Natural biaryls typically occur as one regio- and atropisomeric variant in a given organism. Here, we report on the identification of biosynthetic genes of aurasperone- and bifonsecin-type biaryls in several Aspergillus species. The genes of the tailoring enzymes form a gene cluster that is separate from the polyketide synthase gene. Dimerization of naphthopyrone monomers is catalyzed by members of an undescribed subfamily of cytochrome P450 enzymes. The stereoselectivity of these enzymes is influenced by the two natural monomeric substrates; homodimerization of one monomer yields a stereochemically pure biaryl, while the other monomer yields a mixture of enantiomers.
天然双芳基化合物通常以一种区域和旋光异构体形式存在于特定
生物体中。在此,我们报告了在几种曲霉菌中鉴定出双芳基化合物
生物合成
基因的情况。这些剪裁酶
基因形成了一个与多聚酮合成酶
基因分开的
基因簇。
萘吡喃单体二聚化由细胞色素P450酶的一个未描述的亚家族成员催化。这些酶的立体选择性受两种天然单体底物的影响;一种单体的同二聚化产生一种立体
化学上纯的双芳基化合物,而另一种单体则产生对映异构体的混合物。