Problems involved in structure determination of active principles of plants used in traditional medicine: extraction, separation and determination of characteristics of active principles

A number of examples, mainly from the author's personal researches, give a realistic picture of the complicated methodology and approach to the chemical study of medicinal plants

Biological activity of the alkaloids of Erythroxylum coca and Erythroxylum novogranatense

The cultivated Erythroxylum varieties E. coca var. coca, E. coca var. ipadu, E. novogranatense var. novogranatense and E. novogranatense var. truxillense contain 18 alkaloids, identified so far, belonging to the tropanes, pyrrolidines and pyridines, with cocaine as the main alkaloid. The biological activity of the following alkaloids has been reported in the literature: cocaine, cinnamoylcocaine, benzoylecgonine, methylecgonine, pseudotropine, benzoyltropine, tropacocaine, α- and β-truxilline, hygrine, cuscohygrine and nicotine. The biological activity of cocaine and nicotine is not reviewed here, because it is discussed elsewhere in the literature. Hardly anything is known about the biological activity of the other alkaloids present in the four varieties mentioned. The biosynthesis of the coca alkaloids has been outlined

Cannabis—XV . Pyrolysis of cannabidiol. Structure elucidation of four pyrolytic products

Pyrolysis of cannabidiol in nitrogen atmosphere affords at least six more products with longer GC-retention times than CBD, next to unconverted CBD. Two of these could be identified as Δ1(2)THC and CBN Two further products were investigated and their mass spectrometrical fragmentations and structures are proposed

Lethal mutations induced in Drosophila melanogaster by direct or indirect acid of pteridines

The experiments described in this paper show than synthetic pteridines, especially biopterin and pterin, injected directly into Drosophila melanogaster induce recessive lethals. On the contrary, -neopterin seems to have little effect. A mutagenic effect has previously been shown for an extract of Pieris brassicae in diapause, treated with these pteridines and tetradydrofolic acid (FH4). It appears that chromosome II is more sensitive to these mutagenic treatments than chromosome X

Biomimetic synthesis of neodihydrothebaine and bractazonine from thebaine

Photochemical irradiation of the morphinan alkaloid thebaine 1 followed by reduction, affords the dibenz[d,f]azonine alkaloids neodihydrothebaine 2 and bractazonine 3, in a sequence paralleling the proposed biosynthesis of these alkaloids in Papaver bracteatum

Neodihydrothebaine and bractazonine, two dibenz[d,f]azonine alkaloids of Papaver bracteatum

Two new dibenz[d,f]azonine alkaloids, neodihydrothebaine and bractazonine were isolated from Papaver bracteatum. Their possible biosynthesis from thebaine is discussed. The structures of both new alkaloids are proven by synthesis. An isomeric dibenz[d,f]azonine compound was also prepared