P. De Wit

Carcinogenicity tests of fecapentaene-12 in mice and rats

Fecapentaenes, a class of direct-acting bacterial mutagens, have been isolated from the feces and intestinal tract of humans on a Western meat-containing diet. Two bioassays to test pure fecapentaene-12 (FP-12) for carcinogenicity were performed. FP-12 in dimethylsulfoxide (DMSO) solution was injected i.p. into newborn ICR/MA mice on days 1, 3, 7, 10, 14 and 21. The mice killed after 21 months had neoplasms in liver, lung, glandular stomach and subcutaneous fibrosarcoma. Intrarectal (i.r.) infusion of FP-12 in an aqueous vehicle into male F344 rats for 71 weeks, and killing the rats after 21 weeks more, displayed no evidence of neoplasia associated with FP-12 exposure. The positive control, N-nitrosomethylurea (NMU), given i.r. as 4 2-mg doses in 2 weeks, as expected, yielded multiple colonic neoplasms in less than 11 months. Fecapentaene may exert its effect in bacteria and in newborn mice through the generation of hydroxy radicals. However, adult rodent and human colon may have adequate biochemical defense mechanisms against low level, even continuous exposures to chemicals like FP-12, and thus be at low risk of neoplasia, as was found.

An Intriguing plumbylene: Bis[2-(dimethylaminomethyl)-phenyl]lead

The diaryllead compound bis[2-(dimethylaminomethyl)phenyl]lead has been isolated and characterized. The monomeric composition of the plumbylene has been established by cryoscopic measurements. Comparison of the 1H and 13C NMR data of this plumbylene with those of tetrakis[2-(dimethylaminomethyl)phenyl]lead reveals striking differences

Synthesis, physical properties and microbiological activities of more water soluble silver sulfadiazine derivatives

In this study the preparation of five hydrophilic derivatives of sulfadiazine is reported. The common structural element in the compounds is the 2-sulfonamidopyrimidine moiety. Three of these compounds are suitable for the preparation of a photostable 1∶1 silver compound. These silver compounds are five to ten times more water soluble than silver sulfadiazine. TheIr,1H- and13C-Nmr data point to a similar co-ordination of silver in these compounds as with silver sulfadiazine. The microbiological activity of these silver compounds againstSt. aureus is slightly lower.