During the examination of extracts from Oncinotis tenuilobu STAPF a new polyamine, N4-benzoylspermidine (S), was isolated. For unambiguous structure elucidation, it was transformed into the diacetyl derivative 13, and the three possible N-benzoyl-substituted isomers of spermidine 5 , 8 , and 11 together with their peracetylated derivatives 12-14, respectively, were synthesized and identified.
In an analogy to the potent catechol dopamine D1 agonists dihydrexidine (1) and dinapsoline (2), benzo rings were fused onto the structures of the dopamine D2-selective agonists quinelorane (3) and quinpirole (4). Each of the phenyl ring-substituted derivatives had significant affinity for D2 receptors, albeit somewhat lower than the two parent compounds, 3 and 4. Compounds with N-propyl and N-allyl substituents (5b, 5c, 6c, and 6d) had higher affinity for the D2 dopamine receptor than did their corresponding secondary amines (5a and 6a). Slightly different effects on affinity of an n-propyl and an n-allyl group in the new analogues of 3 and 4 suggest that different binding orientations may be invoked at the receptor.
From the leaves of Oncinotis tenuiloba STAPF, a novel polyamine alkaloid, tenuilobine (9). was isolated. This paper presents the synthesis of 9, as well as the base-catalyzed Zip reaction of 9, leading to the transamidation product isotenuilobine (10). The structure of 10 was further confirmed by 2D-NMR correlation spectroscopy. For analytical purposes, the his-polyamines 9 and 10 were converted into their pentaacetyl derivatives 12 and 11, respectively, which were readily separable by reverse-phase HPLC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.