Development and Validation of a UV Spectrophotometric Method for the Estimation of the Synthesized Lentinan–Congo Red Complex

Abstract

Lentinan, a therapeutic bioactive molecule obtained from Lentinus edodes (Shitake mushrooms), possesses various pharmacological activities. A literature survey reveals that no simple UV-visible technique for the estimation of lentinan has yet been established; hence, there is a pressing need for a simple, yet precise and robust analytical method. We have developed a UV-visible spectrophotometric method for the estimation of lentinan in complex with Congo red azo dye in different concentrations of alkaline solutions. Lentinan was found to be freely soluble in deionized water, and the absorption maximum (λmax) was found to be 486 nm. The validation of the developed method gave satisfactory results, the lentinan–Congo red solution complex gave acceptable linearity within the concentration range 2–10 μg/mL and the correlation coefficient (r²) was found to be >0.99. The developed method was found to be accurate because the mean recovery value at various concentrations gave higher results than 90%. LOD and LOQ for lentinan were reported and found to be 0.014 and 0.0431 μg/mL, respectively. The developed method was found to be simple, specific, economic, reliable, accurate, precise, reproducible, and it could be used as a quality control tool for the analysis of pure lentinan and lentinan in formulations.