The opioid peptide dynorphin A elicits non-opioid receptor-mediated, neurotoxic response in vivo, which is blocked by pretreatment with MK-801, a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist. In the present study, we examined the possible direct interaction of dynorphin A on the NMDAR. A nonopioid dynorphin A analog, (125)I-(des-tyrosyl) dynorphin A(2-17), was used in radioli...

In the title compound, C(24)H(39)NO(2)·H(2)O, the A and C rings of the pregnolene derivative sterol adopt chair conformations, with the B ring in a flattened chair conformation and the five-membered ring in an envelope conformation twisted about the C/D ring junction. The N-tert-butyl-carboxamide substituent is equatorial. The 3β-hydr-oxy H atom and one H atom of the water mol-ecule are disorde...