Utilization of protopine and related alkaloids. XVII. Spectroscopic studies on the ten-membered ring conformations of protopine and .ALPHA.-allocryptopine.

The fluorescence properties and NMR analysis of protopine and allocryptopine

“…[20,21]) as was confirmed by X-ray crystallography and NMR. The alkalization (1 M NaOH) of the samples led to the formation of tricyclic base with no impact on the alkaloid structures.…”

Antimalarial alkaloids from a Bhutanese traditional medicinal plant Corydalis dubia

“…Other known compounds 2-8 were identified through MS library matching techniques (NIST08s) and subsequent comparison of their melting point, optical rotation, mass spectra and NMR spectra ( 1 H and 13 C) with those reported. Compound 2 was identified as scoulerine (Brochmann-Hanssen, Nielson, 1966;Cheng et al, 2008), compound 3 as cheilanthifoline (Okamoto et al, 1971;Haisova and Slavik, 1973;Yeola and Mali, 1984;Rucker et al, 1994;Cheng et al, 2008), compound 4 as protopine (Abou-Donia et al, 1980;Takahashi et al, 1985;Seger et al, 2004), compound 5 as capnoidine Ribar and Meszaros, 1991;Pilar et al, 2010) whose structure was also confirmed from a X-ray crystal structure (not shown here), compound 6 as bicuculline (Edwards and Handa, 1961;Abou-Donia et al, 1980;Blasko et al, 1982;Elango et al, 1982;Basha et al, 2002), compound 7 as corydecumbine (Basnet et al, 1993) and compound 8 as hydrastine Elango et al, 1982).…”

Antiplasmodial agents from the Bhutanese medicinal plant Corydalis calliantha

“…The molecular formula and the ion fragmentation pattern (NIST #49600) corresponded with that of protopine. The identifi cation was confi rmed by comparing the 1 H-NMR and 13 C-NMR spectral values of the alkaloid with those reported for protopine (Takahashi et al, 1985).…”