Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)

Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)

Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)

Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)

Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)

Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)

Medicinal Chemistry Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (R.B.R., J.S.P., M.H.B.); and Department of Chemistry, Drug Discovery Division, Southern Research Institute, Birmingham, Alabama (S.A., S.K.S., O.M.-C., V.P.)