Abstract: Compounds of the formula: ##STR1## wherein R is H, Cl, F, Br, I or R.sub.1 S--, in which R.sub.1 is C.sub.1 -C.sub.10 linear or branched chain alkyl or halogenated linear or branched chain alkyl, andwherein R.sub.2, R.sub.3 and R.sub.4 are the same or different and each is H-- or --OH,with the proviso that at least one of R.sub.2, R.sub.3 and R.sub.4 is hydroxy and the further proviso that when R.sub.2, R.sub.3 and R.sub.4 are all OH, R.sub.1 is other than methyl, are useful in inhibiting the growth of MTR kinase-dependent microorganisms and parasitic protazoans. The compounds wherein R is R.sub.1 S are novel, except those wherein R.sub.1 is methyl or isobutyl when R.sub.2, R.sub.3 and R.sub.4 are all OH.