Altrenogest photochemistry

Synthetic steroid hormones used in agriculture can potentially transform into products with potent retained bioactivity when released into the environment. Altrenogest (ALT) is a potent synthetic steroid pharmaceutical used to synchronize estrus (heat) in swine and mares. Previous work has shown that ALT undergoes direct photolysis to yield one primary photoproduct, an isomer altrenogest-cycloaddition product (ALT-CAP) that retains bioactivity. ALT-CAP subsequently undergoes photohydration to yield secondary product ALT-CAP-OH, which thermally dehydrates in the absence of light to regenerate ALT-CAP in a reversible, light dependent reaction. Previous work with similar synthetic steroids demonstrated that product formation from reversible light dependent reactions can be influenced by multiple day night cycles, and products can react with other reactive species like nucleophiles. However, the products of the altrenogest photolysis were not fully characterized, and the influence of nucleophiles was not examined. To fully characterize the process of altrenogest photolysis, I conducted direct photolysis and day/night cycling experiments under different environmental conditions (pH 5 and 7) as well as in the presence of model and environmentally relevant nucleophiles.