Ponceau 4R (85%)

Ponceau 4R (85%) (Acid Red 18 (85%); New Coccine (85%)) is an orally active synthetic food colorant and a HSA-binding aggregator. Ponceau 4R (85%) binds to HSA, inducing its partial unfolding, conformational changes and aggregation. Ponceau 4R (85%) serves as a food colorant and can be used in research on diseases including type Ⅱ diabetes, Parkinson's disease, Huntington's disease and spongiform encephalopathy^[1][2][3]. In Vitro:Ponceau 4R (5-30 µM) binds to a single site on human serum albumin at pH 2.0 via static fluorescence quenching, with a binding constant of 1.43 × 10⁵ M^-1[1].
Ponceau 4R (80-200 µM; overnight) induces aggregation of human serum albumin at pH 2.0, as measured by increased Rayleigh light scattering at 650 nm^[1]. In Vivo:Ponceau 4R (205 mg/kg; p.o.; daily) causes cognitive deficits in first-generation male rats, while its effects on female rats are inconsistent^[2].
Ponceau 4R causes a significant increase in nuclear DNA migration in multiple organs of mice, with no associated cytotoxicity^[2].
Ponceau 4R (2000 mg/kg; p.o.; single administration) exhibits low acute oral toxicity in male *Mus musculus* (house mouse), with an LD₅₀ greater than 2000 mg/kg bw^[3].