2,3,7-Trimethcxy-8,9-methylenedioxypavinan — A new alkaloid from Thalictrum strictum. II
F rom the epigeal pa r t of Th. s t r i c tum we have i so la ted a new unidentified base B (I). The alkaloid (I) is readi ly soluble in methanol , ethanol, and acetone and when the solvents are evapora ted it s epa ra t e s out in the fo rm of a faint yellowish oil . After chromatography twice on a column of a lumina and concentrat ion of the e therea l eluate, compound (I) c rys ta l l i zed in the fo rm of t r anspa ren t p r i s m s with mp 144-145°C, [o~]~ 1 7 4 ° (c 0.977; methanol).
THE ALKALOIDS OF PAPAVERACEOUS PLANTS: LIV. THE STRUCTURE OF ESCHSCHOLTZINE
Eschscholtzine, a new alkaloid from Eschscholtzia californica, has been shown to be the bismethylenedioxy analogue of N-methylpavine (argemonine). The mass spectrometric fragmentation of alkaloids of the pavine type is discussed.
Mode of action of bredinin with guanylic acid on L5178Y mouse leukemia cells.
Moderate concentrations of bredinin (1.2 X 10(-5) M) strongly inhibited growth of L5178Y cells, with the effect being reversed by guanylic acid (GMP). However, at higher concentrations of breeding the inhibition was not reversed completely by GMP added in excess. Bredinin was cytocidal at concentrations above 2 X 10(-5) M, but 5 X 10(-5) M bredinin in the presence of excess GMP, bredinin was cytostatic. Bredinin inhibited nucleic acid synthesis of L5178Y cells, but bredinin itself was not incorporated into the nucleic acid. Inhibition of nucleic acid synthesis was clearly reversed by GMP. Similarly chromosomal aberrations in L5178Y cells caused by bredinin were reversed by GMP. In contrast, the effect of ahigh concentration of bredinin on cell multiplication was not reversed by GMP. The modal volume of L5178Y cells increased during incubation in the presence of bredinin and GMP for 24 hours, 5 X 10(-5) M bredinin with GMP causing a 70% increase in cell volume. This increase in cell volume was mainly due to an increase in the protein content of the cells. The cytostatic effect of bredinin with GMP was reversed completely by adenosine-3',5'-cyclic monophosphate (cyclic AMP). Other cyclic nucleotides and nucleotides were ineffective. The reversing effect of cyclic AMP on cell survival depended upon the concentration of GMP, and was not seen in the absence of GMP. It was concluded that cyclic AMP influences the secondary cytostatic effect of bredinin, and not the primary cytotoxic effect reversed by GMP.