A. Visconti et M. Solfrizzo, VISOLTRICIN, A NOVEL BIOLOGICALLY-ACTIVE COMPOUND PRODUCED BY FUSARIUM-TRICINCTUM, Food additives and contaminants, 12(3), 1995, pp. 515-519
The major compound responsible for toxicity to Artemia salina of some
Fusarium tricinctum strains has been isolated, and its structure has b
een elucidated by spectroscopical methods, i.e. UV, IR, MS, H-1-NMR an
d C-13-NMR. The novel compound, trivially named visoltricin, is the fi
rst imidazole derivative produced by Fusarium spp., and its structure
has been established as the methyl eater of 3-[1-methyl-4-(3-methyl-2-
butenyl)-imidazol-5yl]- 2-propenoic acid (molecular formula C13H18N2O(
2); MW = 234.297). Visoltricin was toxic to A. salina larvae (LD(50) =
8.5 X 10(-7) M), and inhibited the growth of six human tumour cell li
nes (out of 60 lines tested) at concentrations lower than 10(-5) M. Te
sted on rabbit eye it showed an interesting miotic activity similar to
that of pilocarpine, a miotic agent largely used in the therapy of gl
aucoma. This biological activity could be explained in part by the ant
icholinesterase properties shown by visoltricin towards both human ser
um and pure enzymes (EC 3.1.1.7 and EC 3.1.1.8). Kinetics studies show
ed for visoltricin a mixed-type and reversible inhibition of the EC 3.
1.1.7 enzyme with the competitive inhibition constant(Ki) = 1.9 x 10(-
4) M.