title: Structure-activity relationship of S-benzylisothiourea derivatives to induce spherical cells in Escherichia coli.
abstract: We have previously reported that a novel S-benzylisothiourea derivative, S-(3,4-dichlorobenzyl)isothiourea, tentatively named A22, induced spherical cells in Escherichia coli. To elucidate the structural element(s) required for inducing these spherical cells, the biological activity of S-benzylisothiourea derivatives and related compounds toward E. coli cells was investigated. S-(4-Chlorobenzyl)isothiourea revealed spherical cell-inducing activity, although being slightly less potent than A22, and S-benzylisothiourea itself showed much less activity. S-Cyclohexylmethylisothiourea did not show antibacterial activity and had little effect on the cell shape. S-Heptylisothiourea showed antibacterial activity and induced elongated cells rather than spherical cells. Benzylisothiocyanate inhibited cell growth but did not induce spherical cells. S-Ethylisothiourea, benzylthiocyanate, benzylisocyanate, and N-phenylthiourea did not show any activity under the present experimental conditions. These results indicate that the S-benzylisothiourea structure was necessary and sufficient for inducing spherical cells and that 3- and/or 4-chloro-substitution of the S-benzyl group enhanced this activity.
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Noritaka
authors.initials: N
authors.lastname: Iwai
authors.forename: Takuma
authors.initials: T
authors.lastname: Ebata
authors.forename: Hirokatsu
authors.initials: H
authors.lastname: Nagura
authors.forename: Tomoya
authors.initials: T
authors.lastname: Kitazume
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nagai
authors.forename: Masaaki
authors.initials: M
authors.lastname: Wachi
mesh_terms: D001419:Bacteria / Q000187:drug effects; D001593:Benzyl Compounds / Q000737:chemistry / Q000494:pharmacology*; D004396:Coloring Agents; D004926:Escherichia coli / Q000187:drug effects* / Q000648:ultrastructure*; D008826:Microbial Sensitivity Tests; D013104:Spheroplasts / Q000187:drug effects* / Q000648:ultrastructure*; D013329:Structure-Activity Relationship; D013890:Thiourea / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D001593:Benzyl Compounds; D004396:Coloring Agents; D013890:Thiourea