Simple isoquinoline alkaloids

The Mexican cactus Pachycereus pecten-aboriginum has been shown to contain salsoline (6 R = H, = Me) and the new bases isosalsoline (6 R = Me, R = H), the isomeric arizonine (7) (which has the same orientation of oxygen substituents as is found in tepenine), and heliamine, which is 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline. Salsoline (6 R = H,R = Me) and salsolidine (6 R = R = Me), on treatment with ethylene oxide, afford the/3 hydroxyethyi compounds (8 R = H, R = OH) and (8 R = Me, R = OH), and these have been converted into a series of esters by reaction with acid chlorides. The jS-chloroethyl compound (8 R = H, R = Cl) has been shown to decrease 

Collins and C. D. Weiner, Alcohol Aldehyde Metab. Syst., 1977, 3, 511. 

Thalactamine (15 R = H) and its 6,7-dimethoxy-analogue have been synthesized from the appropriately substituted homophthalic anhydride, e.g. (14) this, with phosphorus oxychloride and dimethylformamide, gives the acid (15 R = CO2H), which can be decarboxylated. The peptide alkaloid amphi-bine (17) has been synthesized by the condensation of the primary amine (16) with N-benzyloxycarbonyl-L-valylglycine, followed by removal of the N-benzyloxy-carbonyl group 

Further examination of Triphiophyllum peltatum has shown that O-methyl-triphiophylline and its 1,2-dehydro-analogue are accompanied by iso-triphiophylline (18), N-methyltriphiophylline (19), and O-methyltetra-dehydrotriphiophylline (20).The structure of hamatine (21) and its absolute stereochemistry have been determined, and an X-ray crystallographic study of ancistrocladine has confirmed the structure previously deduced (see Volume 7, 

Cassia siamea Corydalis speciosa Dolicothele longimamma 

Pachycereus pectenaboriginum Salsolidine C.Tani, N. Nagakura, andN. Sugiyama, Yakugaku Zasshi, 1975,9S,838 Chem.Abs., 1975,83,93 897) 

Narciclasic aldehyde (16 R = CHO), a key degradation product in the structural elucidation of the alkaloid narciclasine, has been synthesized via the isoquinolone 

Reagents i, K3Fe(CN)6 ii, 0. lM NaOMe in MeOH iii, Electrolysis at 0.16 V in wet MeCN at a graphite felt anode with Et4N a04 as an electrolyte. 

The transformation of isoquinolinium salts into naphthalene derivatives described in connection with berberine (c/. Section 11) may have general applicability since similar reaction of isoquinoline methiodide gave -naphthyl acetate, albeit in small yield (see ref. 362). 

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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 range of simple isoquinoline alkaloids, principally obtained from cacti, has recently been greatly expanded by the isolation of isoquinolines, 3,4-dihydroisoquinolines and 1,2,3,4-tetrahydroisoquinolines bearing one, two, three and... 

Possibly as a result of the social implications of the hallucinogenic j5-phenethyl-amines and simple isoquinoline alkaloids, a large number of new plant species suspected to contain these structural types have been closely scrutinized with the aid of sensitive analytical methods. Thus, extensive screening of a large variety of cactus species has been carried out. G.c. analysis has indicated the presence of trace amounts of dimers and trimers of phenethylamine and tetrahydroiso-quinoline types " while combination g.c.-mass spectrometry has enabled rapid identification of alkaloids of 120 cactus species." High voltage electrophoresis has been used for quantitative alkaloid determination.Useful structural information may be obtained from the technique of chemical ionization mass spectrometry. ... 

New, simple isoquinoline alkaloids isolated and assigned structures during the period under review include thalactamine (I), thalifoline (N-methyl derivative of 2 R = Me, R = H), and noroxyhydrastinine (2 RR = CH2), from Thalic-trum minus, and bases of general structure (3) listed in Table 1 have been identified in Peyote. ... 

Chapter 9 ) -Phenethylamines and Simple Isoquinoline Alkaloids By V. A. Snieckus... 

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