Septacidins and spicamycins are acylated 4-aminoheptosyl-β-N-glycosides produced by Streptomyces fimbriatus and S. alanosinicus, respectively. Their structures are highly conserved, but differ in the stereochemistry of the 4-aminoheptosyl residues. The origin of this stereochemistry is unknown, but is presumably because of the difference in their biosynthetic pathways. We have synthesized the septacidin 4-aminoheptose to verify the difference between septacidin and spicamycin. Isotopic enrichment studies were undertaken using S. fimbriatus, and show that the septacidin heptose is derived from the pentose phosphate pathway. This indicates conserved pathways leading to the biosynthesis of 4-amino-4-deoxy-L-gluco-heptose or 4-amino-4-deoxy-L-manno-heptose.
Septacidins和spicamycins分别是链霉菌(Streptomyces fimbriatus)和阿拉诺星霉菌(S. alanosinicus)产生的酰化4-
氨基庚糖-β-N-糖苷。它们的结构高度保守,但在4-
氨基庚糖残基的立体
化学方面有所不同。这种立体
化学的起源尚不清楚,但可能是因为它们的
生物合成途径不同。我们合成了septacidin 4-
氨基庚糖,以验证septacidin和spicamycin之间的差异。使用链霉菌(S. fimbriatus)进行了同位素富集研究,结果表明,septacidin庚糖来自戊糖
磷酸途径。这表明,4-
氨基-4-脱氧-L-
葡萄糖庚糖或4-
氨基-4-脱氧-L-
甘露糖庚糖的
生物合成途径是保守的。