Degradation pathway, proposed

Figure 6 (a) Proposed degradation pathway for luteolin by R. meliloii. (b) Proposed... 

Transformation of quinolones has been reported especially with fungal cells of diverse species, even obtaining partial mineralization, though LAC also proved relative efficiency in the removal of some of them. The abundance of metabolites described, many times analogous from one compound to another, has led to the proposal of several degradation pathways, which usually involve breakdown of the parental molecules and reactions of hydroxylation, acetylation, or formylation, among others. 

Fig. 4 Proposed deca-BDE degradation pathway on mammals. Adapted from Morck et al. [53] and Sandholm et al. [52]...

Figure 4 shows the proposed deca-BDE degradation pathway in mammals according to the research studies in rats. 

Figure 17. The proposed microbial degradation pathway for carbazole.

Fig. 3.77. Proposed degradation pathways for MeOr and MeRed during photocatalysis. The schemes illustrate that two mechanisms of degradation are independently active. Reprinted with permission from R. Comparelli et al. [143],...

Fig. 3.153. The proposed degradation pathway for copper phtalocyanine dyes using P. chrysosporum (white-rot fungi). Reprinted with permission from A. Conneely el al. [194].

Fig. 16.2 Proposed degradation pathway of 2,4-xylidine to oxalic acid. Intermediates A to I have been identified through GC-MS analysis...

Biological. Four Pseudomonas sp., including Pseudomonas putida (ATCC culture 29607) isolated from soil, degraded chloropicrin by sequential reductive dechlorination. The proposed degradative pathway is chloropicrin -> nitrodichloromethane nitrochloromethane nitromethane + small amounts of carbon dioxide. In addition, a highly water soluble substance tentatively identified as a peptide was produced by a nonenzymatic mechanism (Castro et al., 1983). 

Plant. In plants, mevinphos is hydrolyzed to phosphoric acid dimethyl ester, phosphoric acid, and other less toxic compounds (Hartley and Kidd, 1987). In one day, the compound is almost completely degraded in plants (Cremlyn, 1991). Casida et al. (1956) proposed two degradative pathways of mevinphos in bean plants and cabbage. In the first degradative pathway, cleavage of the vinyl phosphate bond affords methylacetoacetate and acetoacetic acid, which may be precursors to the formation of the end products dimethyl phosphoric acid, methanol, acetone, and carbon dioxide. In the other degradative pathway, direct hydrolysis of the carboxylic ester would yield vinyl phosphates as intermediates. The half-life of mevinphos in bean plants was 0.5 d (Casida et ah, 1956). In alfalfa, the half-life was 17 h (Huddelston and Gyrisco, 1961). 

---