Visconti A, Solfrizzo M
Istituto Tossine e Micotossine da Parassiti Vegetali, CNR, Bari, Italy.
Food Addit Contam. 1995 May-Jun;12(3):515-9. doi: 10.1080/02652039509374338.
The major compound responsible for toxicity to Artemia salina of some Fusarium tricinctum strains has been isolated, and its structure has been elucidated by spectroscopical methods, i.e. UV, IR, MS, 1H-NMR and 13C-NMR. The novel compound, trivially named visoltricin, is the first imidazole derivative produced by Fusarium spp., and its structure has been established as the methyl ester of 3-[1-methyl-4-(3-methyl-2-butenyl)-imidazol-5yl]-2-propenoic acid (molecular formula C13H18N2O2; MW = 234.297). Visoltricin was toxic to A. salina larvae (LD50 = 8.5 x 10(-7) M), and inhibited the growth of six human tumour cell lines (out of 60 lines tested) at concentrations lower than 10(-5) M. Tested on rabbit eye it showed an interesting miotic activity similar to that of pilocarpine, a miotic agent largely used in the therapy of glaucoma. This biological activity could be explained in part by the anticholinesterase properties shown by visoltricin towards both human serum and pure enzymes (EC 3.1.1.7 and EC 3.1.1.8). Kinetics studies showed 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.
已分离出某些三线镰刀菌菌株对卤虫具有毒性的主要化合物，并通过光谱方法（即紫外光谱、红外光谱、质谱、氢核磁共振光谱和碳核磁共振光谱）阐明了其结构。这种新化合物被通俗地命名为visoltricin，是镰刀菌属产生的首个咪唑衍生物，其结构已确定为3-[1-甲基-4-(3-甲基-2-丁烯基)-咪唑-5-基]-2-丙烯酸甲酯（分子式C13H18N2O2；分子量=234.297）。Visoltricin对卤虫幼虫有毒性（半数致死剂量LD50 = 8.5×10(-7) M），并且在浓度低于10(-5) M时能抑制六种人类肿瘤细胞系（在测试的60种细胞系中）的生长。在兔眼上进行测试时，它表现出与毛果芸香碱类似的有趣的缩瞳活性，毛果芸香碱是一种广泛用于青光眼治疗的缩瞳剂。这种生物活性部分可以通过visoltricin对人血清和纯酶（EC 3.1.1.7和EC 3.1.1.8）所表现出的抗胆碱酯酶特性来解释。动力学研究表明，visoltricin对EC 3.1.1.7酶具有混合型和可逆性抑制作用，竞争性抑制常数（Ki）= 1.9×10(-4) M。
