A polyaromatic receptor with high androgen affinity.

Abstract

Biological receptors distinguish and bind steroid sex hormones, e.g., androgen-, progestogen-, and estrogen-type hormones, with high selectivity. To date, artificial molecular receptors have been unable to discriminate between these classes of biosubstrates. Here, we report that an artificial polyaromatic receptor preferentially binds a single molecule of androgenic hormones, known as "male" hormones (indicated with <i>m</i>), over progestogens and estrogens, known as "female" hormones (indicated with <i>f</i>), in water. Competitive experiments established the binding selectivity of the synthetic receptor for various sex hormones to be testosterone (<i>m</i>) > androsterone (<i>m</i>) >> progesterone (<i>f</i>) > β-estradiol (<i>f</i>) > pregnenolone (<i>f</i>) > estriol (<i>f</i>). These bindings are driven by the hydrophobic effect, and the observed selectivity arises from multiple CH-π contacts and hydrogen-bonding interactions in the semirigid polyaromatic cavity. Furthermore, micromolar fluorescence detection of androgen was demonstrated using the receptor containing a fluorescent dye in water.