Pteleatinium chloride

The quaternary pteleatinium chloride (CieH2o04N Cl mp 267-270°) isolated from this plant was shown to he bioactive in vitro against Mycobacterium smegmatis and Candida albicans. When heated with pyridine it generates compound 185 (R = H) which on treatment with diazomethane yields (+ )-balfouridine (185, R = Me) of known structure. Consequently the structure of the new base is 184 which exhaustive spectral data confirm (216). 

As a result of the reported antimicrobial action of extracts of the hop tree, Ptelea trifoliata, Mitscher et al. (54) investigated the aboveground constituents and found that the sole active agent was a new phenolic quinolinium derivative pteleatinium salt. The alkaloid was isolated as the chloride, C16H20NO4CI, and was shown to be the 8-hydroxy-Af-methyl-platydesminium salt (38) on the basis of IR, UV, NMR, and mass spectrometry and of correlation with known quinoline alkaloids. Thus, pyridine effected demethylation to the 4-quinolone 39 which, with diazomethane, was converted into (+)-balfourodine (12), while methylation of pteleatinium chloride with methyl iodide and sodium carbonate gave O-methyl-... 

A full report has appeared of the isolation and characterization of the antimicrobial quaternary derivative pteleatinium salt (32). Dehydration of the chloride with concentrated sulphuric acid and recovery of the product from a basic solution gave a yellow compound, CigHigNOa, formulated as the 8-hydroxy-derivative (34), but by analogy with the compound obtained from ribalinium salt (33) the dehydration product of pteleatinium salt is more likely to be the zwitterion... 

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