Synthesis of a Dual-Labeled Probe of Dimethyl Lithospermate B with Photochemical and Fluorescent Properties

Abstract

Dimethyl lithosermate B (DLB) is a highly potent natural antioxidant and antidiabetic polyphenol with unknown mode of action. To determine its cellular targets, a photochemical and fluorescent dimethyl lithopermate B probe was designed and efficiently synthesized. The dual-labeled chemical probe for biological application was evaluated by UV and fluorescence to determine its electrochemical absorption and emission properties. This probe could be valuable for investigating ligand-protein interactions and subcellular localization.

Fishing for Drug Targets: A Focus on Diazirine Photoaffinity Probe Synthesis

“…Popularlized by Nakashima et al, TPD aldehyde 105 and 106 are widely used because they are easily derivatized (Scheme 17). 72 Aldehydes maybe converted to acrylonitrile derivative 107 with the corresponding Wittig reagent in excellent yield (98%) and good stereospecificity (77% trans/23% cis), 73 reduced to benzyl alcohol 108 in quantitative yield with sodium borohydride, 74 oxidized to carboxylic acid 109 with sodium chlorite and sulfamic acid, 75 converted to ester 110 by dissolving in methanol and treating with a suspension of ammonium persulfate and sulfuric acid, refluxed with hydroxylamine hydrochloride in pyridine and ethanol to form oxime 111, 76 or treated with D-or L-cysteine to form thiazolidine 112. 77 Benzyl bromide TPDs (Scheme 18) are employed in highyielding alkylation reactions under basic conditions.…”