The effect of chitinase inhibitors, cyclo(Arg-Pro) against cell separation of Saccharomyces cerevisiae and the morphological change of Candida albicans.

In a previous paperX), we reported a new chitinase inhibitor, cyclo(L-Arg-D-Pro) from marine bacteria. At the budding cell stage of Saccharomyces cerevisiae, chitin is known to be a main constituent of the primary septum between the mother and daughter cells2). Amongthe chitin metabolite enzymes, chitin synthase is essential for the septum formation3). It is known that polyoxin D inhibits chitin synthase of S. cerevisiae leading to cell death4). A pair of cells were observed with an extrusion of cytoplasmic material at their interface5^ In the final fission of the septum, chitinase promotes cell separation^. Chitinase inhibitors are expected to inhibit the cell separation of yeasts. Sakuda et al. have shown that the chitinase inhibitor demethylallosamidin inhibited cell separation of S. cerevisiaen). Onthe other hand, Candida albicans is a yeast that exhibits dimorphism, growing as either a yeast form or a filamentous form. In the yeast form, the C. albicans cells are not pathogenic, but they do exhibit pathogenic characteristics in the filamentous form8). C. albicans