Rotors of BOSCHIBAs as endoplasmic reticulum fluorescent probes in HeLa and human umbilical vein endothelial cells

The fluorescence imaging technique is becoming a useful tool in the natural and life sciences. Commercial biomarkers are available; however, some disadvantages exist like high isolation cost, low-temperature storage, photodegradation, and low yields. Here two new fluorescent molecular rotors (SB-B 2 and SB-B2 3) derived from Boron Schiff bases (BOSCHIBAs) were synthesized and characterized by NMR (H-1 and C-13), UV/Vis, and fluorescence spectroscopy. The crystal structure of SB-B2 3 by X-ray diffraction showed a binuclear complex and C-2 symmetry. Both compounds showed viscochromic and thermochromic properties. The binuclear rotor 3 showed a greater luminescence intensity increase than the mononuclear one at the highest level of viscosity (90%). From the remarkable findings and to our best knowledge this is the first time low cytotoxicity BOSCHIBAs exhibit selective fluorescent staining of endoplasmic reticulum in HeLa cells and HUVECs.

Automated summary

The fluorescence imaging technique is widely used in natural and life sciences, but current commercial biomarkers have several disadvantages. In this study, two new fluorescent molecular rotors (SB-B2 and SB-B23) derived from Boron Schiff bases (BOSCHIBAs) were synthesized and characterized. The crystal structure of SB-B23 showed a binuclear complex. Both compounds exhibited viscochromic and thermochromic properties. These low cytotoxicity BOSCHIBAs showed selective fluorescent staining of the endoplasmic reticulum in HeLa cells and HUVECs.