Chelerythrine from coptisine

Additional results are that (-)-(5)-scoulerine (68) is a precursor for san-guinarine (77) and chelerythrine (78) and labelled (-)-(5)-stylopine (71) is incorporated into coptisine (72). [N-methyl8- H]Stylopine methochloride [as (70)] afforded chelidonine (76) and protopine (73) essentially without change in isotope ratio and must thus be considered as implicated on the pathway to both alkaloids. (The same conclusion for protopine has been reached independently. ) On the other hand radioactive nandinine (79) failed to label chelidonine, stylopine, or protopine, suggesting that the alternative (69) may be an intermediate instead. In agreement with other work (5)-reticuline (67) and (5)-scoulerine (68) were much better precursors than the i -isomers for protopine (73), and incorporation of (68) resulted in complete loss of tritium label from C-14. Allocryptopine (81) was well labelled by radioactive isocorypalmine (82) (which also serves as a precursor for narcotine see below). The combined results lead to the pathways shown in Scheme 3. 

Alkaloids isolated from celandine (chelerythrine, sanguin-arine, berberine, and coptisine) had a significant inhibitory effect in mitochondrial respiration in mouse liver cells (Barreto et al. 2003). 

Cytotoxicity tests in rat hepatocytes indicated that ECgg values for alkaloids isolated from celandine were as follows 5 pg/ml for sanguinarine, 8 pg/ml for chelerythrine, 13 pg/ml for coptisine, 100 pg/ml for prototropine, and over 100 pg/ml for chelidonine (ESCOP 2003). 

Fig. 36.3 Chemical structures of sanguinarine and coptisine and CZE separation of seven alkaloids in an extract of Chelidonium majus L. Peaks (7) sanguinarine, (2) coptisine, (3) chelerythrine, (4) stylopine, (5) chelidtmme, (6) protopine, (7) allocryptopine, and (x) unknown component. Conditions 20 mM phosphate buffer, pH 3.1. Separation capillary 75 pm, i.d. uncoated fused silica, 50 cm in length (40 cm effective length). Applied voltage 16 kV. Light-emitting-diode-induced fluorescence (LED) excitation wavelength 280 nm (Modified from reference [14])...

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