Aporphines spectra

The second dimeric base, (—)-pennsylpavoline (179), was shown to correspond to C-l-demethylpennsylpavine. Specifically, its NMR spectrum was devoid of the 8 3.71 singlet which represents the C-1 methoxyl absorption in (—)-pennsylpavine (178). Evaluation of CD spectra of these novel dimers and comparison with those of the aporphine (+)-A -methyllaurotetanine and the pavine (—)-platycerine led to the assignment of the absolute configurations as depicted in expressions 178 and 179. These dimers are probably derived biosynthetically from the aporphine-benzylisoquinoline dimers, (-)-pennsylvanine and (-)-pennsylvanamine, which were found in the same plant (7,173). 

The H NMR spectrum of glaucine [12] (18) shows features typical of aporphine alkaloid spectra, with low frequency absorption of the... 

A survey of the H NMR spectra of the benzylisoquinoline-aporphine alkaloids [60]—[65] enables assignment of some of the methoxyl proton resonances. The lowest frequency methoxyl proton signals at ca. 8 3-58 are characteristic of a 7 -methoxyl function, and the 10-methoxyl protons are found to absorb to higher frequency of 8 3-90. (52) This latter shift is also shown in the spectrum of fetedine [66] the aromatic proton signals of which are completely resolved at 220 MHz. (53) In the... 

II, C, 109) with those reported (7) for O-desmethyladiantifoline (2) has shown that these materials are different. Notably, the NMR spectrum of 2 shows peaks at 8 5.78 and 3.56, which represent a 8 -H and 7 -OMe, respectively, as determined by comparison of the spectra of several aporphine-benzylisoquinoline... 

Three other new 7-hydroxylated aporphines have also been isolated from the tuberous roots of S. venosa they are all identified to be the /V-oxides of identical configuration, namely, (-)-sukhodianine /3-N-oxide (46), (-)-ushinsunine /3-,/V-oxide (47), and (-)-stephadiolamine f3-N-oxide (48). The cis relationship between H-6a and H-7 is indicated from the NMR spectrum, and a partial NMR NOE study clarified the configuration of the N-oxide function (30). 

V-Formylnornantenine (54), a new amidic aporphine alkaloid, has been isolated from Cyclea atjehensis. Analysis of the NMR spectrum at... 

Belemine (125), from G. schomburgkiana (50, 51), is the oldest example of a 6a,7-didehydro-7-methylaporphine. Its mass spectrum suggested the molecular formula C, Hl7N03, and its UV spectrum was typical of a 6a,7-didehydro-aporphine. Its H-NMR spectrum was characterized by two methyl singlets at 2.57 and 2.78 ppm which were assigned to the C-7 methyl and (V-methyl... 

The H-ll proton of an aporphine incorporating a 1,2-methylenedioxy-group falls relatively upfield in the n.m.r. spectrum, between 57.47 and 57.86.57 The n.m.r. spectra of a number of new aporphines have been tabulated.16... 

The UV-spectrum of the alkaloid in ethanol showed maxima at 310 and 284 m/x (log 4.11 and 3.9) characteristic of a 1,2,9,10-tetrasub-stituted aporphine. The NMR-spectrum exhibited one i -methyl group at 7.53 r. A methylenedioxy group appeared as two doublets centered at 4.04 T and 4.17 t characteristic of C-1,2 disubstitution, while another methylenedioxy group was represented by a singlet at 4.05 t and was therefore assigned the C-9,10 position. Neolitsine must thus be represented by II. 

Mecambroline was isolated from Meconopsis carnbrica Vig. (Papaver-aceae), and the elemental data indicated the value C18H17O3N. The alkaloid melts at 145°, and exhibits [aj +76° (in CHCI3). A hydrochloride salt was obtained (inp 264°-266°) as well as a picrate (mp 179°-180°). Color tests showed the presence of a methylenedioxy and a phenolic group. The UV-spectrum had 308 and 275 mp, (log e 4.0 and 4.2), with a shoulder at 269 mp (log e 4.1), typical of a 1,2,10-tri-substituted aporphine. 0-Methylation with diazomethane gave a base (mp 111°-112°) 6). 

In a footnote to the mecambroline paper, it was suggested (6, 7) that mecambroline may be identical with Yunusov s isofugapavine (VIII) ( ). This is a logical suggestion, since, as previously mentioned, the UV-spectrum of mecambroline is that of a 1,2,10-trisubstituted aporphine. 

Ovigerine, obtained from Hernandia ovigera, crystallized only as the hydrochloride, CigHi504N-HCl (mp 300° decomp. [aj -P 177° in H2O). The UV-spectrum of this salt, 317, 270, 234 mp. (log e 3.77, 4.10, and 4.29), was suggestive of a 1,11-substituted aporphine. The NMR-spectrum of the free base showed no signals characteristic of either X-methyl or methoxyl, but complex signals characteristic of two superimposed methylenedioxy groups appeared centered at 4.12 and 3.99 t. 

The two methoxyls in hernovine are assumed to be at positions 1 and 11 of the aporphine system, since they appear in the NMR-spectrum of N-methylhernovine at relatively high fields (6.57 and 6.50 t) 33b). 

The UV-spectrum of thaliporphine exhibits A 305, 280, and 220 mp, (log e 4.12, 4.12, and 4.52) characteristic of a 1,2,9,10-tetrasubstituted aporphine, and undergoes a bathochromic shift in base. The NMR-spectrum revealed the presence of three methoxyl and one A-methyl groups. Spectral and thin-layer chromatographic comparisons then showed that thaliporphine is identical with l-hydroxy-2,9,10-tri-methoxyaporphine which had been previously synthesized (16, 43). It follows that the unnamed alkaloid from Fagara tinguassoiba (see Section III,B) corresponds to the A-methylthaliporphinium cation. 

A new aporphine found in Thalictrum fendleri is preocoteine (XCIII) (66). This alkaloid was obtained only in small amounts as an oil, but its UV-spectrum showing 312, 302, and 278 mp. (log e 4.22, 4.22, 4.16) is diagnostic of a 1,2,3,9,10-pentasubstituted aporphine, and is close to that of the well-characterized aporphine base ocoteine (XV) which has A , 314, 302, and 283 mp (log e 4.1, 4.2, and 4.2) and is also present in T. fendleri. Additionally, the UV-spectrum of preocoteine shows a bathochromic shift upon the addition of base, so that the molecule must be phenolic. 

Thalifarazine (10), C40H4iOlN2 (682.3254), [a]D +72° (c 0.06, MeOH), was isolated along with eleven other aporphine-benzylisoquinoline dimeric alkaloids from an extract (EtOH) of the whole plant of T. cultratum Wall, in 1986 [2,4], The UV spectrum of this phenolic alkaloid was similar to those of other aporphine-benzylisoquinoline dimers and displayed maxima at 228 nm (log e 4.70), 270 (shX4.29), 283 (4.38), 297 (shX4.25), and 310 (shX4.02)while the CD spectrum... 

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