Spectral data structure

This chapter extends the information provided by the two preceding reviews (1,2) to the literature that appeared within the years 1976-1986, focusing on spectral data, structural elucidation, synthesis, biosynthesis, and pharmacology. Some references that appeared in the foregoing reviews are omitted from this chapter with exception of those related to the present treatise. Although previously presented in Volume 16 of this treatise (2), the numbering system of the hasubanan skeleton (la) and the hasubanalactam skeleton (lb), which is used in this chapter except for the most part of Section V, is represented anew. 

The C NMR spectmm of 13 showed the resonances of all 35 carbon atoms. A combirration of broadband C-NMR and DEPT spectra indicated the presence of 7 methyl, 4 methylene, 16 methine and 8 quaterrrary carbon atoms in compound 13. Complete 13C-NMR chemical shift assignments of 13 are shown around structure 13. Based on these spectral data, structure 13 was established for this new compound. 

In 1996, Wu et al. reported the isolation of clausine E (25) from the stem bark of C. excavata (46). One year later, Ito et al. reported the isolation of the same alkaloid from the same source and named it clauszoline-I (25) (47). This alkaloid showed inhibition of rabbit platelet aggregation and caused vasocontraction. The UV, IR, and H-NMR spectra were similar to those of mukoeic acid (10) with respect to the position of substituents. The presence of a carbomethoxy group at C-3 was indicated by an IR band at 1703 cm . Moreover, two significant mass fragments at m/z 210 (M —OMe) and 182 (M —COOMe) confirmed the presence of a carbomethoxy group. On the basis of these spectral data, structure 25 was assigned to clausine E (clauszoline-I) (Scheme 2.6). 

In 1996, Wu et al. reported the isolation of murrayamine-M (162), a formyl analog of bicyclomahanimbicine (161) from the leaves of M. euchrestifolia collected in November in Taiwan. The UV spectrum Umax 243, 254 (sh), 292, and 325 nm] of murrayamine-M (162) indicated a 3-formylcarbazole. This assignment was supported by the IR spectrum [Vmax 1605 (aromatic system), 1675 (CHO), and 3300 (NH) cm J. The H-NMR spectrum resembled that of bicyclomahanimbicine (161), but exhibited a formyl group ( 10.08) at C-3 instead of the aromatic methyl group. The deshielded mete-coupled (/=1.7Hz) H-4 at 6 8.48 confirmed the position of the formyl group at C-3. Based on the spectral data, structure 162 was assigned to murrayamine-M (Scheme 2.32). The absolute configuration of 162 is not known (130). 

The UV spectrum [7max 237, 250 (sh), 289 (sh), 299, 345, and 357nm] of carbazomadurin A (256) resembled that of carbazomadurin B (257), indicating a similar carbazole framework. The H-NMR spectrum was also similar to that of carbazomadurin B (257), except for the signals of the alkyl side chain. Detailed analysis of the DQF-COSY and HMBC spectra confirmed a 2,5-dimethylhex-l-ene side chain at C-1 with the same configuration of the double bond. Based on the spectral data, structure 256 was assigned to carbazomadurin A (229). 

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