Table 1.

The affinity of tested compounds for α₁- and β₁-adrenoceptors.

Compound	Adrenergic receptors Ki (nM)
	α1	β1
HBK-14	22.8a	n.aa
HBK-15	13.1a	n.aa
HBK-16	5.0	n.a.
HBK-17	12.9	n.a.
HBK-18	5.2	n.a.
HBK-19	22.7	n.a.
Phentolamine	18.3	−
Propranolol	−	7.1
Carvedilol	2.2b	0.8b

Inhibition constants (K_i) were calculated according to the equation of Cheng and Prusoff (1973). The compounds were tested in three separate experiments in duplicates. n.a., compound did not bind to the receptor at the concentration 10⁻⁵ M.

^aPytka et al. (2015).

^bPönicke et al. (2002).