Role of the CAI-1 Fatty Acid Tail in the Vibrio cholerae Quorum Sensing Response
摘要:
Quorum sensing is a mechanism of chemical communication among bacteria that enables collective behaviors. In V. cholerae, the etiological agent of the disease cholera, quorum sensing controls group behaviors including virulence factor production and biofilm formation. The major V. cholerae quorum-sensing system consists of the extracellular signal molecule called CAI-1 and its cognate membrane bound receptor called CqsS. Here, the ligand binding activity of CqsS is probed with structural analogues of the natural signal. Enabled by our discovery of a structurally simplified analogue of CAI-1, we prepared and analyzed a focused library. The molecules were designed to probe the effects of conformational and structural changes along the length of the fatty acid tail of CAI-1. Our results, combined with pharmacophore modeling, suggest a molecular basis for signal molecule recognition and receptor fidelity with respect to the fatty acid tail portion of CAI-1. These efforts provide novel probes to enhance discovery of antivirulence agents for the treatment of V. cholerae.
Spiro(phosphoamidite) ligand (SIPHOS)/Cu(OTf) 2 -catalyzed highly regio- and stereo-selective hydroborations of internal alkynes with diborane in water
作者:Qing-Qing Xuan、Ya-Hui Wei、Qiu-Ling Song
DOI:10.1016/j.cclet.2017.04.031
日期:2017.6
Abstract The highly regio- and stereoselective hydroborations of unactivated internal alkynes with diboron compoundcatalyzed by Cu(OTf) 2 with spiro(phosphoamidite) as ligand in the presence of Cs 2 CO 3 in water was developed. This protocol was applied efficiently in the aqueous synthesis of multi-substituted vinylboranes.
摘要研究了在水中Cs 2 CO 3存在下,Cu(OTf)2与螺(磷酰胺)为配体催化的二硼化合物催化的未活化内炔烃的高度区域选择性和立体选择性硼氢化反应。该方案有效地应用于多取代乙烯基硼烷的水合成中。