Antitumor agents. 89. Psychorubrin, a new cytotoxic naphthoquinone from Psychotria rubra and its structure-activity relationships
作者:Toshimitsu Hayashi、Forrest T. Smith、Kuo Hsiung Lee
DOI:10.1021/jm00394a013
日期:1987.11
A new naphthoquinone, isolated from the alcoholic extract of Psychotria rubra, exhibited significant cytotoxicity in the KB cell assay (ED50 = 3.0 micrograms/mL). Spectral data was used to assign the structure of psychorubrin as 2. Naphthoquinonederivatives 6, 8, 13, and 14 were prepared and exhibited superior cytotoxic activity to that of psychorubrin. All were potential Michael acceptors whose conjugation
Opioid agonist and antagonist bivalent ligands. The relationship between spacer length and selectivity at multiple opioid receptors
作者:P. S. Portoghese、D. L. Larson、L. M. Sayre、C. B. Yim、G. Ronsisvalle、S. W. Tam、A. E. Takemori
DOI:10.1021/jm00160a010
日期:1986.10
mu receptors as a function of spacer length. Also, delta receptorselectivity increased as the spacer was lengthened. The naltrexamine bivalentligands (9-13) effectively antagonized the mu receptor agonist morphine in the GPI at the same optimal spacer length (n = 2) as in the agonist series. However, the peak antagonism of ethylketazocine, a kappa receptor agonist, occurred with the bivalent ligand