Xiaodong Xu,Rui Xu,Qian Jia,Tao Feng,Qingrong Huang,Chi-Tang Ho,Shiqing Song
The volatile compounds of Volvariella volvacea mushroom were investigated by solvent assisted flavor evaporation (SAFE)/gas chromatography-mass spectrometry (GC–MS), gas chromatography-olfactometry (GC-O), odor activity value (OAV), combined with aroma reconstitution and omission. The results showed that a total of 63 compounds were detected after SAFE extraction. A total of 26 compounds were determined after GC-O and 17 compounds whose OAV greater than 1 were subjected to reconstitution and omission experiments. The results showed that dihydro-β-ionone, 1-octen-3-one, 1-octen-3-ol, γ-undecalactone, 3-octanol, 2-octanone, hexanal, 2-methylbutanal, camphene, carvone, 2-nonanone, and phenylacetaldehyde have been successfully identified as the key aroma compounds. More significantly, dihydro-β-ionone as a key aroma compound was first found in Volvariella volvacea mushroom.
Junjie Wu,Mengmeng Zhang,Lulu Song,Yahong Tan,Yosuke Taniguchi,Christopher John Hipolito,Youming Zhang,Yizhen Yin
Oxidative lesions, such as 8-oxo-dG and 8-oxo-dA, are continuously generated from exposure to reactive oxygen species. While 8-oxo-dG has been extensively studied, 8-oxo-dA has not received as much attention until recently. Herein, we report the synthesis of duplex DNAs incorporating dA, 8-oxo-dA, 7-deaza-dA, 8-Br-dA, and 8-Br-7-deaza-dA, which have different substitutions at 7- and 8-position, for the investigation into the implications of N7-hydrogen and C8-keto on the base pairing preference, mutagenic potential and repair of 8-oxo-dA. Base pairing study suggested that the polar N7-hydrogen and C8-keto of 8-oxo-dA, rather than the syn -preference, might be essential for 8-oxo-dA to form a stable base pair with dG. Insertion and extension studies using KF-exo − and human DNA polymerase β indicated that the efficient dGTP insertion opposite 8-oxo-dA and extension past 8-oxo-dA:dG are contingent upon not only the stable base pair with dG, but also the flexibility of the active site in polymerase. The N7-hydrogen in 8-oxo-dA or C7-hydrogen in 7-deaza-dA and 8-Br-7-deaza-dA was suggested to be important for the recognition by hOGG1, although the excision efficiencies of 7-deaza-dA and 8-Br-7-deaza-dA were much lower than 8-oxo-dA. This study provides an insight into the structure-function relationship of 8-oxo-dA by nucleotide analogues.
危险品化学品经营许可证（带存储）