Ava Jingwen Dong

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By bioactivity-guided fractionation, three known steroidal glycosides, beta 2-solamargine (1), solamargine (2), and degalactotigonin (3), were isolated from Solanum nigrum. Compounds 1-3 induced morphological abnormality in Pyricularia oryzae mycelia with MMDC (minimum morphological deformation concentration) values of 63.0, 38.5, and 97.2 microM,(More)
With guidance of Pyricularia oryzae bioassay, daphnoretin (1), (+)-nortrachelogenin (2), genkwanol A (3), wikstrol A (4), wikstrol B (5) and daphnodorin B (6) were isolated from the roots of Wikstroemia indica. Compounds 1-6 induced morphological deformation of P. oryzae mycelia with MMDC values of 68.4 +/- 1.3, 31.3 +/- 1.8, 45.8 +/- 0.5, 70.1 +/- 2.4,(More)
A method using solid phase extraction (SPE) cleanup followed by gas chromatography-mass spectrometry (GC-MS) has been established for quantitative determination of 88 pesticide residues in berry fruits including raspberry, strawberry, blueberry and grape. Based on an appraisal of the characteristics of GC-MS, validation experiments were conducted for 88(More)
By activity-guided fractionation, three known steroidal saponins, prosapogenin A of dioscin, dioscin and gracillin, were isolated from the total saponin fraction of Dioscorea coiletti var. hypoglauca as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. The compounds also exhibited cytotoxic activity against the cancer cell(More)
A rice cDNA encoding a novel calmodulin-like protein was identified. It has 38 additional amino acids at the C-terminus of a complete, typical calmodulin (CaM) sequence of 149 amino acids. The four C-terminal amino acid residues form a CAAL motif which could be a site for protein prenylation and may subsequently cause the protein to become membrane(More)
During activity-guided fractionations to screen for antineoplastic agents, further studies by means of preparative HPLC led to the isolation of four known furostanol saponins: protoneodioscin, protodioscin, protoneogracillin, protogracillin, along with their corresponding artifacts: methyl protoneodioscin, methyl protodioscin, methyl protoneogracillin, and(More)
A method using dispersive solid-phase extraction and dispersive liquid-liquid micro-extraction cleanup followed by high performance liquid chromatography (HPLC) has been established for determination of seven neonicotinoid insecticides residues in grains including brown rice, maize, millet and oat. Based on an appraisal of the characteristics of HPLC,(More)
During further bioactivity-guided fractionation, a new pregnane glycoside, hypoglaucin G (1), and a known compound, pregna-5, 16-dien-3beta-ol-20-one 3-O-alpha-L-rhamnopyranosyl-(1-->2)- [alpha-L-rhamnopyranosyl-(1-->4)] -beta-D-glucopyranoside (2), were isolated from the EtOH extract of Dioscorea collettii var. hypoglauca rhizomes, which induced(More)
The purpose of this research was to establish an analytical method for analysing the 1-[6-chloro-3-methyl-pyridyl-8-nitro-7-methyl-1 2 3 5 6 7-hexahydro imidazo-(1,2a)]-pyridine (IPP) residue levels and to evaluate the difference in plant growth and its physical condition. A high performance liquid chromatography connected to a diode array detector(More)