TABLE 1.

Retention volumes and absorption maxima during HPLC analyses of the products formed from 4,6-dichloro-3-methylcatechol, 3,6-dichloro-4-methylcatechol, and 3,4-dichloro-6-methylcatechol by enzymes of the chlorocatechol ortho-cleavage pathway of Ralstonia sp. strain PS12a

SubstrateProduct[MeOH] (%)bRetention vol (ml)λmax (nm)
4,6-Dichloro-3-methylcatechol3,5-Dichloro-2-methylmuconate35 (+ 0.005 M PicA)3.3270
3,5-Dichloro-2-methylmucono-lactone (compound Ia)504.0221
3,5-Dichloro-2-methylmuconolactone (compound Ib)505.0221
3C2MDL (cis or trans)425.5278
cis-2C5MDL424.0299
2-Chloro-5-methylmaleylacetate or 3-chloro-2-methylmaleylacetate422.7223
3,6-Dichloro-4-methylcatechol2,5-Dichloro-3-methylmuconate35 (+ 0.005 M PicA)3.9273
2,5-Dichloro-3-methylmuconolactone (compound Ic)423.0223
2,5-Dichloro-3-methylmuconolactone (compound Id)423.2223
cis-2C3MDL426.6286
trans-2C3MDL424.3286
2-Chloro-3-methylmaleylacetate422.5225
3,4-Dichloro-6-methylcatechol2,3-Dichloro-5-methylmuconate35 (+ 0.005 M PicA)3.9289
5C2MDL (cis or trans)504.2299
5-Chloro-2-methylmaleylacetate502.6207
  • a Cells of E. coli DH5α(pSTE44) expressing both tetrachlorobenzene dioxygenase TecA and dihydrodiol dehydrogenase TecB from strain PS12 were incubated with dichlorotoluenes. The catechols formed were extracted and used as a substrates for enzymes of the chlorocatechol ortho-cleavage pathway of strain PS12. The proposed products derived from the transformations are shown.

  • b Percentage of the methanol used in the solvent system, with or without PicA reagent.