Isoquinolines, simple

Opium alkaloids are nonpeptide agonists for the opioid peptide hormone receptors. The dried latex of Papaver somniferum (opium), or the seed capsule of the plant itself, are the sources of almost 25 alkaloids. Some simple isoquinolines from opium, like papaverine (5.86), are antispasmodics. The principal alkaloid ( 10% of the total) is morphine (3.11), which is also an isoquinoline (rings C and E) but can addihonally be considered a phenanthrene derivahve (rings A, B, and C). 

Of the alkaloids so far identified in just L. william-sii alone, 15 are Beta-phenethylamine and simple isoquinoline alkaloids. Mescaline, N-methylmescaline, N-acetylemescaline, anhalamine, anhalonine, anhalidine, anhalinine, anhalonidine, lophophorine, O-methylan-halondedine, and pellotine have all been identified as the principal components of the plant. However, only mescaline has so far been determined to cause hallucinations. 

The 13C spectrum of cularine (34) (Fig. 6, Table VI), has been reported by Wenkert et al. (6). The chemical shifts of the aliphatic carbon atoms were assigned by comparison with those of laudanosine (28) and follow also from those of the simple isoquinolines (Section II). In the aromatic region the resonances of the pair of protonated carbon atoms at C-5 and C-6 were differentiated from those at C-2 and C-5 by the observation of... 

The chemical shift assignments (Table XII) for the majority of the carbon atoms were made by comparison with the appropriately substituted simple isoquinolines such as 2 and 4. Since the chemical shifts of the aliphatic... 

The 13C spectrum of emetine (112) (Fig. 23 and Table XXII) was examined by Wenkert and co-workers (69). The chemical shift assignments were made by comparison with the shifts recorded for the simple isoquinolines and pro-toberberine alkaloids such as tetrahydropalmatine (69) (6, 14), and with indolic analogues of emetine (69). The shifts of C-4 and C-6 are characteristic of a trans-quinolizidine conformation for this ring system by analogy... 

The) simple isoquinoline salsolinol (152), a relative of the alkaloid salsoline (153), is mono-O-methylated by an enzyme preparation from rat liver,... 

Simple isoquinolines (IQs) (—)-pellotine (IQ) (Lophophora williamsii (peyote) (Gactaceae) paralytic convulsant) (—)-salsolinol (IQ [Musa paradisiaca (banana) (Musaceae) and Theobroma cacao (cocoa) (Sterculiaceae) dopamine antagonist linked to chocolate craving). 

On the other hand, it provides good methods for the introduction of groups into the 1 - and 3-positions of simple isoquinolines. The compounds prepared by this method are listed in Table I. 

Simple isoquinolines are not found in the Menispermaceae of South America. The isoquinolone thalifoline (1) was identified from Abuta pahni [32], Benzyltetrahydroisoquinolines are the biogenetic precursors for aporphines, proaporphines, and oxoaporphines. Yet the only such compound isolated from South American Menispermaceae is (+) coclaurine (2) obtained from Sciadotema eichleriam [52] and Caryomene olivascens [37-38]. The chemistry of simple isoquinolines [65], isoquinolones [66], and benzyltetrahydroisoquinolines [67] have been reviewed. 

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