Berberis empetrifolia

The following secodimeric alkaloids have been isolated from natural sources (+)-hernandaline (197), from Hernandia ovigera L. (158), (—)-natalinine (198) (759), and (+)-coyhaiquine (199) (160), the two latter from Berberis empetrifolia Lam. with the yields 0.00005 and 0.00008%, respectively. Appropriate aporphine-benzylisoquinoline or proaporphine-benzylisoqui-noline dimers are probably precursors of these seco alkaloids, although... 

Coyhaiquine (107), C26H27N05, from Berberis empetrifolia Lam. (Ber-beridaceae), although not formally a bis alkaloid, appears to be derived by in vivo degradation of a proaporphine-benzylisoquinoline. NMR spin decoupling experiments assigned the chemical shifts of the 6a, 7a, and 7(3 hydrogens. NOE experiments then showed a 3% enhancement of the 7a-H on irradiation of the 8-H, establishing the indicated syn stereochemistry (64). 

Berberis empetrifolia yielded the unstable base coyhaiquinine (471), C26H25N05. The structure was proposed principally from the completely resolved 200-MHz FT NMR spectrum, and the alkaloid was shown to have syn geometiy at the spiro center by NMR correlations with the related syn compounds 46,107,149,262, and 359 and with the anti alkaloids 108 and 109. Insufficient material was available for exact determination of optical rotation, but the general form of the CD curve resembles that of coyhaiquine (107), indicating the absolute configuration shown (554). 

Natalinine (491), C25H23N05, amorphous, is a minor alkaloid of Berberis empetrifolia Lam. MS and high-resolution NMR established the skeletal structure, and CD indicated the (R) configuration (561). Natalinine may be derived biogenetically from catabolism of an aporphine-benzylisoquinoline dimer [such as pakistanine (92), a major co-occurring alkaloid] (561), or by rearrangement of a coyhaiquine (107)-type dimer (562). 

Chilenine, an alkaloid from Berberis empetrifolia, has been... 

Berberis empetrifolia and the tetramethoxy analogue saulatine (370, R =[f =Me) has been obtained from Abuta bullata (Hocque-miller. Cave and A. Fournet, J.nat.Prod., 1984, 47, 539). 

Berberis empetrifolia 90 Corydalis bulbosa protopine protopine... 

Thalictrum foliolosum and Berberis empetrifolia, respectively. Thalic-... 

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