Nauclea diderrichii

Finally, in this group, McLean s work on the alkaloids of Nauclea diderrichii has been published in full.90 The structure earlier given to nauclederine (154) receives support from its synthesis (Scheme 15), although it is admitted that this does not amount to an unequivocal proof of structure, owing to uncertainty concerning the... 

The bark of the Nigerian species Nauclea diderrichii contains Cs-pyridine alkaloids, harman types, and three similar bases, one of which has been synthesised by a standard route and thereby proved to have the structure (15). 

Carbomethoxy-5-(l -hydroxyethyl)pyridine (122), originally isolated from Nauclea diderrichii (Rubiaceae) (175), was reisolated from Isertia haenkeana (Rubiaceae) (131) and the 13C NMR data reported. Although the isolate was optically active ([a]D +23°), no absolute configuration was deduced (see Section III.E). 

Naematolama caerulescens Pat.—317,347 Naematoloma popperianum Singer—317 Nauclea diderrichii—z6 i Nelubium sp.—425 Nelumbo SP.-425... 

The same type of seven-membered d ring occurs in cadambine (74) " and 3a-dihydrocadambine (75a) (which was shown to be identical with the glycosidic alkaloid reported from Nauclea diderrichii) from Anthocephalus cadamba and in nauclechine. " The relationship between cadambine and dihydrocadambine was established (Scheme 8) by the sodium borohydride-acetic acid reduction of the tetra-acetate of the former to a mixture of 3a-dihydro-cadambine (75a) tetra-acetate corresponding to the natural isomer, and its 3 -epimer (major product). The C-3 carbinolamine ether system in cadambine was diagnosed by the u.v. spectral shift observed in acidic solution. Reversible, acid-catalysed cleavage of the N—C—O system led to the well-known, characteristic chromophore (76). 

Nauclea diderrichii (Rubiaceae) [97], Triosteum pinnatifidum (Caprifoliaceae) [96]... 

McLean S, Murray DG (1972) The constituents of Nauclea diderrichii. Part IV. Miscellaneous substances biogenetic considerations. Can J Chem 50 1496-1501... 

The African woods used in the terrestrial exposure, Pterocarpus erinaceus (10), Ongokea gore (9), Nauclea diderrichii (8), Chlorophora excelsa (9), and Erythrophleum ivorense (8) were identified and supplied by the Forest Products Research Institute (FPRI) of Ghana Eusideroxylon zwageri (12) was obtained from Malaysia. The parenthesized numbers... 

Rewarding sources of monoterpene alkaloid glycosides have been the Asiatic tree Adina rubescens Hemsl. and related Rubiaceous plants A. cordifolia (Roxb.) Hook. f. ex Brandis (1, 2), Nauclea latifolia Sm. (3), N. diderrichii Merrill (4), and Anthocephalus cadamba Miq. (5). The heart-wood and bark of the first has yielded so far no less than nine glycoalkaloids... 

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