Studies on the Mode of Action of Antileprous Drugs

III. On the Demasking of several N-Conjugates of Sulfonamide-type Drugs by Various Strains of Micro-organisms

Abstract

Demasking in N-conjugates of sulfone drugs and sulfonamides by the incubation with micro-organisms was examined. Twenty-one strains of mycobacteria together with four of non-mycobacteria) strains were employed in the experiment.
Results found were as follows:
1) The deacetylation of mono-Acetyl DDS (MADDS) was generally more active in mycobacteria than in the non-mycobacterial strains, especially it was active in such strains as the rapid growing mycobacteria except M. balnei, M. tuberculosis H37 Rv, NQ bacilli, and Nonphotochromogens. As for the unclassified mycobacteria, the action in the Nonphotochromogens was more marked than that in the Photo- and Scotochromogens employed in the experiment.
2) In spite of the active deacetylation in the mycobacterial strains, the action could not be found so markedly or was nearly negative in whole the N₄-acetylates of the sulfonamides as well as in the non-mycobacterial strains.
3) Employing NQ bacilli, further studies were carried out to examine the difference between the demasking in several heterogeneous radicals and in A radical, together with the difference between the demasking in N₄-A and N₁-A of the sulfonamides. Tested compounds were: Enantoyl MADDS (MEnADDS), mono-Enantoyl DDS (MEnDDS), monoDiethylamonacetyl MADDS (MEADDS), mono-Morpholinoacetyl MADDS (MMADDS), N-acetylates of Sulfamethoxypyridazine (respectively abbreviated as N₁ASMP, N₄ASMP, and DASMP), and those of Sulfaisoxazole (N₁ASIX, N₄ASIX, and DASIX). The details are shown in Chart 1. Generally, it was found that this strain was apt to demask A more rapidly than En, E, and M from DDS, though the demasking of the latter two was comparatively lower than the former two.
The inactivity in the demasking of N4-A was again noticed in the case of the sulfonamides similarly to (2), and N₁-A suffered severe deacetylation even in the control samples. Therefore, DASMP and DASIX were detected as the corresponding N₄-A even in the controls, as well as the N₁-A were respectively detected as SMP and SIX.
4) Next, the demasking of MADDS by a crude cell-free extract of M phlei (Penso) was examined, and it was found that within 3 hours under shaking-incubation, a gradual increase of freed DDS could be detected with the lapse of the incubation periods. However, the condensation of the activity was failed, resulted in the disappearance of the activity during the fractionation.
5) Employing ³H-glucuronate (³H-GNa) and DDSG-³H, which was synthesized from DDS and ³H-GNa, the influence of E, culi K-12 on the N-G was examined, under the correction of pH during the incubation. Though the intake and the catabolic variation of 3H-GNa freed from DDSG-3H could be noticed, the demasking of N-G by the bacilli could not be elucidated.