Effect of 3-hydroxymethylene-2-thioxopyrrolidine on growth of two species of mutans streptococci and their in vitro plaque formation

3-Hydroxymethylene-2-thioxopyrrolidine (HMTP), the major product derived fr om radish mustard oil, was studied for its activity to inhibit the growth o f mutans streptococci, their in vitro plaque formation and their glucan pro duction. The minimum inhibitory concentration (MIC) (800 1600 mg/l) of HMTP at pH 7.0 was reduced to 200 mg/l by lowering the medium pH to 5.0. A dose -dependent inhibition of in vitro plaque formation was observed at 200-800 mg/l dose of HMTP. Production of water-insoluble glucan (WIG) was effective ly inhibited by 45-98%, depending on HMTP dose (200-800 mg/l), while only 2 2% inhibition of water-soluble glucan (WSG) production was observed at an 8 00 mg/l dose. (C) 2001 Elsevier Science B.V. and International Society of C hemotherapy. All rights reserved.