From the petroleum ether extract of the root bark of Cussonia zimmermannii four polyacetylenes, 1- 4, were isolated, three of which ( 1- 3) were active against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Plasmodium falciparum, and Leishmania donovani.
Summary Substituted 6,6-diphenyl-6 H-chromeno [4,3-b]indoles are forming with acid ring-opened, intensely coloured diphenyl-indol-3-yl-carbenium salts. The preparation of these products is described and the UV./VIS.-spectra are discussed. An investigation of the halochromic properties is made by spectrophotometric determination of E~, * -and eH;-curves in buffered methanovwater solutions. pK*-and pK$-values respectively are calculated and the suitability of substituted 6 Hchromeno [4,3-b]indoles as chromogens in self-duplicating stationery is discussed.
We have synthetized a series of substituted heteroarenoquinazolines. The 90-MHz F T 'H-NMR spectra of starting and final products supported the postulated structures. Fragmentation in the mass spectra also were consistant with the assumed structures. With acid, the compounds partly form ring-opened, intensely coloured triphenylcarbenium salts of the Rhoduline-R type (C.I. 42565). UVjVIS spectra of the salts are discussed on the basis of VEPPP-CI calculations. The cPH. curves in buffered MeOH/H,O solutions and the pK* values are determined. The title compounds undergo very complex protonation equilibria.
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