Pattern Recognition Of Natural Products And Design And Synthesis Of A Dual Channel Chemodosimeter

In the dissertation, a library of simple multi-boronic acid-based receptors with various spacers was synthesized for the sensing of saccharide-based natural products. Based on indicator displacement assay, a cross-reactive sensing array was constructed using the receptors in conjunction with different pairs of indicators. Pattern recognition analysis created from the colorimetric response of the hosts and indicator pairs reveal excellent classification of natural products. Moreover, based on the concept of aldehyde group protection/deprotection, a new BODIPY based dual-channel chemodosimeter for Hg2+ and Ag+ has been developed.The first section studied on the pattern recognition of ginsenosides and ginseng extracts. A library of simple bis-boronic acid based receptors for ginsenosides were designed and synthesized. Multiple boronic acids were incorporated for simultaneous binding of saccharides on two ends of ginsenosides while some of the spacers were used to target hydrophobic steroids. A suite of indicators were screened, and the pairing of indicators (ML-PV or ARS-PV) provided greater absorbance signal modulation. Pattern recognition analysis indicated excellent separation and classification of individual ginsenosides and ginseng extracts with high accuracy.The second section focused on the discrimination of vicinal-diol-containing flavonoids and black tea extracts. Boronic acids are suitable for binding flavonoids because most flavonoids contain catechol groups which can reversibly associate with phenyl boronic acids to form cyclic boronic esters. The resulting dynamic three-component sensing ensembles (H-ML-PV, H-ARS-PV) are capable of responding differently to flavonoids, providing the basis for array sensing. Sensing arrays in 96-well plates were constructed and successfully employed to discriminate both vicinal-diol-containing flavonoids and black tea extracts.The third section described the design, synthesis and spectral characterization of BODIPY-1,3-dithiane-based chemodosimeter, which yields distinctive signal patterns towards Hg2+ and Ag+.