cell line. They all showed strong cytotoxic activities. [ABSTRACT FROM AUTHOR]

A new phenolic glycoside, sinapic acid 4-O-β-d-(6'-sinapoyl)glucopyranoside (1) and a new sucrose ester, 6,6'-di-O-sinapoylsurcose (3), were isolated from the roots of Cynanchum amplexicaule (Sieb. et Zucc.), along with two known compounds, 6-O-[E]-sinapoyl-d-glucopyranoside (2) and sibricose A1 (4). Their structures were elucidated on the basis of both chemical and spectroscopic methods. [ABSTRACT FROM AUTHOR]