Toxicity of primulic acid 1 against a daphnid species Simocephalus expinosus s.l.

Primulic acid 1 is the main saponin present in Primula elatior. The present study describes the isolation of this amphiphilic compound from primula root. It was performed by ultrasonic maceration, reverse-phase column chromatography and crystallization. Investigations of its physicochemical property are represented by the determination of critical micelle concentration (cmc). The cmc value of the amphiphile was 9.4 × 10⁻⁵ mol·dm⁻³. The evaluation of environmental toxicity was performed on a daphnid species Simpocephalus expinosus s.l., which was very sensitive to primulic acids 1. The results from acute immobilisation test show that the tested compound has half maximal effective concentration after 24 hours (EC₅₀-24 h) equal to 6.9 mg·l⁻¹. Saponin can be classified as a toxic compound for aquatic organisms.