Tsou H, Rajan S, Fiala R, Mowery P C, Bullock M W, Borders D B, James J C, Martin J H, Morton G O
J Antibiot (Tokyo). 1984 Dec;37(12):1651-63. doi: 10.7164/antibiotics.37.1651.
The biosynthesis of maduramicin alpha and beta in a culture of Actinomadura yumaensis has been studied using 13C, 14C and 18O labeled precursors. The alpha component of this recently discovered polyether antibiotic, containing forty-seven carbon atoms in a seven-ring system, is derived from eight acetate, seven propionate and four methionine molecules. The beta component which is missing one methoxy group incorporates three methionine methyl groups. The carbohydrate moiety was enriched by methionine, but not significantly by acetate or propionate. Studies of the incorporation of 13C labeled precursors permit the 13C NMR assignment of maduramicin. The origin of oxygen atoms of maduramicin has been examined by feeding [1-13C, 18O2]acetate and [1-13C, 18O2]propionate separately in the fermentation culture and the resulting doubly labeled maduramicin samples were analyzed by the isotopic shifts in the 13C NMR spectra. These results are consistent with the initial formation of a triene, which is converted to maduramicin by cyclization of the triepoxide.
利用13C、14C和18O标记的前体，对尤马马杜拉放线菌培养物中马杜霉素α和β的生物合成进行了研究。这种最近发现的聚醚抗生素的α组分在七环系统中含有47个碳原子，由八个乙酸盐、七个丙酸盐和四个甲硫氨酸分子衍生而来。缺少一个甲氧基的β组分掺入了三个甲硫氨酸甲基。碳水化合物部分由甲硫氨酸富集，但乙酸盐或丙酸盐的富集不明显。对13C标记前体掺入的研究使得能够对马杜霉素进行13C NMR归属。通过在发酵培养物中分别加入[1-13C,18O2]乙酸盐和[1-13C,18O2]丙酸盐，研究了马杜霉素氧原子的来源，并通过13C NMR光谱中的同位素位移分析了所得的双标记马杜霉素样品。这些结果与三烯的初始形成一致，三烯通过三环氧的环化转化为马杜霉素。
