Islam M T, Tahara S
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
Z Naturforsch C J Biosci. 2001 Mar-Apr;56(3-4):253-61. doi: 10.1515/znc-2001-3-414.
Screening chemical compounds, we found that a xenoestrogen, bisphenol A, showed potent repellent activity against the zoospores of Aphanomyces cochlioides. Based on this finding, we tested a number of androgenic and estrogenic compounds (e.g. testosterone, progesterone, estradiols, diethylstilbestrol, estrone, estriol, pregnenolone, dienestrol etc.) on the motility behavior of A. cochlioides zoospores. Interestingly, most of the estrogenic compounds exhibited potent repellent activity (1 microg/ml or less by the "particle method") toward the motile zoospores of A. cochlioides. We derivatized some of the estrogens and discussed the relationship between the structure of active molecules and their repellent activity. Apparently, aromatization of the A ring with a free hydroxyl group at C-3 position of a steroidal structure is necessary for higher repellent activity. Interestingly, methylation of diethylstilbestrol (DES) yielded completely different activity i.e. both mono- and di-methyl ethers of DES showed attractant activity. Moreover, the attracted zoospores were encysted and then germinated in the presence of di-methyl ether of DES. The potential usefulness of this repellent test is discussed for the detection of estrogenic activity of naturally occurring compounds, and the possible role of phytoestrogens in host/parasite interactions. So far, this will be the first report of repellent activity of estrogenic compounds toward trivial fungal zoospores.
在筛选化合物时，我们发现一种异雌激素——双酚A对缢管疫霉游动孢子具有强大的驱避活性。基于这一发现，我们测试了多种雄激素和雌激素化合物（如睾酮、孕酮、雌二醇、己烯雌酚、雌酮、雌三醇、孕烯醇酮、二乙茋酚等）对缢管疫霉游动孢子运动行为的影响。有趣的是，大多数雌激素化合物对缢管疫霉的游动孢子表现出强大的驱避活性（通过“颗粒法”，浓度为1微克/毫升或更低）。我们对一些雌激素进行了衍生化处理，并讨论了活性分子结构与其驱避活性之间的关系。显然，甾体结构中C-3位带有游离羟基的A环芳构化对于更高的驱避活性是必要的。有趣的是，己烯雌酚（DES）的甲基化产生了完全不同的活性，即DES的单甲醚和二甲醚均表现出吸引活性。此外，被吸引的游动孢子会形成包囊，然后在DES二甲醚存在的情况下萌发。本文讨论了这种驱避试验在检测天然化合物雌激素活性以及植物雌激素在宿主/寄生虫相互作用中可能作用方面的潜在用途。到目前为止，这将是关于雌激素化合物对普通真菌游动孢子驱避活性的首次报道。
