1.Glycinergic-fipronil uptake is mediated by an amino acid carrier system and induces the expression of amino acid transporter genes in Ricinus communis seedlings.
Xie Y, Zhao JL, Wang CW, Yu AX, Liu N, Chen L, Lin F, Xu H. J Agric Food Chem. 2016 Apr 19. [Epub ahead of print]
Phloem-mobile insecticides are efficient for piercing and sucking insects control. Introduction of sugar or amino acid groups to the parent compound can improve the phloem mobility of insecticides, so a glycinergic -fipronil conjugate (GlyF), 2-(3-(3-cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-((trifluoromethyl)sulfinyl)-1H-pyrazole-5-yl)ureido) acetic acid, was designed and synthesized. Although the "Kleier model" predicted that this conjugate is not phloem mobile. GlyF can be continually detected during five-hour collecting of Ricinus communis phloem sap. Further, an R. communis seedling cotyledon disc uptake experiment demonstrates that the uptake of GlyF is sensitive to pH, carbonyl cyanide m-chlorophenylhydrazone (CCCP), temperature, and p-chloromercuribenzenesulfonic acid (pCMBS), and is likely mediated by amino acid carrier system. In order to explore the roles of amino acid transporters (AATs) in GlyF uptake, a total of 62 AATs genes were identified from the R.
2.Ultrasensitive fluorescence immunoassay for detection of ochratoxin A using catalase-mediated fluorescence quenching of CdTe QDs.
Huang X1, Zhan S1, Xu H1, Meng X2, Xiong Y1, Chen X3. Nanoscale. 2016 Apr 19. [Epub ahead of print]
Herein, for the first time we report an improved competitive fluorescent enzyme linked immunosorbent assay (ELISA) for the ultrasensitive detection of ochratoxin A (OTA) by using hydrogen peroxide (H2O2)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (QDs). In this immunoassay, catalase (CAT) was labeled with OTA as a competitive antigen to connect the fluorescence signals of the QDs with the concentration of the target. Through the combinatorial use of H2O2-induced fluorescence quenching of CdTe QDs as a fluorescence signal output and the ultrahigh catalytic activity of CAT to H2O2, our proposed method could be used to perform a dynamic linear detection of OTA ranging from 0.05 pg mL-1 to 10 pg mL-1. The half maximal inhibitory concentration was 0.53 pg mL-1 and the limit of detection was 0.05 pg mL-1. These values were approximately 283- and 300-folds lower than those of horseradish peroxidase (HRP)-based conventional ELISA, respectively.
3.First synthesis of 22-oxa-chenodeoxycholic acid analogue.
Wang Y1, Yue Q1, Zhao Y1, Qiu S1, Peng Y1, Li J1, Zhang T2, Hai L1, Guo L3, Wu Y4. Steroids. 2016 Apr 15. pii: S0039-128X(16)30015-0. doi: 10.1016/j.steroids.2016.04.004. [Epub ahead of print]
In this study, we report the first synthesis of 22-oxa-chenodeoxycholic acid analogue via androstenedione and progesterone, in 11 and 8 steps with overall yields of 6.4% and 12.7%, respectively. We anticipate this will help to facilitate the development of new drugs.
4.Visible-Light Photoredox Synthesis of Chiral α-Selenoamino Acids.
Jiang M1, Yang H1, Fu H1. Org Lett. 2016 Apr 19. [Epub ahead of print]
N-Acetoxyphthalimide derivatives of two genetically coded proteinogenic amino acids, l-aspartic acid and glutamic acid, were used as visible light photoredox chiral sources and radical precursors, diorganyl diselenides were used as the radical acceptors, and the diverse chiral α-selenoamino acid derivatives were prepared in good yields at room temperature. Furthermore, decarboxylative coupling of N-protected dipeptide active ester with diphenyl diselenide provided the corresponding selenodipeptide. The simple protocol, mild reaction conditions, high efficiency, and chiral keeping of this method make it an important strategy for the synthesis of chiral molecules.
