Electron impact promoted fragmentation of some phenothiazine derivatives

Analysis of phenoxazine chemosensitizers: an electron ionization and keV-ion beam bombardment mass spectrometry study

The mass spectral behavior of a set of eight 2- and 10-disubstituted phenoxazines putatively possessing anticancer drug enhancer properties was investigated. Both electron ionization (EI) and keV-ion beam bombardment (liquid secondary ion mass spectrometry, LSIMS) were used. As expected, EI led to extensive fragmentation to produce structurally characteristics ions. Except in one example, the molecular ions were reasonably abundant. Two different liquid matrices--sulfolane and 3-nitrobenzyl alcohol--were used to obtain LSIMS data. The use of the latter produced more stable molecular ions. Ion beam bombardment also produced several structure-specific fragments. A unique feature of the LSI spectra obtained using either of the above matrices is production of both M+. and [M + H]+ ions, with the former being more abundant in most cases. Adduct formation with the liquid matrices was also observed for many compounds.

Nematocidal principles in "oakmoss absolute" and nematocidal activity of 2,4-dihydroxybenzoates

Nematocidal principles obtained from oakmoss absolute were identified as methyl 2,4-dihydroxy-3,6-di-methylbenzoate (2), ethyl 3-formyl-2,4-dihydroxy-6-methylbenzoate (4), and ethyl 5-chloro-3-formyl-2,4-dihydroxy-6-methylbenzoate (7). In relation to their structures, the nematocidal activity of 2,4-dihydroxybenzoates of methyl to tetradecyl was tested and the strongest activity was found in the octyl ester (minimal lethal concentration = 13 microM).

Metabolic oxidation of desmethylchlorimipramine in vitro by 9000 g rabbit-liver preparations

1. The metabolism of desmethylchlorimipramine (I) has been investigated in vitro using fortified 9000 g liver homogenates of male rabbits. 2. Four metabolic products: N-hydroxydesmethylchlorimipramine (II), 3-(3-chloro-10, 11-dihydro-5H-dibenz[b,f]azepin-5-yl)propanoic acid (III), 10/11-hydroxydesmethylchlorimipramine (IV) and 2/8-hydroxydesmethylchlorimipramine (V) were isolated and identified by electron-impact mass spectrometry and n.m.r. spectroscopy. 3. Desmethylchlorimipramine (I) undergoes both N- and alpha-carbon oxidation in addition to aromatic and alicyclic carbon oxidation.

Aromatic oxidation of some phenothiazines

The previously reported N-oxidation products phenothiazine-N-OH, N-O. and -NOOH obtained upon chemical and metabolic oxidation of phenothiazine nuclei are now shown to be the C-oxidation products, 7-hydroxyphenothiazines, phenothiazin-3-ones and phenothiazin-7-ones which have the para-hydroquinoneimino and para-quinoneimino type systems. 2. The metabolism of various 2-substituted phenothiazines in vitro gave mainly ring-hydroxylated metabolites and sulphoxides. The phenolic metabolites were further oxidized to phenothiazones either as metabolites or as 'metabonates'. 3. After metabolism of chlorpromazine, nor1-chlorpromazine and nor2-chlorpromazine in vitro, phenothiazones ('pink compounds') were obtained as N-dealkylated products of the phenolic derivatives 7- or 3-hydroxy compounds. 4. The synthesis and physicochemical characteristics including t.l.c., u.v., g.l.c. and mass spectra of the oxidized phenothiazine nuclei and of 8-(N-methyl-anilino)-2-chlorophenothiazin-7-one are reported.