A novel magnetic ß-cyclodextrin modified graphene oxide adsorbent with high recognition capability for 5 plant growth regulators.

ß-Cyclodextrin (ß-CD) modified magnetic graphene oxide material (Fe3O4@SiO2/GO/ß-CD), a novel magnetic sorbent for enrichment and purification of plant growth regulators (PGRs) in vegetables prior to gas chromatograph mass spectrometer (GC-MS) detection, was successfully fabricated. The novel magnetic sorbent geometrically fitted to selectively recognize and enrich PGR analytes especially containing aromatic structure. The selectivity experiment demonstrated the higher selectivity of Fe3O4@SiO2/GO/ß-CD toward 5 PGR compounds than that of Fe3O4@SiO2/GO. Several parameters affecting extraction efficiency including the volume of extraction solvent, amount of adsorbent, extraction time, type and the volume of desorption solvent were optimized. Under the optimized condition, good linear relationships were obtained in the range of 1-100µg/kg with determination coefficients (R2) from 0.9983 to 0.9996. The limits of detection (LODs) of 5 PGRs were from 0.04 to 0.28µg/kg. The proposed method had good potential for the analysis of trace level of 5 PGRs in real vegetable samples.

[Effects of TNBG on the proliferation and apoptosis of human hepatocellular carcinoma cell line QGY-7701].

OBJECTIVE: To investigate the effects and mechanism of TNBG on the proliferation and apoptosis of human hepatocellular carcinoma cell line QGY-7701. METHODS: The 3H-TdR incorporation and MTT assay were used to test the effects of anti-proliferation and cytotoxicity respectively, the morphological changes of the cancer cells were examined under light and electron microscopes. The Flow cytometric analysis was performed to detect the cell cycle distribution and apoptosis. RESULTS: Marked anti- proliferation effect was observed after intervention of 2 microg/ml TNBG for 24 hours,and TNBG killed the cells in concentrition- and time-dependent manners. A lot of lipid droplets accumulated at the cytoplasm under light microscopy, and were confirmed by electron microscopy. Furthermore,the cells showed G2/M arrest and apoptosis. CONCLUSION: The above findings indicate that TNBG inhibits proliferation of tumor cells, induces apoptosis of tumor cells, and thus produces its antitumor effect.