Hasubanan type alkaloid

Zhang, H. and Yue, J.-M. 2005. Hasubanan type alkaloids from Stephania longa. Journal of Natural Products, 68 1201-1207. 

Berthou S, Leboeuf M, Cave A, Mahuteau J, David B, Guinaudeau H (1989) Limalongine, a Modified Hasubanan Type Alkaloid, and Clolimalongine, Its Chlorinated Derivative. J Org Chem 54 3491... 

A major study on 13C-NMR spectroscopy of hasubanan alkaloids was carried out by Matsui et al. (5) (Table III). They proposed assignments of all carbon atoms including the direct and long-range hetero coupling. The C-9 and JV-methyl carbons of hasubanan alkaloids reveal shifts of 6 and 20 ppm higher frequency than those reported for morphinan alkaloids (9). On the other hand, the iV-methyl carbons of hasubanans exhibit a lower frequency shift of 10 ppm relative to those of hasubanalactam-type alkaloids (5). These results have been utilized for structure elucidation in later works (4,7,10-12). 

The structural features of this group are summarized as follows (1) possession of an acetal or a hemiacetal ether linkage between C-8 and C-10, and (2) either absence of a substituent or presence of a hydroxyl group or ester moiety at C-6. Because a large number of hasubanan alkaloids follow this cleavage pattern, the metaphanine-type cleavage may be one of the primary pattern for all hasubanan alkaloids (76). 

Mass Spectral Data for Hasubanan Alkaloids of Metaphanine-Type Cleavage... 

This type of compound seems to derive biogenetically from the morphinan alkaloids, as can be demonstrated with in vivo experiments with S. japonica (JP) or by laboratory chemical transformations (77) (Scheme 15). The chemistry of the hasubanane alkaloids was reviewed in 1988 by Matsui 60). 

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