Sanguinarine synthesis

Scheme 37. Synthesis of chelerythrine (205) and sanguinarine (206) by photocyclization. Reagents a, hv, benzene b, Pd-C, p-cymene c, DDQ, benzene.

The recent synthesis [Eq. (2)] of sanguinarine chloride, involving the irradiation of anhydroprotopine, provides an interesting variant of the more usual coupling procedure.166b... 

Electron chains. The respiratory chain and ATP synthesis in mitochondria demand the controlled flux of electrons. This target seems to be attacked by ellipticine, pseudane, pseudene, alpinigenine, sanguinarine, tetrahydropalmatine, CH3-(CH2)i4-2,6-methyl-piperidines, capsaicin, the hydroxamic acid DIMBOA, and solenopsine. As mentioned before, however, only a few alkaloids have been evaluated in this context (Table V). 

The respiratory chain and ATP-synthesis in mitochondria or photophosporylation in chloroplasts demand the controlled flux of electrons. These targets seem to be attacked by sanguinarine, ellipticine, gramine, alpinigenine, capsaicine, nicotine, and a few other alkaloids [5]. But this activity may have been overlooked since, as has been mentioned before, only a few alkaloids have been checked in depth, except at neuroreceptors and ion channels. 

The syntheses of benzophenanthridine bases were also studied (132, 771-776). Much interest was shown in the synthesis of the alkaloids of this group, particularly after their antitumor activity in mouse leukemia L-1210 (LE) and P-388 (PS) as well as some selected antimicrobial activities had been established (776). On photocyclization, protopine, tetrahydroprotober-berine, and 13-methyltetrahydroprotoberberine yielded sanguinarine via anhydroprotopine (114) (680, 681, 777, 778) (Schemes 33 and 40). 

In the Ames mutagenicity assay, an extract of bloodroot tested weakly positive in Salmonella typhimurium (Ames assay) with metabolic activation, while no mutagenic activity of the compound sanguinarine was observed with or without metabolic activation. No mutagenic activity was observed in E. colt in the unscheduled DNA synthesis assay in rat hepatocytes (Frankos et al. 1990). 

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