Naphthoresorcinol

Naphthoresorcinol (1,3-Dihydroxynaphthalene) is a fluorescent dye (λ_ex=330 nm, λ_em=380 nm) that can react with the NPPD (a tracer) and concentrated HCl and develop a red color. Naphthoresorcinol could be used as a background electrolyte (BGE) to determine the carbohydrates^[1][2][3]. In Vitro: Guidelines (The following is a recommended protocol. This protocol is provided as a guide only and should be modified to suit your specific needs)^[4].
1. Under argon, compound 2 (3 mg) is reacted with 2 N HCl (1:4 in MeOH, 1 mL) at reflux at 90°C for 2 h.
2. The reaction mixture is diluted with water and extracted with CHCl₃ (10 mL). The aqueous layer is neutralized with Amberlite MB-3 and then evaporated under reduced pressure to yield the monosaccharide residue.
3. The residue is extracted with MeOH and analyzed by silica gel HPTLC using MeCO and 2 mM NaOAc (17:3, v/v) as the development medium. A 0.2% Naphthoresorcinol solution in MeCO and 3 N HPO (5:1, v/v) is sprayed in, followed by heating at 105°C for 5 minutes for detection.
4. D-Glucose (HY-B0389) is used as the standard.