Structure-activity relationship analysis of perfluoroalkyl carbonic acids on human and rat placental 3β-hydroxysteroid dehydrogenase activity.

Placenta contains 3β-hydroxysteroid dehydrogenase/steroid Δ-isomerase (HSD3B), which catalyzes pregnenolone to progesterone for maintaining pregnancy. Perfluoroalkyl carbonic acids (PFC) are subclass of perfluoroalkyl substances containing 4-14 carbons (C4-C14) in the carbon backbone and are potential endocrine disruptors. Whether PFC inhibit HSD3B and structure-activity relationship (SAR) remains unclear.

Oxidation of Furfural and Furan Derivatives to Maleic Acid in the Presence of a Simple Catalyst System Based on Acetic Acid and TS-1 and Hydrogen Peroxide.

Titanium silicate molecular sieve (TS-1) and acetic acid efficiently catalyze the oxidation of furan and furan derivatives to the corresponding maleic acid (MA) in very good yields using hydrogen peroxide as an oxidizing agent. The effect of various solvents, the effect of temperature, reaction time, concentration of hydrogen peroxide, and quantities of the catalyst on the MA yield was studied. With the best conditions, MA is the sole product obtained after a fast and simple purification by filtration and evaporation.